Many theists believe there is an objective morality to be discovered. However, since you can't uncover such a morality in the same way you can lift a stone and find a pill bug, empirical systems are not use for this process. Instead, many rely on various works that they give implicit trust to, except when the advice of such books goes against their innate beliefs. Hence, we see homosexuals barred from military service, but don't see single women non-virgins barred in such a fashion, much less executed for being a single non-virgin.
Some attempt a seemingly more sophisticated approach of creating a morality based upon a few accepted notions and creating a formal system to reflect it. That's when you see people like the Maverick Philosopher examining the details on what their basic positions entail when examined in detail. Below the fold, I'll go into why I think this helps to pinpoint the inherent lack of objectivity in this construction of a moral system.
I'm not really concerned with the particular argument that Dr. Vallicella is making in his post, rather, I want to highlight what happens when he finds his argument is inadequate. In particular, he doesn't like the breadth of the conclusion of the argument, so he proposes a new starting point. That is, in creating this supposedly objective moral position, he changed his starting point to get the conclusion that he felt was the right one.
Now, I have no objections to this activity per se. In fact, this is one of the better advantages of operating strictly within a formal system. If the starting positions lead you to a situation you can't use, changing the starting positions is to be expected. If you are tracking the movements of ships on the surface of the earth, you don't pretend that the surface of the earth matches Euclid's parallel postulate; instead you assume that no lines (aka great circles) are parallel and use a Riemannian geometry. It will have the tools you need to look at ship movements around a globe.
However, the process of choosing these starting positions is strictly based on the conclusions you want to derive. That makes the starting positions arbitrary, and those positions will be carefully chosen so the results conform to the desired outcome. So, far from getting some objective morality that can be applied to all, you get a tailored morality designed to support a specific set of positions. Some of these systems, like natural law, were debated for hundreds of years before they were codified, and even then still generate disagreements around the edges.
When people come up with another method of knowing things that can exhibit certainty, reality, and demonstrability, that method of know may indeed lead to an objective morality. Until that time, there will be no such creature. All the construction within formal systems will not be able alter the shaky foundation upon which they rest.
Tuesday, December 7, 2010
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2,208 comments:
«Oldest ‹Older 1201 – 1400 of 2208 Newer› Newest»One Brow said: "The ability to use any inertial rest frame you choose is a physics issue. It renders the preference for a specific frame over any other a philosophical issue."
If you're trying to say what I think you are, then that's to be expected from you. You never change. Anyone who disagrees with you has a "philosophy." You have no philosophy whatsoever, just hard cold irrebuttable scientific fact, that all you rely on.
This relationalist view that you advocate with all the fervor of Mach himself is a philosophical view, sorry. It is not "physics."
aintnuthin said...
But not at the same rate as the spot you're firing at. Different latitudes has different lineal speeds due to greater/lesser circumferences. A missle in the air with a north/south bearing does not "go east" at the same rate as does the ground under it. The old Coriolis effect, ya know?
I see what you mean now.
Every account I've every seen of the lorentzian length contractions says it applies to "objects." Leave it to the metaphysical cult of minkowski geometricians to treat space as an "object" which shrinks, eh?
No, not being treated as an object, and nbot metaphysical. Just shrinking, and physical.
Why does space "contract?" Because some guy somewhere is moving, that's why.
The contraction is a reflection of the different orientations in spacetime from different inertial states.
Well, actually, millions of guys in millions of places and "space" contorts itself to serve them all, simultanously. Heh.
To the degree space even exists, it has no intrinsic change from the effects of SR, just as rods and clocks do not.
But in one sense, yeah, every single frame of reference is always the "privileged" one in SR, it that's what you're saying.
More precisely, that every frame can be treated as being the priviledged frame.
Every one is at rest.
Not in any single frame.
One Brow said: "You are assuming the earth was at rest, and the train is now moving faster."
Not at all. I assume that the earth IS moving, just like the ship with the bug crawling across the floor. Both the train and the bug share equally in the inertial motion of the moving ship. It's just that the bug and the train then "add" something to that motion. It's called acceleration, ya know?
If the bug is crawling from the bow to the stern, it's moving slower than the ship (from the viewpoint of the ocean), it is might even be stationary from that viewpoint. It's called acceleration, ya know?
Compared to what? Mars?
Since the choice of inertial frame is arbitrary, it doesn't have to be compared to any particular object.
If you're trying to say what I think you are, then that's to be expected from you. You never change. Anyone who disagrees with you has a "philosophy."
I have my own philosophy, as well.
This relationalist view
It's not relationist. It's relativistic.
I said: "But a "rotation in four-dimensional spacetime" is not a physical explanation."
"You don't think rotation is a physical process?"
If you want to call the neurons going crazy in your brain as your imagination runs wild while looking at a piece of minkowski graph paper "physical processes," then sure.
wiki said: "The Lorentz transformation geometrically corresponds to a rotation in four-dimensional spacetime, and it can be illustrated by a Minkowski diagram."
If I'm on the corner of 12th and Vine and I got a homey 1 block due east of me and another due north, then the three of us might "correspond" to a euclidean right triangle. But are we a triangle? Does our vague "correspondence" to a geometrical concept say a single thing about why we are there, how we got there, what we're up to, or anything at all the least bit significant about us and our existence. Does it tell you that Hambone is trying to pick up a two dollar ho, even though he only has 50 cents in his pocket? Does it tell you that Finger and Thumb Willie is losin his last dollar in a crap game? I don't think so. Geometrical "correspondence" don't play dat.
One Brow said: "If the bug is crawling from the bow to the stern, it's moving slower than the ship (from the viewpoint of the ocean)..."
Yeah, but how about the viewpoint of the moon? How about from the view point of a shark swimming at 20 knots per hour? How about...
Who cares? The question is who is moving faster with respect to the inertial system (the ship, the earth, whatever) that governs them both. No matter what you say, about anything on any topic, a different pespective can give you a different answer. That doesn't mean that every perspective or wild-ass assumption is "equally valid" with all others, though.
aintnuthin said...
If you want to call the neurons going crazy in your brain as your imagination runs wild while looking at a piece of minkowski graph paper "physical processes," then sure.
Going back to the geocentrism-heliocentrism comparison that so frequently arises, when you try to explain the physical process of the earth's rotation using a mathematical model of it, would you be convinced by the geocentrist saying that it was your imgination running wild?
Geometrical "correspondence" don't play dat.
Of course not. Any geometric model will be an incomplete depiction of the reality, whether it is a Minkowski diagram or a triangle made of three people. It certainly won't dictate the reality. What it can do is model the reality and show some interconnections between different features. The test comes from the ability of the model to be used in new situations to make accurate predicitons.
At any rate, using LET doesn't get you way from Minkowski diagrams. It just changes what you interpret those diagrams to mean.
The question is who is moving faster with respect to the inertial system (the ship, the earth, whatever) that governs them both.
How does an inertial system "govern" something?
No matter what you say, about anything on any topic, a different pespective can give you a different answer. That doesn't mean that every perspective or wild-ass assumption is "equally valid" with all others, though.
The science does not require the selection of a governing system, but is compatible with selecting one. You have made the philosophical choice of deciding there will be a governing system, I have made the philosophical choice that I'm not going to select one.
One Brow said: "Going back to the geocentrism-heliocentrism comparison that so frequently arises, when you try to explain the physical process of the earth's rotation using a mathematical model of it, would you be convinced by the geocentrist saying that it was your imgination running wild?"
It would depend on what you're modelling to begin with. You can show me "models" all day long of space contracting, or the Mars doing double-back flips with a triple twist to explain how it revolves around the earth and I aint gunna buy it as physically meaningful. No matter what kinda fairy tale you want to invent, you can always "model" it mathematically.
When the models are not used to reflect (the word "explain" doesn't seem to fit math models of physical phenomenon in my view) the facts, but rather to tell you what the facts are, then things have been inverted. The medieval astronomers did a whole lot better than "explain" things with math: They built complete working mechanical models of the Ptolemic system. Very ingenious, but the model could not, and does not, "explain" planetary motion. Only concepts "explain," not math or mock-ups.
==
One Brow said: "The test comes from the ability of the model to be used in new situations to make accurate predicitons. At any rate, using LET doesn't get you way from Minkowski diagrams. It just changes what you interpret those diagrams to mean.
1. LR "predicts" things just as well, so where's the "test?"
2. A spacetime graph could have been used with Newtonian physics and Newtonian concepts of time and space the day after he published his theory, but it was not "required" by any means. SR doesn't "require" it either. Einstien invented the whole theory without using (or ever hearing of) Minkowski graphs. In fact he made disparaging initially comments about Minkowski's efforts.
SR has, since it's inception, been a vehicle for those who want to cram it into their brand of philosophy. Sure, they have to alter the theory as they go, and "reinterpret" it, but so what? It's not the theory that's important anyway, it's the philosophy. When the theory gets in the way of the philosophy, so much the worse for the theory--at that point it gets denied, distorted, and/or ignored.
As you probably know, Al once said (paraphrasing from memory): "Since the mathematicians got involved in relativity, I don't understand it myself any more."
Maybe that's because it wasn't even his theory any more, ya know?
If I watch a guy raise an atomic clock by a foot, and see it's rate change when he does it, there's no need for him to start trying to tell me about tilted frames of reference in spacetime. I'm standing there looking at it, and I'm not a tilted frame of reference, and I don't walk around on a piece of graph paper with four dimensions.
One Brow said: "How does an inertial system "govern" something?"
Without special "effort" (acceleration) all objects are governed by the inertial motion of whatever system they're in. You can't just "opt out" and choose to quit moving with the motion of the earth if you're within it's inertial and gravitational system. That's one (of many) reasons you know the bug is crawling toward the desk, and that the desk and everything else isn't moving toward/away from the bug. The bug must share in their motion. He can't remain immobile on the ship while the ship moves under his feets.
It's absurd to think you get on a train to Chicago, sit down, and then, suddenly, Chicago and everything else on the planet is moving toward/away from you.
Talk about a "brain-in-a-vat" philosophy, Jeez. But there's always some "brain in a vat" guys walking around, seriously arguing that you can't KNOW you're not a brain in a vat, therefore you are. They confuse speculative possibilities with common sense, know what I'm sayin.
I said: "But there's always some "brain in a vat" guys walking around, seriously arguing that you can't KNOW you're not a brain in a vat, therefore you are."
I mean, like, think about it, eh? If these "you can never tell who's moving" relationalists who have tried to (and succeeded in) take(ing) over SR were the least bit consistent, what would they say?
They would never say a guy is "entitled" to assume he is at rest. They would insist that he can NEVER know that and is therefore entitled to no such thing.
Neither guy in relative motion to another would have the slightest clue who was moving, and would therefore be completely helpless in deciding which one the Lorentz transformations applied to. Is "his" clock retarded, or the other guy's? No possible way to know--might as go read a comic book now. Don't EVER ask me any questions about relative motion, because the whole subject is simply ineffable, eh?
But consistency would not suit their agenda,so....
Eric, I am aware that inviolable tenant of the relationalist cult to always deny that something can be said to be "really moving." Funny thing is, when it comes to making dogmatic statements about length contract and time dilation when things are (not) really moving, minkowski graph paper gives y'all the special, inside knowledge about what is "real."
You say the changes are "real, physical changes," but that the objects themselves are completely unaltered. Among other problems with that assertion, you are describing a merely apparent, perceptual change. If the objects are not altered, then they are not "really changed."
Another problem is that, as per usual, you end up affirming contradictory claims. Each "sees" the other's times and lengths changed, and what each sees is "real." So each clock "really does" run slower than the other, eh? The old BOTH ARE CORRECT nonsense at work, it would seem.
How can you be so cocksure when affirming the self-contradictory "reality" of speculative graph paper interpretations, but so utterly lost and uncertain when it comes to discerning whether it's your fingers or the keyboard that are (is) moving when you type? Kinda strange.
Don't you ever sense that something might be a little out of whack when, in order to present their claims, the relationalists have to deny what physicists affirm (that motion is discernible) and affirm what every physicist denies (that inherently contradictory claims are acceptable "science")?
One Brow asked: "Going back to the geocentrism-heliocentrism comparison that so frequently arises, when you try to explain the physical process of the earth's rotation using a mathematical model of it, would you be convinced by the geocentrist saying that it was your imgination running wild?"
Most ancients and medievals probably did think it was "imaginative" to consider that the earth could be moving, because no one "felt" it. Galileo showed otherwise, but NOT with a mathematical model. The "math" can "prove" geocentricism just as easily as heliocentricism.
Galileo "demonstrated" why the earth can move without us feeling it, and provided the conceptual framework for understanding (phyically, not mathematically) how and why that is. He basically just noted what was there to see all along. A ball falling from a mast on a moving ship does not end up near the back of the ship. It falls straight down. Why, because a body in motion tends to stay in motion, and a ball does not immediately lose its forward momentum when released. Before that, the notion was that if you threw a ball in the air, and if the earth was moving, then it would not come straight back down. Basically, Galileo demonstrated that the atmosphere also shares in the interial motion of the earth--not a readily apparent thing.
The point is, "math" persuaded nobody, and proved nothing. Only physically understandable explanations have persuasive value in physics, well, except for with the metaphysical branch of "physicists," and they do exist.
aintnuthin said...
... I aint gunna buy it as physically meaningful.
I accept that. I see something a physically meaningful, you don't.
Only concepts "explain," not math or mock-ups.
I think math (which is a concept to begin with) can be useful as a part of an explanation, especially when looking for consequences of other concepts. I agree it doesn't pull the whole load (nor does any other individual type of concept).
1. LR "predicts" things just as well, so where's the "test?"
I was referring to the validity of the model from Minkowski diagrams, which are equally applicable to SR and neo-Lorentzian theories.
SR doesn't "require" it either. Einstien invented the whole theory without using (or ever hearing of) Minkowski graphs.
It's not like SR was a fully fleshed-out, well-understood theory in 1905.
In fact he made disparaging initially comments about Minkowski's efforts.
Only "initially"? Common enough when theories are in their infancy.
SR has, since it's inception, been a vehicle for those who want to cram it into their brand of philosophy.
Much like any other scientific theory.
If I watch a guy raise an atomic clock by a foot, and see it's rate change when he does it, there's no need for him to start trying to tell me about tilted frames of reference in spacetime. I'm standing there looking at it, and I'm not a tilted frame of reference, and I don't walk around on a piece of graph paper with four dimensions.
Since you are comparing two clocks at different levels of gravity, they are in a "tilted" frame of reference (just because you don't notice a tilt doesn't mean it not there). I agree you don't walk around on graph paper and the graph paper model doesn't control you. That doesn't make it wrong.
One Brow said: "How does an inertial system "govern" something?"
Without special "effort" (acceleration) all objects are governed by the inertial motion of whatever system they're in. You can't just "opt out" and choose to quit moving with the motion of the earth if you're within it's inertial and gravitational system. That's one (of many) reasons you know the bug is crawling toward the desk, and that the desk and everything else isn't moving toward/away from the bug. The bug must share in their motion. He can't remain immobile on the ship while the ship moves under his feets.
Wow, that's remarkably fuzzy. So, the inertia of the ship governs the bug, and the inertia of the ocean governs the ship, but the inertia of the ocean doesn't govern the bug?
It's absurd to think you get on a train to Chicago, sit down, and then, suddenly, Chicago and everything else on the planet is moving toward/away from you.
For a variety of reasons. So?
I mean, like, think about it, eh? If these "you can never tell who's moving" relationalists who have tried to (and succeeded in) take(ing) over SR were the least bit consistent,
Fortunately, you are not the least bit correct in this assumption.
Neither guy in relative motion to another would have the slightest clue who was moving, and would therefore be completely helpless in deciding which one the Lorentz transformations applied to.
The transformations apply both ways.
Eric, I am aware that inviolable tenant of the relationalist cult to always deny that something can be said to be "really moving."
I'm still waiting to hear what you mean by that. You have a ship moving 5 mph on a still ocean. You have a bug crawling at 5 mph toward the stern. Is it "really moving"? What is it's speed?
You say the changes are "real, physical changes," but that the objects themselves are completely unaltered.
Yes.
Among other problems with that assertion, you are describing a merely apparent, perceptual change.
No.
If the objects are not altered, then they are not "really changed."
Yes, the objects themselves are not really changed.
Another problem is that, as per usual, you end up affirming contradictory claims. Each "sees" the other's times and lengths changed,
Yes.
and what each sees is "real."
Yes.
So each clock "really does" run slower than the other, eh?
Meaningless. There is no sensible way to interpret that question.
aintnuthin said...
Galileo "demonstrated" why the earth can move without us feeling it, and provided the conceptual framework for understanding (phyically, not mathematically) how and why that is.
Mathematics was part of the framework, even for Galileo. Also, the mathematics for SR and nL are identical, so it's not like you really have a problem with the mathematics.
Only physically understandable explanations have persuasive value in physics, well, except for with the metaphysical branch of "physicists," and they do exist.
The difference between SR and nL is basically one metaphysical propostion added in by nL.
Have you ever really thought about what Al was saying when explaining why the guy on a train will see the light from the front of the train first?
What he's saying is that, with respect to the light from the back of the train, it is travelling toward the passenger relatively slower (c-v) than the light from the front (c+v). We, on the ground, see the light from the front of train travelling toward him faster, and he, on the train, experiences it the same way. This is just the old Galilean transformations at work, where the motion of the observer causes the relative speed of other things to vary.
So what does his theory do to "change" those transformations which explain why the train passenger sees the light from the front first? How does light behaving in accordance with Galilean transformations take on the "appearance" of constancy, regardless of the motion of the observer? By using the same explanation and the same formula Lorentz did, that's how. He shows how, with length contraction and time dilation, something that is "really" moving with respect to something else at c+v and c-v can "appear" to be moving at a constant speed.
Put a different way, time dilation and length contraction can make it appear that a moving object is motionless. But this whole explanation only works if you ASSUME "real" motion which is the thing being disguised by deceptive appearances. Without that actual motion, no part of the explanation would make sense.
The very explanation of SR presupposes actual motion and distinguishes it from the mere "appearance" of lack of motion (as the ancients relied on when rejecting a heliocentric theory). This is what physics does--it tries to explain what is "really" happening, even when appearances may be otherwise.
Any philosophical add-ons about the lack of any "real motion" are NOT part of the theory, and in fact such claims contradict the premises of the theory. The fact that we can't directly detect the earth's motion does NOT make a geocentric explanation equally valid, not in either theory or fact.
In theory, the two views (heliocentric and geocentric) cannot BOTH be correct.
In fact, we have indirect ways of detecting the earth's "real" motion. After being forced to publically recant and renounce the view that the earth moves, he muttered, on his way out the door, "And yet it moves." Galileo wasn't nobody's chump.
One Brow said: "Meaningless. There is no sensible way to interpret that question."
Let me think, now...where have I heard that hollow assertion made 10,000 times before?
Oh, yeah, that's right, from every Machian relationalist and logical positivist who ever came down the pike, that's where. Too bad they had the curtains pulled on them like the wizard of Oz, eh?
To someone who has no sense of meaning, all things are meaningless.
One Brow said: I'm still waiting to hear what you mean by that. You have a ship moving 5 mph on a still ocean. You have a bug crawling at 5 mph toward the stern. Is it "really moving"? What is it's speed?
What are you "still waiting" for? I've already explained what I mean. Yes, the bug is "really moving" at the rate of 5 mph. It is not motionless while only the ship moves.
If an ocean liner passes a buoy floating on the surface of the ocean, how could you ever tell which one is "really moving?"
Hint: Check and see if the buoy has massive engines going full blast when they pass each other. Might give you some kinda vague idea, know what I'm sayin?
If I walk away from my desk, how can I know that the desk isn't moving away from me, while I remain motionless?
How do you know you're not just a brain in a vat?
Simply no possible way to tell, obviously.
It would be "judgmental" to act like there are any kinda standards to differentiate between the two "equally valid" propositions in each case. That (judging) would be, like, the WRONG thing to do wouldn't it?
I take it all back. It is a judgment to say using judgment is wrong. I think it's more like this: Nothing can or should be said to be true about anything. All possibilities are equally valid and equally true. How do I know they're all equally valid? What standard to I use to determine that?
Meaningless question, there are no standards for judging anything, that's the point, and, likewise, there is no standard for me saying there are no standards. It's all arbitrary and all talk is meaningless.
Gorgias, the old greek sophist, had it right when he said:
"Nothing exists. And even if something did exist, nothing could be known about it. And even if something could be known about it, that knowledge could never be communicated to another person."
Brain in a vat, I tellya.
Normal Person: If you look at the "heads" side of a coin, you will see an image of George Washington.
Relationalist: But you won't see that if you're looking at the tails side.
NP: That's right. I see that you understood what I just said perfectly.
R: Looking here, Buster, it YOU who doesn't even understand what I'm saying?
NP: What is it you think you're saying, exactly?
R: That you won't see the heads side of a coin, if you're looking at the tails side, that's what.
NP: Yeah, we agree on that. That's implicit in what I said. What's your point?
R: The point is obvious, fool. You can never know if you're looking at heads or tails, that's the point.
NP: That so?
aintnuthin said...
Have you ever really thought about what Al was saying when explaining why the guy on a train will see the light from the front of the train first?
What he's saying is that, with respect to the light from the back of the train, it is travelling toward the passenger relatively slower (c-v) than the light from the front (c+v).
So, you're saying that, if the guy on train measures the speed of each burst of light as it passes, he'll get a different speed for one than the other? No, Einstein is specifically *not* saying that. The speed of both bursts will be measured as the same by the guy on the train.
He shows how, with length contraction and time dilation, something that is "really" moving with respect to something else at c+v and c-v can "appear" to be moving at a constant speed.
Length contraction and time dilation apply identically to the direction of travel and the opposite direction. They do not apply differently to light going one way versus the other.
Put a different way, time dilation and length contraction can make it appear that a moving object is motionless.
No, the inertial environment is what gives the appearance of motionlessness.
One Brow said: "Meaningless. There is no sensible way to interpret that question."
Let me think, now...where have I heard that hollow assertion made 10,000 times before?
Me, when I asked you to sensibly produce a basis for that question based on the actual postulates of SR, and you failed.
Since youthink the assertion is hollow, feel free to show how your question has meaning.
One Brow said: I'm still waiting to hear what you mean by that. You have a ship moving 5 mph on a still ocean. You have a bug crawling at 5 mph toward the stern. Is it "really moving"? What is it's speed?
What are you "still waiting" for? I've already explained what I mean. Yes, the bug is "really moving" at the rate of 5 mph. It is not motionless while only the ship moves.
So, let's put a clock on the bug, the ship, and the ocean. I believe we agree the best interpretation is that the ocean is not moving, so the clock on the ship is slower than the clock in the ocean. How about the clock on the bug? Is it slower than the clock on the ship? On the ocean? If the ship is really moving at 5 mph and the bug is really moving at 5 mph, will their clock be running at the same rate?
If an ocean liner passes a buoy floating on the surface of the ocean, how could you ever tell which one is "really moving?"
I could tell by applying the principle of conservation of energy. How does that affect relativity?
One Brow said: "So, you're saying that, if the guy on train measures the speed of each burst of light as it passes, he'll get a different speed for one than the other?"
How in the world could you think I said that, or said that Al says that. I explicitly said the opposite. The guy will NOT "measure" the Galilean-travelling light to be such. What's "really" happening, per Al's example, is that the speeds are c+v and c-v, respectively, but he will NOT measure it to be what it really is.
Lorentz used it to show how you can "really" be moving, but not measure your motion due deformed clocks and rods. Same with the guy on the train: He really is moving, but can't detect that motion in his measurements. Light really is travelling in Galilean fashion relative to him, but he mismeasures that fact.
Again, Al's explanation is based on the fact that the guy on the train is "really" moving. If he knows that, then he knows he is mismeasuring the speed of light. If he doesn't know it, or pretends that he doesn't, then he might think (or act like he thinks) that his mismeasurements are accurate, that's all.
If the guy on the train assumes that:
(1) the origination points of the beams are equidistant from him (which they are), and
(2) that he is NOT moving, then, based on those assumptions, he must conclude that:
(3) the beam from the front happened first, because it reached him first.
On the other hand, if he knows he is moving, he will realize that his own motion must be accounted for in any calculation of the speed of the light relative to him, and he will arrive at a different conclusion.
When he concludes that the front beam "occurred first" he only does so because he does not take into account that the light from the front does not travel as far to reach him as does the rear beam. This in spite of the fact that the two (also moving) points of origination remain, at all times, equidistant from him. It is the motion combined with his ignorance (or denial) of the existence of that motion which misleads him.
Al certainly knows, at bottom, that what the guy "thinks" is not the determining factor in what's "really happening."
One Brow said: "How about the clock on the bug? Is it slower than the clock on the ship? On the ocean? If the ship is really moving at 5 mph and the bug is really moving at 5 mph, will their clock be running at the same rate?"
Good question. You have to be careful not to confuse motion resulting from the continuous application of an external force (non-inertial motion) from inertial motion which, by definition, is motion NOT caused by an external force (at least not a continuing one). A body is not necessarily moving under the influence of inertia alone just because it has a uniform speed. There is the additional requirement of the absence of external forces acting upon it. This is often overlooked, and people tend to say that two objects which are simply moving at a uniform speed relative to each other are "both" moving inertially.
The ship is being accelerated with respect to the ocean by measurable forces (wind, horsepower generated by engines, whatever). As soon as those external forces cease to be applied, the motion with respect to the ocean ceases.
Within that framework, the bug is not expending an ounce of individual energy to move with the ship. But the bug is producing additional acceleration when it heads aft, so it seems SR would predict that the bug's clock is slower than the ship's clock, which is slower than a clock on the (unaccelerated in this view) ocean.
The ship is moving with respect to the ocean, and the bug is moving with respect to the ship. You have a double acceleration, not zero acceleration, because the two do not cancel each other out. Each one is an independent motion with takes independent energy (force) to generate it. You could have a baby bug going at the rate of 5 mph in the opposite direction on the back of the first bug. The baby bug's clock would be slower yet, and would not match the ship's clock.
When Al says the "moving clock" (his words, not mine) he apparently means moving with respect to a clock which does not experience additional acceleration and remains in truly inertial motion. A "moving" clock is therefore one which has been accelerated relative to a clock which has not been (further) accelerated.
When you have to apply additional force to effectuate and maintain a change in velocity, then the motion is, by definition, no longer inertial. The bug is not "coasting" on the basis of previously accumulated inertial speed when it moves its legs to head toward the stern. The bug it not going the same speed as the ocean because it is resting (floating) on the ocean. There's a difference. If it was, then it (or it's clocks) would be "governed" by the inertial motion of the ocean, rather than the ship. Put another way, when you have to accelerate a thing to make it match the speed of another thing which is not accelerated (not moving by virtue of the application of external forces) they are not "both" in inertial motion, even if they both happen to be going at the same uniform rate of speed. With the bug, as with the ship, as soon as you remove the influence of the force which is causing their "extra" motion, the extra motion ceases. When the ship docks on the ocean, and the bug stops running around, then all three clocks will run at the same rate.
I hope you don't mind if I ask you a couple more questions.
Let's add a worm and spider to the mix (I'll assume the bug is an insect, and so can't be either a worm or a spider). Both of them have clocks, and are floating by hanging on helium balloons. The worm was never on the ship, it's just been there. The spider started off on the deck while the ship was moving, but then jumped off the deck towards the stern at 5 mph, and is now hanging right next to the worm. With > meaning "faster than", you've already said for the clocks that ocean > boat > bug. How do the worm and the spider fit in?
Also, you said "The ship is being accelerated with respect to the ocean by measurable forces (wind, horsepower generated by engines, whatever). As soon as those external forces cease to be applied, the motion with respect to the ocean ceases." What causes the ship to stop?
One Brow asked: "What causes the ship to stop?"
Well, obviously it's other forces (friction,gravity etc.) at work to alter your inertial momentum then, too. Those were the very forces you were using energy to "overcome" to begin with. That's kinda what a gravito-inertial system does to ya, ya know? It's always trying to oppress you and drag you down to it's level, whether you wanna go there or not.
Are there any "truly free" particles in the universe? Don't ask me, because I don't know. That said, the concept of inertial motion is fundamental to the theory of SR. Maybe SR does not, as a practical matter, apply to any situation in the real world. I'm not really approaching the topic with that question in mind. I'm just trying to understand what the posits and assumes, and what the logical consequences of those assumptions would be. It's not *my* theory, it's Einstien's. Well, it used to be, anyway. It has since been co-opted by people who don't really like Al's theory because of what it implies. Best solution? Change the theory to make it suit you.
One Brow asked: With > meaning "faster than", you've already said for the clocks that ocean > boat > bug. How do the worm and the spider fit in?
