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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«Oldest ‹Older 801 – 1000 of 2208 Newer› Newest»So, basically, what we have is an "ideally knowledgeable observer" (would that be, like, God, I wonder?) who is correctly "measuring" something "real."
It's closer to someone who understands effects like doppler shift or light taking a different amount of time to travel different distances. He uses section 2.2 to discuss this difference.
2. Hogg doesn't always seem to follow his own advice.
Meaning, he doesn't interpret things the way you do.
This whole thing about how "each observes the other's clock as running slower" is strictly conditional. That can only be true when BOTH assume that they are less accelerated. In such a case ONE of them is NOT "ideally knowledgeable."
I have been aware of this philosophical preference of yours for some time now.
1. Do you understand that SR is a mathematical theory?
Yes.
Do you understand that the math dictates certain cold, hard, inescapable conclusions which have nothing to do with my (or your) "interpretation" or "philosophy?'
Yes.
2. Do you understand that SR is a theory about the nature of the physical world, and not the observers in it?
Yes.
Do you understand that's it's necessary implications would hold EVEN IF every observer in the world died off, i.e., do you understand that the consequences of the theory are completely independent of each and every possible observer?
Yes.
3. Do you understand that the predictions that SR makes are completely independent of what YOU, or anybody else, knows about any particular moving object(s)?
Yes.
4. Will you just answer the question asked, rather than evade it?
I'll try again.
Do you think both must actually BE slower?
Different inertial states will measure different cloaks as being slower, because the relative speed of the clock is dependent on the inertial state you are in. If you firmly commit to a particular inertial state, then in that inertial state you can say whether or not one clock is slower, but this does not carry over into every inertial state.
One Brow said: "Different inertial states will measure different cloaks as being slower, because the relative speed of the clock is dependent on the inertial state you are in. If you firmly commit to a particular inertial state, then in that inertial state you can say whether or not one clock is slower, but this does not carry over into every inertial state."
You still didn't even address the question, and simply repeated your previous (non-responsive) comment. You make some other confused claims in the process, though. I'll come back to this, but first:
One Brow said: "Meaning, he doesn't interpret things the way you do."
As I said, this is not a mere matter of interpretation, and I'll show you why. Funny, though, that you want to insist that the mathematical conclusions dictated by SR are, even more than moral theory it seems, strictly a matter of "interpretation."
One Brow said: "I have been aware of this philosophical preference of yours for some time now."
Once again, it is NOT a matter of philosophical preference. It is a matter of simple logic and math. Yet you seem to believe that subjective philosophical preference is all this particular scientific theory (SR)can be composed of. I guess that's why you have, for months and years now, DENIED the mathematical dictates of SR in favor of the strictly subjective "interpretation" and "philosophical preference" that YOU insist on imposing on SR, even though it contradicts the simple, impersonal mathematical implications of the theory. Heh, and you accuse moralists of being "subjective," eh? I'm not sure I've every witnessed such a prolonged, persistent, display of obstinate subjectivity and resistance to simple logic as you have indulged yourself in over the course of this (and the preceding) thread. Your subjective commitments alone (in the face of all logic) seem to predetermine every statement you make, every conclusion you draw, and every claim you assert.
Because of the way this blog displays posts, I only saw your last comment (missing all the intervening ones) when I made my last post. I will continue with my response to that, then come back to the others.
Let's review. I said: "SR predicts that the travelling twin "really will" age less. Al HATED this consequence, but he was stuck with it."
I have previously reveiwed, at some length, Al's frustration with this conclusion. Why didn't he just say: "That's not *my* interpretation of SR? *My* philosophical preference would be that neither twin is any younger or older than the other. It's MY theory, damn it, and I say that NOT the proper conclusion, so I reject it?" He could have said that, but what did about which rods and clocks get deformed?
He said: "A priori it is quite clear that we must be able to learn something about the physical behaviour of measuring-rods and clocks from the equations of transformation...The rigid rod is thus shorter when in motion than when at rest, and the more quickly it is moving, the shorter is the rod...
Let us now consider a seconds-clock...As a consequence of its motion the clock goes more slowly than when at rest."
http://www.bartleby.com/173/12.html
Why didn't he just say: "Both clocks could be slower than the other....We can NEVER say which clock is moving slower, blah, blah?"
Because the math of the Lorentz transformations inescapably dictate a different conclusion, that's why, and Al was not enough of a subjectivist to deny that, in the face of all logic and mathematical rigor.
He says: "As a consequence of its motion the clock goes more slowly than when at rest...The rigid rod is thus shorter when in motion than when at rest, and the more quickly it is moving, the shorter is the rod,"
The math tells you WHICH lengths get shortened "as a consequence of motion" and which clocks slow down. It is not "both clocks," it is not 'either clock depending on your assumptions,' it is the MOVING rods and clocks.
It does not depend on "perspective" (the reference frame you choose), it depends on motion. That's what the theory dictates. The (faster) moving clocks and rods will be deformed. Again, the Lorentz transformations do NOT depend upon whether Eric happens to think he can KNOW which one is moving. Whatever Eric knows or thinks, the transformations will dictate the exact same conclusions: It is the MOVING clocks and rods which get distorted.
Do you deny this, Eric?
Eric, I'll come back. I just made a post quoting Al that is not being displayed. Let me know if you can retrieve or if it is simply irrevocably lost. I'd rather proceed in an orderly fashion.
Hogg said: "Indeed this is true; after all, all of the above arguments are equally applicable if we swap D and E. This is the fundamentally counterintuitive aspect of relativity. How it can be that both observers measure slower rates on the other's clock? The fact is, there is no contradiction, as long as we are willing to give up on a concept of absolute time, agreed-upon by all observers."
Eric, you have, without further comment, posted this quote from Hogg at least twice now. You seem to think it has some special significance that is self-explanatory.
What do you think this means, and what do you see the significance of it to be? Do you think Hogg is saying, in effect, "Each clock is slower than the other?"
Al said: "A priori it is quite clear that we must be able to learn something about the physical behaviour of measuring-rods and clocks from the equations of transformation..."
Notice that Al says the LT tell us (teach us) something about the PHYSICAL BEHAVIOR of rods and clocks.
He does NOT say it tells us something special about which inertial frames each observer might choose to adopt. His theory is NOT about that.
He does NOT say that the LT "teach us" something about an object's "path through time." Rather it teaches us something about the PHYSICAL BEHAVIOR of rods and clocks, not the METAPHYSICAL behavior of time and space.
SR is a theory of physics, not metaphysics. That is also one reason why Hogg feels it is necessary to EMPHASIZE that length contraction and time dilation REALLY occur.
You (re)quote your own explanation of why length contraction, by your idiosyncratic definition is "real," as being: "Neither yeardstick is actually shorter, but the apparent shortness is a real..."
The shortness is not actual, but merely apparent, you say:
Hogg clearly says: "... length contraction is often mistakenly thought to be some optical illusion. But moving things do not "appear" shortened, they actually ARE shortened."
Yet, to hear you tell it, he agrees with you, eh? Heh.
I said: "A "correct measurement" does not imply a correct conclusion about the import of the measurement....I think you may be equating an "observation" with something like "discovery of an indisputable fact." Perhaps you're not, but if so, that is not what an "observation" is."
Yeah, as it turns out that's exactly what you think an "observation" is and you think that's what Hogg is saying it is when I have already demonstrated to you, with Hogg's own words, that that ISN'T what he's trying to claim.
I tried to pre-empt the assertion of yet another, naive, misguided claim by you, but here's all I get:
You said: "The Way [Hogg] uses terminology, what you see can be wrong. What you observe will be correct, because when you observe, as opposed to see, you are using correct experimental technique to adjust for what you see."
I could point out to you, for the 100th time, why this primitive view of what an "observation" is, a view often advanced by rather dim-witted adherents of scientism, like Sharpshooter from Jazzfanz, is mistaken, but what good would it do? You still don't get it, and like Sharpshooter, your retort is to try to ridicule those who do not agree that their stupid-ass views are correct:
"I do laugh a little when you offer something as an authority and then proceed to say they are wrong on the very point you are trying to cite them for."
Laugh on, Eric. Maybe you can head to Jazzfanz and tell Sharpy how you just "showed me," eh? Hogg's own words show that he is NOT saying what you say he is.
One Brow said: "I have said many times the travelling twin is really younger."
Yes, you have, and every time you do you turn around and implicitly deny that it could be true. That is because you have no idea "why" he is younger, you just know that you have been told that he is younger, so you parrot that conclusion.
Hogg told you why, and I just quoted him on that score. Al told you why, and I just quoted him, too. In the past I have quoted (and explained) many other authorities who try to tell anyone who will listen (which excludes you) why.
You just continue to ignore and deny what Al, et al, are trying to tell you. It is because, to use Al's own words, once again:
"As a consequence of its motion the clock goes more slowly than when at rest...The rigid rod is thus shorter when in motion than when at rest, and the more quickly it is moving, the shorter is the rod..."
That's why. Get it? Of course you don't. That fact is incompatible with your subjective interpretations and philosophical preferences.
One Brow said: "Different inertial states will measure different cloaks as being slower, because the relative speed of the clock is dependent on the inertial state you are in. If you firmly commit to a particular inertial state, then in that inertial state you can say whether or not one clock is slower, but this does not carry over into every inertial state."
I said: "You still didn't even address the question, and simply repeated your previous (non-responsive) comment. You make some other confused claims in the process, though. I'll come back to this..."
OK, now I'm coming back to this.
1. First you talk about measurement (which you implicitly say, via your denial of my comments about what Hogg is saying, is indisputable fact): "Different inertial states will measure different cloaks as being slower..." OK, so we're talking about "measurments" here, eh? Needless to say "inertia states" measure nothing, pbservers with measuring instruments do. Let's go on...
2. Now you say: "...the relative speed of the clock is dependent on the inertial state you are in." Not clear what you mean here. Certainly an "inertial state" does not DETERMINE relative speed... Let's go on.
3. Finally you say: "If you firmly commit to a particular inertial state, then in that inertial state you can say whether or not one clock is slower, but this does not carry over into every inertial state."
Is this intended to answer the question of whether each clock actually is running slower than the other in the affirmative?
Take two objects, each inertial, moving at the rate of .5c relative to each other. Is your suggestion this:
1. If I assume that object A is at rest, then object B's clocks are really going slower, and
2. If I assume that object B is at rest, then object A's clocks are really going slower, so
3. Each one really is going slower than the other, because their actual state of motion is completely dependent on my assumptions.
That the idea?