I'm really not sure what you're asking here, but let's start with this: The earth, it's atmosphere, and everything subject to the influence of it's gravitional sphere of influence is not itself a truly inertial system to begin with. It is bound by the sun, which is itself presumably "bound" by the galaxy, which is....ad infinitum. They are all moving in part by virtue of the application of "external" forces. Even so, it still takes an "additional" force to change the path things are already taking. There are obviously inertial sub-systems within larger systems, on up and down the scale.
Not sure it's really relevant here, but to me there is a distinction between the motion of a "system" and the individual objects that are simply "attached" to it in terms of being "along for the ride."
A car travelling down the freeway at 60 miles an hour can be seen as a "system" in the sense I mean. The car is constantly being motivated by mechanical forces generated by a constant use of fuel, etc. It is not moving "inertially."
On the other hand, the passengers in the car, and the dog in the backseat, and the coffee cup on the dash, etc. are not being individually accelerated. The "system" is, and they're simply along for the ride. No additional energy or force need be applied to them individuallly to allow them to "keep up" with the moving "system" (the car). They go along effortlessly, whether they want to or not. In that sense, the passengers are in inertial motion while the car is not.
The pack of camels on the dash is not "moving" with respect to the system, even if it is moving with respect to the ground or the moon. It doesn't start moving around within the car (system) without an "additional" force being applied to it.
When Al talks about a "moving clock" he appears to mean the pack of cigarettes moving with respect to the (sub)system it partakes of, not the ground or some other "system" somewhere else, and not a "super-system" which both the pack of cigarettes and the car are already a part of (as regards, for example, the earth's orbit around the sun).
If a pack of cigarettes is picked up and put into your pocket, then it is moving (and moving "faster") with respect to other objects in the system which most immediately governs it (the car, and all of it's complex motions through space, along the surface of the earth, etc.).
"Motion" can therefore have different meanings in different contexts. When the cigarettes go "backwards" (with respect to the motion of the car) when being transferred from the dash to your shirt pocket, they, not the car, is what is moving it that context. They are moving toward your shirt pocket--your shirt pocket is not moving towards them in that context. Since they are moving, and the passenger is not, they are necessarily moving "faster" in that context. The same would be true if the car was parked at the time. The generalized collateral motion that the car, the passenger, and the pack of cigarettes all share in common is not part of the equation when determining which one is "moving faster."
Within the context of a larger sub-system of "inertial" motion, the car, the passengers and the pack of cigarettes are all moving "faster" than the earth. But even so, it is the car that is moving under the influence of an "external" force, not the passengers per se.
Words like "external" can have no meaning without a conception of what would be "internal" in that context. A pack of cigarettes could be "external" to me while being "internal" to the atmosphere of the earth. Such words (any words, actually) have no inherent, invariable meaning, regardless of context.
Jumping off a ship is not "acceleration" with respect to the lateral motion of the ship, although it is acceleration with respect to the surface of the ocean. Again, ya gotta look at the context. There is not one, invariable, notion of acceleration or movement. All motion, indeed all concepts, are relative in the sense that their meaning depends on the context.
That said, the pack of cigarettes is the thing that is "really moving." And in context it is "moving faster" than the shirt pocket. In that same general type of context, the train is moving, not the earth. The cigarettes are moving with respect to the system a as whole, the shirt pocket aint.
Al, without trying to address each of trillions of clocks scattered throughout the universe, says that as between two particular clocks the one which is moving (has been given an additonal motion due to a non-shared external force) will run slower than the one that aint.
Don't ask me why. I don't know why. I just know that's what the theory appears to predict.
One thing is indubitable: The shirt pocket and the pack of cigarettes are not each motionless with respect to each other while the tranfer to the shirt pocket is being made. After that, sure, but....
Likewise, there are reliable objective indicia, independent of idiosyncratic perspectives, of "which one" (the cigarettes or the shirt pocket) is "really moving."
As I've said before, all objects have a long prior history of previous accelerations (external forces being applied to them at various times throughout history). These accelerations are "absolute" and are seen as such by all (non-hallucinating)observers. Within all of history, some objects have been accerated more often, and/or in greater degrees, than others. That's why all things are not moving at the exact same speed right now. Things don't have to share the exact same local inertial system for that to result. They need only share the same "universe."
In SR, the meaning of "moving" is not, contrary to some popular opinions, determined as between two (or more) observers. It is a comparison of the motion between a given object and the state of motion of the location where the standards for length and time (proper time, and proper length, in SR terminology) are established. That is what "motion" in SR is "relative to."
And I should have added that determination of which frame has the "proper time" and the "proper length" is not merely arbitary and reciprocal in SR. It is the system which has not been accelerated (not "both" systems) that serves to set those standards. If you don't know which one has been accelerated, then you don't know which system sets the standard for motion. But, either way (whether you know which one has been accelerated, or not) it is still the one which has not been accelerated which serves to set the standard within the confines of SR theory.
What is the speed of the earth with respect to Mars? To Mercury? To Venus? To Jupiter? I could ask the same question singling out a million different objects for comparison and get a different "speed" for the earth in each case. Are all those speeds "equally valid?" Is the earth in fact going millions of different speeds, all at once?
Of course not, with respect to both questions. If you change the object of comparison (the "perspective") every time you turn around, you will get a different answer each time. That's the nature of different perspectives. The only possible way to get any consistency in statements about the relative speeds of various object is to quit changing perspectives, willy-nilly. That is pure sophistic equivocation--nothing more, nothing less.
As I've mentioned before, Newton treated the entire solar system as a single interial system. Within the context of that system, there is a point which is motionless with respect to every other object governed by the interia of the system. It is the center of mass of the whole system. Everything within the system orbits that point, including the sun.
So, for a variety of good reasons, Newton used that point as the single reference point for all motion within the system. Due to a variety of considerations that point of reference is "more valid" than any other point you could pick within the solar system. With that consistent point of reference, the earth (and all other solar objects) is "moving" at a consistent rate of speed (about 30,000 mps) which does not change with every distant observer who happens to glance at the earth and compare it to himself.
Again, an infinite number of "standards" is the equivalent of no standards at all. With no standards at all, related concepts lose all meaning and any hope of ever having meaning. To deny a standard is the quickest and easiest path to concluding that "everything is meaningless" and that knowledge is impossible, if that happens to be your philosophical goal.
This method also gives consistent and meaningful comparisons of the relative speed of Earth and Mars, because you are comparing apples to apples and oranges to oranges. In no case is the "speed" of Mars and earth determined only with respect to each other (although that is a simple calculation to make also). The idea that any kind of consistency or meaningful idea of "speed" can only be obtained by comparing any two moving objects to each other without resort to a broader, more inclusive overall context is severely misguided.
Thank you for laying out your ideas of motion. It's very interesting reading.
When you said that the ship would stop if you removed all external forces, and then said that it would be stopped by friction and gravity, did you mean friction and gravity were not external forces on the ship? If so, does that mean they have no relativistic influences?
I'm really not sure what you're asking here, ...
I was asking you for your analysis on the rates of the clocks attached to the worm and the spider. I will have a few more questions and ideas that lay beyond it, but they will be different depending upon your answers. Ultimately, I'm looking to see if your framework is going to wind up in a consistent, physical interpretation.
Since they are moving, and the passenger is not, they are necessarily moving "faster" in that context.
How is this different from the usual "perspective"-oriented view of motion you argue against? What distinguishes "context" from "perspective"?
Don't ask me why. I don't know why. I just know that's what the theory appears to predict.
So, while you reject four-dimensional rotation as a physical explanation ofr the effects of relativity, you don't endorse Lorentzian ether or any or physical notion?
In SR, the meaning of "moving" is not, contrary to some popular opinions, determined as between two (or more) observers. It is a comparison of the motion between a given object and the state of motion of the location where the standards for length and time (proper time, and proper length, in SR terminology) are established. That is what "motion" in SR is "relative to."
You seem to be saying the presence of the observers is not relevant to the physics. Do you think there are many main-stream physicists (as opposed to philosophers) who would argue differently?
Is the earth in fact going millions of different speeds, all at once?
Is there a main-stream physicist who says something like that directly, or is that basically your inferral from what they say?
One Brow said: "did you mean friction and gravity were not external forces on the ship?"
No, I didn't. They are external forces.
One Brow said: "How is this different from the usual "perspective"-oriented view of motion you argue against? What distinguishes "context" from "perspective"?"
I have said many times, (after you keep bringing it up), that you can have no view at all if it's not from some perspective. Perspective is a sine qua non of all thought and perception. I'm not "arguing against it," in any general sense. We agree that when you talk about "motion" you are necessarily, even if implicitly, talking about motion with respect to something, even if that "something" is absolute space.
One Brow said: "So, while you reject four-dimensional rotation as a physical explanation ofr the effects of relativity, you don't endorse Lorentzian ether or any or physical notion?"
I refuse to take an abstract mathematical analysis as a physical explanation. If it happens, there is a physical explanation, whatever it might be. I don't claim to know what it is. I've seen a variety of theoretical explanations, but I don't pay close attention to any of them.
One Brow said: "Is the earth in fact going millions of different speeds, all at once?
Is there a main-stream physicist who says something like that directly, or is that basically your inferral from what they say?
The length of a football field "really does" range from 100 yards down to billionths of an inch, in an infinite continum, all depending on the observer looking at it, they say. All at the same time, too. Just one example.
One Brow said: "You seem to be saying the presence of the observers is not relevant to the physics. Do you think there are many main-stream physicists (as opposed to philosophers) who would argue differently?"
No, I don't think physicists would generally argue with the proposition that physics, as a topic, is concerned with objective physical events and not, except in passing to reconcile apparent inconsistencies, with the subjective perceptions of individual observers.
Not in general. But many of those touting SR take a contrary approach when it comes to SR. Now, suddenly, the "speed of light" is "relative to the observer," and strictly depends on the assumptions and (mis)measurements he makes. Why the sudden switch in fundamental premises?
Such an approach basically anti-physical, and adopts the approach of a Berklean solipsists. Decartes asserted that there is a duality of "substances" (mind and body). Some have tried to deny any such duality by asserting a monism of substance. Some say there is only body (matter). Some, like Berkeley, say that there is only mind, and that the suggestion of the existence of an objective, material world which "really exists" is false and illusory.
I don't agree with either form of monism, but if I had to pick one over the other, it would definitely be materialism over solipsism. As would your average physicists (unless he happens to be "explaining" SR in the manner he was taught to explain it).
Eric, I responded to one or two more of your questions (can't remember how many now), but one or more apparently went into the spam bin.
I'm standing five feet away from two atomic clocks. One is raised one foot and the digital time display readout changes from the other clock.
Doodle around on a piece of graph paper for me sometime, eh, Eric, and get your "frame of reference pointing away" as it relates me and what I just saw. Then show me how your doodles somehow enter my brain and make my optical nerves see a different display on the two clocks.
You say there is no physical change to the clock, so tell me exactly how I see those digital readouts change, eh? How does that happen with no phsyicial changes to the clock whatsover, exactly? Magic?
Al said, and I quoted him for you, that if his constancy postulate is true, it follows by logical necessity that clocks and rods get distorted with speed. You have seemingly refuted this, since there are no distortions. You should publish your refutation, doncha think?
Eric, you always ignore, and never respond to (at least not in any substantive way) the question about the travelling twin. If he adheres to the demand that the lorentz transformations must be reciprocal (which demands that he MUST consider himself to be at rest), what does he find when he returns? He finds out he was wrong, that's what. Based on the reciprocity requirements, he assumed that his twin was aging more slowly, but, turns out, that aint true.
How does he "readjust" to this sad fact? Well, next time he gets his ass accelerated to a distant star, he will not assume he is motonless and that the earth is moving away from him, that's how. He will still use the lorentz transformations to calculate the actual state of affairs, but he will apply the transformations to his own clock, not to the clocks on earth. He will realze that he, not his twin brother, is the one who is aging more slowly and that his clocks, not his twin's, have slowed down.
Or do you deny the outcome predicted by SR? Will it actually be the travelling twin who is older, while the other is younger? Will they both age at the same rate, with each of them having been mistaken in thinking that there was ever any clock difference, or what?
No, I didn't. They are external forces.
So, if you remove all the external forces on the ship, does it stop moving with respect to the ocean?
Also, since the external force of the propulsion is being balanced by the external force of the friction, doesn't that mean the net external force on the ship is zero? Earlier, you said, "You have to be careful not to confuse motion resulting from the continuous application of an external force (non-inertial motion) from inertial motion which, by definition, is motion NOT caused by an external force (at least not a continuing one). A body is not necessarily moving under the influence of inertia alone just because it has a uniform speed." Is there a difference a continuous application of equal, opposing external forces versus that under no external forces that affects clocks and rods inside the ship?
I have said many times, (after you keep bringing it up), that you can have no view at all if it's not from some perspective.
Of course. I'm just asking you to clarify the difference between your use of perspective (which you called context) and my use of perspective.
I refuse to take an abstract mathematical analysis as a physical explanation.
As you should. However, that is not the same thing as saying you reject the physical interpretation of four-dimensional rotation, which is also true as far as I can tell. I would hope you are able to reject both while seeing that a rotation is not an abstract mathematical analysis.
If it happens, there is a physical explanation, whatever it might be. I don't claim to know what it is. I've seen a variety of theoretical explanations, but I don't pay close attention to any of them.
OK.
The length of a football field "really does" range from 100 yards down to billionths of an inch, in an infinite continum, all depending on the observer looking at it, they say. All at the same time, too. Just one example.
Since the observed length in the football field between observers in different inertial states, let's call it L, is a function of both the length of the football in it's own inertial state (the maximum length it can be measured at), let's call it l, and the difference between the intertial states of the football field and the observer (let's call that d), this is not really an objection. You're saying that mainstream-SR-interpretation says L(l) =/= L(l), but it is really saying L(l,d1) =/= L(l,d2).
One Brow said: "You seem to be saying the presence of the observers is not relevant to the physics. Do you think there are many main-stream physicists (as opposed to philosophers) who would argue differently?"
Not in general. But many of those touting SR take a contrary approach when it comes to SR. Now, suddenly, the "speed of light" is "relative to the observer," and strictly depends on the assumptions and (mis)measurements he makes. Why the sudden switch in fundamental premises?
By "relative to the observer", they actually mean "relative to the oberserver's inertial state". The presence of the observer in that state is not relevant (except to the degree that one is needed to make measurements).
Then show me how your doodles somehow enter my brain and make my optical nerves see a different display on the two clocks.
Why should I show you something I, and physicists, don't believe?
You say there is no physical change to the clock, so tell me exactly how I see those digital readouts change, eh? How does that happen with no phsyicial changes to the clock whatsover, exactly? Magic?
You don't think raising the clock a foot, and altering gravity field around it, is a physical change?
You have seemingly refuted this, since there are no distortions. You should publish your refutation, doncha think?
My refutation was to your interpretation, not SR.
Eric, you always ignore, and never respond to (at least not in any substantive way) the question about the travelling twin. If he adheres to the demand that the lorentz transformations must be reciprocal (which demands that he MUST consider himself to be at rest), what does he find when he returns? He finds out he was wrong, that's what. Based on the reciprocity requirements, he assumed that his twin was aging more slowly, but, turns out, that aint true.
Why would he assume anything at all? If he adheres to the demand that the lorentz transformation are reciprocal, he has also accepted the notion that events separted by large amounts of distance don't have a true idea of simultaneous or a common basis for a timeframe, so the very concept of "aging more slowly" doesn't apply.
Or do you deny the outcome predicted by SR? Will it actually be the travelling twin who is older, while the other is younger? Will they both age at the same rate, with each of them having been mistaken in thinking that there was ever any clock difference, or what?
Your questions presume a common control of the twins by some overarching time stream which doesn not apply.
Heh. Yes or no?:
Or do you deny the outcome predicted by SR?
Do you deny that one twin will age less and one more?
One Brow asked: "You don't think raising the clock a foot, and altering gravity field around it, is a physical change?"
Does you always "answer" a question by asking an irrelevant question?
It's a physical change in the clock's position, just as moving the clock a foot to the left would be. Is that a change to "the clock?" Or just some physical change in something else? I'm talking about the change in the clock's digital readout. Does that change? I understood you do adamantly maintain that there are no physical changes to the clock itself.
Or do you deny the outcome predicted by SR?
I endorse the outcome predicted by SR.
Do you deny that one twin will age less and one more?
When the twins are reunited, the twin that accelerated will have aged less.
It's a physical change in the clock's position, just as moving the clock a foot to the left would be. Is that a change to "the clock?"
A change in the clock's position is not a change internal to the clock.
Or just some physical change in something else?
The gravitational field around the clock.
I'm talking about the change in the clock's digital readout. Does that change?
Yes. the clock in the weaker gravitational field will fun faster.
Einstein's words: "If we placed a living organism in a box ... one could arrange that the organism, after any arbitrary lengthy flight, could be returned to its original spot in a scarcely altered condition, while corresponding organisms which had remained in their original positions had already long since given way to new generations. For the moving organism, the lengthy time of the journey was a mere instant, provided the motion took place with approximately the speed of light."
So, he says, the "moving organism" ages slower "provided the MOTION (my emphasis, of course) took place with approximately the speed of light."
So, now, he has this "moving organism" moving at approximately the speed of light. How does that work? How is the premise that he is moving at close to the speed of light reconciled with the claim the speed of light is unchanged for him?
If it is the "moving organism" who ages less, then I guess the "travelling twin" must be the one who was "moving," not the earth twin, eh? Is Al actually suggesting that motion is discernible? Is he suggesting that some things maintain their position in "absolute space?" He refers to "organisms which had remained in their original positions."
I'm sure you don't (or if you do, you will pretend you don't)even understand the question, but I pose it anyway.
Here's some variations of the twin scenario for you. Each has three clocks in ships, none of them accelerating. In each, one of the clocks has an observer with them.
1) Person A has clock A1. As clock A2 passes, the clocks synchronize (are set to the same time). Then, A observes clocks A2 and and A3 syncrhonize as they pass each other. Finally, A3 passes by A1, and A compares the readout on A3 to that on A1.
Comparing A1 and A3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person B has clock B1. As clock B2 passes, the clocks synchronize. Then, as clock B3 passes, B1 and B3 synchronize. Finally, B3 and B2 pass each other, and B compares the readout on B2 to that on B3.
Comparing B2 and B3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person C has clock C1. As clock C2 passes clock C3, those clocks synchronize. Then, as clock C2 passes C, C1 and C2 synchronize. Finally, C3 passes C, and C compares the readout on C1 to that on C3.
Comparing C1 and C3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
I think that, in addition to the ones aboe not answereed yet (the spider and the worm, does the ship stop, is the clock inside teh ship affected by cacelled out external forces differently than if those forces did not exist, the difference between the context you say is important to include and the perspective yousay I should not be including) will wrap up my questions.
"Yes. the clock in the weaker gravitational field will fun faster."
Is time dilation caused by gravity an entirely different breed of time dilation than the kind which results results from "moving" (to us Al's words)? Would the digital readout also change if the time dilation was the result of motion, rather than gravity, or would the clock in that case not reveal any physical change with respect to it's readout?
aintnuthin said...
So, now, he has this "moving organism" moving at approximately the speed of light. How does that work? How is the premise that he is moving at close to the speed of light reconciled with the claim the speed of light is unchanged for him?
Einstein is using the initial/final inertial state as the determinitive state for the speed of the microorganism.
Is Al actually suggesting that motion is discernible?
I've always said that you can determine when something is moving after chossing an inertial rest state.
Is he suggesting that some things maintain their position in "absolute space?" He refers to "organisms which had remained in their original positions."
Again, under the assumption that the initial/final inertial state of teh traveling microorganism is the rest state, that's where the other microorganisms stayed.
aintnuthin said...
Is time dilation caused by gravity an entirely different breed of time dilation than the kind which results results from "moving" (to us Al's words)?
Time is only one-dimensinal, so all dilations would be of the same "breed" in that regard.
Would the digital readout also change if the time dilation was the result of motion, rather than gravity,
Yes.
or would the clock in that case not reveal any physical change with respect to it's readout?
Not sure what you mean here, but I'll try to interpret. You are asking if each clock will see the other clock as reading the exact same time? No.
Synchronize clocks K and L. Pick up L, and walk with it for 100 feet, then set it down. The time K sees from clock L will be slightly behind the time K reads for itself. The time L sees from clock K will be slightly behind the time L reads for itself.
One Brow said: "1) Person A has clock A1. As clock A2 passes, the clocks synchronize (are set to the same time). Then, A observes clocks A2 and and A3 syncrhonize as they pass each other. Finally, A3 passes by A1, and A compares the readout on A3 to that on A1."
I don't see where you've given enough information to possibly answer the question. The way you have it A2 could have changed his clock again or not have changed his clock.
You ask: a) Which readout does mainstream SR say will show less time has passed?"
a) you mean as seen by A1?
b) you mean as seen by A3?
c) you mean as seen from the God (absolute) perspective
SR says the "moving" clock will actually record less time, whether perceived that way by all parties or not. Who's moving here?
In each scenario, there is only one person doing the viewing. In each scenario, the clocks you are comparing are right next to each other at the time they are being viewed, to the difference in their readouts will be the same to all observers.
For either mainstream-SR or nL, it will not matter which you decide is moving, but if it helps you, assume each time the person with the clock is not moving.
Also, I'm not going to be able to check back before Sunday morning, maybe Monday morning, so take your time, and enjoy the weekend.
One Brow said: "Synchronize clocks K and L. Pick up L, and walk with it for 100 feet, then set it down. The time K sees from clock L will be slightly behind the time K reads for itself. The time L sees from clock K will be slightly behind the time L reads for itself."
And why would that be? Because of the delay caused by the light to travel between the two, that it?
How would a guy standing halfway in between them see it? Would he see that clock that moved as always running a bit behind the unmoved clock, even though they were now keeping time at the same rate?
Does it make any difference if, contrary to your example, the two clocks are moving with respect to each other? Because that's the only time time dilation occurs, not when they are at rest with respect to each, and my question was about time dilation, not whether it take light to time to travel from point A to point B (which does not, in itself, cause any time dilateion at all).
One Brow said "For either mainstream-SR or nL, it will not matter which you decide is moving"
It won't, eh? I don't know what you mean by "nL," by the way.
If we go back to the example provided by the professor where each sees 10 seconds elapsed on one clock and 8 on the other, why does the one show 10, and the other 8? Why isn't the situation reversed with the opposite clock showing 8 and the other one 10? Why do they differ at all, for that matter?
The answer seems to be "Jill’s spaceship, carrying a clock C', is traveling at 0.6c,..."
So, Jill, not Jack, is travelling. As I said, SR says the "moving" clock will run slower, so it DEFINITELY matters who is moving in that respect. The reason her clock shows 8 seconds, and his 10 is because she is moving and he isn't. If he were the the one travelling, the situation would be reversed, and his clock would show 8, and hers would show 10.
In your first example (where you give no indication of which direction or speed any one is "travelling," and in which you claim it makes no difference who is travelling) you say A2 "synchronizes" with A3. Does that entail
1)A2 changing his clock to match A3,
2)A3 changing his clock to match A2's, or
3)both A2 and A3 making some compromise in their clocks to that they "match?"
Are both clocks set to zero when they pass? If so, then A2 has erased all the time off his clock that accrued since he "passed" A1 while A1 is not re-starting his clock.
You throw out the word "synchronized" like it has some invariable meaning, but it doesn't. See next post.
What is "synchronized" even supposed to mean? In the convoluted example by the prof, he first tells us that:
"Suppose C' is synchronized with C1 as they pass, so both read zero."
OK, that's why her clock reads 8, and his 10, because the clocks were "synchronized." They started at zero, she is moving, therefore her clock runs slower, therefore she shows only 8 seconds elapsing while he shows 10. Now what?
Since he is trying to reach a particular answer the prof later says: "To Jill, C1, C2 are running slow, but remember they are not synchronized. To Jill, C1 is behind C2..."
But the clocks ARE synchronized according to Jack, and it is implied that Jill understands that. So again the answer you get to whether two clocks are "synchronized" depends on who you ask and whether, in giving their answer, the moving observer tries to deny that he is moving. Their answers depend on who is moving--in this example, Jack is not moving, and Jill is, but incorrectly claims she is not).
Your "question" has no answer in SR, given the (lack of pertinent) information you have provided. Your assertion that it doesn't matter who's moving is contrary to the premises of SR, so whatever answer you reach must be on some non-SR basis that you like to call "mainstream SR."
Speaking of this prof guy, why does he take some circuitous route back to the first clock to try to explain things? Jill says it must read 6.4 when she passes the second clock, yet her picture shows it reading 4 seconds despite her claims.
But the question is this: Why doesn't she simply say: "Since I passed that point (the first clock) your clock shows 10 seconds elapsed, mine shows 8, therefore, per SR, I must be the one moving, because yours is running faster and mine slower"? It is implied that she knows Jack's clock 2 is synchronized with C 1 in his frame. She went from point A to point B in a time she measured to be 8 seconds while he measured it to be 10.
The "first clock" has nothing to do with it anymore, and it never did, really. It could have just been a point in space and not a clock at all. They both started at zero at that point, which had nothing to do with what that clock was "reading" (it read zero, and it is implied that clock 2 also read zero at that time, so no need to talk about the first clock any more).
The supposition behind the relationship between the two clocks is this, he says: "Suppose that in Jack’s frame we have two synchronized clocks C1 and C2 set 18 x 108 meters apart (that’s about a million miles, or 6 light-seconds)." But, nonetheless, he later says: "Therefore, Jill will conclude that since C2 reads 10 seconds as she passes it, at that instant C1 must be registering 6.4 seconds." Why in the world would see make that assertion to begin with? Given the premises, the only possible conclusion is that clock 1 is now reading 10 also (see note 1, below), since it is synchronized with clock 2 in Jack's frame (which is where BOTH see clock 2 reading 10).
Note 1: He says: "Jack, of course, knows that C1 is 6 light seconds away, and is synchronized with C2 which at that instant is reading 10 seconds, so his snapshot must show C1 to read 4 seconds. That is, looking at C1 he sees it as it was six seconds ago."
So, he says, the "snapshot" will "show" it reading 4 seconds because it actually reads 10 at that moment, after adjusting for light travel. Why would Jill think otherwise?
Once again, the "next post" disappears.
One Brow said: "Einstein is using the initial/final inertial state as the determinitive state for the speed of the microorganism."
Yes, he is, with the key word here being "determinitive." That (not anybody's "choice) is what determines which one ages slower in SR.
One Brow said: "I've always said that you can determine when something is moving after chossing an inertial rest state."
Does your "choice" make the travelling organism age less, or does the fact that it is travelling, whether you choose to acknowledge that or not, make it age less?
One Brow said: "assume each time the person with the clock is not moving."
Heh, typical SR advice and logic. They all have clocks. So assume none of them are moving.
What is all this "Jack and Jill" example really about? As the prof himself acknowledges:".. it seems impossible for two observers moving relative to each other to both maintain that the other one’s clocks run slow."
So why does Jill struggle so hard, so illogically, and so unconvincingly to persuade herself that an assumption which is contrary to SR is true? In SR, the moving clock runs slower, and all the evidence, however you look at it (except in illogical, inconsistent ways, as Jill tries to do) says she is the one moving, not him, which is the true case. Why does she insist, come hell or high water, that she is not moving but he is? The prof claims she "knows her SR," but she obviously doesn't.
Why is that? He knows his SR. He knows she's moving. Why isn't she allowed to know it? Why does she deny the facts in the face of all evidence?
Ever wonder about that?
One Brow said: "Time is only one-dimensinal, so all dilations would be of the same "breed" in that regard."
Well, I agree. The reason I ask is because I'm trying to figure out how minkowski spacetime graphs cause me to see the two clocks differently. That would not explain the time dilation in GR, because GR dispenses with the flat euclidean spacetime of Minkowski, and further abandons the premise that the speed of light is always constant.
As we have seen, the "curvature" of space by the earth is minscule in GR (a centimeter or so over the whole diameter of the earth). For this reason, "experts" have claimed that it is the "downward pointing of time arrows" that "cause" gravity. What the hell does that mean?
Other authors have put it this way: In GR, the relevant "curvature" of spacetime is the "curvature" of time, not space. "Gravity" is "equivalent to" acceleration only in the sense that both cause time dilation. This, despite the knowledge that acceleration, per se, does not cause time dilation in SR.
The old "rubber sheet with a bowling ball in the middle" (with, it seems, a Newtonian gravitional field under it) analogy is totally misleading and distorts the situation. Yet it continues to be hauled out as an "explanation" by every "expert" and his brother. Why is that?
One Brow said: "When the twins are reunited, the twin that accelerated will have aged less."
So why do you continue to claim that you will get the "same answer" in SR regardless of who you assume is moving?
You, Eric, are the master of trying to make a distinction without a difference. In your mind, the irrevelant distinction then decides all matters in your favor.