George Orwell, in 1937, said:
"The mere words ‘special relativity’ and ‘communism’ draw towards them with magnetic force every fruit-juice-drinker, nudist, sandal-wearer, sex maniac, Quaker, 'Nature cure' quack, pacifist and feminist in England.”
OK, I fess up. He didn't actually say "special relativity" (he said "socialism), but the phenomenon seems to be the same.
What started out as the "Ernst Mach Society" and later become almost-universally known as the "Vienna Circle," was a collection of bright young men who were almost religiously devoted to "speading the word" of a new philosophical truth they called "logical positivism." Like the dialectical materialism of Marx, it had a certain irresistable appeal to certain types of thinkers. It was agressively promoted by its adherents, and gained many followers. By 1950, it had become the dominant philosophy of science in America, England, and other places.
During the period it was in vogue, its (since discredited) doctrines and maxims were eagerly incorporated into interpretations of scientific theories, such as SR and GR, which were particularly ripe fields for speculation. Such thought firmly entrenched itself in textbooks on the topics.
As I have noted, the whole "philosophy" completely crumbled under the weight of its own inconsistencies, but not before leaving its legacy for impressionable student of physics, taught by professors inundated with positivistic precepts using textbooks which codifed then, to absorb and "understand." Of course some of those impressionable student when on to "teach" the next generation of impressionable students, and so on. Theoretical physics has still not completely recovered from what one author I cited called (paraphrasing) "a black comedy in the history of philosophy."
Eric, I have tried to discuss certain philosophical concepts, with the history of those concepts in mind, with you in this thread. I'm afraid I've been quite unsucessful in getting you to give much thought to such concepts. It seems to me that you would much rather advocate and assert than discuss and understand.
One Brow said: "Yet, you offer no evidence for length dilation when something is moving slower, nor a reason why the moving observer will observe contraction instead of dilation."
I have given you the reason, dozens of times, expressed in dozens of different ways, in the hopes that a re-phrasing might trigger some inclination you might have to think about your assertions (rather than merely re-assert them).
But you don't listen to reason. You reject reason. You ignore reason. You "laugh" at anything reasonable as you irrationally reject it. Therefore you don't "hear" a single thing I say, or dispassionately consider any reason I give.
One Brow said: "I don't deny SR's conclusion, because SR's conclusion does not rely on absolute motion. I just your interpretation of that conclusion, which does."
Eric, it is quite typical of you to ignore all content of something someone says and for you to reject, without further thought, everything a person says, based on the way YOU define a word. You don't give a rat's ass about what the other person means by a word, the word (as ONLY you define it) decides the issue for you. That's why I asked this question:
What do you think "absolute" means, I wonder?
You responded: "That there is some inertial state that represent "really" not moving, and all other inertial states are really moving."
Of course, prior to that response, I had already told you that is NOT what I mean. Does that in any way lead you to reconsider or re-evalute what I have said? Naw, you've already decided that issue.
Not that it would matter, when you ask questions like this:
One Brow asked: "If you can't put a number on the speed of Pioneer or on our speed, how do you know Pioneer is faster?"
Are you serious? You ARE serious, aren't you? I dunno, how can I tell which horse is winning the Kentucky Derby if I haven't made a precise calculation of the speed at which they are running?
You have some very confused thinking going on. I will give you the benefit of the doubt and assume that these questions are based on some assumptions (and not just arbitrarily asked for the sense of disruption). But what those assumptions could possibly be are beyond my ability to speculate. It does all kinda suggest some underlying platonic metaphysical views, though. Like it's either absolute or else it's pure illusion, ya know?
If I don't know the exact speed of a baseball which I have just hauled off and smashed with a bat, how can I know it is is moving at all? Quite mysterious, no doubt.
If I don't exactly how tall Spud Webb and Abdul Jabbar are, how can I possibly say one is any taller than the other when I see them standing next to each other? Any conclusion I might draw would have to be purely illusory, I spoze. Like Plato done said, if it aint in the world of forms, it's an illusion
Skit of the day...the scene: Mach confronting Al, with Eric in attendance.
Mach: Al, when I first heard about your new SR theory, and the philosophical claims about it (which agree perfectly with mine), I was very anxious to review it. I come to find out that you have misrepresented your theory, and now I'm very disappointed.
Al: Why is that, Ernie? I mean, I suspect I know, but tell me.
Mach: Because your spacetime intervals are constant, and you posit an absolute spacetime. You make "predictions" about motion which presuppose that motion is not strictly relational. Such talk is utter hogwash. Your theory is nothing more than a speculative metaphysical exercise, utterly fictitious and meaningless, and I reject it completely. Your theory treats motion as something that can be ascertained and ascribed to particular objects.
Al: Well, yeah, I see what you're sayin....
Mach: I absolutely reject your metaphysical bullshit. Ya with me, Eric!?
Eric:
I said: "During the period it was in vogue, its (since discredited) doctrines and maxims were eagerly incorporated into interpretations of scientific theories, such as SR and GR, which were particularly ripe fields for speculation. Such thought firmly entrenched itself in textbooks on the topics."
Suppose one of your kids tells you he got a ride home from school from his friend's Dad. Did you ever stop to wonder why you don't feel compelled to point out to him that, motion being absolutely undetectable, and all, he has no way of knowing that your house didn't come to the car he was sitting in, while it remained motionless?
Because you weren't "trained" by logical positivism to give that response in that situation, that's why. They didn't (and couldn't) "descend on" common people, concerned with common things, and present a "plausible" argument about how all motion was undetectable. By and large, only "sophisticated" academics, trained to deal with abstract matters, became enchanted by the call of the positivists.
Like I said, the "new-fangled" theory of SR, little understood by even many of the academics at the time (and rejected by many, if not most, of them), was a perfect "battleground" for the positivists. And they hit that battleground hard, in full force, with devotion and commitment to success. It was all just so perfect for them....
There is a difference between a philosophical theory of epistemology and a physical theory of matter in motion. They made it their business to stamp their epistemological theory on SR so hard that it became "part of" the otherwise totally unrelated physical aspect the theory. You have repeatedly demonstrated that you are incapable of differentiating between the two (and you are far from along in this respect), so their success continues to this day.
I asked:
Take two objects, each inertial, moving at the rate of .5c relative to each other. Is your suggestion this:
1. If I assume that object A is at rest, then object B's clocks are really going slower, and
2. If I assume that object B is at rest, then object A's clocks are really going slower, so
3. Each one really is going slower than the other, because their actual state of motion is completely dependent on my assumptions.
That the idea?
=====
It's been a couple of days, Eric, and you havn't answered this question about the intended meaning of your claims, so I'll answer for you. Yes, that is the idea. That is the idea of our physicist friend, who insisted "both are right", and who you insisted was right to say that.
In this view, what is right and wrong depends on the assumptions of the observer. If I assume the earth is standing still, then it is. If I reverse my assumption, and assume that the earth is revolving around the sun, then, SUDDENLY, the whole universe reverses direction. I, sitting on my crusty-ass couch, can control all motion in the universe just by making assumptions. Great thing is, you can you do same. If you are assuming the earth is standing still while I am assuming the sun is motionless, then the entire universe acts BOTH ways at the same time, just to accomodate the subjective imaginations of each of us. It's a dreamer's paradise, I tell ya!
What do we have if we leave YOUR ASSUMPTIONS, out of it? This:
1. If A is at rest, then object B's clocks are really going slower, and
2. If B is at rest, then object A's clocks are really going slower, so
3.
I left the conclusion blank, for you to fill in. Where do these claims lead now that YOUR ASSUMPTIONS have been omitted as the all-determinative source and cause of all motion?
Our physicist friend provides an excellent demonstration of how canned answers (developed in the 1920's by people who thought they were logical positivists) get handed down for decades, unaltered, and unrelected upon.
I mean, look at it...some questioner (I'm going to assume it's some young kid) asks a perfectly reasonable question that reduces to "all motion in the entire universe is not merely a product of the subjective imagination of each of us, is it?"
The physicist says it is a "profound question" and then proceeds to "answer" it, sending the kid off with the implicit assurance that BOTH are CORRECT, and, indeed, all physical reality depends on the subjective imagination of the observer.
So, now, this once-rational kid has also been trained to give an irrational, subjective answer, if and when he becomes an "expert" and teaches it. You, having already been "taught," assure me that the physicist is correct. It's a sorry state of affairs, especially for our impressionable youth, who are generally confused enough as it is.
Note the "standard" technique used by the physicist. First he repeatedly asserts that "both are correct." Then at some point, he purports to explicitly address the question (as though he hadn't already). But he doesn't answer the question in so many words, actually. What does he do?
He makes a (bogus) epistemological claim: We can NEVER say who's moving." Even if this claim is true, it does NOT answer the question, like this guy thinks it does.
Again, epistemlogical convictions, whatever their stripe, in NO WAY affect the content of Al's physical theory. The predictions remain the same, either say. SR in NOT an epistemological theory, it is a physical theory.
But our physicist friend has been brainwashed to vaguely think otherwise, and to think that making an assertion about an unrelated topic, actually "answers" a straight-forward question about a physical theory.
Among many other problems, the logical posistivists claims ultimately implied, for example, that:
1. All laws of science are metaphysical, fictitious, and meaningless, and
2. All "real" knowledge is strictly private, and subjective.
To quote the wiki author, once again:
"By the late 1970s, [logical positivism's] ideas were so generally recognized to be seriously defective that one of its own chief proponents, A. J. Ayer, could say in a interview: "I suppose the most important [defect]...was that nearly all of it was false."
I seem to recall you suggesting to me that, if I didn't agree with logical positivism, then I shouldn't adhere to it. Good suggestion. I don't agree with it, and I refuse to adhere to it. How about you?
Speakin a good ole A. J. Ayer (who wrote "Logic, Truth, and Language" which was quite influential in it's day) he once happened to get on an elevator in NYC with Mike Tyson (the boxer) and a couple of his hos.
They were a little too loud and raucous for his refined sensibilities, and he asked them to quiet down and quit playin grab-ass.
Tyson said: "Shut the fuck up and just mind your own damn bidnizz, old-timer."
Ayer said: Do you realize who you're talking to? I'm A. J. Ayer!
Tyson said: No, I don't know who I'm talkin to, and obviously you don't either. I don't know who A. J. Ayer is, but I know there are only two types of A. J. Ayers; Live ones, and dead ones. Which it gunna be, old-timer?
I read every word, but the discussion is becoming repetitive, so I don't find much to respond to.
You still didn't even address the question, and simply repeated your previous (non-responsive) comment.
That's as close to a definitive answer as can be had. In any particular inertial state, you can get a definitive answer. In some situations, the answer will vary depending on the inertial state.
As I said, this is not a mere matter of interpretation, and I'll show you why. Funny, though, that you want to insist that the mathematical conclusions dictated by SR are, even more than moral theory it seems, strictly a matter of "interpretation."
There is nothing in the mathematics of SR that says one observer of a situation has to be "WRONG". If you truly think you can show otherwise, feel free to do so.
Once again, it is NOT a matter of philosophical preference. It is a matter of simple logic and math.
1) Logic is a branch of philosophy, and mathematics is a close cousin of philosophy.
2) Any deterrmination of what the mathematics and logic mean in the real world is of course a matter of interpretation, as you were pointing out over the first 750 comments in this thread.
Why didn't he just say: "Both clocks could be slower than the other....We can NEVER say which clock is moving slower, blah, blah?"
Because he is answering the specific question, "What is the length of the metre-rod relatively to the system K?" As I pointed out, When you work from an existing inertial state, you can get definitive answers.
It does not depend on "perspective" (the reference frame you choose), it depends on motion.
Yet, that's not how he framed his question.
It is the MOVING clocks and rods which get distorted.
Do you deny this, Eric?
The rods and clocks that are moving with respect to a specific inertial state get distorted according to the observations in that state.
What do you think this means, and what do you see the significance of it to be? Do you think Hogg is saying, in effect, "Each clock is slower than the other?"
It means that there is no one correct inertial state from which to juge things, and the determinations can vary according to the inertial state.
Notice that Al says the LT tell us (teach us) something about the PHYSICAL BEHAVIOR of rods and clocks.
My position has been concerning a change in physical behavior.
He does NOT say that the LT "teach us" something about an object's "path through time." Rather it teaches us something about the PHYSICAL BEHAVIOR of rods and clocks, not the METAPHYSICAL behavior of time and space.
Changing your path through time is no more a "METAPHYSICAL behavior of time and space" than changing your path through space is. It is a physical behavior. Just like turning left and going straight are different physical behaviors, so traveling at 20 mph and 50 mph relative to some point are different physical behaviors, and one of the consequences of these different behaviors is a change in time-path.
Hogg clearly says: "... length contraction is often mistakenly thought to be some optical illusion. But moving things do not "appear" shortened, they actually ARE shortened."
Yet, to hear you tell it, he agrees with you, eh? Heh.
Hogg is describing it in a different way. But yes, we are describing the same thing. We both describe the shortening as being real in a specific inertial frame, but not the inertial frame of the stick itself. Further, the weakness of your analysis is emphasized by your continued refusal to quote my referring to the phenomenon as a real event with real consequences.
Laugh on, Eric. Maybe you can head to Jazzfanz and tell Sharpy how you just "showed me," eh? Hogg's own words show that he is NOT saying what you say he is.
I have a better idea. Why don't you email colton and tell him how badly I misunderstand relativity? Or, come down to talk to one of the physics faculty at SWIC, tell them what I have been saying, and have them come talk to me?
Yes, you have, and every time you do you turn around and implicitly deny that it could be true.
Quote it. Quote any implicit denial the travelling twin would be younger.
That is because you have no idea "why" he is younger, you just know that you have been told that he is younger, so you parrot that conclusion.
He's younger because he travled through less time than his twin.
Hogg told you why, and I just quoted him on that score. Al told you why, and I just quoted him, too. In the past I have quoted (and explained) many other authorities who try to tell anyone who will listen (which excludes you) why.
Is your explanation that he really is younger, or that he just looks younger because his metabolism slowed? I think more the latter, while Hogg/Einstein would say he really is younger, as I have.
2. Now you say: "...the relative speed of the clock is dependent on the inertial state you are in." Not clear what you mean here. Certainly an "inertial state" does not DETERMINE relative speed... Let's go on.
This is truly basic relativity theory. Obervers in different inertial states will measure the same clock differently.
3. Finally you say: "If you firmly commit to a particular inertial state, then in that inertial state you can say whether or not one clock is slower, but this does not carry over into every inertial state."
Is this intended to answer the question of whether each clock actually is running slower than the other in the affirmative?
No. It's saying there is no one inertial state where that's true, and the answer is different depending upon the inertial state you exist in.
Take two objects, each inertial, moving at the rate of .5c relative to each other. Is your suggestion this:
1. If I assume that object A is at rest, then object B's clocks are really going slower, and
2. If I assume that object B is at rest, then object A's clocks are really going slower, so
Yes.
3. Each one really is going slower than the other, because their actual state of motion is completely dependent on my assumptions.
No, because of the assumption of an "actual atate of motion". Any "actual state of motion" would preclude at least one of 1 or 2, possibly both.
Eric, I have tried to discuss certain philosophical concepts, with the history of those concepts in mind, with you in this thread.
I haven't read up on logical positivism much, as the position does not describe my position and holds little interest for me generally. If you really want to discuss this history in detail, I can do some research into it. However, my impression has been that your primary motivation for this position is some misguided notion that I hold to it in some fashion, and so you are attempting to persuade me not to hold a position I have repeatedly told you I did not hold. You'll understand I'm not interested in being converted from being a Hindu or Asatru. If there is a different reason for your discussing this beside proselytization, what is it?
One Brow said: "Yet, you offer no evidence for length dilation when something is moving slower, nor a reason why the moving observer will observe contraction instead of dilation."
I have given you the reason, dozens of times, expressed in dozens of different ways, in the hopes that a re-phrasing might trigger some inclination you might have to think about your assertions (rather than merely re-assert them).
Nope, I missed all of them. All I can recall is that the observer is WRONG. Incorrect. That he see things the right way. Etc. Repeating that he doesn't see things the right way is *not* an explanation for why he does not see things the right way.
With clocks it's very simple. If you have a standard stopwatch and I have one that moves four times every five seconds, and we hold them next to each other, you'll observe my watch as being slower, but I'll observe your watch as being faster, clicking off five ticks to my every four.
Now, suppose instead we have standard stop watches that call off time the same way. I leave the planet, turn aroung, and rush past you at .6c. You will observe my watch as being slower, moving four times every five seconds. That we both agree upon. Under SR, I'll observe the your watch as moving four times for every five of my seconds. However, according to you, your watch is really moving at five seconds for each of my four in some objective fashion. So, according to you, why do I observe your watch to be slower when it is really faster. It's not enough to say my obervations are wrong. Why do I observe the wrong thing? What is your explanation?
What do you think "absolute" means, I wonder?
You responded: "That there is some inertial state that represent "really" not moving, and all other inertial states are really moving."
Of course, prior to that response, I had already told you that is NOT what I mean. Does that in any way lead you to reconsider or re-evalute what I have said?
I apologize for having missed that. You of course deserve to have your actual ideas discussed, and not some characature. Please describe what you actually mean by absolute again, and how it differs from my description, and I will endeavor to use the term as you intend in this discussion. An example of a situation you define as absolute, that does not match my sentence, and does not match "determining some inertial state as correct because it is convenient", would be helpful.
Are you serious? You ARE serious, aren't you? I dunno, how can I tell which horse is winning the Kentucky Derby if I haven't made a precise calculation of the speed at which they are running?
You can tell by who has traveled a longer path from an intial point, because they are traveling *on the same path*. Since Pioneer's takeoff, has the spaceship traveled a longer path or has the planet earth? How can you tell without measuring the paths, since they are different?
If I don't know the exact speed of a baseball which I have just hauled off and smashed with a bat, how can I know it is is moving at all?
If, standing at the same spot, you throw a baseball north and I throw one south, how can you tell which was fasterr without measuring something in some way?
If I don't exactly how tall Spud Webb and Abdul Jabbar are, how can I possibly say one is any taller than the other when I see them standing next to each other?
Are Pioneer and Earth in som esense "next to each other"? If yes, explain how. If not, why is this analogy relevant?
1. If A is at rest, then object B's clocks are really going slower, and
2. If B is at rest, then object A's clocks are really going slower, so
3. The determination of which clock is slower is dependent on how the oberserver is moving with respect the clocks.
I left the conclusion blank, for you to fill in.
Done.
One Brow said: "3. The determination of which clock is slower is dependent on how the oberserver is moving with respect the clocks."
It always comes back to you (assuming you're the observer) doesn't it, Eric? Now it is your particular motion which DETERMINES the state of all other motion in the universe. Good thing you're here, so other things can move too. Without you, there would be no motion, I spect.
YOUR DETERMINATION is the crucial aspect of all motion. Got it.
You're right, there's no more to say. You just denied that observers determined motion, but such admissions only last for as long as it takes you to type a response. Thereafter your own statements are conveniently ignored and contradicted so you can keep mouthing the ideas you have been taught to promote.
Ask yourself sometime:
Is SR a theory of physics, or a theory of epistemology?
Is there any difference whatsover between physics and epistemology?
If so, can you even begin to say what that difference is?
It always comes back to you (assuming you're the observer) doesn't it, Eric? Now it is your particular motion which DETERMINES the state of all other motion in the universe.
Determining (making an evaluation of) which clock is slower is not the same thing as determining (controlling the conditions of) their motion. You are engaging in word-play here, intentionally of otherwise.
I don't care about your evaluations. They are yours alone. How are they relevant to the question? It's like every time I ask you how far it is from St. Louis to Chicago you answer "Paris is in France." That's not the question Can you see any conclusion that follows from (1) and (2) above that are not centered on YOU?
====
Is there any difference whatsover between physics and epistemology?
If so, can you even begin to say what that difference is?
You are such a subjectivist that you can't even begin to imagine that anything you don't think or know could possibly exist or occur.
Someone asks me, given two clocks moving relative to each other, which one is running slower than the other.
My answer: If you believe SR, then, assuming they are not moving at the same speed, the one that is moving faster will have slower clocks.
Q: How do you know which one is moving faster?
A: Is this case I don't. But it's irrelevant. SR gives the same answer whether I know anything about the actualy state of motion of the object.
Q: If you don't know that, isn't each correct, and each running slower than the other?
A: Not if you believe SR. SR makes no such claim, and in fact denies it.
Does the Bible claim there is a God?
Yes.
Does it tell you where he lives?
No.
If the Bible doesn't know where he lives, how can it tell you there is a God?
Don't ask me. That wasn't your question. Your question was about what the Bible says. If you don't like the Bible, reject it, but, either way, it says there is a God.
"Mach: I absolutely reject your metaphysical bullshit. Ya with me, Eric!?