I figure you will say that the "reunification" somehow "causes" the difference, just as you tried to suggest with the Keating experiments. How would "reunification" be the least bit relevant to what happens to the clocks while they are travelling faster? Why is it that clocks on satellites in the GPS continue to run at a different rate without ever having "returned to earth?" Seems impossible (to a relationalist trainee who has been conditioned to say it "somehow" matters) don't it?
I asked: "Would the digital readout also change if the time dilation was the result of motion, rather than gravity..."
One Brow answered: "Yes."
So, are you finally willing to concede, all your past denials nothwithstanding, that motion causes actual physical changes in clocks themselves and that time dilation is not just a product of pointing arrows on a piece of minkowski spacetime graph paper?
Of course the change in the digital readout is itself just a function of complex underlying physical events, whose frequency must change for the readout to change:
"NIST-F1 is referred to as a fountain clock because it uses a fountain-like movement of atoms to measure frequency and time interval. First, a gas of cesium atoms is introduced into the clock's vacuum chamber. Six infrared laser beams then are directed at right angles to each other at the center of the chamber. The lasers gently push the cesium atoms together into a ball. In the process of creating this ball, the lasers slow down the movement of the atoms and cool them to temperatures near absolute zero.
Two vertical lasers are used to gently toss the ball upward (the "fountain" action), and then all of the lasers are turned off. This little push is just enough to loft the ball about a meter high through a microwave-filled cavity. Under the influence of gravity, the ball then falls back down through the microwave cavity...."
The rest can be found here: http://www.nist.gov/pml/div688/grp50/primary-frequency-standards.cfm
I mean, does anyone really thing that a "tilted inertial frame" on a piece of graph paper causes these physical processes, or causes them to change with motion? The whole suggestion makes absolutely zero sense.
As Hogg, and every other practical (as opposed to "mathematical) physicist acknowledges, clocks do not change the readouts they display without a corresponding change in the underlying events whose frequency the readout reflects. In other words, a "real, physical change" to the "clock itself."
Any suggestion to the contrary would make the changes merely illusory--a function of changed perspective. Such a view would invalidate the basic premises of SR. They slowing of clocks cannot, consistently with SR, be mere products of perception.
A couple of physicists from UC-Davis, Andreas Albrecht and Alberto Iglesias, claim to demonstrate that "a theory set up to describe one set of physical laws can equally well be interpreted as describing any other laws of physics by making a different choice of time variable or clock."
http://prd.aps.org/abstract/PRD/v77/i6/e063506
In non-technical language, Albrecht describes their conclusions as follows:
“Your first job is to identify what you mean by time...I showed that you could make different choices of what you mean by time and get any laws of physics you want...We tried to show that there was something wrong with this picture, that the freedom to choose any clock would somehow contradict itself. But it didn’t...It seems to me like it’s a time in the development of physics,where it’s time to look at how we think about space and time very differently.”
He is suggesting that the arbitrary choice of choosing a definition for time can lead you to any physical laws you want. If this is true, what does that say about your initial premise in this thread that "science" is based on theories "dictated" by observation?
What does it say about the role of "philosophy" in the construction of physical theories?
"According to relativity, moving clocks tick more slowly than static clocks."
http://www2.slac.stanford.edu/vvc/theory/relativity.html
"As observed from stationary frames, moving clocks run slower. This phenomenon is the basis of time dilation."
http://webphysics.davidson.edu/course_material/py230l/relativity/relativity-ex1.htm
"Since gamma > 1, the interval between ticks of a "moving" (relative to the observer) clock is greater than for a "stationary" clock, so "a moving clock runs slow". This effect has been verified by carrying highly-accurate atomic clocks aboard aircraft and comparing their "readings" with those of an identical clock which remained stationary."
http://web.pdx.edu/~egertonr/ph311-12/relativ.htm
"Time dilation refers to the fact that clocks moving at close to the speed of light run slow...So, during the trip the observer on Earth ages 10 years. Anyone on the spaceship only ages 3.122 years."
http://physics.bu.edu/py106/notes/Relativity.html
1. Get it Eric? It is the moving clock which slows down, not (1) well, it could be either, and not (2) both slow down. ONLY one clock really slows down according to SR, and it is the moving clock (as on a GPS satellite).
2. It has nothing to do with "reunification." The last cite (from Boston University) is analyzing a one-way trip, not a round trip.
Can you remember that, and incorporate that theoretical consequence of SR into your future pronouncements on the topic? Or do you dispute it?
If you want to argue that "it's impossible to tell who's moving," then argue that. But try to understand that such a position has NOTHING to do with the predictions of SR. It simply denies that SR is anything more than metaphysical speculation about unknown and unknowable topics with no practical value whatsoever--not a testable scientific theory--that's all.
Fan 1: Jerry Sloan and Pete Maravich both played professional ball in the '70's.
Fan 2: Sloan was taller than Maravich.
Fan 1: Yeah, I spoze he was, and that's an interesting observation, but it really has nothing to do with what I was talking about, which is the era they played in.
Fan 2: I beg to differ. It has everything thing to do with your claim. It proves your claim is wrong.
Fan 1: How so, what in the world does your height have do to the the years in which you played?
Fan 2: A taller player does not play in the same way a shorter player. Nothing they do is the same. Therefore they can't possibly have played at the same time. It wouldn't be "the same," see?
Fan 1: Yeah, I see. Gotta run...catch ya later.
Take two cars going down the freeway, one at 60 mph and one at 70 mph, with the faster car behind, but catching up. Relative to each other they are going 10 mph. There's no question about who is moving, and who is going faster. The car in front knows he isn't going backwards. He fueled up his vehicle, hit the gas pedal, and he knows he's going east at 60 mph.
Now take away the earth and road, take away the fuel-powered vehicles and put the guys in clear bubbles, take away the stars and every other material thing in the universe. Now what? Well, they still know they are going 10 mph relative to each (which presupposes a lot of things, but let's grant those). And, whatever else they know, they know they are NOT each at rest. If they were, they wouldn't be getting closer to each other.
Unless you want to assert the obscene "geometrical SR" proposition that both ARE at complete rest and completely motionless, but the space between them is merely contracting. Those kinda guys would have been completely swayed by Zeno's paradoxes, designed to prove that all motion is an illusion. The chumps, them.
But, what's the point? The point is that there is no basis for taking extreme circumstances, such as being deprived of all naturally occuring sensory input, and then extrapolating the consequences of such limited access to knowledge to every situation everywhere. But that's what the relationalists want to do. They claim that if you wouldn't be able to tell who was moving if you were one of only two objects in the universe, then that "proves" that you can NEVER KNOW WHO'S MOVING!
And, if you were a brain in a vat, then what? A little quote from our pal, Al:
"A body removed sufficiently far from other bodies continues in a state of rest or of uniform motion in a straight line. This law not only says something about the motion of the bodies, but it also indicates the reference-bodies or systems of co-ordinates, permissible in mechanics, which can be used in mechanical description. The visible fixed stars are bodies for which the law of inertia certainly holds to a high degree of approximation. Now if we use a system of co-ordinates which is rigidly attached to the earth, then, relative to this system, every fixed star describes a circle of immense radius in the course of an astronomical day, a result which is opposed to the statement of the law of inertia."
Al seems to be suggesting that certain views of what's moving and what's not are simply impermissible. He does seem to think that all frames of reference are "equally valid" for some reason. But that's not the way the Minkowski cult of metaphysicians want to tell the story, so it doesn't matter what the theory or it's inventor said. They simply "reinterpret" what Al "intended" to say, and then represent their own concoctions as his theory.
Peter Hayes "The Ideology of Relativity: The Case of the Clock Paradox" : Social Epistemology, Volume 23, Issue 1 January 2009, pages 57-78 http://www.informaworld.com/smpp/content~content=a909857880
"The clock paradox illustrates how relativity theory does indeed contain inconsistencies that make it scientifically problematic. These same inconsistencies, however, make the theory ideologically powerful... The clock paradox, however, is only one of a number of simple objections that have been raised to different aspects of Einstein's theory of relativity.
"It is rare to find any attempt at a detailed rebuttal of these criticisms by professional physicists. However, physicists do sometimes give a general response to criticisms that relativity theory is syncretic by asserting that Einstein is logically consistent, but that to explain why is so difficult that critics lack the capacity to understand the argument. In this way, the handy claim that there are unspecified, highly complex resolutions of simple apparent inconsistencies in the theory can be linked to the charge that antirelativists have only a shallow understanding of the matter, probably gleaned from misleading popular accounts of the theory.
"The defence of complexity implies that the novice wishing to enter the profession of theoretical physics must accept relativity on faith. It implicitly concedes that, without an understanding of relativity theory's higher complexities, it appears illogical, which means that popular "explanations" of relativity are necessarily misleading... The argument of complexity suggests that to pass the first steps necessary to join the physics profession, students must either be willing to suspend disbelief and go along with a theory that appears illogical; or fail to notice the apparent inconsistencies in the theory; or notice the inconsistencies and maintain a guilty silence in the belief that this merely shows that they are unable to understand the theory...
The argument that Einstein fomented an ideological rather than a scientific revolution helps to explain of one of the features of this revolution that puzzled Kuhn: despite the apparent scope of the general theory, very little has come out of it. Viewing relativity theory as an ideology also helps to account for Poppers doubts over whether special theory can be retained, given experimental results in quantum mechanics and Einsteins questionable approach to defining simultaneity. Both Kuhn and Popper have looked to the other branch of the theory - Popper to the general and Kuhn to the special - to try and retain their view of Einstein as a revolutionary scientist. According to the view proposed here, this only indicates how special and general theories function together as an ideology, as when one side of the theory is called into question, the other can be called upon to rescue it...
The triumph of relativity theory represents the triumph of ideology not only in the profession of physics bur also in the philosophy of science. These conclusions are of considerable interest to both theoretical physics and to social epistemology. It would, however, be naïve to think that theoretical physicists will take the slightest notice of them."
Ideology, eh? Like, whooda thunk, I ax ya?
This is a follow-up to a post that went into the spam bin.
Ya know, for some reason it never even occurred to me that the defenders of SR do so on ideological grounds that are not merely philosophical. Is there some common perception that Jew-hating right wingers oppose SR, so that left-wingers are therefore duty-bound to defend it, by any means, and with any necessary tactics?
It makes sense in that light. For decades I've heard the same non-sensical claims and non-responsive "responses" from just about any "defender" of SR I've run into. It does all have a "common manifesto" ring to it, as though the disciples had been trained with respect to the exact responses to give, and when to give them. There never seems to be any real thought or analysis behind it--as though they were merely parroting the words their elders had trained them to say. It all takes on the appearance of a quasi-religious catechism.
The logical positivists issued a "manifesto" together with a "call to arms" and agressively sought to spread their philosophical ideology in the 20's and 30's, I knew that. They were quite successful, too, for a period. But is there some perceived political duty to oppose or support SR, depending on your socio-political self-identification?
A random commentary about things we've discussed in the past:
"In taking Richard Dawkins as an example, I will be one of the first people to applaud Richard Dawkins on his scientific work, especially his public advocacy for scientific education...His touring of the world, dispelling the myths about biological evolution while repeatedly demonstrating the incoherence of Creationism is sufficient to earn my respect. However, the critiques that Dawkins and the rest of the “new atheists” make of religion are somewhat laughable. Granted, cultural critiques are one thing and for the most part I agree with Dawkins on these matters, but when he attempts to speak on the actual existence of God it is ignorance on parade.
"The same goes for many, if not all of the “new atheists”. They are quite adept at pointing out the societal problems of religion but they seem to fall apart when they are asked to philosophically validate their position...
What concerns me more than the lack of philosophical grounding espoused by these atheists is the rise of Scientism. This idea that the natural sciences hold primacy over ALL interpretations of life is ironically akin to a religious system itself!
"I am not denying the importance of scientific progress, merely the extrapolation of science from a tool to a worldview in itself. The claims of Scientism fall victim to the fate of logical positivism (which said that only statements which can be empirically tested are meaningful)...
"It becomes clear and evident that Scientism is a self-refuting position, it simply cannot be the case and it’s logically absurd to say otherwise. Yet, given this obvious incoherence, Scientism is espoused still as being the only arbiter of truth. In a conversation with one such person, Philosophy was critiqued as being “metaphysical navel gazing” as this person further went on to affirm that science could stand without philosophical justification.
Such claims, it seems to me, are akin to certain types of religious claims. The attitude of the scientistic person seems almost that of a close-minded, indoctrinated individual. In fact, I would go so far as to categorize Scientism as a belief system which shares many similarities with religion (how ironic)."
http://urbanphilosophy.net/philosophy/scientism-and-the-new-atheism/
More than once I have seen it stated, at university websites composed by professors of physics, that the relativity principle is: "It is impossible to determine who is moving" (or words to that effect).
This is not, was not when Eistien extended it, and never was what the relativity principle holds, nor did Al ever say otherwise. Why? Why do they feel it is necessary to re-write and misrepresent the relativity principle when "teaching" (indoctrinating is the better word) SR? There is a reason. What is it?
Why, when a question such as "doesn't one of these guys have to be moving, and doesn't SR always assume one is really moving" do they refuse to answer the question, and instead, insist that the question is "meaningless" because it cannot possibly be answered? Of course then they go straight to their next example where they tell you one guy is moving.
If the question of "what is moving" is meaningless, then all of physics is meaningless. Why do they find it necessary to use such evasive, inconsistent, and intellectually dishonest tactics? There is a reason. What is it?
Why do they, seemingly with no shame at all, insist without qualification, that "both are correct" when it is a logical contradiction and contrary to the content of SR itself?
Galileo unequivocally stated that absolute speed could not be detected or measured and that only relative speed could be. Newton fully agreed. Why do these profs tell their students that thoroughly moden Al corrected the antiquated and misguided notions these men had about "absolute motion?"
Why do they insist that SR has no truck with "absolute space," as Newton did, when SR in fact relies on absolute space even moreso than Newton? What is the game being played here?
Why are these students trained to snicker and guffaw at the mere mention of the word "ether" when Al himself said that GR was unthinkable without an ether? What's up with that?
This too is a follow-up comment to a previous post which does not currently appear. It goes back to this guy:
http://galileoandeinstein.physics.virginia.edu/lectures/time_dil.html
He says: "...it seems impossible for two observers moving relative to each other to both maintain that the other one’s clocks run slow."
Why doesn't he just honestly say: "Given the content of SR it IS impossible" (rather than merely "seems)? Well, because that would refute the interpretation of SR he is trying to present, so of course he can't consistenly say that.
So, look closely at what he does instead, which is to use logically inconsistent and fallacious arguments to try to "prove" an illogical point.
He doesn't explicitly say it, and he doesn't say how, but the whole example presupposes that when clock 1 is set to zero, so is clock 2 (which is synchronized with clock 2 in Jack's frame). Of course there is no need to set clock 1 to "zero," it could simply be hypothesized that she passes clock 1 when it says 12:00.00 and arrives at clock 2 when clock 2 reads 12:00.10. It is understood by all that the two clocks are synchronized. If Jill didn't assume this, what clock 2 read would be totally irrelevant to her. It could read one million seconds, and that would simply be totally irrelevant--she wouldn't think a thing about it. She would not "deduce" what clock 1 "now" says from any time shown on clock 2 unless she assumed they were related.
Of course, as I've already noted, clock 1 is totally irrelevant at this point. There is no need whatsoever for it to even be a clock instead of a "mile marker." It's only practical function in this whole example is to establish point A (the starting point at which the measurement of time begins for both Jack and Jill). But the prof makes it a "clock" because he has some fallacious misrepresentations about SR he wants to make, so it being a clock does have a definite, alternative "function" for his purposes.
Now the result is this: By Jill's measurements, she has gone from point A to point B in what she measures to be only 8 seconds while Jack measures 10 seconds for her her to travel between those same two points. Given SR, the only reasonable conclusion is that it is HER clock which is the moving one, since it is HER clock that is running slower.
End of story. No need to go on. But of course he does.
Now he starts talking about what Jill "deduces" about what clock 1 must say "now." As noted, totally irrelevant to begin with, but that aside:
1. What does what she thinks the clock must say "now" have to do with anything to begin with, and
2. Why in the world would she erroneously "think" clock 1 "now" reads 6.4 seconds? It read zero when she passed it (or 12:00, depending on how you set up the hypothetical). It is synchorized with clock 2 (which reads 10 seconds), so it must necessarily read 10 seconds "now" also.
The reason she has to "think" things which contradict what she already knows is so that the prof can try to convince his student's that her reasoning is valid by means of fallacious equivocation, invalid logic, and a revision of the "facts." He probably believes his own example demonstrates something meaningful because, in his mind, it HAS to. Therefore he sees no need to analyze the misleading mess he has created any further, once it gives the appearance he wants to create.
In the Hafele-Keating experiment the time elasped on two travelling clocks (one flying around the world in a eastward direction and one westward) was compared to the time elapsed on a stationary clock located at a Naval Station in Maryland.
If the stationary clock is treated as the "observer" then the predictions of SR with respect to the clocks of two different observers failed. The time difference from east to west varied. The raw results "agreed" with SR prections only when a particular frame was chosen to replace the "location" of the stationary clock. That "location was the center the earth. Only if this hypothetical frame was selected, and the data adjusted accordingly, did the "observer" see the effects predicted by SR.
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html#c3
Kinda funny if all frames are equal, eh? But, that aside, the moving clocks actually ran slower. When the experiment was repeated, the moving clocks did not "sometimes" run slower and the theoretical (located at the center of the earth) clock sometimes run slower, as though it "could be either, who knows--you just can't predict which one will end up running slower until you reunite them and compare them." Nor did each run slower than the other. Why is that?
There's a youtube video I've seen where Keating goes up in a plane with his clock. He tells the passengers, at certain just what the earth clock is now reading compared to the clock on the plane. He does NOT say the earth clock is running slower. He says it is running faster.
When the land, sure enough, the readings of the two clocks read just what he predicted. He could "predict" this ONLY by NOT "seeing" the earth clocks run slower, but rather faster.
Go figure, eh? Do you understand how these experiments clearly answer the "insurmountable" problems you say LR poses with respect to how each "sees" the other's clock? "See" (deduce) the time on the other clock correctly and there is no discrepancy. If, however, you "saw" (and hence predicted) that the earth clocks were running slower, as you insist MUST happen, you would be dead wrong.
The principle of relativity holds that the laws of physics are the same in every inertial location. It says nothing about how observer #1 sees things in the frame of observer #2, and vice versa.
If you assume that the principle of relativity requires that the speed of any given object be perceived as the same in all frames (which it definitely does NOT, see below), then Al's extension of the principle superficially maintains the "requirement" that the laws of physics are "the same."
I say "superficial" because the "sameness" is nominal only, and does not hold in substance. SR merely says the observers in differently moving inertial frames will "measure" the speed of light to be the same as all other frames do.
But this is only because their measuring instruments get distorted with speed. The underlying, substantive "reality" which SR establishes is that the speed of light is not "actually" the same in each frame, but it does "appear" to be and, therefore, the appearance for purposes of evaluating the laws of physics does not change.
LR merely corrects the for known distortions which SR concedes are created, whereas SR insists that they should remain uncorrected, even though known to be erroneous, so that the "appearance" of the validity of the relativity principle can be maintained.
But, the principle of relativity does not require that the speed of objects must be "seen" to be the same to begin with. That was never the case. The same horse "seen" to be moving at 20 mph in one frame (say the spectator in his seat) and "seen" to be 0 mph in another frame (the rider of the horse next to the one in question). No "violation" of relativty there at all. In fact, that's what the principle of relativity predicts with respect to moving objects--there speeds will be different (not the same) as seen from different frames of reference.
What purpose does it serve to try to base your notions of "true" time and space on what are known to be errors? There is no need for that, even if you consider it "necessary" that the principle of relativity be "true." It is true either way, it's just that with LR there is no revision of the tried and true Gallilean transformations.
Back in 1968, it was still possible (without contradicting the results of known experiments) for guys like Dorling to suggest that the "changes" in the rods and clocks postulated by Al didn't occur at all, and were merely illusionary artifacts of perception based on perspective, which perspective and resultant illusions could be seen to "correspond" to certain interpretations of a minkowski spacetime graph.
This view kinda became the rage, and is apparently what you were taught, Eric. It was so attractive to a certain type of mentality that the results of Hafele-Keating and subsequent experiments showing that the physical processes which mechanical clocks measure really do slow down with speed, were simply ignored in favor of "aethetic" considerations. A "scientific" approach? Hardly.
It has long been known that the rate of physical processes change with temperature.
As soon as this was discovered, why didn't anyone proclaim that our notions of time had to be radically altered? Why wasn't a "revolutionary" view of time introduced where time is strictly relative to temperature, and can't be the same on the sun or in outer space, or any other place with a different temperature than our own. Why isn't time different in Moscow in the winter than it is in Acupulco in the summer?
That wasn't seen as necessary for some reason, and I suspect any proposal made at that time to change all standards of time accordingly would have been mockingly rejected by the scientific community. Why should it be any different if motion, as well as temperature, also affects the rate at which physical processes occur?
aintnuthin said...
One Brow said: "Synchronize clocks K and L. Pick up L, and walk with it for 100 feet, then set it down. The time K sees from clock L will be slightly behind the time K reads for itself. The time L sees from clock K will be slightly behind the time L reads for itself."
And why would that be? Because of the delay caused by the light to travel between the two, that it?
How would a guy standing halfway in between them see it? Would he see that clock that moved as always running a bit behind the unmoved clock, even though they were now keeping time at the same rate?
To my understanding, he reads them to have the same time.
Does it make any difference if, contrary to your example, the two clocks are moving with respect to each other?
Clock K would see clock L as running slower and as showing a later time. Clock L would see clock K as running slower and as showing a later time.
It won't, eh? I don't know what you mean by "nL," by the way.
nL = "neo-Lorenztian". LR can be mainstream SR or nL, at the least.
If we go back to the example provided by the professor where each sees 10 seconds elapsed on one clock and 8 on the other, why does the one show 10, and the other 8? Why isn't the situation reversed with the opposite clock showing 8 and the other one 10? Why do they differ at all, for that matter?
If for no other reason, lightspeed delay prevents them from reading each other to be the same.
You throw out the word "synchronized" like it has some invariable meaning, but it doesn't.
I'll clarify it.
1) Person A has clock A1. As clock A2 passes, A1 and A2 are set to zero. Then, A observes clock A3 being set to the current time as clock A2 as they pass each other. Finally, A3 passes by A1, and A compares the readout on A3 to that on A1.
Comparing A1 and A3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person B has clock B1. As clock B2 passes, B1 and B2 are set to zero. Then, as clock B3 passes, B3 is set to the current time as B1. Finally, B3 and B2 pass each other, and B compares the readout on B2 to that on B3.
Comparing B2 and B3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person C has clock C1. As clock C2 passes clock C3, those clocks are set to zero. Then, as clock C2 passes C, C1 is set to the time on C2. Finally, C3 passes C, and C compares the readout on C1 to that on C3.
Comparing C1 and C3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
I think that, in addition to the ones above not answereed yet (the spider and the worm, does the ship stop when you remove all external forces, is the clock inside the ship affected by cancelled out external forces differently than if those forces did not exist, the difference between the context you say is important to include and the perspective you say I should not be including) will wrap up my questions.
But the clocks ARE synchronized according to Jack, and it is implied that Jill understands that. So again the answer you get to whether two clocks are "synchronized" depends on who you ask and whether, in giving their answer, the moving observer tries to deny that he is moving. Their answers depend on who is moving--in this example, Jack is not moving, and Jill is, but incorrectly claims she is not).
"Synchronized" means shows the same time. The clocks are initally synchronized, but fall out of synchronization. Neither Jack nor Jill reads the clocks to be showing the same time.
Your "question" has no answer in SR, given the (lack of pertinent) information you have provided. Your assertion that it doesn't matter who's moving is contrary to the premises of SR, so whatever answer you reach must be on some non-SR basis that you like to call "mainstream SR."
As I said, feel free within each scenario to say it is the observer who is at rest (each scenario only has one observer).
So, he says, the "snapshot" will "show" it reading 4 seconds because it actually reads 10 at that moment, after adjusting for light travel. Why would Jill think otherwise?
His point is that she wouldn't.
Does your "choice" make the travelling organism age less,
No. It just allows you a basis from which to make actual calculations.
or does the fact that it is travelling, whether you choose to acknowledge that or not, make it age less?
The fact that it accelerated out of an inertial state, traveled, and returned to that location and that intertial state makes it to have unequivalcally aged less.
Heh, typical SR advice and logic. They all have clocks. So assume none of them are moving.
Three separate scenarios, one observer in each. Is that a problem?
Why is that? He knows his SR. He knows she's moving.
You are confusing a description of what Jill can determine through observation with an ontological statement of true movement.
Well, I agree. The reason I ask is because I'm trying to figure out how minkowski spacetime graphs cause me to see the two clocks differently.
Spacetime diagrams are mathematical models of physical effects. The better question is how the various physical effects cause you to see things.
That would not explain the time dilation in GR, because GR dispenses with the flat euclidean spacetime of Minkowski,
Minkowski space is flat, but I'm not sure it's Euclidean.
and further abandons the premise that the speed of light is always constant.
Only when you mix different inertial frames, just like in SR. Light within an inertial frame is constant in GR.
As we have seen, the "curvature" of space by the earth is minscule in GR (a centimeter or so over the whole diameter of the earth). For this reason, "experts" have claimed that it is the "downward pointing of time arrows" that "cause" gravity. What the hell does that mean?
It's a description of the appearance of a mathematical model for a physical effect.
Other authors have put it this way: In GR, the relevant "curvature" of spacetime is the "curvature" of time, not space. "Gravity" is "equivalent to" acceleration only in the sense that both cause time dilation. This, despite the knowledge that acceleration, per se, does not cause time dilation in SR.
The old "rubber sheet with a bowling ball in the middle" (with, it seems, a Newtonian gravitional field under it) analogy is totally misleading and distorts the situation. Yet it continues to be hauled out as an "explanation" by every "expert" and his brother. Why is that?
One of the nifty things about mathematical models is that they can be rotated to look at a varitiety of ways of viewing things. The rubber sheet analogy works with one interpretation of the models, but not with others.
One Brow said: "When the twins are reunited, the twin that accelerated will have aged less."
So why do you continue to claim that you will get the "same answer" in SR regardless of who you assume is moving?
Because it is correct.
I figure you will say that the "reunification" somehow "causes" the difference, just as you tried to suggest with the Keating experiments.
Reunificaiton is the only time the difference in the clock readings or the different ages of the twins, becaomes a scalar in Hogg's parlance (something that appears the same to all observers). It's not a cause.
So, are you finally willing to concede, all your past denials nothwithstanding, that motion causes actual physical changes in clocks themselves and that time dilation is not just a product of pointing arrows on a piece of minkowski spacetime graph paper?
Motion causes actual physical changes in clocks themselves: No.
Time dilation is not just a product of pointing arrows on a piece of minkowski spacetime graph paper: Yes.
Both have been my positions for this whole post. No concession involved.
I mean, does anyone really thing that a "tilted inertial frame" on a piece of graph paper causes these physical processes,
No.
As Hogg, and every other practical (as opposed to "mathematical) physicist acknowledges, clocks do not change the readouts they display without a corresponding change in the underlying events whose frequency the readout reflects. In other words, a "real, physical change"
Yes.
to the "clock itself."
No. A real, physical change, but not to the clock itself.
They slowing of clocks cannot, consistently with SR, be mere products of perception.
I agree.
In non-technical language, Albrecht describes their conclusions as follows:
Do you have a link for that description?
He is suggesting that the arbitrary choice of choosing a definition for time can lead you to any physical laws you want.
He seems to be saying physical laws should be changing if you re-paramerterize time. I'm not sure what that is supposed to mean. That you would lose entropy in a closed system, or conservation of mass-energy?
If this is true, what does that say about your initial premise in this thread that "science" is based on theories "dictated" by observation?
What observations support the notion of being able to change physical laws in this way?
What does it say about the role of "philosophy" in the construction of physical theories?
I don't know what this is saying at all, based only on an abstract and four snippets.
1. Get it Eric?
Better than you.
Can you remember that, and incorporate that theoretical consequence of SR into your future pronouncements on the topic? Or do you dispute it?
I do remember it, do incorporate it, and do not dispute it.
If you want to argue that "it's impossible to tell who's moving," then argue that. But try to understand that such a position has NOTHING to do with the predictions of SR.
You mean, outside of being one of the two foundational principles of SR.
But, what's the point? The point is that there is no basis for taking extreme circumstances, such as being deprived of all naturally occuring sensory input, and then extrapolating the consequences of such limited access to knowledge to every situation everywhere.