Eric: "
Are you with Mach, or not, Eric? If you are, then REJECT all of Al' meaningless metaphysical bullshit, just like you reject the Bible. But DON'T claim SR agrees with you and Mach. Mach knows better. You should too.
In other words, don't try to claim that the Bible denies there is a God just because you do. Not everyone always agrees with you. In this case the Bible disagrees with you. Reject the Bible, don't try to rewrite it to fit your personal beliefs.
I don't care about your evaluations. ... Can you see any conclusion that follows from (1) and (2) above that are not centered on YOU?
If by "yours alone", you mean "the evaluation of any objective observer in the same inertial state", OK. I see no conclusion from (1) and (2) that is not referenced by some an inertial state.
My answer: If you believe SR, then, assuming they are not moving at the same speed, the one that is moving faster will have slower clocks.
Q: How do you know which one is moving faster?
A: Is this case I don't. But it's irrelevant. SR gives the same answer whether I know anything about the actualy state of motion of the object.
Q: If you don't know that, isn't each correct, and each running slower than the other?
A: Not if you believe SR. SR makes no such claim, and in fact denies it.
The clock that is moving faster compared to any particular inertial frame will be running slower compared to the other clock, according to the observers of that frame.
If you mean that there is a specific, special inertial frame which is the real inertial frame, and where you can really tell which clock runs faster, that sounds a lot like the definition of an absolute frame you just denied having.
Otherwise, your comments really don't make much sense.
In other words, don't try to claim that the Bible denies there is a God just because you do. Not everyone always agrees with you. In this case the Bible disagrees with you. Reject the Bible, don't try to rewrite it to fit your personal beliefs.
The problem is that you believe you're holding the Bible, but the book in your hand is "The God Delusion". So, when you ask ask me if the Bible teaches God exixts, sure. When you ask me if the book in your hand teaches God exists, I say no. Then you ask me why I'm contradicting myself.
One Brow said: "Any "actual state of motion" would preclude at least one of 1 or 2, possibly both."
That's all I've ever said. Both cannot be correct, each clock cannot be slower than the other. You invariably deny this, so what it your point? Is it that there can be no "actual motion?" That's your implicit claim, that you, and you alone, with your arbitrary and subjective assumption, determine what is moving. That there can be no "actual motion," only "apparent motion," as you perceive it to be.
Are you saying that there is no such thing as actual motion? If not, what ARE you saying? How can BOTH BE CORRECT if "Any "actual state of motion" would preclude at least one of 1 or 2?"
One Brow said: "If you mean that there is a specific, special inertial frame which is the real inertial frame, and where you can really tell which clock runs faster, that sounds a lot like the definition of an absolute frame you just denied having.
Otherwise, your comments really don't make much sense.
Nothing objective make sense to an utter subjectist.
Two questions:
Is it possible for something to be in motion?
If so, is it possible, even when you're not aware of it?
Is there any POsSIBLE difference between what YOU think and/or what YOU know, and what actually is? Or are they simply one and the same?
Can you even distinguish the two questions? Young children cannot. What they believe is what is true, and for them, there can be no possible distinction between what they believe and what is. They have to arrive at a certain state of development before the concept of "objective reality" makes any sense at all to them.
One Brow said: "One Brow said: "If you mean that there is a specific, special inertial frame which is the real inertial frame, and where you CAN REALLY TELL which clock runs faster, that sounds a lot like the definition of an absolute frame you just denied having."
I don't give a fuck what you can really tell. Don't you see that isn't the question at all? You don't, because you cannot separate your subjective sense of being the ultimate arbiter of all that is from any question you consider.
"Man is the measure of all things: Of those that are, that they are; of those that are not, that they are not." Protagorist, the Sophist (whose devoted followers include Eric, the Sophist).
Eric, you aggressively, relentlessly, and unthinkingly (pointlessly) promote a theory of epistemoloy that you don't really even understand. You think your epistemological theory is physics, showing just how little you understand. Any question about phsyics can only elicit an epistemogical reply from you, because that's how you've been trained to respond.
It is possible, but highly doubtful at this point, that you will ever be able to see the distinction between physics and epistemology when it comes to SR. You have been so well trained that you can't even think of a possible difference any more.
Einstien: "The rigid rod is thus shorter when in motion than when at rest, and the more quickly it is moving, the shorter is the rod..."
Can't you see where that buffoon used the words "more quickly?" He is a FRAUD. Denounce him. Don't pretend he shares your viewpoint, because he rejects it, just like you reject his.
For Berkeley, to be is to be perceived. If you turn your ahead away from a tree, it disappears. Berkeley, like Mach, and like the logical positivists, was a "radical empiricist." Everything you say about "both being correct" demonstrates that you are with them, ontologically, epistemologically, and metaphyically. Don't deny your true mentors, and embrace a fraud like Einstein. You can't serve two masters.
I said: "Q: If you don't know that, isn't each correct, and each running slower than the other?
A: Not if you believe SR. SR makes no such claim, and in fact denies it."
True, or not?: "SR makes no such claim, and in fact denies it."
Just answer that question. What claim does SR (nor Mach, not Berkeley, not the logical posistivists, not your physics teacher, but SR, as a physical--not epistemological--theory) make with respect to "both being correct?"
Do the physical predictions of SR lead to the conclusion that each twin is correct in thinking the other is younger? Yes, or no?
By "absolute" I merely mean something that does not vary with perspective (a proper perspective, anyway).
1. "If you look at a quarter, you will see George Washington's face." That is a relative, contingent, and perspectival statement. It would depend on which side of the quarter you are looking at (if not the edge).
2. Four quarters equal one dollar. This is an absolute statement--it doesn't vary, just depending on how you care to look at it.
In SR, acceleration is absolute (not a matter of mere perspective), and, consequently, so is accelerated motion. When we send the Pioneer hurtling into space at 20,000+ mph, it retains all of the speed it had on earth, and acquires an ADDITIONAL amount of speed, not shared by the earth, which was imparted to it via rocket fuel. Or so the theory of SR says. This is true with, or without, reference to the concept of "absolute space."
True, the pioneer could smash straight into Jupiter and thereby cease all the "accelerated" motion it had in free space. That acceleration would also be absolute, not relative. Unless acted upon by an external force, it will continue in it's accelerated (relative to earth) motion forever.
One Brow said: "The clock that is moving faster compared to any particular inertial frame will be running slower compared to the other clock, according to the observers of that frame."
Over and over and over you talk about a "frame" as though it is some kinda omnipotent causal agent, with a real existence. But what is a "frame" as you're using it? It boils down to this: "A frame is created when I assume I am not moving and it consists of my assumption that I am not moving." So, once again, your assumptions DETERMINE motion (for you). And it's all about how it is "seen" in light of your assumption.
If and when you ever get over the notion that YOUR assumptions cause motion, we might be able to make some progress. Until then, your solipsism makes any rational discussion impossible.
A couple of quotes from Einstein himself opposing what he called "the positivistically inclined modern physicist...:"
"What I dislike in this kind of argumentation is the basic positivistic attitude, which from my point of view is untenable, and which seems to me to come to the same thing as Berkeley’s principle, esse est percipi...A few more remarks of a general nature concerning concepts and [also] concerning the insinuation that a concept — for example that of the real — is something metaphysical (and therefore to be rejected)....
"...external conditions, which are set for [the scientist] by the facts of experience, do not permit him to let himself be too much restricted in the construction of his conceptual world by the adherence to an epistemological system. He therefore must appear to the systematic epistemologist as a type of unscrupulous opportunist: he appears as realist insofar as he seeks to describe a world independent of the acts of perception; as idealist insofar as he looks upon the concepts and theories as the free inventions of the human spirit (not logically derivable from what is empirically given..."
http://www.marxists.org/reference/archive/einstein/works/1940s/reply.htm
I'm with Al on this one.
That's all I've ever said. Both cannot be correct, each clock cannot be slower than the other.
As long as you specify an actual stat4 of motion.
Is it that there can be no "actual motion?"
You can pick any inertial state and declare to be an actual state of motion, as long as you leave one potential state of motion to be the state of not being in motion. So there are an infinite number of potential states of motion, some finite number of which are states that describe actual things, and therrefore are actual states of motion.
... only "apparent motion," ...
Yawn. Every time you try to tell me what I think about this, you fail.
How can BOTH BE CORRECT if "Any "actual state of motion" would preclude at least one of 1 or 2?"
Because when the physicists say "both are correct", they have not yet specified a preferred rest state, so there is no actual state of motion.
Is it possible for something to be in motion?
Of course.
If so, is it possible, even when you're not aware of it?
Awareness has no effect.
Is there any POsSIBLE difference between what YOU think and/or what YOU know, and what actually is?
Sure.
I don't give a fuck what you can really tell.
So, you don't care if there is no reason to say something is really in motion?
Can't you see where that buffoon used the words "more quickly?" He is a FRAUD. Denounce him. Don't pretend he shares your viewpoint, because he rejects it, just like you reject his.
What part of that do I reject?
True, or not?: "SR makes no such claim, and in fact denies it."
I don't truly know what you mean by "each runs slower than the other." Absent more detail, it's a self-contradiction. When you add in the extra detail, SR might confirm or deny it, but I can't agree to either based on that sentence.
Just answer that question. What claim does SR ... make with respect to "both being correct?"
Either point of view could be correct, depending on the intertial state of the observer of the clock speeds.
Do the physical predictions of SR lead to the conclusion that each twin is correct in thinking the other is younger? Yes, or no?
No.
By "absolute" I merely mean something that does not vary with perspective (a proper perspective, anyway).
What is a "proper perspective"?
In SR, acceleration is absolute (not a matter of mere perspective), and, consequently, so is accelerated motion. When we send the Pioneer hurtling into space at 20,000+ mph, it retains all of the speed it had on earth, and acquires an ADDITIONAL amount of speed, not shared by the earth, which was imparted to it via rocket fuel.
Unless it leaves orbit going opposite the direction of earth's motion, in which case it leaves at 20,000- mph compared to earth.
Over and over and over you talk about a "frame" as though it is some kinda omnipotent causal agent, with a real existence.
Nope.
But what is a "frame" as you're using it? It boils down to this: "A frame is created when I assume I am not moving and it consists of my assumption that I am not moving."
Actually, a frame is created when you assume any potential inertial state is the one that is not moveing, whether you are in that state or not. Your personal participation in that state is irrelevant.
So, once again, your assumptions DETERMINE motion (for you). And it's all about how it is "seen" in light of your assumption.
If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?
If and when you ever get over the notion that YOUR assumptions cause motion,
Not my assumption, never has been throughout this discussion.
I'm with Al on this one.
As am I.
One Brow said: "Quote it. Quote any implicit denial the travelling twin would be younger.
One Brow said: "Both are correct."
On what POSSIBLE basis can you say the standard answer given to this question is correct?
On the basis that we are told to assume that one has been accelerated, maybe?
But is the travelling twin "really" younger? Would he still be younger if we hadn't been told he was the one moving, and only he and his twin knew it? Does it depend on what we know? Or does it simply depend on who has been accelerated? Which? Which is it?
Suppose neither twin even knew they were twins. Suppose they were separated at birth, and one was blasted off into space, then abandoned by their parents. Would the travelling twin "still" be younger? Or would they each be younger than the other now, since neither knows who was moving?
Does SR predict a different outcome, and say both are correct in their respective conclusion that their clock runs slower now, because they don't know whose clock has been running slower all these years?
Was neither one "really" accelerated if neither of them know which one of them was? Is each one now actually younger than the other? That's seems to be your idiosyncratic prediction, but quote the passage where Al says that's what his theory predicts, eh?
No need to post your response. I know what it will be, and it will consist of 4 words: "There is no contradiction."
One Brow said: "Because when the physicists say "both are correct", they have not yet specified a preferred rest state, so there is no actual state of motion."
So, once again, you expressly affirm that "actual motion" is completely dependent on what some physicist says, eh? There is no actual motion, only "supposed" or "posited" motion. The guy on the train is motionless, unless and until you say he aint.
Nice try.
One Brow asked: "If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
You tell me, Ernie. Is motion a physical state, or a state of knowledge?
Lets say I shoot a rocket into space, then all other matter disappears, but it does not change speed or direction.
It is still moving, or does movement depend on the existence of, and knowledge of, an observer?
====
I asked: "Is it possible for something to be in motion?"
Of course.
"If so, is it possible, even when you're not aware of it?"
Awareness has no effect.
Does "awareness" have an effect, or not?
One Brow said: "Actually, a frame is created when you assume any potential inertial state is the one that is not moveing, whether you are in that state or not. Your personal participation in that state is irrelevant."
Yeah, I agree, but it's the same difference. From now on, rather than using the word "frame" would you mind just using the word assumption, for the sake of clarity?
If I assume that the sun is orbiting the earth, in what way does that affect the motion of either?
If I assume that the earth is orbiting the sun in what way does that affect the motion of either?
In what way does my assumption (frame) have any effect whatsoever on the motion of either body? It what way is my assumption the least bit relevant to physical motion? Can you explain that part?
One Brow asked: "What is a "proper perspective"?
Well, you know...like one not taken by a hallucinating paranoid-schizophrenic, know what I'm sayin?
One Brow said: "Unless it leaves orbit going opposite the direction of earth's motion, in which case it leaves at 20,000- mph compared to earth."
Either way, it will leave the solar system, and we won't, and it will keep moving, getting farther and farther way from us all the time. Or is your suggestion that it stopped, on a dime, and then the sun started moving away from it?
Of course it won't leave the solar system without the necessary "escape velocity." As far as I know, escape velocity is an amount of speed, resulting from real, non-illusory accelerated motion, and it can actually be calculated, almost to the mph.
One Brow said: "You can pick any inertial state and declare to be an actual state of motion, as long as you leave one potential state of motion to be the state of not being in motion. So there are an infinite number of potential states of motion, some finite number of which are states that describe actual things, and therrefore are actual states of motion.
Yawn. Every time you try to tell me what I think about this, you fail."
You mean every time I point out the incoherency of your claims, you fail to see it, eh?
"You can pick any inertial state and declare to be an actual state of motion..."
What do your "picks" and your "declarations" have to do with the "actual state of motion?" That's what I've been asking you for over a year now. Contrary to what you think, your glib assertions have not served to "explain" how your picks and declarations affect "actual states of motion."
How does that work, exactly?
One Brow said: "What claim does SR ... make with respect to "both being correct?"
"Either point of view could be correct, depending on the intertial state of the observer of the clock speeds."
Does anything here ever depend on moving objects, or is all motion and all "correct" answers, strictly dependent on "points view?"
Does the predicted slowly of the travelling twin's clock depend on his point of view, or his actual accelerated motion?
One Brow asked: "If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
Al was (at the time) extremely unhappy to have to acknowledge that, according to the math of theory of GR, a solitary rotating globe, being the only object in the universe, would still bulge at it's equator. That's NOT what he wanted to prove. He wanted to appease Mach, but...
But, of course, all Mach has to do is say GR is wrong. Purty simple, actually.
Eric, let's suppose two brothers assure us that one of them is 3 years older than the other, and we have no possible reason to disbelieve them. One of them was born in 1926, and one in 1929.
You and I each make our assessement, and you conclude that brother A appears (and therefore is) younger, and I conclude that brother B appears (and therefore actually is) younger. But neither of us know for sure which one really is younger.
We do you and I stand?
Since neither one of use knows, are we both "equally right" in our conclusions? Neither one of us can prove the other wrong, after all, and neither one of us KNOWS anything for sure.
Second question: Where do the brothers stand due to our uncertainty? Is there now no "fact of the matter" as to which one was born in 1926?
Of course, it just the same question I've been asking you for over a year now. In what way does our lack of knowledge affect the actual birthdates of the brothers? Does it go back in time and changes their birthdates?
Suppose they don't actually even know when they were born? Is the year of their respective births now "meaningless?" Does that ignorance have any effect on the year in which their mother gave birth?
In short, what is the necessary connection between (1) what one knows about what actually happened, and (2) what actually happened, known or not? Is there one?
Suppose I make some tautogoical claim like "whoever was born first is older."
Now suppose Sharpy, ever alert for the inevitable self-contraction that certain people display, jumps in and says:
YOU CAN'T POSSILBLY KNOW THAT. YOU DON'T KNOW WHO WAS BORN FIRST!
He got me, dead to rights, ya figure?
Sharpy stops in here, bringing his incomparable wit with him, and I can hear him now:
Me: Both clocks can't each be slower than the other.
SHARPY: YOU CAN'T KNOW THAT. YOU DON'T EVEN KNOW WHICH CLOCK IS SLOWER!
Me: SR predicts that the clock which is moving faster (has previously been more accelerated) will be slower.
SHARPY: YOU CAN'T KNOW THAT. YOU DON'T EVEN KNOW WHICH CLOCK IS MOVING FASTER!
Sharp, as always, is highly attuned to relevancy and logical subtlety. Now he knows he just finished me off, sho nuff.
Of course, Sharpy would have a point if SR predicted that the more accelerated clock runs slower, but ONLY IF you know it has been accelerated. If you don't know that, then each clock actually runs slower than the other.
Is that what SR predicts? Not to my knowledge, it aint. The whole prediction is predicated on the objective motion of the clock, not the state of knowledge of the person trying to make a prediction in an actual case.
One Brow said: "Quote it. Quote any implicit denial the travelling twin would be younger.
I think you have confused implication with inferral. I did not imply that the traveling twin would not be younger, you inferred it.
One Brow said: "Both are correct."
On what POSSIBLE basis can you say the standard answer given to this question is correct?
At the end of the traveling twin scenario, the two travelers are in the same inertial state with a negligible separation in space and time. Any observer in any inertial frame would see the traveling twin is younger.
On the basis that we are told to assume that one has been accelerated, maybe?
Yes.
But is the travelling twin "really" younger?
Yes. He has trveled through less time, and is therefore younger.
Would he still be younger if we hadn't been told he was the one moving, and only he and his twin knew it?
Yes.
Does it depend on what we know?
No.
Or does it simply depend on who has been accelerated?
Yes.
Suppose neither twin even knew they were twins. Suppose they were separated at birth, and one was blasted off into space, then abandoned by their parents. Would the travelling twin "still" be younger?
Yes.
Or would they each be younger than the other now, since neither knows who was moving?
Your question does not make sense.
Does SR predict a different outcome, and say both are correct in their respective conclusion that their clock runs slower now, because they don't know whose clock has been running slower all these years?
No.
Was neither one "really" accelerated if neither of them know which one of them was?
No.
Is each one now actually younger than the other?
Again, that doesn't make any sense.
That's seems to be your idiosyncratic prediction,
No, that is your inferral.
One Brow said: "Because when the physicists say "both are correct", they have not yet specified a preferred rest state, so there is no actual state of motion."
So, once again, you expressly affirm that "actual motion" is completely dependent on what some physicist says, eh?
Actual motion is something that occurs relative to something that is/was determined to be not in motion.
One Brow asked: "If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
You tell me, Ernie. Is motion a physical state, or a state of knowledge?
A physical state. Now, your turn to answer my question, rather than dodge it. If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?
Lets say I shoot a rocket into space, then all other matter disappears, but it does not change speed or direction.
It is still moving, or does movement depend on the existence of, and knowledge of, an observer?
It is still moving compared to its former state, the presumed rest state.
One Brow: Awareness has no effect.
Does "awareness" have an effect, or not?
If I repeat it three times, will that be sufficient? Five? Twenty?
Yeah, I agree, but it's the same difference. From now on, rather than using the word "frame" would you mind just using the word assumption, for the sake of clarity?
Not every frame is something assumed. Anything in inertial motion has a realized frame.
It what way is my assumption the least bit relevant to physical motion?
It isn't.
One Brow asked: "What is a "proper perspective"?
Well, you know...like one not taken by a hallucinating paranoid-schizophrenic, know what I'm sayin?
You seem to be asking for more than that, unless you think most physicists fit that description.
Either way, it will leave the solar system, and we won't, and it will keep moving, getting farther and farther way from us all the time.
Exactly. "away from us".
Of course it won't leave the solar system without the necessary "escape velocity." As far as I know, escape velocity is an amount of speed, resulting from real, non-illusory accelerated motion, and it can actually be calculated, almost to the mph.
Under constant propulsion, you can leave a gravity field at under escapte velocity. It just uses more energy. Even then, Pioneer would have slowed down due to gravity over time. Even if when Pioneer left orbit it was traveling faster than earth, using the sun's center as a rest point, it would be traveling much slower now.
You mean every time I point out the incoherency of your claims, you fail to see it, eh?
No, I believe you find them incoherent, and I think I have a decent handle on why you find them incoherent. It's just that your explanations of the perceived sorurce of incoherency fail.
What do your "picks" and your "declarations" have to do with the "actual state of motion?"