Just like there's no point of pretending friction doesn't occur when using Newtonls Laws of motion (except, that's exactly what those laws do). Just like, there's no point in pretending random neclear decay doesn't happen when you are converting moles in checial equations (except, that's exactly what you do). All of science uses a certain subset of the available information to make predicitons based upon that particular obdy of knowledge. Except for SR, according to you. Although not really, because SR still has no terms for friction, light penetration of the observer's retina, etc. So, SR actually does engage in all the typical myriad simplificaitons of any other scientific theory, except for one particular simplification you say MUST NOT BE USED. BECAUSE. IT'S WRONG.
Apparently, most scientists don't feel the need to preserve the one thing you feel must not be simplified.
He does seem to think that all frames of reference are "equally valid" for some reason.
In particular, referring to a frame under acceleration.
Peter Hayes
Yawn.
Is there some common perception that Jew-hating right wingers oppose SR, so that left-wingers are therefore duty-bound to defend it, by any means, and with any necessary tactics?
Not that I'm aware of. Religious fundamentalists typically only object to sciences that question their religious beliefs, and relativity is usually not among them.
What concerns me more than the lack of philosophical grounding espoused by these atheists is the rise of Scientism. This idea that the natural sciences hold primacy over ALL interpretations of life is ironically akin to a religious system itself!
I agree.
"It becomes clear and evident that Scientism is a self-refuting position, it simply cannot be the case and it’s logically absurd to say otherwise.
I don't hold to Scientism, but this objection is rather dim-witted.
Why, when a question such as "doesn't one of these guys have to be moving, and doesn't SR always assume one is really moving" do they refuse to answer the question, and instead, insist that the question is "meaningless" because it cannot possibly be answered?
...
Galileo unequivocally stated that absolute speed could not be detected or measured and that only relative speed could be. Newton fully agreed. Why do these profs tell their students that thoroughly moden Al corrected the antiquated and misguided notions these men had about "absolute motion?"
You have no idea how much humor it brings meto see you argue both sides of the same position in consecutive posts.
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html#c3
Kinda funny if all frames are equal, eh?
Not all frames are equal, just all inertial frames. "The problem encountered with measuring the difference between a surface clock and one on an aircraft is that neither location is really an inertial frame."
Why is that?
Why would it be otherwise? Who says it should be, outside of your fevered-imagination misinterpretation of other people's opinions?
When the land, sure enough, the readings of the two clocks read just what he predicted. He could "predict" this ONLY by NOT "seeing" the earth clocks run slower, but rather faster.
1) He doesn't see the stationary clock at all. If he did, would what he saw match what he said?
2) He is traveling in an accelerated path, making comparisons to an accelerated clock.
Go figure, eh? Do you understand how these experiments clearly answer the "insurmountable" problems you say LR poses with respect to how each "sees" the other's clock?
LR (whether of the SR or nL variety) doesn't have that problem. It's just your interpretation of SR.
merely illusionary artifacts of perception based on perspective, ... what you were taught, Eric.
No. I'm really getting tired of reminding you of that.
This is an incredible discussion.. . . . not in terms of content but extent. It's got be some kind of record.
So where are you from, aint? I'm still being accused of being "Hopper"/Ain't/Millsapa by some in the JF forums, including Cat the Mod. I'm not even in the same class. I wish we could be friends.
OneBrow, I can't think of a "defender of the faith" on the side of nothingness I'd rather banter with about God.
The whole idea of human intellectual sufficiency and our capacity to know the universe is really just so far out in the ether of speculation it's incredible to me to see intelligent people just choosing not to believe in "God".
Well, maybe I can understand it when we just consider the forms of "God" human beings "understand". But don't you see that's just a whole raft of straw-man arguments?
What we can conceive and contain within our little skulls has got to look pretty silly to Anyone/Anything that could have created our universe. . . .
But hey, we have nothing better to do with our lives than try to understand it all.
I think you are great, too.
babe,
Thjanks for stopping by. I hope to see you around a lot more.
One of the themes of my blog is that humans don't have access to any sort of truth/knowledge that really fits what we would consider ideal. All the methods we use fall short of attaining The Truth. So, I'm not an atheist because of any particular hubris or belief in the sufficiency of human knowledge.
In fact, I'm not really an atheist by choice. I've always found it odd when people refer to their religious belief as a choice, or decide to convert in a fundamental way based on something like a marriage. I'm an atheist because, after you discard that raft of strawman humans have conceived, what's left to actually believe in? Since we don't understand much at all, how can we understand enough to say God/a god/gods exist when they have not given us any good reason for so doing?
Basically, what abvout the universe makes you think it was conceived?
Zup, there, eh, Babe,ya perv,ya?
Babe said: "I'm still being accused of being "Hopper"/Ain't/Millsapa by some in the JF forums, including Cat the Mod."
Well, Babe, ya know, aint none of them JF mods ever been accused of bein the sharpest tool in the shed, I don't expect, know what I'm sayin? Same goes for most of the other posters, too, of course.
Sure, we can be homeys. I kinda figured we already was, it's just that I got banned by the fags that be before we had a chance to get to know each other.
Babe asked: "So where are you from, aint?"
My address is listed somewheres in the excellent, but long-neglected, blues thread. If ya aint seen it, ya really should oughta. That thread, it ROCKS, eh!?
Poor Sapa...People at that site always think that anyone who doesn't openly and vociferously denounce me is me. I miss that fine-ass Babe. Tell her I done said "Hay" when ya run across her, kay?
aintnuthin,
If Millsapa turned out to be you, I would be sorely disappointed in you for acting that uninformed.
Eric, I may break down and ask you a few more questions about your incoherent responses, but I'm currently resisting any inclination to do so.
I don't argue issues of religion with people, as it is a fruitless undertaking to try to do so. All you can expect is assertions and affirmations of positions which are not rationally explained.
The same goes for ideological positions held on the basis of unwavering convictions based on faith. There is simply nothing to discuss about such matters. For the adherents it is not a topic open for "discussion."
I said: "I don't argue issues of religion with people, as it is a fruitless undertaking to try to do so. All you can expect is assertions and affirmations of positions which are not rationally explained."
I should have qualified this statement. Needless to say, topics that may be called "religious" in nature are topics that some people are quite capable of discussing openly and honestly, and such discussions can be rewarding. I was only referring to people who have strong a pre-existing religious dogma which they adhere to, come hell or high water.
aintnuthin said...
Eric, I may break down and ask you a few more questions about your incoherent responses, but I'm currently resisting any inclination to do so.
How about we split the difference there? Why don't you answer some of my questions while you are thinking about it?
As a reminder, and I have added some detail that was implied:
1) Person A has clock A1. As clock A2 passes, A1 and A2 are set to zero. Then, A observes clock A3 being set to the time on clock A2 as they pass each other. Finally, A3 passes by A1, and A compares the readout on A3 to that on A1. Since A3 and A1 are in close proximity, this reading would be the same to all observers. A sees A2 and A3 as traveling at the same speed.
Comparing A1 and A3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person B has clock B1. As clock B2 passes, B1 and B2 are set to zero. Then, as clock B3 passes, B3 is set to the time on B1. Finally, B3 and B2 pass each other, and B compares the readout on B2 to that on B3. Since B2 and B3 are in close proximity, this reading would be the same to all observers. B sees clock B3 traveling faster than B2.
Comparing B2 and B3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
2) Person C has clock C1. As clock C2 passes clock C3, those clocks are set to zero. Then, as clock C2 passes C, C1 is set to the time on C2. Finally, C3 passes C, and C compares the readout on C1 to that on C3. Since C1 and C3 are in close proximity, this reading would be the same to all observers. C sees clock C2 traveling faster than C3.
Comparing C1 and C3:
a) Which readout does mainstream SR say will show less time has passed?
b) Which readout does nL say will show less time has passed?
c) Which readout do you say will show less time has passed?
As a reminder, a ship is moving in the ocean at 5mph, and a bug is crawling on the ship from bow to stern at 5 mph (so it looks like it is not moving with respect tot he ocean). Let's add a worm and spider to the mix (I'll assume the bug is an insect, and so can't be either a worm or a spider). Both of them have clocks, and are floating by hanging on helium balloons. The worm was never on the ship, it's just been there. The spider started off on the deck while the ship was moving, but then jumped off the deck towards the stern at 5 mph, and is now hanging right next to the worm. With > meaning "faster than", you've already said for the clocks that ocean > boat > bug. How do the worm and the spider fit in?
Does the ship stop when you remove all external forces, as opposed to all the non-frictional forces?
Assuming yo say the ship will not stop if you remove all external forces, is the clock inside the ship affected by cancelled out external forces differently than if those forces did not exist? Particularly, will the clock change its speed?
What is the difference between the context you say is important to include and the perspective you say I should not be including?
I agree the difference between SR (mainstream) and nL (neo-Lorenzian theory) is much more akin to religion than science. I don't mindif you don't want to argue aobut it.
One Brow said:" Why don't you answer some of my questions while you are thinking about it?"
1. I've already said that I am not particularly interested in trying to work out particular problems as you claim are answered by "mainstream SR." I am more interested in discussing the inherent problems generated by what you call "mainstream SR," than I am in seeing what answers an inconsistent approach will supposedly generate. I have not even made an attempt to understand the question, because it's irrelevant to me.
2. With what you call "mainstream SR" all motion is relative to something else, which other motion is relative to something else, which is relative to[c], which is relative to [d], ad infinitum. As a result, there is, and can be, no unambigous answer to any such questions, which is all part of the inherent inconsistency. LR does not have any such problems, because it does not try to posit an infinite number of "time zones."
I said: "LR does not have any such problems, because it does not try to posit an infinite number of "time zones."
Any answer given by SR can only be "correct" if one particular time frame is designated, implicitly or explicitly, as the "standard" one which others are compared to. In other words, it must revert to the premises of LR to have anything definite or meaningful to say about the matter.
One Brow said: "You are confusing a description of what Jill can determine through observation with an ontological statement of true movement."
Heh, you want to claim *I'm* confused. Jill sees (observationally) that her clock shows only 8 seconds passed, while he sees 10. He sees the same thing. They agree on that.
It is only by virtue of shoddy and wholly fallacious "logic," all distorted by the determination to justify an unjustifiable conclusion, that Jill can claim, on a basis supposedly consistent with SR (but not consistent), that he is the one moving while she is at rest.
I know you can't see that, because you don't even try to evaluate the issue. You already "know" she is somehow correct in the invalid logic she tries to use to "invalidate" her indisputable observations.
One Brow said:"Just like there's no point of pretending friction doesn't occur when using Newtonls Laws of motion (except, that's exactly what those laws do)."
I have no clue what you are talking about. I can't think of anything at all in Newton's laws of motion" which "pretends" friction doen't exist. On the contrary, the laws of motion are used to quantify and explain the presence, and effect of, friction and other "external" forces.
One Brow said:"You mean, outside of being one of the two foundational principles of SR."
Where in the world do you get the idea that this ia a "foundational principle" of SR (as a scientific/mathematical theory, as opposed to a extraneous assertion of a philosophical (relationalist) proposition)? Does that follow from the first or second postulate of SR?
I said: "So, he says, the "snapshot" will "show" it reading 4 seconds because it actually reads 10 at that moment, after adjusting for light travel. Why would Jill think otherwise?"
You responded: "His point is that she wouldn't."
No, his point was that she predicted the first clock would read 6.4 seconds, and the snapshot was taken to "settle the argument." You don't even seem to comprehend the problem he's posing.
I said:"If we go back to the example provided by the professor where each sees 10 seconds elapsed on one clock and 8 on the other, why does the one show 10, and the other 8? Why isn't the situation reversed with the opposite clock showing 8 and the other one 10? Why do they differ at all, for that matter?"
You responded: "if for no other reason, lightspeed delay prevents them from reading each other to be the same."
Ya see, Eric, it is just this kinda red herring non sequitur that convinces me you have no real desire for honest discussion (as opposed to unqualified assertion and "defense" of you assertion by any means).
1. The example says that both see her clock as showing 8 seconds of time elapsed and his 10 seconds. This is a case of both looking at the same item(s) at the same time, from the same place. Light delays are totally irrelevant in this example.
2. They are totally irrelevant in all predictions of SR. Signal delay is NOT what SR is about. It is merely an artifact that can easily be corrected for and has nothing(of substance) to do with SR. It is NOT why the claim is made (by some) that each will "see"("assume" or "deduce" is the appropriate word here, not "see"), so why bring it up except perhaps as an attempt to confuse and/or evade the issue with sophistry?
Left something out. Meant to say:
"It is NOT why the claim is made (by some) that each will "see"("assume" or "deduce" is the appropriate word here, not "see"),THE OTHER'S CLOCK AS RUNNING SLOWER, so why bring it up except perhaps as an attempt to confuse and/or evade the issue with sophistry?
I said:"If you want to argue that "it's impossible to tell who's moving," then argue that. But try to understand that such a position has NOTHING to do with the predictions of SR."
You responded: "You mean, outside of being one of the two foundational principles of SR."
In a rather lengthy article at mathpages discussing Dingle's misconceptions about relativity, Dingle is quoted as saying:
"In an article in Nature I claimed that the twins must necessarily age at the same rate because it was an essential requirement of the special theory of relativity, which I then believed to be sound, that no observation was possible that would enable one to ascribe the motion preferentially to either twin."
The author then notes that Dingle "...still claimed to be adhering to “special relativity” (obviously conflating it with relationism)..."
Earlier in the article, the author quotes Dingle as saying:
"There is no meaning in absolute motion. The principle of relativity is a generalization from the fact that all known effects, apparently caused by the intrinsic motion of a single body, depend on the motion of that body with respect to another object."
To this the author responds as follows:
"Far from being an accurate summary of the principle of relativity (which is synonymous with the principle of inertia as defined in both Newtonian mechanics and special relativity), what Dingle actually articulated was the antithesis of relativity, namely, the principle of relationism..."
Other excerpts from this article follow:
1. "Needless to say, the competing doctrines of relationism and absolute motion have been debated throughout the history of science.According to the absolutist view there exists something called absolute space and time, within which objects exist and move, whereas according to the relationist view only the relations between physical entities have physical meaning... In the absolute-vs-relational debate, special relativity is squarely on the absolute Newtonian side, which is to say, special relativity is based on the principle of inertia no less than is Newtonian mechanics."
2. "Throughout all of Dingle’s writings, at least from 1921 until about 1959, we can see that he was laboring under the mistaken belief that Einstein’s theory of relativity was the embodiment of Leibnizian relationism, whereas in fact it is fully in the Newtonian tradition of absolute inertia...
3. "Dingle’s monograph “The Special Theory of Relativity” (1940) reveals quite plainly that he always misunderstood the subject...Dingle’s monograph “The Special Theory of Relativity” (1940) reveals quite plainly that he always misunderstood the subject...Dingle himself was one of the early expositors of the theory, i.e., one of the authors who told people that Einstein’s theory means “everything is relative”, etc., and thereby set the stage for generations of misunderstanding."
4. [Dingle] says Einstein’s theory “takes no account of acceleration”, so it has no way of distinguishing absolutely between the polar and equatorial clocks, but this is flatly false... Even the first principle of relativity states not that all motion is relational, but that any system of inertial coordinates is equally suitable for the formulation of physical laws. Hence Dingle’s claim that special relativity takes no account of absolute acceleration is utterly false. The existence of absolute acceleration is the very essence of the principle of inertia, on which special relativity is based."
Continued in next post
5. "...relativity (unlike quantum mechanics) is an entirely classical theory, firmly based on a perfectly coherent model of objective external reality. The young Dingle never grasped this model - indeed his whole philosophy of science (in those years) was that relativity had rendered all such models unviable...Then, in his later years, he rejected this approach (as did most of the formerly enthusiastic circle of operationalists and logical positivists), and decided that we cannot reasonably dispense with the idea of an objective reality. (Ironically, this was also Einstein's mature view.)...he had spent much of his life trying to convince himself and others that no such model was possible, and indeed that this impossibility was the whole message of relativity. He could not, in his old age, accept the idea that, as a matter of fact, relativity has a perfectly simple objective model..."
If you care to read this article you may also wish to reconsider your assertion that the notion that "it's impossible to tell who's moving" is a "foundational principle of SR." Then again, like Dingle you may not, who knows?
ttp://www.mathpages.com/home/kmath024/kmath024.htmv
I made a post prior to the one starting out with "5." that disappeared. In the spam bin, I spoze. The one which shows is merely a continuation of that (missing) post.
One Brow said:"You have no idea how much humor it brings meto see you argue both sides of the same position in consecutive posts."
I don't find it humorous so much as stunning that you think the questions of detecting absolute motion and detecting relative motion are "the same."
OneBrow, I sincerely appreciate your response. In my estimation, it would mean your position is something much more "evolved" than the sort of atheist who is merely reacting negatively to some variety of religious zealot, essentially declaring indepence from some orthodoxy.
Actually, it resembles that Ambrose Bierce quote Ain't quoted back in January. Newton felt the same way while continuing to be quite religious, just seeing how ultimate comprehension seemed far over that horizon he could see. . . .
I change hats quite freely. I remember years ago when my LDS bishop(and father of the girl of my dreams, as I choose to remember her)asked me if I knew the Mormon Church was true. I said "I don't know." It sorta shocked him because his dau had been going home almost every day for a year and talking about me in fairly glowing terms. So he asked me why I wanted to go on a mission. I said I believed it was the best religion we had, and worth sharing with others. So he let me go. . . .
I believe in God like I believe in electricity, heat, mass, energy, and in fact any fundamental existence.
But I know that "knowledge" or "belief" cannot be accessed by intellectual effort, any more than a man with nonfunctioning eyes can "see" by intellectual effort.
Then I can put on my "scientific" hat and accept the premises of investigation and evidence and follow it just the same as others folks who are working with what we have in the same manner.
In fact, I would consider it a tragedy for mankind if someone found a way to scientifically prove the fundamental claims of a religion, as it would destroy our freedom to either believe or disbelieve as we wish. If God ever comes in such an irrefutable presence, as bible scripture anticipates, it would have to just signal the end of the age. And about the only purpose of doing so, as I envision God, would be something like a teacher giving an exam and declaring the test finished. "I have always known you, and could have told you how you would do. This test is just for you to see for yourselves."
And oh ya, in the LDS cosmology of Joseph Smith, there isn't really sulfurous cauldron when folks will endlessly burn if we just don't go along with the pulpit pounders.
And oh ya, in my own belief which may not be fully employed by many Mormons, or even Christians, that thing about Jesus and his sacrifice is so whenever we realize our need, we can be forgiven just for the accepting of that gift. It means God knew we would just need something beyond our own abilities. . . . and that it isn't all just about us. . . . and what we are . . . . but perhaps more significantly about Him and what He has done for us.
Well, I love the God I think I know, but there is no way I can "see" for you or "know" for you, and in fact no way any of us can "see" or "know" Him unless we just turn ourselves to Him, sorta like a lot of BAC folks say.
So, that said, I think I'll just join this scientific discussion and try to discuss it like a person relying principles of logic.
About the clocks:
When I was in college I found some books on the subject in the library and looked at the pictures of clocks being held by folks riding on trains going opposite directions. . . and such. . . . and wondered if the people who drew the pics, or the profs themselves, knew anything at all.
I'm pretty sure I didn't.
But this open rebellion to the pure religion of science as taught by profs which Ain't is working on is pretty entertaining.
I always suspected there might be something different in the actual relation of math to the universe.
Right now I'm teaching my kids to figure our how long it's gonna take us to get home. They give me these blank looks when I ask them where we are, and impatiently declare that I'm giving them one minute to come up with an answer. I finally got it through to them what the milepost signs along the highway meant.
Math is a tool we use to quantitatively explore the world, not necessary the ultimate system which the world/universe naturally operates with in any way.
Look at what the idea of a quanta did to us. When we gave up the claim of absolute certainty about some detail in the math system we use, we found we could explain a lot of phenomena we had just argued about for years.
I wonder if nature even has a "clock". I know I threw mine out a long time ago, except on occasions when I'm being a worker bee in the great "socialist" establishment that has decided I'm a resource not a human. owned, not an owner. hmmm. .... must be lie to call that "socialism" instead of fascism. "socialism" has that homehearth glow to it because the teachers tell us "we" run it. . . .
alright, well, there's a lot of that clock disease and I just try not to see it in myself. But I do look at the sun and figure on it goin' down, so there I guess is "my" clock.
As I understand it, this whole thing about time/velocity and frames of reference came from the observation that when you run into a brick wall doing sixty, it's not as bad as hitting a semi doing sixty as well, but coming at you.
a photon of light emitted from some other galaxy, say from a certain electronic orbital transition of hydrogen for example, is seen in our telescopes with a shifted "frequency" or energy.
The same radiated light from galaxies receding in space or approaching us relatively speaking, is seen here with two different energies, on account of our relative speed to theirs.
No clock required. The "energy" we see includes a portion of our own, and portions of the various momentums of the irradiating sources.
talking about clocks going different speeds is just silly.
The idea of an actual speed limit might just as well be the product of intrinsic energies within systems. . . . and our means of determining them. . .
The idea of "ether" might also be merely an observational phenomena arising from our means of exploration. How can a "wave' exist in "nothing", what is rising and falling to convey the sense or mathematics of "wave" behavior?
there's stuff out there, behaving on its own terms. Our problem is to invent language, or math, capable of reliable "predictive" or "explanatory" power. So we can understand it in our minds.
Kinda like "God".
1. I've already said that I am not particularly interested in trying to work out particular problems as you claim are answered by "mainstream SR." I am more interested in discussing the inherent problems generated by what you call "mainstream SR," than I am in seeing what answers an inconsistent approach will supposedly generate. I have not even made an attempt to understand the question, because it's irrelevant to me.
Well, that's certainly your perogative. It's a shame, because trying to answer those questions might have forced you to confront a coule of deep flaws in your understanding of SR and nL.
With what you call "mainstream SR" all motion is relative to something else, which other motion is relative to something else, which is relative to[c], which is relative to [d], ad infinitum. As a result, there is, and can be, no unambigous answer to any such questions, which is all part of the inherent inconsistency.
This would be one of the flaws. As I pointed out, all of the answers in the A-B-C questions are scalars, identical to all observers regardless of rest frame. They have unambiguous answers in mainstream SR.
LR does not have any such problems, because it does not try to posit an infinite number of "time zones."
Then, care to give the LR answers?
Heh, you want to claim *I'm* confused. Jill sees (observationally) that her clock shows only 8 seconds passed, while he sees 10. He sees the same thing. They agree on that.
Your use of "while" here is meaningless. It makes sense to use it to compare two different things that occupy the same time interval to Jill (or to Jack), but not to compare an interval of jack to that of Jill, unless they are in the same location at the beginning and end of that interval. Jill sees 8 seconds pass on her clock while seeing 6.4 second pass on Jack's clock. Jack sees 8 seconds pass on his clock while seeing 10 seconds pass on his own. So, he doesn't see the same thing.
It is only by virtue of shoddy and wholly fallacious "logic," all distorted by the determination to justify an unjustifiable conclusion, that Jill can claim, on a basis supposedly consistent with SR (but not consistent), that he is the one moving while she is at rest.
You have some empirical test Jill can conduct to verify she is moving?
One Brow said:"Just like there's no point of pretending friction doesn't occur when using Newtonls Laws of motion (except, that's exactly what those laws do)."
I have no clue what you are talking about. I can't think of anything at all in Newton's laws of motion" which "pretends" friction doen't exist.
In the two-body collision, we calculate m1v1 + m2v2 = m1v3 + m1v4 using conservation of momentum, ignoring the effects of friction. F = ma ignores friction. The notion of an equal and opposite reaction ignores friction.
If you wnat to continue insisting there needs to ber a locally absolute rest frame in all relatiistic situations, go ahead. It adds little, and is occasionally inconvenient, but if it makes you comfortable, why not? It's kind of silly to insist everyone share your preference.
Where in the world do you get the idea that this ia a "foundational principle" of SR (as a scientific/mathematical theory, as opposed to a extraneous assertion of a philosophical (relationalist) proposition)? Does that follow from the first or second postulate of SR?
Assuming the second is the constancy of light, the first would be that identical experiments in inertial environments give identical results. that basically means you can't tell who is really moving, because any experiment made by the person at rest to detect motion will give the same results as the same experiment run by the other guy (again, in inertial environments).
No, his point was that she predicted the first clock would read 6.4 seconds, and the snapshot was taken to "settle the argument." You don't even seem to comprehend the problem he's posing.
Awww, that's so cute. Her prediction of the clock reading 6.4 seconds is based on a naive notion of simultaneity, where she starts with her travel time, converts it to time units in another inertial frame, and applies them direcdtly to an object without accounting for the distance she traveled. So the "problem", to the degree there was one, was the inappropriate notion of simultaneity.
Ya see, Eric, it is just this kinda red herring non sequitur that convinces me you have no real desire for honest discussion (as opposed to unqualified assertion and "defense" of you assertion by any means).
1. The example says that both see her clock as showing 8 seconds of time elapsed and his 10 seconds. This is a case of both looking at the same item(s) at the same time, from the same place. Light delays are totally irrelevant in this example.
You think Jill can start from the same place Jack does, move for 8 seconds (in Jack's frame) at a speed of .6c (relative to Jack, this is speed needed to make the ten seconds for Jill appear to be 8 for Jack) and winds up in the same place, or so close light-delay would not be significant? At no time after the start would Jack and Jill be able to see "the same thing".
... so why bring it up except perhaps as an attempt to confuse and/or evade the issue with sophistry?
To point out that, regardless of your philosophical preference, Jack and Jill will not be seeing the same thing at the same time. If you believe that they will, it is a hurdle you need to get over.
Dingle "...still claimed to be adhering to “special relativity” (obviously conflating it with relationism)..."
Bad on Dingle, then.
1. "Needless to say, the competing doctrines of relationism and absolute motion have been debated throughout the history of science.According to the absolutist view there exists something called absolute space and time, within which objects exist and move, whereas according to the relationist view only the relations between physical entities have physical meaning... In the absolute-vs-relational debate, special relativity is squarely on the absolute Newtonian side, which is to say, special relativity is based on the principle of inertia no less than is Newtonian mechanics."
False dichotomy used to construct a false dilemma.
One Brow said:"You have no idea how much humor it brings meto see you argue both sides of the same position in consecutive posts."
I don't find it humorous so much as stunning that you think the questions of detecting absolute motion and detecting relative motion are "the same."
By all means, clarify. Because I saw one quote decrying the professor for refusing to acknowledge the relevance of absolute motion, and the other as saying that we have know since Galileo you could not detect absolute motion. Which was the one about detecting relative motion?
babe,
It's nocde to have a discussion with you outside the confines of JazzFanz. I hope to see you aroung here often.
babe said...
I change hats quite freely.
A person should always try to follow the truth. In my life, I've gone from Catholocism to JW Fundamentalism to deism to atheism. Myh wife is a Baptist, and when our kids go to church, they go to a Baptist church. It doen't bother me.
I believe in God like I believe in electricity, heat, mass, energy, and in fact any fundamental existence.
OK. I've experienced electricity, heat, mass, and energy in fashions that I have never experienced God/a god/gods. That gives me no cause to diminish your experiences, though.
But I know that "knowledge" or "belief" cannot be accessed by intellectual effort, any more than a man with nonfunctioning eyes can "see" by intellectual effort.
I would say that there are different types of knowledge, and that the knowledge we identify with "belief" can not be accessed by intellectual effort.
Then I can put on my "scientific" hat and accept the premises of investigation and evidence and follow it just the same as others folks who are working with what we have in the same manner.
That puts you ahead of many believers.
And oh ya, in the LDS cosmology of Joseph Smith, there isn't really sulfurous cauldron when folks will endlessly burn if we just don't go along with the pulpit pounders.
Not for the JWs, either. The JWs are near-universalists.
So, that said, I think I'll just join this scientific discussion and try to discuss it like a person relying principles of logic.
Mixing different types of knowledge is fun.
Math is a tool we use to quantitatively explore the world, not necessary the ultimate system which the world/universe naturally operates with in any way.
I agree, and I believe aintnuthin will agree, as well. Math is a formal system, which means it can takes certain pre-defined assumptions, use pre-approved calculations, and arrive at a specific answer. We have absolutely know way of showng the assumptions are true or the calculations are a reliable method of analysis.
Look at what the idea of a quanta did to us. When we gave up the claim of absolute certainty about some detail in the math system we use, we found we could explain a lot of phenomena we had just argued about for years.
I would characterize it as giving up the claim of certainty in the measurements we make and greatly increasing the complexity of the math. the math itself is not fuzzy math.
I wonder if nature even has a "clock".
I would say no. Certainly not one single clock.
As I understand it, this whole thing about time/velocity and frames of reference came from the observation that when you run into a brick wall doing sixty, it's not as bad as hitting a semi doing sixty as well, but coming at you.
Well, you have an idea, although you don't need relativity for that conclusion.
a photon of light emitted from some other galaxy, say from a certain electronic orbital transition of hydrogen for example, is seen in our telescopes with a shifted "frequency" or energy.
Usually, assuming the laws of nature are the same in that galaxy.
The same radiated light from galaxies receding in space or approaching us relatively speaking, is seen here with two different energies, on account of our relative speed to theirs.
No clock required. The "energy" we see includes a portion of our own, and portions of the various momentums of the irradiating sources.
talking about clocks going different speeds is just silly.
How so? Depending on the sense in which you mean this, I might agree or disagree.
The idea of an actual speed limit might just as well be the product of intrinsic energies within systems. . . . and our means of determining them. . .
I'm not sure what you mean here.
The idea of "ether" might also be merely an observational phenomena arising from our means of exploration. How can a "wave' exist in "nothing", what is rising and falling to convey the sense or mathematics of "wave" behavior?
Light is not just a wave, it also has propertie of particles.
there's stuff out there, behaving on its own terms. Our problem is to invent language, or math, capable of reliable "predictive" or "explanatory" power. So we can understand it in our minds.
Kinda like "God".
Yup.
One Brow said: "Jill sees 8 seconds pass on her clock while seeing 6.4 second pass on Jack's clock. Jack sees 8 seconds pass on his clock while seeing 10 seconds pass on his own. So, he doesn't see the same thing."
Michael Fowler, Physics Professor at the Univerity of Virginia, said:
"Thus if both Jack and Jill are at C2 as Jill and her clock C' pass C2 , both will agree that the clocks look like: {drawing not displayed here)--As Jill passes Jack’s second clock, both see that his clock reads 10 seconds, hers reads 8 seconds"
Maybe you should take to teachin physics and learn this here prof., and his students, the real truth about what Jack and Jill will "see," eh, Eric?
One Brow said: "Assuming the second is the constancy of light, the first would be that identical experiments in inertial environments give identical results. that basically means you can't tell who is really moving..."
As I have repeatedly said, with elaborate explanations as to "why," the relativity principle "basically means" no such thing. I also just referred to an online article which repeatedly makes the same point, which, predictably, you totally ignore. That author makes the same point over and over, including here"
Dingle: "There is no meaning in absolute motion. The principle of relativity is a generalization from the fact that all known effects, apparently caused by the intrinsic motion of a single body, depend on the motion of that body with respect to another object."
Author's response:
"Far from being an accurate summary of the principle of relativity (which is synonymous with the principle of inertia as defined in both Newtonian mechanics and special relativity), what Dingle actually articulated was the antithesis of relativity, namely, the principle of relationism... Throughout all of Dingle’s writings, at least from 1921 until about 1959, we can see that he was laboring under the mistaken belief that Einstein’s theory of relativity was the embodiment of Leibnizian relationism, whereas in fact it is fully in the Newtonian tradition of absolute inertia."
Elsewhere: "Dingle and a few others like him were responsible for obfuscating the theory of relativity beginning in the 1920’s, spreading false and confused ideas about it in popular accounts...As explained above, he failed to realize that special relativity, no less than Newtonian mechanics, is founded firmly on Galileo’s principle of inertia, not on Leibniz’s principle of relationism...Even the first principle of relativity states NOT[original emphasis] that all motion is relational, but that any system of inertial coordinates is equally suitable for the formulation of physical laws. Hence Dingle’s claim that special relativity takes no account of absolute acceleration is utterly false. The existence of absolute acceleration is the very essence of the principle of inertia, on which special relativity is based."
To repeat what I already said:
"If you care to read this article you may also wish to reconsider your assertion that the notion that "it's impossible to tell who's moving" is a "foundational principle of SR." Then again, like Dingle you may not, who knows?"
Dingle, like some others we know, was rather obstinate and bigoted in his misconceptions. As the author notes:
"...[Dingle]had spent much of his life trying to convince himself and others that no such [i.e., objective] model was possible, and indeed that this impossibility was the whole message of relativity. He could not, in his old age, accept the idea that, as a matter of fact, relativity has a perfectly simple objective model..."
Time is an abstraction and it useage raises some rather trivial semantic issues. As I understand your position, clocks do not change with motion, but "time" does. How do you define "time" in this context? As "what clocks measure?" Or as sometime having meaning independent of clocks, as Newton claimed?
Let's skip the "time" issue, and go to something a little less abstract, like "length." As I understand your position, rods undergo no physical changes with motion but "length" (which you interpret to include "distance," and hence space itself) does(change, that is).
How does that work? Does the length of everything EXCEPT rods change? Or do all physical objects remain completely unaltered, while only "space" contracts?
I'm afraid I just don't get it.
Babe: I will simply quote good ole Sam Cooke on clocks, and leave it be at that, eh?
Sun in the sky is sinkin low...
Clock on the wall says it's time to go...
I gotz my plans, aint knowin bout you...
Tellya zakly what Imma do...
Imma kick back, and letz them good times roll....
It might be one o'clock, it might be three....
Time, it don't mean nuthin to me...
Aint had this much fun since I dunno when...
Might not never feel this good again....
So, Imma kick back and letz them good times roll....
Gunna staze here til I soothe my soul....
Iffit take all night long.
Gunna staze here til I soothe ma soul...
Iffit take all night long...
Nuff said, then, eh?
Oops, that got put in the wrong order, eh? Aint but one thing to do now, and that's make it right:
Sun in the sky is sinkin low...
Clock on the wall says it's time to go...
I gotz my plans, aint knowin bout you...
Tellya zakly what Imma do...
So, Imma kick back and letz them good times roll....
Gunna staze here til I soothe my soul....
Iffit take all night long.
It might be one o'clock, it might be three....
Time, it don't mean nuthin to me...
Aint had this much fun since I dunno when...
Might not never feel this good again....
So, Imma kick back and letz them good times roll....
Gunna staze here til I soothe my soul....
Iffit take all night long.
There, that's more betta, eh?
I spoze sumbuddy gunna haul off and say "Link?" Just to beat they ass to it, here ya goes:
http://www.youtube.com/watch?v=bQr2NR57F6Q
One Brow asked: "You have some empirical test Jill can conduct to verify she is moving?"
I don't, but SR (like LR) does, if you choose to accept it. When Jill sees that her clock is running slow compared to Jack's, she can assume that she is moving relative to Jack, not vice versa. GPS clocks also serve to verify that they are the ones moving relative to "stationary" clocks on earth. When the travelling twin gets his ass blasted into space, he can, given SR, safely assume that he is aging slower than his twin on earth, and this assumption will be confirmed when he returns.
Mach was, at first, enthused about SR, based on the representations that it was a relational theory of motion. When he found out it wasn't, he rejected it. Dingle went a different route, and refused to believe that SR actually predicted asymmetrical aging for the two twins.
Once he became convinced that SR did indeed predict asymmetrical aging, he at least saw (as Mach did) that this was inconsistent with the claim that "it is impossible to tell who is moving," i.e., with a relationalist position. He therefore claimed that SR was inconsistent and contradictory because he clung to the widespread misconception that SR was a relational theory that posited the impossibility of detecting which of two objects was moving relative to the other.
As confused as Dingle was, he was less confused than those who inconsistently hold that 1. clocks really do slow down with motion and this effect is not reciprocal, and who 2. simultaneously claim that SR posits that one has no way of knowing which of two objects is moving.
If one is convinced that it is impossible to say which of two objects is moving relative to the other, then he must simply reject SR, as Mach did. You can't have both.
"Thus if both Jack and Jill are at C2 as Jill and her clock C' pass C2 , both will agree that the clocks look like: {drawing not displayed here)--As Jill passes Jack’s second clock, both see that his clock reads 10 seconds, hers reads 8 seconds"
Maybe you should take to teachin physics and learn this here prof., and his students, the real truth about what Jack and Jill will "see," eh, Eric?
If they were at the same point after Jill travel for ten seconds at .6 c (according to Jack), then they were never at a point where Jill nor Jack would read both clocks to be 0 at the same time. However you lay it out, your 'both seeing 10 and 8 at the same time' idea is wrong.
One Brow said: "Assuming the second is the constancy of light, the first would be that identical experiments in inertial environments give identical results. that basically means you can't tell who is really moving..."
...Even the first principle of relativity states NOT[original emphasis] that all motion is relational, but that any system of inertial coordinates is equally suitable for the formulation of physical laws. ...
This is basically what I just said. If any system is equally suitable if and only if you can't empirically verify which system represents being truly at rest.
"If you care to read this article you may also wish to reconsider your assertion that the notion that "it's impossible to tell who's moving" is a "foundational principle of SR."
There was nothing in the article to contradict that. It was my error to rely on your summary, thank you for encouraging me to read more of it.
Then again, like Dingle you may not, who knows?"
Then, according to special relativity, at the instants when B reads 1 and 2 o'clock, A reads 2 and 4 o'clock respectively… Einstein himself made just this calculation, and concluded that since B recorded a smaller interval than A between the same events, it was working more slowly. But if he had similarly calculated the reading of B for the readings 1 and 2 o'clock of A he would have got 2 and 4 o'clock respectively, and must have reached the opposite conclusion: he did not do this, so missed the contradiction.
That sounds just like you. Very revealing.
Time is an abstraction and it useage raises some rather trivial semantic issues. As I understand your position, clocks do not change with motion, but "time" does. How do you define "time" in this context? As "what clocks measure?" Or as sometime having meaning independent of clocks, as Newton claimed?
Well, you don't need a physical measuring device for time to pass. So, while you could indeed define time as "what clocks measure", and any other definiton would in some way be synonymous, time is an independent physical phenomenon not dependent on clocks, electrons circling atoms, nor any other physical phenomenon.
Again, the best coparison is to distance being "what rulers measure". When we accelerate, we change our path through time, just as turning changes our path through space.
Let's skip the "time" issue, and go to something a little less abstract, like "length." As I understand your position, rods undergo no physical changes with motion but "length" (which you interpret to include "distance," and hence space itself) does(change, that is).
How does that work? Does the length of everything EXCEPT rods change? Or do all physical objects remain completely unaltered, while only "space" contracts?
I'm afraid I just don't get it.
Relativity is an empirical theory, being about what youcan measure and observe. Yes, there are ontological derivatives from the empirical results, but the first way you should look at any result is "this is how I would measure it". The reason for the contraction is that the rods in a different inertial state are pointing away from you into spacetime, but you can't point your yardstick in the same direction unless you are in the same inertial state. Note that while you see the other rod pointing away from you, from the other viewpoint, you are pointing away from it, so it also sees you as being shorter.
Imagine two yardsticks joined at one end by a device that allows you to create angles. If you make a 60-degree angle between the yardsticks, and put yardstick A on the ground, then measure how far across the ground yardstick B goes, it will be one-half yard. Yardstick B has not changed, but the distance yardstick A can measure of it has changed. Further, if you put yardstick B on the ground, yardstick A will only cover half a yard on the ground. One you close the angle (the metaphorical equivalent of joining the same inertial state), they will measure each other to be a yard.
One Brow asked: "You have some empirical test Jill can conduct to verify she is moving?"
I don't, but SR (like LR) does, if you choose to accept it. When Jill sees that her clock is running slow compared to Jack's, she can assume that she is moving relative to Jack, not vice versa.
She can assume it, but not empirically verify it.
GPS clocks also serve to verify that they are the ones moving relative to "stationary" clocks on earth.
Since we use them for our benefit, why shoudl it be otherwise?
When the travelling twin gets his ass blasted into space, he can, given SR, safely assume that he is aging slower than his twin on earth, and this assumption will be confirmed when he returns.
The traveling twin changes inertial frames, the stationary does not.
As confused as Dingle was, he was less confused than those who inconsistently hold that 1. clocks really do slow down with motion and this effect is not reciprocal, and who 2. simultaneously claim that SR posits that one has no way of knowing which of two objects is moving.
It's not reciprocal when one of the clocks changes inertial frames.
If one is convinced that it is impossible to say which of two objects is moving relative to the other, then he must simply reject SR, as Mach did. You can't have both.
Is there a difference between "impossible" and "emprically unverifiable"?
Since you have decided not to look at the scenarios above, I will provide their answers.
First, you are wrong about the bug on the ocean liner, with regard to both SR and nL. In nL, the local gravitaional field of the ship is dominated by that of the planet, so the ether is motionless with respect to the bug, as well. In SR, the bug and the ocean are in a common inertial state. That means the clock on the bug moves eactly like the clock on the ocean (same for the clock on the spider and the worm). Only the ship clock is slowed. Further, the ship clock is slowed by the same amount even if you remove all external forces, the existence of propulsion and friction do not affect the clock on the ship.
A3 shows less time passed than A1, to any observer, in both SR and nL. The time recorded by A1 was recorded in a single inertial state, while the time recorded by A3 passed through two inertial states.
B3 shows less time passed than B2, to any observer, in both SR and nL. The time recorded by B2 was recorded in a single inertial state, while the time recorded by B3 passed through two inertial states.
C1 shows less time passed than C3, to any observer, in both SR and nL. The time recorded by C3 was recorded in a single inertial state, while the time recorded by B1 passed through two inertial states.
You may or may not have realized this, but all three scenarios were descriptions of the same event. A1 = B2 = C3, A3 = B3 = C1, A2 = B1 = C2. Feel free to ask some other physicist about this, since I know you won't take my word for it. The point is that propulsion/acceleration has nothing to do with the determinations of SR, it is the real, objective, physical, absolute differences in inertial states. That makes acceleration an absolute, by the way, because acceleration is a change in inertial state.
One Brow said:"The point is that propulsion/acceleration has nothing to do with the determinations of SR, it is the real, objective, physical, absolute differences in inertial states. That makes acceleration an absolute, by the way, because acceleration is a change in inertial state."
Simply another case where you demonstrate your proclivity to believe that if you choose a different word to describe the same thing you are now talking about two different things.
On the one hand you say: "acceleration is a change in inertial state."
I agree. But on the other hand you say: "The point is that propulsion/acceleration has nothing to do with the determinations of SR"
=====
One Brow said: The point is that propulsion/acceleration has nothing to do with the determinations of SR, it is the real, objective, physical, absolute differences in inertial states. That makes acceleration an absolute, by the way, because acceleration is a change in inertial state."
Yeah, as I said, SR must revert to the premise of LR, and abandon any pretense that "it's all relative" in order to have anything definite or meaningful to say about the matter.
====
One Brow said: "If they were at the same point after Jill travel for ten seconds at .6 c (according to Jack), then they were never at a point where Jill nor Jack would read both clocks to be 0 at the same time."
I have already noted, in a prior post, that the prof. here skips an important step in setting up the example. But the omission is not serious or substantial. He makes the assumption that when clock 1 (in Jack's frame) is "set to zero" clock 2 also "magicially" gets set to zero. He does this because the clocks are synchonized in Jack's frame, but he creates confusion this way.
There is absolutely no need to set either clock to "zero;" he only does this for didatic purposes of simplicity.
Here's what he seems to be implying:
Clocks 1 and 2 are, and remain, synchronized in Jack's frame. Forget setting either clock to "zero." Assume there is an observer at clock one who notes the exact time at which Jill passes. He then radios ahead to Jack, at clock 2, his observation, e.g. "She passed here at noon sharp." Clock 2 will therefore read 10 seconds past noon when she reaches it.
A mere technical detail which in no way changes the point.
One Brow said: "One you close the angle (the metaphorical equivalent of joining the same inertial state), they will measure each other to be a yard."
Your example is an obvious and mundane example of how conclusions are necessarily dependent on assumptions (starting points) and perspective. But, so what? A yardstick is still one yard long as measured along the(60 degree) line it is on.
The problem here is that such an observation explains absolutely nothing about length contraction as it pertains to SR. As I said before, you are merely detailing a mundane example of how observations can change with perspective.
You have also agreed that "length contraction" cannot be a mere matter of perspective for purposes of SR.
So what is your point? How is your example relevant to SR?
If I move 10 feet, a square table-top will no longer have the same appearance from my new position as it did before. It is true that ME moving 10 feet is a "real, physical change" in MY position, but it changes nothing in the tabletop. Nor do *my* perceptions cause any change whatsoever to the physical structure of the tabletop.
You still seem to think that perception and perspective dictate physical reality. The idea still seems to be, as you present it, that whichever thunderclap a particular observer "hears" first had to have happened first.
I said: "A mere technical detail which in no way changes the point."
Put another way, the scenario the prof. is setting up is actually this: When Jill passes clock 1, she sets HER clock to match it. If it reads noon, she sets her clock to noon, and no resetting of clock 1 is involved.
When she reaches clock 2, her clock will read 8 seconds past noon, and Jack's will read 10 seconds past noon.
This will happen because she is moving, which means that physical processes have "really" slowed down for her relative to Jack. As a result her clock record only 8 "ticks" in the same duration that Jack's records 10 ticks.
Therefore, if she "knows her SR," she will know she is moving relative to Jack, not vice versa.
One Brow said: "Relativity is an empirical theory, being about what youcan measure and observe."
Or so it is (was) claimed by logical positivists, operationalists, and relationalists. Of course Al, and other thinking people, denied this spurious claim.
One Brow said: "The traveling twin changes inertial frames, the stationary does not."
Yes, exactly. The traveling twin accelerates, absolutely, and the stationary twin does not. He is "really" moving relative to the earth twin, and we know it.
One Brow asked: "Is there a difference between "impossible" and "emprically unverifiable"?
Of course there is a difference, unless maybe you subsbribe to a solipsistic logical positivistic, relationalist view of "reality."
But neither is the case here. If Barry Bonds bashes a baseball and, as a result, it ends up moving a total of 700 feet, that fact is easily verfied, qualitatively, by merely watching the event. Quantitatively is can be verified by breaking out the tape measures.
I said: "If you care to read this article you may also wish to reconsider your assertion that the notion that "it's impossible to tell who's moving" is a "foundational principle of SR."
You replied: "There was nothing in the article to contradict that."
I'm sure Dingle would have said the same thing.
It's pretty simple, actually. If you're convinced something is true, then it must be true. Since it is true, nothing can possibly contradict it, because truth cannot (truthfully) be contradicted.
==
Dingle: "There is no meaning in absolute motion.
Author: "Far from being an accurate summary of the principle of relativity...what Dingle actually articulated was the antithesis of relativity, namely, the principle of relationism."
One Brow said: "That sounds just like you. Very revealing."
It does? How so? I never said there was any logical or mathmatical inconsistency in SR. I said the opposite.
The authoris pointing out a techincal mathematical error here made by Dingle, but this error in no way refutes Dingle's point.
The author says: "Again the fallacy is the erroneous assumption that partial derivatives can be algebraically inverted. Of course, we can invert total derivatives, so let's see what happens if we take the absolute differentials (for any constant v) of the time transformation equations."
OK, so now what do we see? This:
"Solving for u gives the familiar formula [mathematical symbols omitted]which is the relativistic speed composition formula."
And the "relativistic speed composition formula" tells you what? Does it deny the reciprocity of the Lorentz transformation and it's inverse? Of course not. As the author himself notes that, with regard to this reciprocity, "was the whole basis of the special theory of relativity."
Dingle may have gotten the precise details mathematical details wrong, but his substantive point was in no way undermined by that technical error. The supposed "reciprocity" here cannot be literally true, even if it can be mathematically consistent.
As the resolution of the twin paradox shows, one clock really is running faster and one really is running slower. The "reciprocity" is a product of a limited mathematical calculation ony.
aintnuthin said...
Simply another case where you demonstrate your proclivity to believe that if you choose a different word to describe the same thing you are now talking about two different things.
On the one hand you say: "acceleration is a change in inertial state."
I agree. But on the other hand you say: "The point is that propulsion/acceleration has nothing to do with the determinations of SR"
Both are true. Acceleration causes a change in inertial state, and the change in inertial state results in the changes predicted by SR. However, no acceleration is needed. If teh changes in inertail state are pre-existing, the fininds of SR are not changed by the lack of acceleration.
One Brow said: The point is that propulsion/acceleration has nothing to do with the determinations of SR, it is the real, objective, physical, absolute differences in inertial states. That makes acceleration an absolute, by the way, because acceleration is a change in inertial state."
Yeah, as I said, SR must revert to the premise of LR, and abandon any pretense that "it's all relative" in order to have anything definite or meaningful to say about the matter.
If LR only acknowledged differences in inertail states as being absolute, there would be no difference with SR. However, LR also proposes a (possibly locally) absolute rest frame.
Clocks 1 and 2 are, and remain, synchronized in Jack's frame. Forget setting either clock to "zero." Assume there is an observer at clock one who notes the exact time at which Jill passes. He then radios ahead to Jack, at clock 2, his observation, e.g. "She passed here at noon sharp." Clock 2 will therefore read 10 seconds past noon when she reaches it.
A mere technical detail which in no way changes the point.
The radioing ahead is done at the speed of light. By the time Jack gets the message that Jill passed some point at noon sharp, Jill will no longer read noon. It doesn't matter whether the synchronization occurs at 0 or any other time. If Jill passes by Jack after ten seconds according to jack's inertial state and eight seconds in Jill's inertial state, neither would oberve the other to be synchronized with them 10 (or 8 for Jill) seconds previously.
A yardstick is still one yard long as measured along the(60 degree) line it is on.
That was my point, exactly. The yeardstick is not shorter. Rods don't contract. Nonetheless, the change in the measurement of the yardstick is real, physical, and objective, just as the contraction of the rod is real, physical, and objective.
The problem here is that such an observation explains absolutely nothing about length contraction as it pertains to SR. As I said before, you are merely detailing a mundane example of how observations can change with perspective.
The actual term is angle of incidence, and it is a physical property with physical consequences, both in terms of the yardsticks and in terms of SR. As long as you continue to confuse an angle of incidence with a subjective perspective, you will continue to miss the point.
If I move 10 feet, a square table-top will no longer have the same appearance from my new position as it did before. It is true that ME moving 10 feet is a "real, physical change" in MY position, but it changes nothing in the tabletop. Nor do *my* perceptions cause any change whatsoever to the physical structure of the tabletop.
You are correct.
You still seem to think that perception and perspective dictate physical reality.
No. But physical reality is affected by the distqance you are from the table, as you acknowledge above.
The idea still seems to be, as you present it, that whichever thunderclap a particular observer "hears" first had to have happened first.
When they are the same distance away and the sounds move at the same speed.
Put another way, the scenario the prof. is setting up is actually this: When Jill passes clock 1, she sets HER clock to match it. If it reads noon, she sets her clock to noon, and no resetting of clock 1 is involved.
When she reaches clock 2, her clock will read 8 seconds past noon, and Jack's will read 10 seconds past noon.
How do you know Jack's clock is synchronized to clock 1? They are separated by six light-seconds. Will both Jack and Jill see Jack's clock and clock one to be synchronized at the same time?
This will happen because she is moving, which means that physical processes have "really" slowed down for her relative to Jack. As a result her clock record only 8 "ticks" in the same duration that Jack's records 10 ticks.
Therefore, if she "knows her SR," she will know she is moving relative to Jack, not vice versa.
Does Jill measure ten ticks of Jack's clocks on her journey? Does she measure ten ticks of clock 1? If they are both on train cars, is there any difference in the measurement when it is the train of Jack/clock1 that is moving? What is the difference?
Or so it is (was) claimed by logical positivists, operationalists, and relationalists. Of course Al, and other thinking people, denied this spurious claim.
Not in anything you have presented so far. You can use relativity along with otherr other, often ontological assumptions, such as classical LR or nL does, but basic SR is empirical, producing ontological outcomes (aka scalars) only in special circumstances.
One Brow asked: "Is there a difference between "impossible" and "emprically unverifiable"?
Of course there is a difference, unless maybe you subsbribe to a solipsistic logical positivistic, relationalist view of "reality."
So, when mainstream physicists talk about the empirical unverifiability of determining who is moving, there is no reason to get that confused with an ontological claim, agreed?
But neither is the case here. If Barry Bonds bashes a baseball and, as a result, it ends up moving a total of 700 feet, that fact is easily verfied, qualitatively, by merely watching the event. Quantitatively is can be verified by breaking out the tape measures.
Yup.
I'm sure Dingle would have said the same thing.
Broken clocks are still right twice a day. Whether Dingle would have said it has little to do with it's accuracy.
It does? How so? I never said there was any logical or mathmatical inconsistency in SR. I said the opposite
Nice job of focusing on the last phrase while ignoring the previous parts of the paragraph. You and Dingle make nearly identical arguments, and identify the same thing as a contradiciton. Dingle says its a problem with SR, you say it's because its not SR. You're both wrong.
Dingle may have gotten the precise details mathematical details wrong, but his substantive point was in no way undermined by that technical error. The supposed "reciprocity" here cannot be literally true, even if it can be mathematically consistent.
Yet, the author of mathpages would describe it as being literally, empirically true.
As the resolution of the twin paradox shows, one clock really is running faster and one really is running slower. The "reciprocity" is a product of a limited mathematical calculation ony.
In the twin paradox, the change in inertial frames shows which frame is correct.
One Brow said: "The radioing ahead is done at the speed of light. By the time Jack gets the message that Jill passed some point at noon sharp, Jill will no longer read noon [Of course not, so what?] It doesn't matter whether the synchronization occurs at 0 or any other time. If Jill passes by Jack after ten seconds according to jack's inertial state and eight seconds in Jill's inertial state, neither would oberve the other to be synchronized with them 10 (or 8 for Jill) seconds previously."
The question is not about "observing the other to be synchonized." The whole point is that Jill's and Jack's (second) clock will NOT be synchronized, so why do you bring this up.
The prof says Jack will see 12:00:08 on Jill's clock, and so will Jill. Likewise, Jill will see 12:00:10 on Jack's clock and so will Jill.
They will NOT both see the other's clock running slower. They will both see Jack's clock running faster, and Jill's running slower. Go apply for this guy's job and teach the class yourself if you think he's wrong. He aint--they are looking at the same things, from the same place, at the same time.
I know this contradicts what you have repeatedly said they would see, so I now expect you to deny it until your dying day.
One Brow said: "Yet, the author of mathpages would describe it as being literally, empirically true."
Nobody in their right mind has ever claimed that two clocks literally and truly, as a matter of empirical fact, each run slower than the other. Certainly SR does not. You obviously have not understood anything he said. You have never understood that this is a logical impossibility, actually, no matter how many times it is explained to you, or by whom.
One Brow said: "That sounds just like you. Very revealing."
What you fail/refuse to acknowledge and understand, Eric, is that the author is taking Dingle to task for making the claims that YOU consistently make, not the techincal math error which the author say is "not terribly interesting."
The fundamental misunderstanging that Dingle displays is found in his imputation of a Liebnizian/Machian relationalist philosophy into SR, and a corresponding subjecivist claim that there basically is no "objective reality."
Dingle problem lies primarily in the claim that SR fundamentally precludes the possiblity of ascertaining which of two objects is in motion (a claim which was, in fact, initally condoned by Al, who had strong relationalist leanings at the time). Dingle was hardly alone, and still isn't, as you yourself demonstrate when you make all the arguments that one might expect from a devout Dingle disciple in this respect.
Thus the author faults and blames Dingle (due to his influence in promulgating misconceptions) for claiming, as you do, that the proposition that "you can never tell who's moving" is a "foundational principle" of SR.
"Dingle himself was one of the early expositors of the theory, i.e., one of the authors who told people that Einstein’s theory means “everything is relative”, etc., and thereby set the stage for generations of misunderstanding...The young Dingle never grasped this [objective] model - indeed his whole philosophy of science (in those years) was that relativity had rendered all such models unviable.... He could not, in his old age, accept the idea that, as a matter of fact, relativity has a perfectly simple objective model, and that his views on this subject, to which he had devoted much of his life, had always been fundamentally flawed and misguided."
I ran across an exposition about the constant speed of like by the famed astrophysicist, Arthur Eddington where is "objective model" which Dingle (and you) rejected is quite evident:
"It is no use trying to overtake a flash of light; however fast you go it is always traveling away from you at 186,000 miles a second. Now from one point of view this is a rather unworthy deception that Nature has practiced upon us. Let us take our favourite observer who travels at 161,000 miles a second and send him in pursuit of the flash of light. It is going 25,000 miles a second faster than he is; but that is not what he will report. Owing to the contraction of his standard scale his miles are only half-miles; owing to the slowing down of his clocks his seconds are double-seconds. His measurement would therefore make the speed 100,000 miles a second (really half-miles per double-second). He makes a further mistake in synchronizing the clocks with which he records the velocity….This brings the speed up to 186,000 miles a second. From his own point of view the traveler is lagging hopelessly behind the light; he does not realize what a close race he is making of it, because his measuring appliances have been upset." [Sir Arthur Eddington, The Nature of the Physical World, from the 1927 Gifford Lectures, 1929, p. 54.]