Because ultimately, the choice of any inertial state/frame as the rest state is arbitrary, and motion will be relative to that state.
That's what I've been asking you for over a year now. Contrary to what you think, your glib assertions have not served to "explain" how your picks and declarations affect "actual states of motion."
They don't affect actual motion. If the difference in the inertial states of A and B is 50 miles per hour in the rest state of A, they will be in motion relative to each other regardless of the rest frame.
One Brow said: "What claim does SR ... make with respect to "both being correct?"
"Either point of view could be correct, depending on the intertial state of the observer of the clock speeds."
Does anything here ever depend on moving objects, or is all motion and all "correct" answers, strictly dependent on "points view?"
Of course it depends on the moving objects. BTW, the observer is also a moving object, you know.
Does the predicted slowly of the travelling twin's clock depend on his point of view, or his actual accelerated motion?
His actual motion relative to his initial inertial frame.
One Brow asked: "If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
Al was (at the time) extremely unhappy to have to acknowledge that, according to the math of theory of GR, a solitary rotating globe, being the only object in the universe, would still bulge at it's equator.
The surface of a rotating planet is under acceleration, even in GR.
Eric, let's suppose two brothers ...
Yawn. You're still trying to argue against a subjectivity I'm not arguing in favor of.
On what POSSIBLE basis can you say the standard answer given to this question is correct?
At the end of the traveling twin scenario, the two travelers are in the same inertial state with a negligible separation in space and time. Any observer in any inertial frame would see the traveling twin is younger.
How is this in any way relevant? Next you say:
Or does it simply depend on who has been accelerated?
"Yes."
So, in what way would his "travel through time" be different, even if he never came back? Does "neglible separation is space and time" change his aging process in any way? Is "seeing" that he is younger necessary to him actually being younger? If so, how? If not why are these statements relevant? How do they provide tha basis for saying the answer is correct? The basis for the answer is the Lorentz contractions, isn't it? And those would apply even if no one ever "saw" the results of them, wouldn't they?
====
One Brow said: "Actual motion is something that occurs relative to something that is/was determined to be not in motion."
How so?
One Brow said: "BTW, the observer is also a moving object, you know."
Yeah, I know, so why must we determine that he is "not in motion" in order to determine "actual motion?"
====
One Brow asked: "If you're not in motion relative to something, in what way are you in motion?"
I asked: It is still moving, or does movement depend on the existence of, and knowledge of, an observer?"
One Brow said: "It is still moving compared to its former state, the presumed rest state."
You just answered the question for me. I have no problem saying that "actual motion" can exist independent of our ability to detect it. I have no problem with saying that an object is moving with respect to "empty space," either, whether we can empirically measure empty space or not. These our two DISTINCT THINGS:
1. Our ability to detect a physical state and
2. The actual existence of a physical state.
I believe, for example, that microscopic matter existed before microscopes were invented, whether we could "see" them or not.
You, on the other hand, keep implying that the two are somehow mutually dependent. You say, for example:
"His actual motion relative to his initial inertial frame."
That's just one example, you say basically the same thing several times in your last two posts.
Again, in what possible way does the "inertial frame" (assumptions) cause, or contribute to "actual motion?"
The supposed need for an "inertial frame" requires, in essence an observer. My question wasn't "In what possible way can an observer DETECT actual motion. It was about "actual motion" irrespective of any observers.
Your position becomes especially clear after I ask:
"what do your "picks" and your "declarations" have to do with the "actual state of motion?"
You say: "Because ultimately, the choice of any inertial state/frame as the rest state is arbitrary, and motion will be relative to that state."
Again, the claim is clearly that "actual motion" is dependent upon your arbitrary choices. "Actual motion" must necessarily be "relative to" your assumption of a "rest state. This is contrary to such claims, made elsewhere, as:
Q. "Does anything here ever depend on moving objects, or is all motion and all "correct" answers, strictly dependent on "points view?"
A: "Of course it depends on the moving objects."
If I'm moving with respect to any one inertial frame, I'm also moving with respect to an infinite number of possilbe inertial frames, aren't I? In what way does the arbitrary selection of one "cause" my motion?
One Brow said: "Yawn. You're still trying to argue against a subjectivity I'm not arguing in favor of.
Needless to say, you miss the entire point. Just answer this:
"In short, what is the necessary connection between (1) what one knows about what actually happened, and (2) what actually happened, known or not? Is there one?"
Likewise, what is the necessary connection between (1) what one knows or assumes about a present state of motion and (2) the existent state of actual motion, known, assumed, or not? Is there one?"
As long as every response you give inexricably ties "actual motion" to the selection of an observer's assumption of rest, motion can NEVER be independent of an observer. In effect, it will be the observer who causes all actual motion. You deny being subjective, all while continuing to make subjective elements a crucal aspect of "actual motion."
So, let me make the question clear: Is the detection of motion by a human observer an indispensable aspect of "actual motion?"
If you say no, then please don't try to explain "actual motion" by exclusive reliance on an arbitrarily assumed subjective "frame of reference" in your very next post.
In other words, can we discuss motion in the absract at all without you insisting, at every turn, that motion depends of detection of it by an observer?
Damn, I just made a long-ass post (so long that it wouldn't allow me to post it at first) quoting your last two responses at some length, and responding to some of your questions, and it doesn't appear now. I'll wait and see if it can be retrieved before posting anything else.
One Brow said: "Now, your turn to answer my question, rather than dodge it. If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
Actually, I had already answered this when I said: "In SR, acceleration is absolute (not a matter of mere perspective), and, consequently, so is accelerated motion." As noted, you went on to indirectly answer it yourself, when you noted that an object would still be moving, if, after being accelerated, all other matter disappeared. Again, our ability to "detect" motion is an entirely separate issue from motion itself.
As far as "absolute velocity" goes, Builder pointed out that its existence is implied by SR, over 50 years ago (at which time he was just repeating obvious observations from 1907 and earlier).
Recall, that Dingle, a relationalist, correctly pointed out that the resolution to the twin paradox was an "absolute effect," saying: "It should be obvious that if there is an absolute effect which is a function of velocity then the
velocity must be absolute. No manipUlation of formulae or devising of ingenious experiments can alter that simple fact."
Dingle, being a relationist who insisted that SR must also be relationalist (as it's adherents repeatedly claimed it was) said there must be no age difference, and therefore rejected SR as "inconsistent."
Builder took a different approach. Rather than reject the time dilation of SR (which would have been a mistake, as shown by Hafele-Keating, et al), he affirmed the theory's predictions. Then he examined it's implications. See next post.
So, in what way would his "travel through time" be different, even if he never came back?
It is not longer true that the answer would be the same for the observer in every inertial state.
Does "neglible separation is space and time" change his aging process in any way?
No.
Is "seeing" that he is younger necessary to him actually being younger?
When they are separated by a great distance, what does "actually being younger" mean, to you? How do you tell, without setting an initial rest frame?
If not why are these statements relevant?
Because the correct answer will be different for different inertial states in the separation is not megligible.
The basis for the answer is the Lorentz contractions, isn't it?
In part, yes.
And those would apply even if no one ever "saw" the results of them, wouldn't they?
Yes.
One Brow said: "Actual motion is something that occurs relative to something that is/was determined to be not in motion."
How so?
What else is motion?
Yeah, I know, so why must we determine that he is "not in motion" in order to determine "actual motion?"
We don't have to. You can make calculations assuming the observer is in any inertial state. Typically, we assume the oberserver is in the initial state under investigation for simplicity's sake.
You just answered the question for me. I have no problem saying that "actual motion" can exist independent of our ability to detect it.
Nor do I. It merely requires a presumed rest state to which it can be compared.
I have no problem with saying that an object is moving with respect to "empty space," either, whether we can empirically measure empty space or not.
What is the rest state of "empty space"?
Again, in what possible way does the "inertial frame" (assumptions) cause, or contribute to "actual motion?"
In what way does motion exist if there is nothing to be in motion versus?
The supposed need for an "inertial frame" requires, in essence an observer.
Why?
Your position becomes especially clear after I ask:
"what do your "picks" and your "declarations" have to do with the "actual state of motion?"
You say: "Because ultimately, the choice of any inertial state/frame as the rest state is arbitrary, and motion will be relative to that state."
Again, the claim is clearly that "actual motion" is dependent upon your arbitrary choices.
Perhaps you are having confusion with "cause of" and "relative to". Any actual motion has to be relative to an arbitrary choice of a rest frame, but the rest frame isnot a cause of the motion.
If you really think that is not true, please describe an instance of motion that does not rely on a nor imply a rest frame.
"Actual motion" must necessarily be "relative to" your assumption of a "rest state. This is contrary to such claims, made elsewhere, as:
Q. "Does anything here ever depend on moving objects, or is all motion and all "correct" answers, strictly dependent on "points view?"
A: "Of course it depends on the moving objects."
If I'm moving with respect to any one inertial frame, I'm also moving with respect to an infinite number of possilbe inertial frames, aren't I? In what way does the arbitrary selection of one "cause" my motion?
It doesn't.
"In short, what is the necessary connection between (1) what one knows about what actually happened, and (2) what actually happened, known or not? Is there one?"
There is no necessary connection.
Likewise, what is the necessary connection between (1) what one knows or assumes about a present state of motion and (2) the existent state of actual motion, known, assumed, or not? Is there one?"
There is no necessary connection. The declaration of an actual state or motion will imply the existence of a rest frame, whether their is a mind to infer it or not.
As long as every response you give inexricably ties "actual motion" to the selection of an observer's assumption of rest, motion can NEVER be independent of an observer.
By it's nature, motion must be in comparison to a rest frame, whether an observer exists or not.
So, let me make the question clear: Is the detection of motion by a human observer an indispensable aspect of "actual motion?"
No.
If you say no, then please don't try to explain "actual motion" by exclusive reliance on an arbitrarily assumed subjective "frame of reference" in your very next post.
There very existence of the motion itself implies the rest frame.
In other words, can we discuss motion in the absract at all without you insisting, at every turn, that motion depends of detection of it by an observer?
I have never claimed it did.
One Brow said: "Now, your turn to answer my question, rather than dodge it. If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?"
Actually, I had already answered this when I said: "In SR, acceleration is absolute (not a matter of mere perspective), and, consequently, so is accelerated motion." As noted, you went on to indirectly answer it yourself, when you noted that an object would still be moving, if, after being accelerated, all other matter disappeared.
Actually, I specifically said, "It is still moving compared to its former state, the presumed rest state." So, there was still a rest state that I compared to the motion to.