Notice that Eddington makes a clear distinction between what the traveller "reports" and what is really happening. Due to distortion measuring instruments he "reports" that a beam of light is receding from him at the rate of 186,000 mps, and what is really happening, i.e. "It is going 25,000miles a second faster than he is... From his own point of view the traveler is lagging hopelessly behind the light; he does not realize what a close race he is making of it, because his measuring appliances have been upset."
According to Eddington, the traveller misperceives the objective facts. To hear you (or Dingle) tell it, his misperception ARE the objective facts. You simply seem unable to make a meaningful and consistent distinction between subjective and objective factors, Eric? Of course this is basically true of all radical empiricists, like Berkeley, Mach, the logical positivists, etc.
But, like I said, Dingle had one clear advantage over you in the logical consistency department. He saw that one could not consistently claim that it is impossible to detect motion and that the reciprocity of Lorentz transformations is "literally, empirically true" AND also affirm the predictions of SR with respect to asymmetrical aging of the two twins.
You do not, and can not, grasp this fundamental inconsistentcy, while Dingle could, and did.
This math guy reiterates virtually every argument I have made in this thread, but, like Dingle, you seem to be pyschologically incapable of comprehending his points. Like Dingle, no matter how often you are given reasonable counter-arguments to your assertions, you merely ignore them and repeat your assertions.
A few examples:
1. The claim that SR implies that all viewpoints are "equally valid:" "Leibniz maintained that all phenomena should be explainable purely in terms of the relations between substantial entities, and hence any object could, with equal justification, be regarded as being continually at rest. In opposition to this, Clarke and Newton argued (by means of the famous spinning pail experiment, for example) that arbitrary motions are not all equivalent, i.e., it is not possible to account for all the physical phenomena associated with motion merely in terms of the relative kinematic relations between entities...Clarke (speaking for Newton) made the case for absolute motion – a case that essentially amounts to the assertion of Galileo’s principle of inertia....special relativity is based on the principle of inertia no less than is Newtonian mechanics."
2. The claim that, according to SR, absolute motion is "meaningless: "...what Dingle actually articulated [when stating that absolute motion has no meaning] was the antithesis of relativity, namely, the principle of relationism." By way of elaboration, the author quotes Einsttien and asserts that Al's explanation directly expresses the absolutist principle of inertia, which was anathema to (among others) Leibniz."
3. The claim that SR implies that there is no objective reality and that "all is relative:" "Even the first principle of relativity states not that all motion is relational...Dingle and a few others like him were responsible for obfuscating the theory of relativity beginning in the 1920’s... [Dingle was]one of the authors who told people that Einstein’s theory means “everything is relative”, etc., and thereby set the stage for generations of misunderstanding."
By the way, I found the Eddngton quote on a website that evidently promotes geocentricism:
tp://bellarmineforum.xanga.com/720205115/question-208---struggling-with-question-on-geocentrism/
Among other things, they claim that the Michelson-Morley experiment merely proves that the earth is not moving, and assert that concoctions such as length contraction and time dilation were created solely because physicists rejected the possibility that the earth truly is stationary. An excerpt:
"Having no other way to prohibit the Earth from being motionless in space, most scientists succumbed to the “shrinking matter” hypothesis, and soon it became standard fare in the world of physics. Dubbed as the “Fitzgerald contraction,” and later made into an equation called the “Lorentz transformation,” it was so readily accepted that it became the pat answer to every motion problem in physics...they committed the most egregious fallacy in logic: using as proof that which they had not first proven. To put it bluntly, they assumed the Earth was moving as the basis to interpret the experiment that appeared to show the Earth wasn’t moving."
Like LR versus SR, both geocentrism and heliocentricism are capable of predicting and explaining the known phenomena. They are, you might say (if you're a relationalist), "equally valid."
Which goes back to the first question I raised in this thread. Scientific theories are no more "empirical" in nature than are other theories (of economics, ethics, or whatever). Granted, the subject matter of physics is probably more routinely "empirical" than are ethical theories, but, as Al insisted, scientific theories are NOT "dictated by the facts," as you like to believe.
I think you do have a streak of scientism in your thought patterns, and that, because you have (or had) subjective faith in certain theories (such as the modern synthetic theory of evolution), you simply conclude that they embody undeniable "fact" and give no further reflection about the derivation of the (value-laden) premises underlying such theories.
Once you decide they are "true," all further discussion of the topic reduces to polemical assertion for you, and foregoes thoughtful analysis.
As previously noted, Gallileo noted that a cannonball dropped from a moving ship's mast would appear to follow a parabolic path to an observer on shore, while it appears to drop in a straight line to observers on a ship.
I raised the question of why this does not imply time dilation. Obviously, a parabolic path is longer than a straight one. How can the ball travel further in the same "time," unless time changes?
The answer, as I see it, is that the parabolic path is merely an appearance, much like the light clock examples where the light on a moving object "appears" to travel farther to a stationary observer, and just as a bird flying alongside a moving car may "appear" to be stationary to the passengers and appear to be moving to a roadside observer. The difference in perspective does not imply a change to "time itself."
Gallileo's point was that a cannonball will ALWAYS appear to fall straight down as perceived by a co-moving intertial observer. But again, this, by itself, certainly implies no "time dilation" amongst different frames.
To me, the "light clock" explanations of time dilation and length contraction explain nothing of the kind. If you analyze any of them, you will see the the constant speed of light is merely assumed, ab initio, and not "demonstrated" by those examples.
The time dilation posited by SR MUST be something more than a mere difference in appearance caused by a difference in perspective. The light clock examples ignore this, as does the "geometrical." interpretation which you want to rely on to "explain" those phenomena.
If these were merely artifacts of perspective, the whole theory would fall apart. They would have no objective effect on anything, and the posited "time dilation" would not exist. Hence the speed of light would not "really" appear to be constant in all inertial frames. If one yard always remained one yard, observers travelling at different speeds would measure the speed of light to be different.
You say rods do not really contract. Tell me, does space (distance) "really" shrink at relativistic speeds, or is that too just a matter of perspective caused by "angles of coincidence" on a piece of graph paper?
I said: "To me, the "light clock" explanations of time dilation and length contraction explain nothing of the kind."
We had a disagreement about the meaning of Hogg's claim that the raw number of ticks of a clock on a moving object is a scalar.
Let's forget about that, and talk about a ball being thrown in the air on a moving airplane. Nobody claims that material objects always travel at some definite, unvarying speed, so that isn't an issue.
The physicists I have read say that an observer on the ground will seen the ball leave and return to the plane traveller's hand at the same times that the plane traveller does. Yet, in that same duration, the ball "appears" to travel much farther to the observer on earth than it does to the guy on the plane tossing it.
How is this different from the light clock examples? Why doesn't the thrown ball necessitate the conclusion that time dilates?
aintnuthin said...
[Of course not, so what?]
So, Jill does not see 10 seconds pass on clock 1, nor on Jack's clock.
The question is not about "observing the other to be synchonized." The whole point is that Jill's and Jack's (second) clock will NOT be synchronized, so why do you bring this up.
My point was that Jack does not see himself to be synchronized with clock1, either. Jack sees clock1 running six seconds slower than Jack. An observer at clock1 would see Jack running six seconds behind clock1.
The prof says Jack will see 12:00:08 on Jill's clock, and so will Jill. Likewise, Jill will see 12:00:10 on Jack's clock and so will Jill.
They will NOT both see the other's clock running slower.
Why not? "Seeing each other running slower" is a measure of the rate of change of a clock, not the reading on a clock.
They will both see Jack's clock running faster, and Jill's running slower. Go apply for this guy's job and teach the class yourself if you think he's wrong.
As usual, I think he's right, and you are interpreting him badly.
I know this contradicts what you have repeatedly said they would see, so I now expect you to deny it until your dying day.
Except, there is no contradiction between I and the author of mathpages..
Nobody in their right mind has ever claimed that two clocks literally and truly, as a matter of empirical fact, each run slower than the other.
For one thing, it would be a category error. An empirical fact would be each person measuring the other's clock as running slower. A "literally and truly" issue would be an ontological fact.
You have never understood that this is a logical impossibility, actually, no matter how many times it is explained to you, or by whom.
You are a true disciple of Dingle (on SR, not on relationalsm).
What you fail/refuse to acknowledge and understand, Eric, is that the author is taking Dingle to task for making the claims that YOU consistently make, not the techincal math error which the author say is "not terribly interesting."
What you fail to realize is that I'm not making Dingle's error, you are imputing it to me falsely. I'll snip the rant on relationalism as irrelevant, since I'm bored of pointing out I not a relationalist.
Notice that Eddington makes a clear distinction between what the traveller "reports" and what is really happening.
A valid philosophical, ontological interpretation, as I have mentioned.
Among other things, they claim that the Michelson-Morley experiment merely proves that the earth is not moving, and assert that concoctions such as length contraction and time dilation were created solely because physicists rejected the possibility that the earth truly is stationary.
The motion of the earth was carefully measured long before Michaelson-Morely. This is a re-write of history, and you know it.
Like LR versus SR, both geocentrism and heliocentricism are capable of predicting and explaining the known phenomena. They are, you might say (if you're a relationalist), "equally valid."
Geocentrism throws out principles like consevation of energy. You have to re-write most of physics for it to be true. It is not a philosophical preference. The difference between geocentrism and heliocentrism does not compare to the difference between SR and LR.
I raised the question of why this does not imply time dilation. Obviously, a parabolic path is longer than a straight one. How can the ball travel further in the same "time," unless time changes?
The ball has more speed on the parabolic path (the same vertical velocity, but an additonal horizontal velocity). So, it covers more distance in the same time.
To me, the "light clock" explanations of time dilation and length contraction explain nothing of the kind.
If light can move at different velocities, sure.
If you analyze any of them, you will see the the constant speed of light is merely assumed, ab initio, and not "demonstrated" by those examples.
Right. The constancy of light is an intuitive leap from experimental results. We've covered that before.
You say rods do not really contract. Tell me, does space (distance) "really" shrink at relativistic speeds,
We both agree that distance is not the type of concrete thing that could shrink.
or is that too just a matter of perspective caused by "angles of coincidence" on a piece of graph paper?
We both agree that y6ou can describe angles of incidence on graph paper, but the description is not a cause.
We have had a few discussions about subjective versus objective facts. Generally speaking, if I say an effect is "real" I mean objectively (not subjectively) real. What do you mean?
Let me give an example or two. If I close my eyes, the computer screen in front of me will disappear. But the cause of that disappearance lies in the subject (me) not the computer screen (the object). Hence I would say it does not "really" disappear even if it does "really" disappear for me, and me alone.
Likewise, I would say the demented hallucinations of a raving paranoid-schizophrenic are not "real" even though they "really" occur for him. They are not objectively real, only subjectively.
It seems to me that you want to say that both the content of the hallucination and the disappearance of the computer are "real, physical" changes. But do you contend that they are objective, as opposed to merely subjective, changes?
One Brow said: "So, Jill does not see 10 seconds pass on clock 1, nor on Jack's clock."
1. Is she even looking at clock 1? If so, after allowing for light delays, she would presumably see the exact same digital readouts as the clock shows. This is demonstrated by her (mistaken) argument that clock 1 MUST be reading 6.4 seconds when she reaches clock 2. However, the snapshot taken to settle the argument shows it reading 4 seconds(for both her and Jack), just as Jack (correctly) predicted. His reads 10, clock 1 is 6 light-seconds away from him, so the snapshot shows it reading 4 seconds (it's reading 6 seconds ago by Jack's clock, since it is 6 light seconds away).
2. Of course she does not see "10 seconds pass on clock 1," at least not if you believe the predictions of SR. The whole theorem of SR is that her clock is running at a slower rate because she it moving. If you expected her to see the same, you would effectively be denying the validity of SR.
These comments of yours do nothing to address the issue.
One Brow said:"Why not? "Seeing each other running slower" is a measure of the rate of change of a clock, not the reading on a clock."
So now your definition of a correct observation (which contradict what one sees with his/her own eyes) is what is deduced by a mistaken "thinker?" If 8 seconds have passed for her, then, of course, only 6.4 seconds will have passed for Jack IF(and only if) he is the one moving. He aint. And this is proven by the fact that the clocks in his frame show that 10 seconds have elasped in that frame, NOT 6.4 seconds. She "sees" this with her own eyes, and hence has no reason to think Jack's clock "really" shows that only 6.4 seconds have passed.
Ya see, Eric, we KNOW (because the prof posits it) that Jill, not Jack, is the one moving here. He knows it, and we know it because he tells us. But, now, for reasons we have discussed, he feels compelled to argue that Jill MUST remain deluded about the status of her motion. She MUST insist that she is stationary. If no one can tell who's moving, why should she be so insistent that she aint moving? She supposedly has no way of knowing that. She has no way of "seeing" how much time passes in Jack's frame, other than to see what his clocks show.
There are ulterior motives for advancing the kind of fallacious logic the prof imputes to Jill here, and I have explained them at some length in prior posts.
One Brow said: "We both agree that distance is not the type of concrete thing that could shrink."
We do? I could have sworn that you claimed the opposite. I offered an explanation of time and length distortion very similar to that presented by Eddington, as it turns out (I may have read his work, years ago, but, of course, many authors give the same type of explanation).
I gave that explanation (basically that distorted rods and clocks made the same distance "appear," but not actually be, shorter) after noting that every physicist I could remember said merely that the length of material objects contracted, not space itself (distance).
As I recall, you said that was the way some people "used to think," but modern thought said that space itself actually shrank, i.e., that the distance to an object 2 light years away would immediately shorten to 1 light year when a guy accelerated to 161,000 mps.
Do you recall this exhange?
One Brow said:"What you fail to realize is that I'm not making Dingle's error, you are imputing it to me falsely. I'll snip the rant on relationalism as irrelevant, since I'm bored of pointing out I not a relationalist."
Yeah, and if a biological male claims he is not a male, but rather a female by birth, then he is a female, too, I spoze. It's not what you attempt to "point out" that determines these things, it is the type of assumptions you make and the type of arguments you present.
You just said that the proposition that "you can't tell which of two objects is moving" is a "foundational principle" of SR. The math guy clearly denies this, and says it is the statement of a relationalist, not a relativist, position.
But, of course, without responding to a thing he says, or quoting passages which you think qualify to clarify the many particular statements of his that I have quoted, you merely issue your standard blanket denial with no supporting facts or reasoning to suppport it whatsoever. I'm sure you're method of arguing and "proving" your assertions would be utterly compelling to any juror trying to decide an issue, eh?
You would be the most successful bottom-feeder who ever lived. You could just sit there, idly, while days worth of compelling evidence against your client was presented. Then, when they finally quit, you would offer no counter-evidence whatsover. But when time came for closing arguments, you would stand up and say: "My client didn't do it," then sit down. A unamimous verdict if your favor every time, I betcha!
One Brow said: "Geocentrism throws out principles like consevation of energy. You have to re-write most of physics for it to be true. It is not a philosophical preference."
As the math guy noted, the principle of inertia was "anathema" to Liebniz, and others. Conservation of energy, momentum, and all related notions stem from Newton's laws of motion, which are based on inertia (which also give you a method of ascertaining which of two objects is really moving).
As a matter of pure philosophical preference, you can simply deny the validity of inertia or any other concept. There is no "re-writing" of anything that you have always denied to begin with. Liebniz was a complete philosophical rationalist who derived his conclusions from a priori principles he believed in (e.g., the principle of sufficient reason, the principle of the indiscernability of equivalents, etc.).
You claim that "The motion of the earth was carefully measured long before Michaelson-Morely. This is a re-write of history, and you know it."
The "motion of the earth" was "carefully measured" if, and only if, you presume certain things about the nature of "reality." If you don't assume those things, then nothing was accurately measured. For many centuries the "fact" that the earth could not possibly be moving was taken for granted by western civilization. Anyone claiming to have "measured" the motion of the earth would have been mocked as a total fool, because his premises would have been rejected out of hand.
Mach, by the way, explicitly said, in the 20th century, that geocentric and heliocentric views of the solar system were "equally valid." If my recollection isn't mistaken, Einstein made the same statement along about 1918 or 1920, in his reply to objections by his critics.
These are philosophical claims, at bottom. Just to be clear about my position, I do NOT believe that all philosophical claims are "equally valid" simply because they are philosophical in nature, rather than empirical. Like the pigs in Animal Farm, some animals are more equal than others.
One Brow said: "My point was that Jack does not see himself to be synchronized with clock1, either. Jack sees clock1 running six seconds slower than Jack. An observer at clock1 would see Jack running six seconds behind clock1."
Once again, you revert to your own subjective definitions to "prove" your point. But your "point" is irrelevant, and your defintion is erroneous. Fowler says clocks 1 and 2 ARE synchronized and they are. Light delays do not change that, a point which Hogg tried hard to make, but which you basically denied when he made it too. Light delays do not change the fact that clock 1 MUST be reading 10 seconds now (the same as clock 2) if you "see it" as reading 4 seconds from 6 light seconds away.
If, for example, I know that a particular (defective) yardstick is actually only 35 inches long, then I will correct for that distortion when using it. I will say that 10 of them add up to 350 inches, not 360 inches as one would expect from an accurate yardstick. 350 inches is 350 inches and 360 inches is 360 inches regardless of what reading a "defective" yardstick might give you. 350 does not magically "become" 360 inches just because that's what you "see" on your yardstick(s).
Correcting for known discrepancies is an essential part of correct observation, as Hogg notes. You do NOT say 2 clocks which read the same time are not "synchronized" merely because they are a mile apart.
Again, this claim appears to just another instance of your failure to distinguish objective from subjective "reality."
Fowler basically ends up trying to do the same thing, and seems to think bringing in a "magic word" (i.e., "synchronized") somehow effects a substantive difference. It doesn't.
Basically he points out that, to Jill (not to Jack), clocks 1 and 2 do not appear to be synchronized. Fair enough, standing alone, but the whole example presupposes that Jill knows (has been told) that clocks 1 and 2 ARE synchronized in Jack's frame. Of course they don't appear to be synchronized to her, because her clocks are running at a different rate.
That's what SR tells you. Two clocks moving relative to each other will not(without further adjustments such as are made to clocks on GPS satellites) REMAIN synchronized after being set to the same time BECAUSE they are running at different rates.
Jill should not expect to see Jack's clocks to be synchronized with hers, because one of them is moving. That said, the mere fact that her clock did not remain synchronized with Jack's clocks say absolutely NOTHING about who is moving. To answer that question one must determine whose clock is running slower, knowing they are not "synchronized." That, in this case, is Jill's clocks, not Jack's. The lack of synchronization is, by itself, totally irrelevant to that queston.
aintnuthin said...
We have had a few discussions about subjective versus objective facts. Generally speaking, if I say an effect is "real" I mean objectively (not subjectively) real. What do you mean?
In this context, I mean that two different observers making the same measurements in the same manner from the same location will report the same result.
Hence I would say it does not "really" disappear even if it does "really" disappear for me, and me alone.
Agreed. I would not say it "really" disappears for you, it only subjectively becomes hard to see.
Likewise, I would say the demented hallucinations of a raving paranoid-schizophrenic are not "real" even though they "really" occur for him. They are not objectively real, only subjectively.
Agreed.
It seems to me that you want to say that both the content of the hallucination and the disappearance of the computer are "real, physical" changes.
I agree that it seems that way to you. I disagree that this is my intent.
But do you contend that they are objective, as opposed to merely subjective, changes?
The disappearnace of the computer and the voices of the schizophrenic are not objective.
One Brow said: "So, Jill does not see 10 seconds pass on clock 1, nor on Jack's clock."
1. Is she even looking at clock 1?
How would that change the reading of clock 1?
If so, after allowing for light delays, she would presumably see the exact same digital readouts as the clock shows.
If they both use relativity properly, both would predict that clock1 will show 4 seconds. That was the professors point.
2. Of course she does not see "10 seconds pass on clock 1," at least not if you believe the predictions of SR. The whole theorem of SR is that her clock is running at a slower rate because she it moving. If you expected her to see the same, you would effectively be denying the validity of SR.
You seem to think JIll would see 10 seconds pass on Jack's clock. Are you backing away from that? If clock1 and Jack and in a common inertial frame, and run at the same rate, why would she see 10 seconds on Jack's and not on clock1?
So now your definition of a correct observation (which contradict what one sees with his/her own eyes) is what is deduced by a mistaken "thinker?"
Jill is "mistaken" about the results of her measurements? How are measurements "mistaken"?
If 8 seconds have passed for her, then, of course, only 6.4 seconds will have passed for Jack IF(and only if) he is the one moving.
What does "passed for Jack" mean in this context? While Jack sees 10 of his seconds pass, he sees 8 seconds pass for Jill. When Jill sees 8 seconds pass for her, she sees 6.4 seconds pass for Jack. Is that what you meant?
He aint. And this is proven by the fact that the clocks in his frame show that 10 seconds have elasped in that frame, NOT 6.4 seconds. She "sees" this with her own eyes, and hence has no reason to think Jack's clock "really" shows that only 6.4 seconds have passed.
With her own eyes, she sees 4 seconds pass, but calculates an addiitonal light delay of 2.4 seconds based on the distance and relative speed, for a total of 6.4. Jill never sees ten seconds pass.
Ya see, Eric, we KNOW (because the prof posits it) that Jill, not Jack, is the one moving here. He knows it, and we know it because he tells us. But, now, for reasons we have discussed, he feels compelled to argue that Jill MUST remain deluded about the status of her motion.
Again, you confuse the ontological idea of who is realy moving with the epistemological idea that Jill can make no observations within her environment, or see any results in Jack's environment, that verifies she is moving as opposed to Jack.
You just said that the proposition that "you can't tell which of two objects is moving" is a "foundational principle" of SR. The math guy clearly denies this, and says it is the statement of a relationalist, not a relativist, position.
No, he doesn't. Feel free to find a quote where the "math guy" says you can run an experiment to see who is "really" moving.
But, of course, without responding to a thing he says, or quoting passages which you think qualify to clarify the many particular statements of his that I have quoted,
That would convince you? I think not. Still, I'll give it a try.
The first example, mentioned in a previous lecture, is what is called “Galilean relativity” and is nothing but Galileo’s perception that by observing the motion of objects, alive or dead, in a closed room there is no way to tell if the room is at rest or is in fact in a boat moving at a steady speed in a fixed direction. (You can tell if the room is accelerating or turning around.) Everything looks the same in a room in steady motion as it does in a room at rest.
Then we set up another frame of reference, moving at a steady velocity relative to the first one, and find that Newton’s laws are o.k. in this frame too. The point to notice here is that it is not at all obvious which—if either—of these frames is "at rest". We can, however, assert that they are both inertial frames, after we’ve checked that in both of them, a body with no forces acting on it moves at a steady speed in a straight line (the speed could be zero).
You'll find it in 23.1.
Just for fun, the title of Section 23.3: 23.3 You Really Can’t Tell You’re Moving!
From the mathpages guy, in the article on Dingle you quoted:
Hence Newtonian mechanics gives a distinguished place to a particular set of motions, called inertial motions, and to a particular equivalence class of space and time coordinate systems, called inertial coordinate systems. In the absolute-vs-relational debate, special relativity is squarely on the absolute Newtonian side, which is to say, special relativity is based on the principle of inertia no less than is Newtonian mechanics.
Notice it is the entire set set of motion, not an individual motion, an entire set of coordinate systems, not an individual coordinate system.
Throughout all of Dingle’s writings, at least from 1921 until about 1959, we can see that he was laboring under the mistaken belief that Einstein’s theory of relativity was the embodiment of Leibnizian relationism, whereas in fact it is fully in the Newtonian tradition of absolute inertia.
Inertia, not motion, is absolute.
As the math guy noted, the principle of inertia was "anathema" to Liebniz, and others. Conservation of energy, momentum, and all related notions stem from Newton's laws of motion, which are based on inertia (which also give you a method of ascertaining which of two objects is really moving).
Bzzzzzzz. Wow, that's a really fundamental error. Inertia is resistance to *acceleration*. It tells you nothing about which of two inertial objects is really moving. Nada, zip.
Relationalism: all motion is determinined by the relations between bodies
Relativism: Acceleration (and inertia) are absolute, but velocity and postion are relative
Absolutism (I disagree with the mathpages usage in the Dingle article): velocity is absolute.
We do? I could have sworn that you claimed the opposite.
I may have, at one point. We've had many pages of discussion, and not just in this thread. Currently, my understanding is that you can travel different paths in space (or spacetime), and so travel a different distance to get between two points.
Do you recall this exhange?
Somewhat. That's a more naive way of looking at it. At any rate, that must be at least a few months old. I have amended that position since then in this thread.
Oh, I forgot. According to you, I'm completely inflexible in my positions and never change them (even after acknowledging I have altered them), while you are completely willing to change your opinions according to evidence (even though they have shown no sign of change).
Yeah, and if a biological male claims he is not a male, but rather a female by birth, then he is a female, too, I spoze.
Yawn. It must be difficult for you that I refuse to characterize myself acording to the categories you have pre-determined.
The "motion of the earth" was "carefully measured" if, and only if, you presume certain things about the nature of "reality."
Which changes nothing about the re-wrinting of history. I agree if you want to throw homogeneity and isotropy out the window, youcan put together any sort of system you like, but the result is not science, because homogeneity and isotropy are fundamental assumptions of science. However, if you want to keep them, then geocentrism must go.
"Jack sees clock1 running six seconds slower than Jack. An observer at clock1 would see Jack running six seconds behind clock1."
Once again, you revert to your own subjective definitions to "prove" your point.
What is subjective about what I said? You seem to be confusing "subjective" with "physical measurments from a specific location". They are not the same.
Fowler says clocks 1 and 2 ARE synchronized and they are.
I agree. You can use the real synchronization, and you can use the objective measurements that Jack makes, as long as you are carefule to separate them. However, when you mix and match them willy-nilly, you get nonesense.
Light delays do not change the fact that clock 1 MUST be reading 10 seconds now (the same as clock 2) if you "see it" as reading 4 seconds from 6 light seconds away.
Of course. The clock is 6 light-seconds away from jack, and 2.4 light-seconds away from Jill.
Correcting for known discrepancies is an essential part of correct observation, as Hogg notes. You do NOT say 2 clocks which read the same time are not "synchronized" merely because they are a mile apart.
If they are synchronized, they will not read the same expect to an observer who is the same distance between them. You are again confusing what is know with what is seen.
Basically he points out that, to Jill (not to Jack), clocks 1 and 2 do not appear to be synchronized. Fair enough, standing alone, but the whole example presupposes that Jill knows (has been told) that clocks 1 and 2 ARE synchronized in Jack's frame. Of course they don't appear to be synchronized to her, because her clocks are running at a different rate.
Are you saying Jill observes, or sees, clock1 and clock2 (Jack's clock) to be running at different rates?
Two clocks moving relative to each other will not ... REMAIN synchronized after being set to the same time BECAUSE they are running at different rates.
Why would that desynchronize clock1 and clock2? They are in the same inertial frame.
One Brow sais: "You'll find it in 23.1."
You have your authors confused. I'm not talking about Fowler from UV (who here recites the standard Dingle fare), I am talking about the author at mathpages.com.
Fowler's "summary" of what Gallileo said is inaccurate and inconsistent with what Galileo did in fact say, as I have pointed out before. He has obviously been influenced by the mistaken Dingle mindset.
To simplistically over-generalize Gallileo's statement about a closed cabin is absurd, yet Fowler and others rountinely mischaracterize what Galileo said to suit their purposes.
Galileo explicitly stated that the observations made in the sheltered cabin of ship would be different if one were on deck, rather than sheltered. Fowler and others try to pretend that this distinction doesn't exist, but their pretense is not an honest reiteration of Galileo's statements on the topic.
My computer screen "disappears" when I close my eyes (i.e., deliberately cut off all my access to external objects) yet reappears when I open them (actually avail myself to empirical information). The same is true of Galileo's "you can't tell who's moving" scenario. He says that on the deck of the ship you can tell if it moving relative to the shore by merely looking.
Once again, I am not referring to Fowler. Did you even read the mathpages article I cited?
aintnuthin said...
Once again, I am not referring to Fowler. Did you even read the mathpages article I cited?
I quoted twice from the article on Dingle you linked.
I made a point responding to your statement about inertia (nada) which failed to post. It was somewhat lengthy and I'm not going to recompose it. I assume it is in the spam bin.
In short, your "nada" claim is mistaken.
I said: "Two clocks moving relative to each other will not ... REMAIN synchronized after being set to the same time BECAUSE they are running at different rates."
One Brow asked: Why would that desynchronize clock1 and clock2? They are in the same inertial frame.
I clearly said that it does NOT desynchronize clocks 1 and 2, which are, and which remain, synchronized with each other the whole time
Jill's clock will not stay synchronized with clock 1, even if they are intially set to read the same time, because her clocks are running at slower rate, due to her motion. That's the point.