I am still waiting for you to answer the question. If you're not in motion relative to something, in what way are you in motion? Is motion an absolute, like acceleration?
As far as "absolute velocity" goes, Builder pointed out that its existence is implied by SR, over 50 years ago (at which time he was just repeating obvious observations from 1907 and earlier).
Velocity compared to what?
Recall, that Dingle, a relationalist, correctly pointed out that the resolution to the twin paradox was an "absolute effect," saying: "It should be obvious that if there is an absolute effect which is a function of velocity then the
velocity must be absolute. No manipUlation of formulae or devising of ingenious experiments can alter that simple fact."
Velocity compared to a given rest frame, such as the frame of the stationary twin is an absolute. Velocity without such a frame is meaningless.
Builder took a different approach. Rather than reject the time dilation of SR (which would have been a mistake, as shown by Hafele-Keating, et al), he affirmed the theory's predictions. Then he examined it's implications. See next post.
Oh, goody. another person claiming an absolute rest state exists. I thought you didn't agree with that?
Builder's conclusion was:
"...if the [time dilation] prediction is correct, the restricted theory thereby demands our recognition of the causal significance of absolute velocities, even although it requires that we should be unable to detect or measure such velocities by observations of dynamical and electro dynamical phenomena....
"...the calculation of the relative retardation of the two clocks requires a knowledge of their individual speeds as measured in some inertial reference system. It is not sufficient to know the velocity of the clocks relative to one another; it would still be necessary to know the velocity of one of the clocks and we would then know the speeds of both...
"...Acceleration of a body relative to this absolute system must, by the definition of acceleration, result in a change in its absolute velocity....any two bodies which are in motion relative to one another must be moving with different absolute velocities. These statements are necessarily true even though we cannot measure the individual absolute velocities. We can therefore determine whether the absolute velocity
of a body remains constant or changes, and we can determine whether two bodies have the same or different absolute velocities. Moreover, these determinations can be made by purely kinematical observations.
"Thus the restricted theory itself requires our recognition of the existence of an absolute inertial system which interacts with bodies and physical systems in a manner depending on their absolute velocities. In other words, it requires our recognition of the causal significance of absolute velocities."
http://www.publish.csiro.au/?act=view_file&file_id=PH580279.pdf
And this is why the twin paradox persists. The real question has nothing to do with the how one twin can be "younger" (have aged less) than the other.
What is undermined, and indeed, put down for the count, is the philosophical (not physical) claims of some SR adherents. Motion that is "merely relative" (relational) cannot cause absolute effects. All attempts to deny this conclusion are doomed to failure. Time dilation does not occur because the twins are travelling "relative to each other." Both are presumably moving at some definite velocity which is absolute, but which is higher for the travelling twin, and it is this velocity which, for each, determines the rate of clock retardation.
Builder
One Brow said: "Oh, goody. another person claiming an absolute rest state exists. I thought you didn't agree with that?"
I never said I agreed with that. I merely said that I agreed with Newton that one couldn't be pinpointed and that reference to a "spot" which was at absolute rest was in no way necessary or essential to discussing motion as it is perceived in the laws of physics, etc.
One Brow said: There very existence of the motion itself implies the rest frame.
Yeah, so what? Why bring that up 5,000 in a conversation. That is true of EVERYTHING, EVERWHERE, AT ALL TIMES. It is nothing unique to motion, SR, GR or unique to anything else. Why keep saying it, as though it relates to motion itself?
Tell me anything coherent about anything...your kids, the state you were born in, evolution, your favorite color, your ethics...anything, and I will show you that there is an implicit constrast in everything you say. I could, of course, say it after each sentence. Or I could interrupt all your sentences several times to say it. But that would be pointless.
No word or concept has any meaning without a contrasting background. Not tall, taller, or tallest, or any other concept. "White" means nothing unless there is some other color to contrast it with, and so on down the line.
Why act as though the "frame of reference" for motion is some highly revealing and significant revelation of metaphysical truth only when it comes to the concept of "motion." Every concept has a "frame of reference."
There is a (historical) answer to that, but I doubt that you realize what it is.
"As far as "absolute velocity" goes, Builder pointed out that its existence is implied by SR, over 50 years ago (at which time he was just repeating obvious observations from 1907 and earlier)."
"Velocity compared to what?"
Read his oft-cited article and find out, eh? Not all that different than what you said, actually:
One Brow said: "Velocity compared to a given rest frame, such as the frame of the stationary twin is an absolute. "
I asked: So, in what way would his "travel through time" be different, even if he never came back?
One Brow said: It is not longer true that the answer would be the same for the observer in every inertial state.
What "answer?" You mean some inertial frames would give the wrong answer, or do you mean that SR predictions would changes with respect to the different aging rates of the two twins?
What does "the observer in every inertial state" have to do with anything? Do we now have to consider, not just the observers at hand, but also those in "every inertial state" before we can know if SR's predictions about time dilation will apply?
SR simply says the "moving clock" will slow down? Are you back to saying that the "moving clock" can only be ascertained by the subjective states of observers?
More disappearing posts, Eric. I never know--do you manually retrieve them, or do they just reappear after a spell? Sometimes I see a post, then, later, it's gone, then, still later, it's back. I never really know why.
One Brow said: "Oh, goody. another person claiming an absolute rest state exists. I thought you didn't agree with that?"
Once again, you seem to implicitly equate "existence" with detection. I actually thought we both agreed that an absolute state of rest could exists, but also agreed that it might be hard to identify it with measurements.
I asked: If not why are these statements relevant?
One Brow aaid: "Because the correct answer will be different for different inertial states in the separation is not megligible."
So there are many different "correct" answers? How can that be? The travelling twin either will, or will not, age less than his twin. How many correct answer to the question of "which is it?' are there?
Eric, you constantly deny that you are inconsistent, yet you are consistently inconsistent in your claims and their implications. A minute ago, the "correct answer" about time dilation was arrived at via reference to acceleration and actual motion. Now there are different correct answers, in different frames, just because the travelling twin is not making a round trip.
Let me ask you....while (in the round trip scenario) the travelling twin was heading AWAY from earth, was his time dilated? If so, why would that change if he didn't bother to turn around?
And this is why the twin paradox persists. The real question has nothing to do with the how one twin can be "younger" (have aged less) than the other.
What do you see the "real question as?
What is undermined, and indeed, put down for the count, is the philosophical (not physical) claims of some SR adherents.
Until you answer a couple of questions on the inconsistencies of your proposition, it's a little premature for you to declare someone else's consisent system put down for the count.
If I am "moving faster" than you, according to you, you will cbserve my clock slowing down. I will observe your clock slowing down, but this is not correct, because your clock is going faster. What is your explanation for my seeing your clock slowing down, instead of speeding up? Why does that happen?
G Builder refers to an absolute rest system for the universe in his abstract. You have denied you hold to this. Please describe what you actually mean by absolute again, and how it differs from that description. An example of a situation you define as absolute, that does not match G Builder's universal rest frame, and does not match "determining some inertial state as correct because it is convenient", would be helpful.
Motion that is "merely relative" (relational) cannot cause absolute effects.
Why not?
All attempts to deny this conclusion are doomed to failure.
Feel free to prove that, any time.
Time dilation does not occur because the twins are travelling "relative to each other."
Again, feel fre to prove that.
One Brow said: There very existence of the motion itself implies the rest frame.
Yeah, so what?
So, we can drop any argument that there is some difference between my notion of motion and yours. Both of them require the notion of a rest frame, neither requires an observer.
Read his oft-cited article and find out, eh? Not all that different than what you said, actually:
One Brow said: "Velocity compared to a given rest frame, such as the frame of the stationary twin is an absolute. "
You are incorrect. Builder argues for the existence of a unversal, absolute rest frame. That is very different from saying once you slect the rest frame, the velocity is an absolute.
I asked: So, in what way would his "travel through time" be different, even if he never came back?
One Brow said: It is not longer true that the answer would be the same for the observer in every inertial state.
What "answer?"
The answer of whether there is a difference in aging.
You mean some inertial frames would give the wrong answer, or do you mean that SR predictions would changes with respect to the different aging rates of the two twins?
I mean that the SR predictions on the differening ages of the twins will be different in different inertial frames, and unless you initially assume one rest frame is the right one, no answer will be superior.
SR simply says the "moving clock" will slow down? Are you back to saying that the "moving clock" can only be ascertained by the subjective states of observers?
It's not determined by the subjective states of the observers, but is determined in part by the objective differences in the inertial states of the observers and the clocks.
More disappearing posts, Eric. I never know--do you manually retrieve them, or do they just reappear after a spell?
I regularly empty the spam box for you. If you made longer, less frequent posts, less would be put into spam.
Once again, you seem to implicitly equate "existence" with detection. I actually thought we both agreed that an absolute state of rest could exists, but also agreed that it might be hard to identify it with measurements.
We agreed that you could make a reasonable, natural choice for such a state. It's still a choice.
So there are many different "correct" answers?
In any inertial state these is one correct answer.
How can that be? The travelling twin either will, or will not, age less than his twin.
In the traveling twin scenario, the space and time differences between them are negligible at the end, so every inertial state notes the diference in time traveled.
Eric, you constantly deny that you are inconsistent, yet you are consistently inconsistent in your claims and their implications. A minute ago, the "correct answer" about time dilation was arrived at via reference to acceleration and actual motion. Now there are different correct answers, in different frames, just because the travelling twin is not making a round trip.
So, what's the inconsistency, keeping in mind that to refer to "actual motion", you must assume a specific inertial state?
Let me ask you....while (in the round trip scenario) the travelling twin was heading AWAY from earth, was his time dilated?
The stationary twin certainly thinks so. The traveling twin does not.
If so, why would that change if he didn't bother to turn around?
It wouldn't.
One Brow said: "If I am "moving faster" than you, according to you, you will cbserve my clock slowing down. I will observe your clock slowing down, but this is not correct, because your clock is going faster. What is your explanation for my seeing your clock slowing down, instead of speeding up? Why does that happen?"
Keeping in mind Hogg's distinction between "seeing" and "observing" what makes you think that a traveller would "see," let alone "observe." My clock to be slower?
Look at how Al explains it (I already gave you the page). Look at the pictures he draws about what one "sees" (they don't exist, it is all an "a priori" deduction from the Lorentz formulas.
What does Hogg say about it? First he says what one "sees" can be quite different that what one "observes." After giving an example from a "light clock," the question arises about whether a wrist watch would also keep different time. He says it has to, by SUPPOSITION (not by seeing or by observation).