One Brow said: "At any rate, that must be at least a few months old. I have amended that position since then in this thread.
Oh, I forgot. According to you, I'm completely inflexible in my positions and never change them."
1. It was a few weeks ago, not months, and a part of that exchange appears on this page (I have pasted it below).
2. You can change your mind every day, I don't care, but don't expect me to know it if you don't tell me.
Me: Every account I've every seen of the lorentzian length contractions says it applies to "objects." Leave it to the metaphysical cult of minkowski geometricians to treat space as an "object" which shrinks, eh?
You: No, not being treated as an object, and nbot metaphysical. Just shrinking, and physical.
Me: Why does space "contract?" Because some guy somewhere is moving, that's why.
You: The contraction is a reflection of the different orientations in spacetime from different inertial states
Sidenote: Eric, just look at that last "explanatory" sentence of yours. Stringing together a bunch of words that are devoid of any apparent meaningful content is not helpful.
One Brow said: "If they both use relativity properly, both would predict that clock1 will show 4 seconds. That was the professors point."
That was the point he "tried" to make but have you analyzed it? It is full of sophistical equivocation and other fallacious claims.
"If she knew her SR," then she would simply know she is the one moving, and not engage in specious, convoluted, rationalized to deny that she is moving.
But, of course, for Fowler, "knowing your SR" includes the"requirement" that all observers in all examples insist they are motionless, even when they have a million good reasons to believe and know that they are not.
One Brow said: "I agree. You can use the real synchronization, and you can use the objective measurements that Jack makes, as long as you are carefule to separate them. However, when you mix and match them willy-nilly, you get nonesense."
I agree completely with your last sentence, and your awareness of this should make it easy for you to spot the flaws in Fowler's claim that Jill will "predict" that the first clock will read 4 seconds (even though she has already erroneously predicted otherwise). He begins to mix and match frames of reference willy nilly in order to appear to "properly" reach the conclusion he is determined to reach. This, of course, is in addition to bringing in totally irrelevant and factors as an "explanation."
I said: The "motion of the earth" was "carefully measured" if, and only if, you presume certain things about the nature of "reality."
You said:Which changes nothing about the re-wrinting of history.
One thing that you would have to assume in order to carefully measure the motion of the earth is that's the earth's motion can be detected. I agree that it can, but according to the Dingle brand of "relativity" (relationalism), which you claim to subscribe to, it is impossible to tell if an object is moving.
How can you reconcile your claim that the motion of the earth has been "measured" with your assertion that you cannot tell if a particular object is moving.
To the extent that denying the measurability of the motion of the earth "re-writes history" doen't the Dingle/Fowler version blatantly "re-write history?"
I said: The "motion of the earth" was "carefully measured" if, and only if, you presume certain things about the nature of "reality."
You said:Which changes nothing about the re-wrinting of history.
One thing that you would have to assume in order to carefully measure the motion of the earth is that's the earth's motion can be detected. I agree that it can, but according to the Dingle brand of "relativity" (relationalism), which you claim to subscribe to, it is impossible to tell if an object is moving.
How can you reconcile your claim that the motion of the earth has been "measured" with your assertion that you cannot tell if a particular object is moving.
To the extent that denying the measurability of the motion of the earth "re-writes history" doen't the Dingle/Fowler version blatantly "re-write history?"
I said: The "motion of the earth" was "carefully measured" if, and only if, you presume certain things about the nature of "reality."
You said:Which changes nothing about the re-wrinting of history.
One thing that you would have to assume in order to carefully measure the motion of the earth is that's the earth's motion can be detected. I agree that it can, but according to the Dingle brand of "relativity" (relationalism), which you claim to subscribe to, it is impossible to tell if an object is moving.
How can you reconcile your claim that the motion of the earth has been "measured" with your assertion that you cannot tell if a particular object is moving.
To the extent that denying the measurability of the motion of the earth "re-writes history" doen't the Dingle/Fowler version blatantly "re-write history?"
Heh, this website acts strangely sometimes. Often if will not display a post at all. Now it repeats the same post several times. You might think it would recognize multiple posts with the exact same content as "spam," eh?
One Brow asked:"Are you saying Jill observes, or sees, clock1 and clock2 (Jack's clock) to be running at different rates?"
I am simply saying that Jill's clock will not remain synchronized with clock 1 even though they were just recently "synchronized" to read the same time. No more, no less. Beyond that, what irrelavancies she might "deduce" with fallacious logic is something you would have to ask her about, not me.
I said: You just said that the proposition that "you can't tell which of two objects is moving" is a "foundational principle" of SR. The math guy clearly denies this, and says it is the statement of a relationalist, not a relativist, position.
You said: No, he doesn't. Feel free to find a quote where the "math guy" says you can run an experiment to see who is "really" moving.
By your way of reasoning, Eric, if the math guy doesn't explicitly say there is no Santa Claus, then he is saying there is a Santa Claus.
He explicitly points out that the galilean/einstienian "principle of relativity" does not say that all motion is relational, and that it merely addresses the laws of physics.
What does he mean by "relational" or "not relational?" That is clearly explained by him, too:
"Leibniz maintained that...any object could, with equal justification, be regarded as being continually at rest...Newton argued (by means of the famous spinning pail experiment, for example) that arbitrary motions are not all equivalent...
====
Mathguy says:"Einstein’s theory of relativity was the embodiment of Leibnizian relationism, whereas in fact it is fully in the Newtonian tradition of absolute inertia."
From this, you fallaciously conclude that "Inertia, not motion, is absolute."
Mathguy is merely saying that inertia plays a crucial role in our determination of what is moving.
Dingle says: "There is no meaning in absolute motion." [Notice Dingle does NOT say "there is no meaning to "absolute inertia"].
In response to Dingle's claim about MOTION, the mathguy says: "...what Dingle actually articulated was the antithesis of relativity, namely, the principle of relationism."
Mathguy brings in inertia to show the MEANS by which Newton argued that all objects cannot, as Liebniz claimed, "with equal justification, be regarded as being continually at rest."
He says that in opposing Liebniz's claim "[Newton] made the case for absolute motion – a case that essentially amounts to the assertion of Galileo’s principle of inertia." [Note that he says Newton is making a case for "absolute motion," not "absolute inertia"].
I have long observed that you will always superficially and selectively misread any article I cite you to in order to convince yourself that all experts always agree with you. Why I bother citing anything to you is a question I have trouble answering.
How is inertia relevant to motion? Well, for one thing, it is one of 3 of Newton's basic laws of motion which, taken together, provide us with our mechanics or "laws of motion." Al explicitly ratified these laws, saying they held good in inertial frames. Of course if Al believed that motion can't be detected, then he would presumably reject, not affirm, any "laws" which purports to identify and explain the undetectable.
But let's go on. A batter at home plate bashes a baseball. As a consequence, the ball begins to get closer to the outfield wall, and farther away from the batter and home plate. How can you possibly say that the baseball is not motionless, while the batter and wall are moving?
Perhaps the stupidest question you could possibly ask of a person who relies on common sense and inertia and does not become confounded by ill-advised philosophical propositions (of the "brain in a vat" variety). The law of inertia tells you that neither the ball, the outfield wall, nor home plate, can just decide, on their own, to just change the state of their pre-existing motion at will. An independent force is required for that.
If, unlike Liebniz, you do not find inertia to be 'anathema" then you might ask yourself a couple questions:
1. Has a force been applied to the baseball? If so, what is it?
2. Has a force instead been applied to the wall, home plate, the bleacher seats, and everything else on the planet within eyesight? If so, what is it.
If you concede that a force must have been applied to either the baseball or everything else, then it is certainly is not "equally valid" to conclude that the baseball remains at rest as it is to conclude that the baseball has been absolutely accelerated by the application of a force.
I actually feel like a damn fool taking the time to "explain" the most obvious thing imaginable to a person who can't imagine the obvious.
Anonymous said...
I made a point responding to your statement about inertia (nada) which failed to post. It was somewhat lengthy and I'm not going to recompose it. I assume it is in the spam bin.
In short, your "nada" claim is mistaken.
Sorry, not in the spam box. If you did not repost the information, feel free to do so. If you're trying to prove absolute inertia implies being able to say something about who is "really" moving, it should be good for a laugh.
One Brow said:"Bzzzzzzz. Wow, that's a really fundamental error. Inertia is resistance to *acceleration*. "
Wow, that's a really fundamental error. MASS, not inertia, is resistance to acceleration. Inertia is merely the tendency of an object to maintain whatever speed and direction it currently has. It takes a force to overcome this tendency. An object in an inertial state is not thereby "resisting" acceleration, it simply is not accelerating of its own accord.
In F=MA, it is the "M" (for mass) which measures the resistance to acceleration, not "inertia."
I'll get to the rest tomorrow, but wanted to respond to this tonight.
Wow, that's a really fundamental error. MASS, not inertia, is resistance to acceleration.
Actually, both are. I'll quote from the first sentence of the wikipedia page, but it you don't trust that, find a source you condiser authoritative.
Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass.
"change in motion" = acceleration.
Inertia is merely the tendency of an object to maintain whatever speed and direction it currently has.
If this tendency has a size associated with it (and it does), it is a measure of resistance to acceleration.
It takes a force to overcome this tendency.
If it takes a force to overcome that tendency, how is that not "resistance"?
One Brow said: "Actually, both are. I'll quote from the first sentence of the wikipedia page..."
Well, I'm really not serious about exact word useage, but "mass" is resistance to acceleration, and, when pushed, physicists tend to equate mass with "matter." It is a different concept than inertia, which is not identified with matter.
Wiki notes these distinctions, and distinguishes common, or "lay" useage, from scientific use of the term "inertia," as follows:
"In common usage the term "inertia" may refer to an object's "amount of resistance to change in velocity" (which is quantified by its mass), or sometimes to its momentum, depending on the context. The term "inertia" is more properly understood as shorthand for "the principle of inertia" as described by Newton in his First Law of Motion; that an object not subject to any net external force moves at a constant velocity."
Notice that Newton's definition refers to "motion," not resistance to it. The point here is that objects don't just haul off and start moving, willy-nilly, on their own accord for unknown and unpredictable reasons. They must be accelerated by a force. This is how we know that it is the "space twin" who's moving, not the earth twin. As wiki further notes:
"the principle of inertia is intimately linked with the principles of conservation of energy and conservation of momentum."
Don't you, yourself, rely on the principle of conservation of momentum to argue for a heliocentric over a geocentric theory? That is just one way by which "inertia" helps us detect motion.
I said: "This is how we know that it is the "space twin" who's moving, not the earth twin."
I'm pretty certain that the vast majority of people agree with me when I say that anyone who tries to argue that there's no way to tell whether the space ship moves away from the earth or the earth moves away from the spaceship while it remains motionless, is nothing more than a stubborn, ignorant jackass without a lick of common sense.
The same would be true of any jackass who tried to hedge and just claim that "we can't be sure" which one is moving.
You might think that anyone who feels that it is necessary to resort to raging jackassery in an attempt to support his preferred philosophy and to import that philosophy into physical theories might stop for a minute to reflect on what they are claiming, but, noooooooo.
No matter where we are, we always see water boiling by virtue of the same observation--bubbles start forming when the external pressure equals the internal pressure.
The boiling temperature is ABSOLUTE. Once liquid water reaches it boling point, the water will NEVER get any hotter, no matter how much additional hear you apply.
By way of analogy:
SR: This proves that the magnitude of a degree centigrade changes every time you move your elevation up or down by even a fraction of a millimeter.
LR: There is no reason to have an infinite number of different scales of degrees with different values. Just set a standard elevation, say sea level, for the 100 degree mark on your thermometer, and acknowledge that water boils at different absolute temperatures depending on elevation. Just say it may boil at 90 degrees C at 10,000 feet, ya know?
SR: The boiling is strictly relative, so you must have an infinite number of scales, even if this approach is the equivalent of having no scale or "standard" at all.
LR: Yeah, right.
=====
If you are watching a guy chop wood from a half a mile away, the sound made by the ax hitting the wood will not appear to be "synchronized" with the striking motion itself. The guy may have re-raised the ax completely over his head again before you the sound of the last strike, and this will just keep happening.
SR: This proves that simultaneity is relative. If you, subjectively, don't perceive the strike and the sound simultaneously, then they couldn't have happened simultaneously. Simultaneity simply has no meaning.
LR: Yeah, right, solipsist.
If a cesium clock is sent into space on a GPS satellite unadjusted, it will, because it's atoms are oscillating at a slower rate, soon be hopelessly out of sync with a "stationary" earth clock and the system would be unworkable.
However, by tinkering with the way it's readout registers the passage of time, you can make it stay synchronized with an earth clock indefinitely.
My question is this: When the guys back at the NASA lab (or wherever it's done) adjust the space clock, do they also somehow make the "pointing arrows" which indicate the angle of incidence on a piece of Minkowski graph paper start "pointing" a different way, too?
It's only fair to tell you I've stopped taking this conversation seriously. I have no expectation of getting you to recognize your misunerstandings, and you misunderstand my position to a degree so fundametal that you really aren't arguing with me at all.
aintnuthin said...
Fowler's "summary" of what Gallileo said is inaccurate and inconsistent with what Galileo did in fact say, as I have pointed out before. He has obviously been influenced by the mistaken Dingle mindset.
No doubt Fowler feels free to interpret Galileo within modern physics, emphasizing agreements. He is not speaking as a historian.
Galileo explicitly stated that the observations made in the sheltered cabin of ship would be different if one were on deck, rather than sheltered.
Among other things, there would be wind. It's not relevant to SR.
I clearly said that it does NOT desynchronize clocks 1 and 2, which are, and which remain, synchronized with each other the whole time.
In some third-person omnisicent fashion, perhaps. Jack does not see clock1 and clock2 as being synchronized. They run in parallel, but show different times.
2. You can change your mind every day, I don't care, but don't expect me to know it if you don't tell me.
If we are discussing expectations, I don't expect you to know even when I do tell you, based on past experience.
You: The contraction is a reflection of the different orientations in spacetime from different inertial states
Sidenote: Eric, just look at that last "explanatory" sentence of yours. Stringing together a bunch of words that are devoid of any apparent meaningful content is not helpful.
It wqas a highly simplified dscription of the physical reality, but not devoid of meaningful content. Further, since I believe you understand the different phrases individually (correct me if there is a specifc phrase you find confusing or unintelligible), you seem to think that the combination has no physical interpretation.
It's interesting. You agree that separation between object in space is a real thing, but that the notion of distance is an abstraction of that. Yet, you are wedded to some notion that this abstraction of distance is absolute, and can't change.
That was the point he "tried" to make but have you analyzed it? It is full of sophistical equivocation and other fallacious claims.
I'm well aware of your opinion of it.
... to deny that she is moving.
whether Jill is moving or not is not relevant to Fowler's point.
... insist they are motionless, ...
Again, the motionlessness is irrelevant.
I agree completely with your last sentence, and your awareness of this should make it easy for you to spot the flaws in Fowler's claim that Jill will "predict" that the first clock will read 4 seconds (even though she has already erroneously predicted otherwise).
Both are correct. Jill's prediction that the clock reads 6.4 seconds (in some third-person omniscient sense) is correct. Jill's prediction that she sees the clock reading 4 seconds is correct.
Dingle brand of "relativity" (relationalism),
Yawn.
which you claim to subscribe to,
You seem to confuse "claim" and "deny".
...it is impossible to tell if an object is moving.
You seem to confuse "tell" and "determine by experiment".
... the Dingle/Fowler ...
Fowler doesn't adopt Dingle's viewpoint.
Heh, this website acts strangely sometimes. Often if will not display a post at all. Now it repeats the same post several times. You might think it would recognize multiple posts with the exact same content as "spam," eh?
I can see why so many people move on to wordpress or similar sites.
I said: You just said that the proposition that "you can't tell which of two objects is moving" is a "foundational principle" of SR. The math guy clearly denies this, and says it is the statement of a relationalist, not a relativist, position.
You said: No, he doesn't. Feel free to find a quote where the "math guy" says you can run an experiment to see who is "really" moving.
By your way of reasoning, Eric, if the math guy doesn't explicitly say there is no Santa Claus, then he is saying there is a Santa Claus.
By your way of reasoning, if the mathpages guy does not explicitly endorse a position, he has clearly denied it. If you had said that the mathpages guy at no point in the Dingle article explicitly endorses the statement that you can't experimentally determine which of two objects is moving, that's something I would take your word on. when you claim he has clearly denied something, I would expect you to provide a clear denial, not a Santa Claus metaphor.
He explicitly points out that the galilean/einstienian "principle of relativity" does not say that all motion is relational, and that it merely addresses the laws of physics.
Nor does the claim that "you can't tell which of two objects is moving" say that all motion is relational. That statement is also within the sphere of absolute inertia.
Mathguy is merely saying that inertia plays a crucial role in our determination of what is moving.
show me the math, then. You have two objects moving inertially in different states. Show me where the concept of absolute inertia allows you to determine which of those objects is really moving.
Mathguy brings in inertia to show the MEANS by which Newton argued that all objects cannot, as Liebniz claimed, "with equal justification, be regarded as being continually at rest."
Right, the spinning pail can't be at rest. Now, apply the reasoning to two different objects in different inert5ial states, if you can.
He says that in opposing Liebniz's claim "[Newton] made the case for absolute motion – a case that essentially amounts to the assertion of Galileo’s principle of inertia." [Note that he says Newton is making a case for "absolute motion," not "absolute inertia"].
And them equates it to absolute inertia.
Why I bother citing anything to you is a question I have trouble answering.
Since you cite what you don't understand, your confusion is natural.
But let's go on. A batter at home plate bashes a baseball. As a consequence, the ball begins to get closer to the outfield wall, and farther away from the batter and home plate. How can you possibly say that the baseball is not motionless, while the batter and wall are moving?
The ball accelerated. Of course is it moving at some point, whether or not the batter and the wall are.
If you concede that a force must have been applied to either the baseball or everything else, then it is certainly is not "equally valid" to conclude that the baseball remains at rest as it is to conclude that the baseball has been absolutely accelerated by the application of a force.
Applicaton of force over time is energy. So, you are applying the conservation of energy to determine who is moving, which I have stated all along is appropriate.
I actually feel like a damn fool taking the time to "explain" the most obvious thing imaginable to a person who can't imagine the obvious.
Yet, you don't feel like a damn fool explaining to me what I have used as an explanation all along. Curious.
"In common usage the term "inertia" may refer to an object's "amount of resistance to change in velocity" (which is quantified by its mass), or sometimes to its momentum, depending on the context. The term "inertia" is more properly understood as shorthand for "the principle of inertia" as described by Newton in his First Law of Motion; that an object not subject to any net external force moves at a constant velocity."
Notice that Newton's definition refers to "motion," not resistance to it.
Do you think the use of "constant" in that description is relevant or superfluous? After all, if inertia only refers to constant velocity, that means it is resisting acceleration.
"the principle of inertia is intimately linked with the principles of conservation of energy and conservation of momentum."
Don't you, yourself, rely on the principle of conservation of momentum to argue for a heliocentric over a geocentric theory? That is just one way by which "inertia" helps us detect motion.
Yet, not one refers to the momentum or the energy of a system as absolutes, just as conserved.
My question is this: When the guys back at the NASA lab (or wherever it's done) adjust the space clock, do they also somehow make the "pointing arrows" which indicate the angle of incidence on a piece of Minkowski graph paper start "pointing" a different way, too?
Since the guys as NASA control the pointing arrows on the graph paper, why wouldn't they?
folks, I'm sorry I'm not getting enough spare time to follow this discussion. But I've been thinking about it while I've been watching the floods around my place, throwing a sandbad in some gap that would cause a lot of trouble if it got going strong. . . .
If I hijack a photon and ride off it's not going to change the speed of that water.
If a philosopher on the other side of the universe hijacks another photon, it's not going to give me any more time to deal with my problems. . . .
The problem with all this talk about different clocks is just this. There has to be a uniform "time" which pertains to everything in this universe, or even elsewhere. Nobody/nothing can hitch a ride to a different time.
That truth is intuitive, self-evident. All we humans, "brain in a vat" or not, are just deluding ourselves with "explanations" based on any notion of "time" that is not uniform and coherent in all existence.
Just my opinion. If our "laws of physics" as contemplated using our mathematical tools don't get us to that conclusion somehow, the right conclusion to make is that our "laws" or "math" is in error.
makes as much sense shape-shifting the laws or math as it does to shape-shift "time".
one of the incongruities of trying to compare clocks held by observers with varying motion, and trying to figure out how the rate of time is changing, or the "absolute" time being shown on the moving clocks will vary. . . . is however regulated, the clocks are not reality in and of themselves. . . . . reality is just what is "out there". . . . now.
Thus for us to make any meaningful observations about time, or more precisely about now, and how things have progressed to, or will progress from, "now", we have to be making an axiom essentially that the "now" that exists "out there" is the same for the entire domain, for the entire universe, for the entire "existence" however existing anywhere, everywhere.
Still it is just this idea of "now" that we imagine connects it all in a format that can be subjected to observation or testing and "knowing".
How does this relate to the difficulties, philosophical or otherwise, in asserting the validity of any humon comprehension of "morality" whether objective or mystical?
Just as we assume congruous "time" we assume congruous "right" or "wrong". To say there is none is like saying there is no "time".
Just as "God" is presumed to have spoken a word, and the universe came into existence, we are presumed to have the god-like power to compose morals in the absence of any God who can arguably be believed in for having beat us to it.
Funny thing is, if we don't just postulate such a God and "believe", we have in that "failure to assume" simultaneously made the positive assertion that we, in God's sted as some would paint it, are empowered to assert our own morals, our own version of "right" and "wrong".
Perhaps Ain't is closer to his Ambrose Bierce quotations.
Here is my loose rendition of one:
"Lufifer, having made himself multifariously objectionable in heaven, was cast down to Earth. As he fell, he begged for one request. "What is that?" God answered.
"Man will soon be also going to earth. He will need laws. . . ." Satan began. . . .
"What!", God exclaimed, "You, the sworn enemy of Mankind. . . . want to make his laws?" with marked indignation. . . .
"No", Satan replied. "I wish that man should be permitted to make his own laws."
The request was granted.
Well, that's the sense of what Ambrose Bierce wrote I believe. And I share the pathos of that reality. . . . and can only hope God somewhere, sometime, did indeed establish a better set of laws by which we might one day hope to be judged. . . .
The idea of God should properly be studied much as we study and reflect on the idea of time.
A consistent field theory of the universe with one pervasive unifying truth which perhaps we might one day comprehend.
Well, actually, that is the very premise of science, come to think of it.
babe,
Sorry for the delay in getting back to you.
babe said...
If I hijack a photon and ride off it's not going to change the speed of that water.
Speed is relative. If you hijack a photon and ride off at the speed of light, it won't change the speed of the water relative to the ground.
There has to be a uniform "time" which pertains to everything in this universe, or even elsewhere.
Why?
That truth is intuitive, self-evident.
Intuition is used to justify homeopathy and accupuncture. It's not a reliable source of information.
Just my opinion. If our "laws of physics" as contemplated using our mathematical tools don't get us to that conclusion somehow, the right conclusion to make is that our "laws" or "math" is in error.
The "laws of physics" are the simplest explanation we have for the observations we have made. You can replace them with other laws, but you won't get something closer to your intuition.
Thus for us to make any meaningful observations about time, or more precisely about now, and how things have progressed to, or will progress from, "now", we have to be making an axiom essentially that the "now" that exists "out there" is the same for the entire domain, for the entire universe, for the entire "existence" however existing anywhere, everywhere.
Physicists have been able to say many meaningful things about what is "out there" without needing a "now" that is the same for the "entire domain".
Funny thing is, if we don't just postulate such a God and "believe", we have in that "failure to assume" simultaneously made the positive assertion that we, in God's sted as some would paint it, are empowered to assert our own morals, our own version of "right" and "wrong".
Functionally, there is no difference. Even those who do postulate such a God assert their own morals, their own version of right and wrong, and put them in the mouth of their putative God.
Well, that's the sense of what Ambrose Bierce wrote I believe. And I share the pathos of that reality. . . . and can only hope God somewhere, sometime, did indeed establish a better set of laws by which we might one day hope to be judged. . . .
Perhaps one day They will share those laws with humans in an unambiguous fashion.
The idea of God should properly be studied much as we study and reflect on the idea of time.
Studying god in the manner most physicists study time would be anathema to most religious people.
A consistent field theory of the universe with one pervasive unifying truth which perhaps we might one day comprehend.
Well, actually, that is the very premise of science, come to think of it.
It's an ideal, which may never be reached.
One Brow said: "It's only fair to tell you I've stopped taking this conversation seriously. I have no expectation of getting you to recognize your misunerstandings, and you misunderstand my position to a degree so fundametal that you really aren't arguing with me at all.
One Brow said: "Since you cite what you don't understand, your confusion is natural."
Eric, when I saw comments like this I just chuckled at the typical display of your unwarranted conceit about your intellectual superiority and decided (once and for all, I thought) not to say another word in this thread, and I should not really bother making this post.
But now, browsing around Jazzfanz, I see your public declarations of your self-styled superiority and ability to judge my understanding such as this:
One Brow said: "The smartest people are useless when they don't have the experience adn training to propery interpret and apply their abilities. aintnuthin is a smart guy, but much of the time doesn't really understand what he is talking about enough to use his intelligence well."
Of course the fag contingent, such as Trout and Krazyeyez, jump right on that to high-five you, and their estimation of your brilliance may have now even increased to the point where they believe your claim to be "one of the three smartest people at Jazzfanz."
There is no need for me to respond, and I really shouldn't, but that kinda stuff is kinda provocative, ya know? Oh, well, at least my response is to your face and made in a personal forum where you can respond for your own satisfaction or for the presumed edification of any "listeners," such as Babe.
Frankly, Eric, I find you to be virtually without any substantial mental acuity. You strike me as a very plodding "thinker," who doesn't really think at all once he feels he has been adequately indoctrinated with the dogma propounded by "powers that be" in the fields of faith you choose to adhere to.
Like some religious fundie with an 8th grade education, you seem be utterly incapable of questioning or analyzing the articles of faith which you have adopted. Such people utterly fail to see even the slightest practical or logical problems raised by their dogma, even when such problems are severe in the eyes of infidels who do not share their faith. Such believers take the most simplistic, self-refuting "answer" to any such questions to be utterly dispositive of the issue. And, needless to say, for them the infidels are simply incapable of "understanding" the issues.
There is no possiblility of discussion with such types, which is why I never should have posted here to begin with.
You're welcome to your opinion, but don't think I share it or concede to your proclamations of superior understanding just because I didn't bother responding before.
Predictably, my opinion is about the opposite of yours. In my view, you have very little basic conceptual understanding of most of the things you faithfully believe in, precisely because your nature is not to think or strive to understand, but rather to assert and pose as an authority on who understands what.
If you were even 1/10th as smart as you like to act, pretend, and think that you are, you would make Einstien look like he should be riding the short bus.
Babe has made a couple of references to my "Bierce" quote. I have quoted Bierce on several topics, but I assume he means this one, which seems particularly germane at this point:
"Education is that which discloses to the wise and disguises from the foolish their lack of understanding."
aintnuthin said...
Such people utterly fail to see even the slightest practical or logical problems raised by their dogma,
If you showed the ability to accurate state my "dogma", I would take this conversation more seriously. Do you think you can make such a statement with precision, after over 1300 comments in this thread alone? Here's an easy one: name a substantive point of difference between my understanding of SR (or motion in general) and Dingle's. If you can do that, I will be happy to apologize for saying that you didn't understand this topic suffciently to use your intelligence well, both in this thread and in the thread on JazzFanz.
Eric, when I saw comments like this I just chuckled at the typical display of your unwarranted conceit about your intellectual superiority and decided (once and for all, I thought) not to say another word in this thread, and I should not really bother making this post.
As humans, we all let human nature get the better of us.
There is no need for me to respond, and I really shouldn't, but that kinda stuff is kinda provocative, ya know?
One man's compliment is another man's provocation. Yes, it was intended as a compliment and defense of your native intelligence, in addition to a frank appraisal of your deficiencies.
Oh, well, at least my response is to your face and made in a personal forum where you can respond for your own satisfaction or for the presumed edification of any "listeners," such as Babe.
It's not like I turned the conversation to you. You were already in it. However, if you prefer, I'll not say another word about you in JazzFanz, no matter how unfair I think a characterization of you is.
Frankly, Eric, I find you to be virtually without any substantial mental acuity.
I take that with all the merit you have earned.
You strike me as a very plodding "thinker," who doesn't really think at all once he feels he has been adequately indoctrinated with the dogma propounded by "powers that be" in the fields of faith you choose to adhere to.
When I asked you a about a series of occurences and how they would look under your interpretation of relativity, you punted. You couldn't be bothered to answer them. That is a characteristic of a plodder who feels he has adequate indoctrination and and dogma. I at least try to rise to the challenges you provide.
Such believers take the most simplistic, self-refuting "answer" to any such questions to be utterly dispositive of the issue.
Careful, your projection is showing.
You're welcome to your opinion, but don't think I share it or concede to your proclamations of superior understanding just because I didn't bother responding before.
I never made that mistake.
"Education is that which discloses to the wise and disguises from the foolish their lack of understanding."
I think we agree that this quote is very appropriate for this conversation.
Dingle seems to claim that acceleration in SR is "relative" and cannot be used to account for differences in motion of objects. This is precisely the claim you initally made on this topic (that, in SR, acceleration was "relative," not absolute). You appear to have abandonded that position, and in this respect, you differ from Dingle.
I have already pointed out other differences. Like Dingle, you mistakenly claim that the proposition that "you can never tell which of two inertial objects is moving" is a foundational principal of SR. It aint, and you are both wrong on that score, but...
Dingle at least sees that the resolution to the twin paradox is inconsistent with the (erroneous) claim that SR says you can't tell who's moving. You think the two are perfectly consistent.
I don't believe any respectble physicist would claim, in a considered statement, that there is no way to tell which of two objects is moving.
They would say that in a completely closed system where all resort to external information has been temporarily withheld, one could not, by conducting physical experiments within that closed system, detect if you were moving.
It should be noted that this, in itself, does not address two (or more) objects moving relative to each other. It simply relates to what one can discern about the motion of one object, absent external information.
Serious scientists are now regularly disputing this longstanding belief, claiming that it is possible, EVEN WITHIN an entirely closed system, to determine if the system is moving. These claims are often based on exploiting the knowledge that time runs at different rates which changes in speed.
One Brow said:"When I asked you a about a series of occurences and how they would look under your interpretation of relativity, you punted. You couldn't be bothered to answer them."
No, I did not "punt." I didn't want to get entangled with trying to understand your incomprehensible(as written) scenarios, and the inconsistent claims you were making about them.
I will say it again:
1. Under SR, as I understand it, it will be the moving clock which runs slower. If you don't have that information, then you can't answer the question, and
2. Such questions will NEVER have an answer under the mistaken interpretation that SR says you never know who's moving. No answer can be given until you abandon all pretense that "all motion is strictly relative," and resort to the basic premise of LR (i.e., that you must resort to a single time zone as the standard--in SR it's called "proper time") to even address the question.
A guy is on a sailboat and happens to notice that he is moving relative to the shore. He also notices that an appreciable wind is blowing and that his sails are fully billowed. Now:
1. Would his perceptions be identical if he were absolutely motionless and the shoreline was moving? Yes
2. Does that mean he can't tell if he is moving relative to the shore or if the shore is moving relative to him? No
3. Would any physicist have different answers to the first two questions? Very unlikely.
aintnuthin said...
Dingle seems to claim that acceleration in SR is "relative" and cannot be used to account for differences in motion of objects.
Technically, SR doesn't really consider acceleration at all, but you can use SR in scenarios that have acceleration.
This is precisely the claim you initally made on this topic (that, in SR, acceleration was "relative," not absolute). You appear to have abandonded that position, and in this respect, you differ from Dingle.
I apologize for saying you didn't have the background to understand the difference. I'll make the apology in JazzFanz the next time I log in. Yes, I was in error when I said you could never experiementally verify that you were under acceleration or in a gravitational field, as you can experiementally verify the difference between rotational acceleration and a gravitational field.
I have already pointed out other differences. Like Dingle, you mistakenly claim that the proposition that "you can never tell which of two inertial objects is moving" is a foundational principal of SR.
Actually, that's never been a position of mine in the most general sense, nor have I said it was a position of SR. Here, it is you conflating "never tell" with "never experiementally verify". I'll just snip the paragraphs where you continue to assume the first when the second is meant.
They would say that in a completely closed system where all resort to external information has been temporarily withheld, one could not, by conducting physical experiments within that closed system, detect if you were moving.
It should be noted that this, in itself, does not address two (or more) objects moving relative to each other. It simply relates to what one can discern about the motion of one object, absent external information.
Let's say you can see your own closed environment, and another closed environment (such as two spaceships), and therefore can determine relative motion. What experiment can you run to determine which of the two objects is really moving? Use any instruments you want (clocks, scales), and describe the oberservations that lead you to make this determination.
Serious scientists are now regularly disputing this longstanding belief, claiming that it is possible, EVEN WITHIN an entirely closed system, to determine if the system is moving. These claims are often based on exploiting the knowledge that time runs at different rates which changes in speed.
Until they (or like-minded individuals) conduct experiments that can verify this, they are not serious scientists. They may be serious, and they may be scientists, but the combination of words doesn't apply.
No, I did not "punt." I didn't want to get entangled with trying to understand your incomprehensible(as written) scenarios, and the inconsistent claims you were making about them.
I didn't make any claims, I asked you questions. When you asked for a clairification, I reworded the ones you wanted clarified. I would have been happy to do so again. Instead, you could not be bothered to examine the results of your position as applied to different situations. For that matter, you could still go back and provide your own answers.
1. Under SR, as I understand it, it will be the moving clock which runs slower. If you don't have that information, then you can't answer the question, and
I reworded the questions to say specifically which clocks were moving slower and more quickly.
2. Such questions will NEVER have an answer under the mistaken interpretation that SR says you never know who's moving.
Except, they do as long as acceleration is treated as an absolute. This is where you mistakenly adopt Dingle's position.
No answer can be given until you abandon all pretense that "all motion is strictly relative,"
Of course not all motion is not relative. Acceleration and higher levels of change in motion are not relative, so obviously all motion is not relative.
and resort to the basic premise of LR (i.e., that you must resort to a single time zone as the standard--in SR it's called "proper time") to even address the question.
As long as the answer is based on an observation is a single locaiton at a single time, it is identical to every inertial frame, regardless of which frame is "really" not moving, in standard, mainstream SR.
I wasn't requesting an apology, but thanks for acknowledging that you didn't precisely understand what I understand (or don't).
One Brow said: "Actually, that's never been a position of mine in the most general sense, nor have I said it was a position of SR."
Really? You sure could have fooled me or anyone else who has read every post you have made in this (and the prior thread) over the last year or two.
Just recently you claimed that although SR supposedly takes "no position" on Galileo's claim that, by looking at the shoreline, a moving sailor could tell if he was moving. The same with a bug in a ship’s cabin (which I compared to a train riding on tracks across the open plains). An excerpt:
I said: "Galileo did NOT say that if you were in a closed ship cabin, you would have no way of knowing whether a bug moving across the cabin floor was really moving with respect to the cabin or if the bug was actually motionless while the ship moved."
One Brow said: "Not really relevant."
I said: “Not really revelant to what? Your philosophy? It's quite relevant to the issues I'm raising, but, of course, if you can't, or won't, understand those issues, you won't see the relevancy of anything which relates to them.”
You said: “Mainstream SR, which takes no position on whether the bug or the ship is really moving.”
Most recently, and perhaps most directly on point, is this exchange:
I said: “If you want to argue that "it's impossible to tell who's moving," then argue that. But try to understand that such a position has NOTHING to do with the predictions of SR.
You said: “You mean, outside of being one of the two foundational principles of SR.”
I swear, Eric, I pay more attention to what you say in this thread than you do. Which is probably one reason that I see apparent inconsistencies while you see none. You don't even remember your recent claims.
Aristotle, misled by appearances and not understanding forces of fricton and gravity, etc., believed that an object would continue to move only so long as the original "impetus" imparted to it remained undepleted. In order for an object to move continuously and indefinitely, a continous and indefinite "impetus" must be supplied, Aristotle said.
As I have previously noted, Galileo's "parable of the ship" was NOT designed to create an independent "principle of relativity" by any means. It was designed to explicate his novel noton of "inertia." After talking about butterflies scurrying about and fish swimming in bowls in the cabin of a moving ship, he noted that nothing would be different in this respect if the ship were sailing at sea or docked in port. The reason, he said, is that all objects in the cabin shared in the "common motion" of the ship, and hence no relative effect of motion could be detected. The butterlies did not have to flap their wings like crazy just to keep up with the ship, even though they were detached from it.
Newton's first law of motion (yes, motion) exploited this insight, and his other laws were founded upon it.
Einstien fully ratified Newton's laws of motion, and Galileo's insight that the motion of an object, such as a ship, does not change those laws.
SR is completely in the Galilean/Newtonian tradition in this respect. Therefore it definitely DOES take a position on whether (and even how) you can tell which of two objects is moving.
All your repeated assertions about what positions "mainstream SR" takes on such matters are merely a recitation of conclusion based on erroneous understandings of SR, such as those widely promulgated by Dingle, and many others like him.
One Brow said: "Let's say you can see your own closed environment, and another closed environment (such as two spaceships), and therefore can determine relative motion. What experiment can you run to determine which of the two objects is really moving? Use any instruments you want (clocks, scales), and describe the oberservations that lead you to make this determination."
Not sure what you're asking here. You are not in a "closed system" if you can see another "closed system."
Let me substitute a couple of other "closed systems" for your spaceships. Let's consider the earth, the sun, and the fixed stars. Since we can see these, our system is not "closed" in that sense.
How do we know that the earth is orbiting the sun and not vice versa? How do we know that the earth is rotating on it's axis rather than remaining motionless while the fixed stars whirl around it every 24 hours and the visible constellations in the zodiac change on a predictable, recurring basis.
The answers are obvious, aren't they? Foucalts' pendulum. Stellar aberration, etc. But, of course, you must have perceptual access to these other "systems" in order to draw the logical deductions those observations imply (the exception perhaps being Foucalt's pendulum).
More generally, if a travelling twin gets his ass blasted off into space via tremendous acceleration, then later settles into uniform motion, the newly achieved status does NOT cancel out the former acceleration. Like the cannonball falling from the mast of Galileo's ship, which does not instantly "lose" it's pre-existing inertial motion the second it is dropped, the travelling twin does not "lose" the speed it has accumulated via absolute acceleration the instant it quits accelerating.
Hey, Babe...while talking, in passing, about good ole Jazzfanz, lemme ax ya a couple of things, eh?
1. Ya ever say "Hey" to Millsapa for me? That BABE, she ROCKS, eh!?
2. Instead of gittin annoyed by these chumps you think you're me, you should play them, know what I'm sayin? Stimulate their irrational and unfounded speculations into runnin wild, and all that there, ya know?
Here's a suggestion. Run down the old blues thread I started long ago(probably on about page 15 by now). Make one short entry in it, along these lines: "This here thread, it ROCKS, eh!?"
After that, no amount of reason will ever persuade them to abandon their irrationality about your identity. The chumps, them.
One Brow said: "Until they (or like-minded individuals) conduct experiments that can verify this, they are not serious scientists. They may be serious, and they may be scientists, but the combination of words doesn't apply."
This seems to be just another of a seemingly endless series of attempts to dismiss and ignore issues by way of semantic fiat, dictated by you, Eric.
I totally disagree with your semantical conclusion. I have seen scientific articles about 20 pages long, chock-full of mathematical proofs, etc., which specially suggest the precise experimental apparatus and methods to be used, and the precise reasons for the predicted outcome.
But of course not every theoretical physicist has, at his personal disposal, the required resources and technology required to conduct a suggested experiment. It may never be conducted, but that does not change the "serous" theoretical issues being raised, or render them frivolous.
One Brow said: "As long as the answer is based on an observation is a single locaiton at a single time, it is identical to every inertial frame, regardless of which frame is "really" not moving, in standard, mainstream SR."
Yes, we just discussed that, and if that was your only point, then there was no need for long-winded questions. But it still doesn't tell you who will see what. This goes back to an erroneous assertion you routinely make, to wit:
"One Brow said "For either mainstream-SR or nL, it will not matter which you decide is moving"
This is a crucial point. My (most recent response was:
"It won't, eh? If we go back to the example provided by the professor where each sees 10 seconds elapsed on one clock and 8 on the other, why does the one show 10, and the other 8? Why isn't the situation reversed with the opposite clock showing 8 and the other one 10? Why do they differ at all, for that matter?
The answer seems to be "Jill’s spaceship, carrying a clock C', is traveling at 0.6c,..."
So, Jill, not Jack, is travelling. As I said, SR says the "moving" clock will run slower, so it DEFINITELY matters who is moving in that respect."
If Jack were the one moving, his clock would read 8 seconds, and hers 10 seconds. Even though it would still be true that"an observation is a single locaiton at a single time, it is identical to every inertial frame, regardless of which frame is "really" not moving," the answer would be the opposite.
I don't recall you responding to this. Can't you see the implications? The asserted "reciprocity" of the Lorentz transformations is merely formal, not actual. It is always the moving clock which runs slow. Another built-in way in which SR allows you to ascertain which one is moving.
As G. Burniston Brown put it, over50 years ago:
"Half a century of argumentation has not removed [the serious contradictions which have marred SR] and the device of calling them only apparent contradictions (paradoxes) has not succeeded in preventing the special theory of relativity from becoming untenable as a physical theory.
The most outstanding contradiction is what the relativists call the clock paradox. We have two clocks, A and B, exactly similar in every way, moving relatively to one another with uniform velocity along a line joining them. If their own interaction is ignored and they are far removed from other matter, they continue to move with uniform velocity, and so each clock can be considered as being the origin of a set of inertial axes. The Lorentz transformations show that the clock which is treated as moving goes slow.
The principle of relativity, however, asserts that, as A and B both provide inertial frames, they are equivalent for the description of Nature, and all mechanical phenomena take the same course of development in each. Referred to A, B goes slow; referred to B, A goes slow. It is not possible for each of two clocks to go slower than the other. There is thus a contradiction between the Lorentz transformations and the principle."
http://homepage.ntlworld.com/academ/whatswrongwithrelativity.html
As G. Burniston Brown put it, over50 years ago:
"Half a century of argumentation has not removed [the serious contradictions which have marred SR] and the device of calling them only apparent contradictions (paradoxes) has not succeeded in preventing the special theory of relativity from becoming untenable as a physical theory.
The most outstanding contradiction is what the relativists call the clock paradox. We have two clocks, A and B, exactly similar in every way, moving relatively to one another with uniform velocity along a line joining them. If their own interaction is ignored and they are far removed from other matter, they continue to move with uniform velocity, and so each clock can be considered as being the origin of a set of inertial axes. The Lorentz transformations show that the clock which is treated as moving goes slow.
The principle of relativity, however, asserts that, as A and B both provide inertial frames, they are equivalent for the description of Nature, and all mechanical phenomena take the same course of development in each. Referred to A, B goes slow; referred to B, A goes slow. It is not possible for each of two clocks to go slower than the other. There is thus a contradiction between the Lorentz transformations and the principle."
http://homepage.ntlworld.com/academ/whatswrongwithrelativity.html
In 1971 Louis Essen wrote a monograph, which I have not read, called: "The Special Theory of Relativity: A Critical Analysis" which I have not read, but intend to. Some of his conclusions have been summarized as follows:
"Possibly still the world's leading scientist on time measurement, L. Essen OBE (being inventor of the atomic clock and used with his approval in relativity experiments), rejects Einstein's relativity. He is also an FRS and has written a book and several articles which expose serious errors in the theory. For example, one brief letter (1977), even though rejected by the leading journal Nature, is sufficient to refute the claim that atomic clocks flown around the world confirmed Einstein's "shortening of time" with motion. In a later article (1988), he stated 1) "Einstein's theory of relativity is invalidated by its internal errors", 2) "Einstein's use of a thought experiment, together with his ignorance of experimental techniques, gave a result which fooled himself and generations of scientists", 3) "Claims frequently made that the theory is supported by experimental evidence do not withstand a close scrutiny"; and in closing he remarks, "Insofar as the theory is thought to explain the result of the Michelson-Morley experiment I am inclined to agree with Soddy that it is a swindle; and I do not think Rutherford would have regarded it as a joke [as said in 1954] had he realised how it would retard the rational development of science."
http://www.wbabin.net/physics/marcus.htm
Skimming his article, I see that he makes the same observation and draws the same conclusion that Brown and many, many others have, to wit:
"In accepting this result [i.e., the result that a clock really does run slower with increased speed], Einstien abandoned his relativity postulate and returned to the position stated ealier by Lonrentz."
http://www.fileden.com/files/2008/8/24/2063601/physics/Oxford5-Essen.pdf
The first citation given in this post contains a partical summary of respected scientists to reject SR and a number of quotes from scientists, such as Popper, who believe that science is often adopted as an ideology and treated as such in an uncritical way.
Some thoughts of Vannevar Bush's comments on the topic are expressed as follows:
"Vannevar Bush has emphasised the fact that our system of education is not producing fundamental thinkers of the calibre of Gibbs, Helmholtz, Lorentz or Poincare. It is difficult to see how we can produce fundamental thinkers when our teachers cannot detect the fallacies in Einstein's theories, paradoxes and postulates, but instead rush to climb aboard the Einstein bandwagon where further straight thinking becomes impossible."
Something to think about, eh?
Beginning to read Essen's monograph, wherein he concedes that, like many others, he, without really taking the time to understanding SR, assumed it must be correct because it was so widely accepted. He then makes a reference to a presumably "ideological" climate about SR when he says: "In the existing climate of opinion, one needs to be very confident to speak of definite errors in the theory."
Apparently Essen has such confidence. According to wiki(on the topic of the speed of light):
Essen had to withstand some fierce criticism and disbelief. Even NPL director Sir Charles Galton Darwin, while supporting the work, observed that Essen would get the correct result once he had perfected the technique... However, a combination of Essen's stubbornness, his iconoclasm and his belief in his own skill at measurement (and a little help with calculations from Alan Turing) inspired him to refine his apparatus and to repeat his measurement in 1950, establishing a result of 299,792.5±1 km/s, . This was the value adopted by the 12th General Assembly of the Radio-Scientific Union in 1957.
http://en.wikipedia.org/wiki/Louis_Essen
I notice a post about Essen, Popper, and others is missing. In the spam box, I guess. To very broadly sum up Essen's methods and conclusion, I submit the following excerpts(which may contain some typos, because I can't just cut and paste them:
"The author's views expressed in this paper were reached slowly and after a long consideration of the initial and supporting papers....it has been suggested that the theory consists of a number of contradictory assumptions and adds nothing significant to that of Lorentz."
Eric, your comments, attitudes, and (non) responses in these threads have often given the impression that you think on "cranks" like Van Flandern and uninformed sloppy thinkers like me could possibly fail to fully endorse SR as you interpret it.
If you were actually well-versed in the concepts in question, however, you would realize this is far from true, and Essen's analysis demonstrates. Another modern critic is N.L. Brillouin. According to wiki, among other achievements,
"Brillouin's thesis jury was composed of Langevin, Marie Curie, and Jean Perrin and his thesis topic was on the quantum theory of solids. In his thesis, he proposed an equation of state based on the atomic vibrations (phonons) that propagate through it. He also studied the propagation of monochromatic light waves and their interaction with acoustic waves, i.e., scattering of light with a frequency change, which became known as Brillouin scattering...In 1926, Gregor Wentzel,[5] Hendrik Kramers,[6] and Brillouin[7] independently developed what is known as the Wentzel–Kramers–Brillouin approximation, also known as the WKB method, classical approach, and phase integral method... During his work on the propagation of electron waves in a crystal lattice, he introduced the concept of Brillouin zones in 1930. Quantum mechanical perturbations techniques by Brillouin and by Eugene Wigner resulted in what is known as the Brillouin–Wigner formula...he was interested and did pioneering work in the diffraction of electromagnetic radiation in a dispersive media....Brillouin was a founder of modern solid state physics for which he discovered, among other things, Brillouin zones. He applied information theory to physics and the design of computers and coined the concept of negentropy to demonstrate the similarity between entropy and information..."
http://en.wikipedia.org/wiki/L%C3%A9on_Brillouin
He was also an outspoken critic of relativity theory. As noted in the last sentence of that wiki entry:
"In his book, Relativity Reexamined, he called for a "painful and complete re-appraisal" of relativity theory which "is now absolutely necessary."
That book was published over 40 years ago, but the "complete reappraisal" he called for did not occur, if your education and attitudes on the topic are typical, anyway.
The missing post I just referred to contained a question posed by Vannevar Bush which I liked to much that I'm going to repeat it here, just in case the "lost post" stays lost:
"It is difficult to see how we can produce fundamental thinkers when our teachers cannot detect the fallacies in Einstein's theories, paradoxes and postulates, but instead rush to climb aboard the Einstein bandwagon where further straight thinking becomes impossible."
aintnuthin said...
Really? You sure could have fooled me or anyone else who has read every post you have made in this (and the prior thread) over the last year or two.
Well, it wouldn't have fooled anyone who was paying attention and knew enough about the topic to understand the difference between being able to make an empirical determination and making an determination based upon including other factors, like the conservation of energy. hence, my careful inclusion of "most general sense", as opposed to more specific notions.
Just recently you claimed that although SR supposedly takes "no position" on Galileo's claim ...
So, you think that saying "you can never tell which of two inertial objects is moving" using the technigues SR availas itself of is the same as sayinf "you can never tell which of two inertial objects is moving" in the most general sense? No wonder you're so confused.
I swear, Eric, I pay more attention to what you say in this thread than you do.
If so, you do it without comprehension or concern for that comprehension. It seems more likely you pay attention to what you think I'm saying than to what I'm actually saying.
Which is probably one reason that I see apparent inconsistencies while you see none. You don't even remember your recent claims.
On the contrary, you see inconsistancies by taking my statement "A is true using the toolset B" and insisting on interpreting that as "A is true at all times in every way". I like to think you'll understand why I'm not impressed by that, but so far I see no sign you do.
SR is completely in the Galilean/Newtonian tradition in this respect. Therefore it definitely DOES take a position on whether (and even how) you can tell which of two objects is moving.
Describe how. Where in the equations of SR is the "really moving" term?
All your repeated assertions about what positions "mainstream SR" takes on such matters are merely a recitation of conclusion based on erroneous understandings of SR, such as those widely promulgated by Dingle, and many others like him.
Yet, it is you who copies the arguments of Dingle to argue against my position, not I. Dingle interpreted SR as a relationist theory, I do not.
Let me substitute a couple of other "closed systems" for your spaceships.
Why? I'll grant you one of the spaceships is really at rest. Describe the observations you can use to determine which spaceship is really moving. Let's call them A and B. what does A see at which event. What does B see at each event? How does this make the determination? You claim one of the clocks must be truly moving slower. How do you show it? Can you put up? Why can't you do this with SR on spaceships?
Let's consider the earth, the sun, and the fixed stars.
You mean, so you can use conservation of energy and similar notions? Those are not within SR theory, they're in a separate area of physics.
How do we know that the earth is orbiting the sun and not vice versa?
Conservation of energy, based on the mass of the sun and the earth.
The answers are obvious, aren't they? Foucalts' pendulum. Stellar aberration, etc.
Even then, you need physics principles like conservation of evergy, etc. So what? What does this have to do with showing these things using SR?
More generally, if a travelling twin gets his ass blasted off into space via tremendous acceleration, then later settles into uniform motion, the newy achieved status does NOT cancel out the former acceleration.
Acceleration does not cause the effects of SR, remember? It comes from being in different inertial states.
I have seen scientific articles about 20 pages long, chock-full of mathematical proofs, etc., ...
Do you think you have the expertise to tel the difference between 20 pages of valid mathematical proof and 20 pages of nonesense?
... which specially suggest the precise experimental apparatus and methods to be used, and the precise reasons for the predicted outcome.
An outcome that disagrees with mainstream SR/nL (which always give the same answer anyhow, as Van Flandern acknowledged)?
But of course not every theoretical physicist has, at his personal disposal, the required resources and technology required to conduct a suggested experiment.
Almost none of them do. If they were serious, and able to do something relevant, they would se getting grants for the work.
It may never be conducted, but that does not change the "serous" theoretical issues being raised, or render them frivolous.
I agree not being conducted is not the cause of the claims being frivolous.
"It won't, eh? If we go back to the example provided by the professor where each sees 10 seconds elapsed on one clock and 8 on the other, why does the one show 10, and the other 8? Why isn't the situation reversed with the opposite clock showing 8 and the other one 10? Why do they differ at all, for that matter?
Jill does not see 10 seconds pass on Jack's clock (nor on clock 1) while seeing eight pass on hers. In fact, she doesn't see the same amount of time pass on clock 1 and Jack's clock, although she calculates 6.4 seconds to pass on both after accounting for the effects of relativity and light-speed delay.
If Jack were the one moving,
If Jack (and clock 1) were the ones moving, Jill would see eight seconds pass on her clock between when clock 1 and Jack's clock passed here, would see a different amount of time pass on the those two clocks, but calculate each to be 6.4 seconds after correcting for lightspeed delay.
I don't recall you responding to this. Can't you see the implications?
Yes, but apparaently you don't.
The asserted "reciprocity" of the Lorentz transformations is merely formal, not actual.
It is empirical, not merely formal.
As G. Burniston Brown put it, over50 years ago:
Repeating Dingle's error.
Referred to A, B goes slow; referred to B, A goes slow. It is not possible for each of two clocks to go slower than the other.
It is also not possible to refer B to A and A to B at the same time. Since you can't use both measurement systems at the same time, it makes no sense to say that 'the two clocks go slower than each other when using both measurement systems at the same time, therefore there is a contradiction'. Repeating Dingle's error, and quoting other people who repeat it, does not make for a convincing argument. Claiming that I am making Dingle's error is even less convincing when you know I don't hold to Dingle's interpretations, and you have acknowledged such.
In 1971 Louis Essen wrote a monograph,
If a thousand people repeat the error of Dingle, or similar errors, is it less of an error?
Some thoughts of Vannevar Bush's comments on the topic are expressed as follows:
"... the fallacies in Einstein's theories, paradoxes and postulates, ..."
Something to think about, eh?
You mean, that Vannevar Bush was so mired in a specific understanding of the world that he saw fallacies where none existed in a different understanding of the worlde? That he felt anyone who adopted that interpretation was not thinking critically? Sounds a lot like you.
Essen had to withstand some fierce criticism and disbelief. ... This was the value adopted by the 12th General Assembly of the Radio-Scientific Union in 1957.
Essen got a speed for light that few people tghought was accurate. He held to his work, did the science, and persuaded other people that he was right about the speed of light. Good for him. Thank you providing evidence that when Essen was able to provide a compelling case, he was able to persuade other scientists. Do you think that when he presented another compelling case, he was then ignored, or is it that the second case was based on a misunderstanding?
http://www.wbabin.net/historical/essen1.pdf
"Taking into account the basic assumption of the theory that uniform velocity is purely relative, it follows that each clock goes more slowly than the other when viewed from the position of the other. This prediction is strange but not logically impossible."
So, not quite the error of Dingle/Brown.
"He conclucled that on its return the moving clock was slower than the stationary clock. Moreover. since only uniform motion is involved there is no way of distinguishing between the two and each clock goes more slowly than the other."
Except, there is a way. There is no inertial frame in which the travelling twin experiences uniform motion over the course of his journey. Essen is making the error of using the travelling twins outgoing inertial frame and then using its incoming inertial frame. If you play mix-and-match with inertial frames, of course you get contradictory results, but then you're not using SR.
babe,
Here's a suggestion. Run down the old blues thread I started long ago(probably on about page 15 by now). Make one short entry in it, along these lines: "This here thread, it ROCKS, eh!?"
After that, no amount of reason will ever persuade them to abandon their irrationality about your identity. The chumps, them.
As a former moderator, I am fairly sure that simply imitating aintnuthin in a couple of posts will not suffice to convince any moderator you (or Millsapa) are aintnuthin, based on your posting history. So, you should be safe if you think doing so will be fun.
Eric, your comments, attitudes, and (non) responses in these threads have often given the impression that you think on "cranks" like Van Flandern and uninformed sloppy thinkers like me could possibly fail to fully endorse SR as you interpret it.
You think I place limits on the perversity of humans to believe what they wish to, and rationalize those beliefs?
If you were actually well-versed in the concepts in question, however, you would realize this is far from true, and Essen's analysis demonstrates.
I'm not going to read the entirety of Essen's analysis if he makes the elementary error of mixing two different inertial frames to describe the end result of the experiences of the travelling twin. If you feel you can mine3 significant crticism from it, feel free to present it.
Another modern critic is N.L. Brillouin.
"In his book, Relativity Reexamined, he called for a "painful and complete re-appraisal" of relativity theory which "is now absolutely necessary."
That book was published over 40 years ago, but the "complete reappraisal" he called for did not occur, if your education and attitudes on the topic are typical, anyway.
Feel free to present his actual criticisms here, if you think they hold up to scrutiny.
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