As I pointed out, no accelerated traveller could ever "observe" (under Hogg's definition) the stationary clocker going "slower." He would simple use the Lorentz transformation to show the relative difference in clocks, and then apply them to HIS clock (since his is the moving clock) and NOT to my clock (as SR says he "must" do because he "must" always assume he is stationary, even if he knows he aint).
When he mistakenly ASSUMES that he is motionless, and I am moving, the he corrects what he "sees" by his "observational" manipulation of the LT which he then imputes to MY clock, because it is the one supposedly moving.
A person who knows he is moving will "observe" HIS OWN clocks as slow. A moving person who mistakenly assumes he is motionless will say his own clocks are correct, and impute the LT to MY clock.
I've been through all this several times, at least.
One Brow said: "Please describe what you actually mean by absolute again, and how it differs from that description."
Well, let's clear about how Builder defines it. He makes it quite clear he is not trying to get philosophical about it:
It must be recognized that these definitions of absolute space and of absolute motion are, respectively, purely geometrical and purely kinematical. They
imply nothing whatsoever about the dynamical aspects of motion or about the physical characteristics of space. They do, however, make definite the concepts of absolute acceleration and of absolute velocity and enable us to prescribe how these are to be measured, i.e. relative to the universe or, approximately, relative to the fixed stars.
The term "absolute" must therefore be understood here to characterize anything which is defined, or measured, relative to the universe. To accept any more abstract interpretation of the absolute would be meaningless
in the context of physics, since all our physical measurements and all our physical theories relate to this universe and to it alone. Any question as to whether the
universe itself is at rest, or in motion, in some broader or more abstract "absolute" sense lies outside the domain of physical enquiry.
He seems to make it clear that he is not trying to engage in abstract, philosophical definitions, but rather just using a definition that allows and permits the concepts of "absolute acceleration" and "absolute velocity," which, he says, the relativists try to (philosophically, not by means of the actual theory of SR) "forbid."
Elsewhere, he notes that:
"Thus it has been shown that the dynamical and electrodynamical effects, both of absolute accelerations and of absolute velocities, are obserVable and must be ascribed to interaction of the affected bodies and physical systems with the universe.
To account for the absolute character of acceleration, Newton had postulated an "absolute space". Mach, like Poincare, interpreted this concept of Newton
in an abstract sense and rejected it as inadmissible in the context of physics...
It is to be noted that our definition of the " absolute" cuts across the distinction, much
discussed by philosophers, between Absolute and Relational Theories of Motion (e.g. see Broad
1923). Yet if we are to continue to use the word" absolute" at all n physics, we cannot ascribe
any useful meaning to it other than that adopted here. As a philosopher, Professor Alan Stout's
reference to this as the "relatively ahsolute", though perhaps not very seriously intended, is not without point."
Stout's "relatively absolute" is fine with me.
Building seems to believe that "inertia" (as a concept, not as state of motion or a "frame of reference") and "fictitious" inertial forces must play some part in the fact that motion has an affect on the measuring instruments of moving observers.
One Brow said: "So, what's the inconsistency, keeping in mind that to refer to "actual motion", you must assume a specific inertial state?"
Keeping that in mind, what difference does it make. Like I said, it applies to everything.
If I bash a baseball, it moves. Engage in your mental masturbation about theoretical "inertial states" all you want. It moves. If some guy on the sun sees it otherwise, then he is misperceiving things, that's all. The baseball does not, I repeat NOT, remain motionless while I and the entire earth move away from it.
If your misplaced notion of an "inertial frame" DICTATES otherwise, then it is wrong. You can cram it. It is false, misleading, and quite ill-considered.
So there are many different "correct" answers?
"In any inertial state these is one correct answer."
This is the inconsistency which to continue to flagrantly flount, all while denying you adhere to it.
There is ONE, and only one, "correct'" answer to the question of which clock slows down under SR. It is, always is, and always will be, the MOVING clock.
The theory does not hold that inertial frames dictate clock retardation. Acceleration does, nothing else.
Mach and the relationalists dispute this claim. So do you. REJECT SR, like Mach. Quit trying to say that you are faithfully explaining the precepts of SR. You are NOT.
That is your inconsistency, and (although I already answered it) it is also the answer to your question about the "real issue" raised by the Twin paradox.
The real issue arises because relationalists try to latch onto SR as a vehicle with which to promote their ontology, and claim that SR is compatible with, and exemplifies, their sorry-ass, woebegotten, claims. It doesn't.
"Let me ask you....while (in the round trip scenario) the travelling twin was heading AWAY from earth, was his time dilated?"
"The stationary twin certainly thinks so. The traveling twin does not."
The stationary twin thinks that, relative to him, the travelling twin has been accelerated, and hence that it is the clocks of the traveller which are the MOVING clocks (relative to his), and hence it is those clocks that have slowed down. The stationary twin is correct. His answer is correct. His answer is the ONLY correct answer. Anyone who comes to a different conclusion, whether based on the mistaken assumption that the earth has been accelerated relative to the twin sitting in the ship, or based on any other assumption whatsoever is WRONG. Their answer is "incorrect."
At least that's what SR says. Mach says otherwise.
One Brow said: "I mean that the SR predictions on the differening ages of the twins will be different in different inertial frames, and unless you initially assume one rest frame is the right one, no answer will be superior."
Once again displaying your inability to distinguish assumption about fact from fact itself; to distinguish subjective (mis)perception from physical reality; and your inability to refrain from imputing your relationalist epistemology/ontology/metaphysics to a physical theory which, as mathematical theory, is devoid of such philosophy. All, of course, while denying that there is anything the least bit subjective, relational, or assumptive about your claims.
I'll say it one more time. The predictions of SR do NOT vary from frame to frame, observer to observer. It is AlWAYS the moving clock which gets retarded. Hence this claim misunderstands and misrepresents SR: "SR predictions on the differening ages of the twins will be different in different inertial frames,"
As a consequence, one frame is ALWAYS superior. It is the frame in which the actual motion is correctly perceived and explained (for example, the "heliocentric frame" is superior to the "geocentric" one). Hence this claim also blatantly misrepresents the position of SR (although it DOES faithfully represent the, alien, invading, Machian view): "unless you initially assume one rest frame is the right one, no answer will be superior."
The superior answer will always be the correct one (whether known or not). It depends solely on objective motion (known or not). It does NOT depends on your assumptions, as you once again claim (after explicitly denying on other occasions).
Motion that is "merely relative" (relational) cannot cause absolute effects.
Why not?
All attempts to deny this conclusion are doomed to failure.
Feel free to prove that, any time.
Time dilation does not occur because the twins are travelling "relative to each other."
Again, feel fre to prove that.
====
As for your last challenge, you have already conceded this. Time dilation for B does not occur because Twins A and B are travelling "relative to each other." It occurs for B because he has been accelerated relative to A (and/or A's "frame of reference," if you prefer). If it was due to merely relative motion (rather than absolute acceleration) then the effects would be symmetrical (neither would be slower than the other, irrespective of any possible deceptive appearances to the contrary). This also responds to your first two comments. As does this quote, which I have posted before:
"Early in his career, Einstein was sympathetic to the idea of relationism, and entertained hopes of banishing absolute space from physics but, like Newton before him, he was forced to abandon this hope in order to produce a theory that satisfactorily represents our observations.
The absolute significance of spacetime in the theory of relativity was already obvious from trivial considerations of the special theory. The twins paradox is a good illustration of why relativity cannot be a relational (and local) theory, because the relation between the twins is perfectly symmetrical, i.e., the spatial distance between them starts at zero, increases to some maximum value, and then decreases back to zero. The distinction between the twins cannot be expressed in terms of their mutual relations to each other..."
http://www.mathpages.com/rr/s4-01/4-01.htm
By the way, this same article reinforces Builder's suggestion that Mach and Poincare misinterpreted Newton's notion of "absolute space" as being an abstract, metaphysical notion:
"On the other hand, special relativity is arguably a strongly absolute theory, even more so than was the relativity of Galileo and Newton....in several famous passages of the first Scholium of the Principia Newton seems to reject the very relativity on which his physics is founded, and to insist on distinctly metaphysical conceptions of absolute space and time...
On one hand we have absolute, true, mathematical quantities, and on the other we have relative, apparent, common quantities. The latter are understood to be founded on our sense perceptions, so the former presumably are not, which seems to imply that they are metaphysical. However, Newton also says that this distinction is useful for dispelling certain prejudices, which suggests that his motives are utilitarian and/or pedagogical rather than to establish an ontology....
What, then, did Newton mean when he wrote that true motions must be referred to immovable space?...This makes it clear that Newton's purpose all along has been not to deny Galilean relativity or the fundamental principle of inertia, but simply to show that a suitable system of reference for determining true inertial motions need not be centered on some material body. This was foreshadowed in the first Scholium when he wrote "it may be that there is no body really at rest, to which the places and motions of others may be referred".
This makes it clear that Newton's purpose all along has been not to deny Galilean relativity or the fundamental principle of inertia, but simply to show that a suitable system of reference for determining true inertial motions need not be centered on some material body. This was foreshadowed in the first Scholium when he wrote "it may be that there is no body really at rest, to which the places and motions of others may be referred"...
The modern confusion over Newton's first Scholium arises from trying to impose an ontological interpretation on a 17th century attempt to isolate the concept of pure inertia...he needed to convey the fact that the seat of inertia is not the Earth's center, or the Sun, or any other material body, but is instead absolute space and time - in precisely the same sense that spacetime is absolute in special relativity. This is distinct from asserting an absolute state of rest, which Newton explicitly recognized as a matter of convention."
I said: "He would simply use the Lorentz transformation to show the relative difference in clocks, and then apply them to HIS clock (since his is the moving clock) and NOT to my clock (as SR says he "must" do because he "must" always assume he is stationary, even if he knows he aint)."
I was sloppy here. It is not SR which insists that every observer MUST view himself as stationary, even when he knows he aint. It is the relatonalist "hangers-on" who make that false claim about about what SR "demands" because it seems to make their sophistical "case" for relationalism more compelling. SR itself contains no such insistence.
One more quote (same source) on relationalism versus (true) relativism:
"Physicists have always recognized the appeal of a purely relational outlook, since our measurements seem to be always reducible to the determination of relations, and yet every such theory has foundered on the same problem, namely, the apparent absoluteness of acceleration....
But this explanation [of the moon's centripetal acceleration] evidently depends on a strictly non-relational concept of motion. In fact, it might be said that the adoption of this non-relational view of motion was the crucial insight of Newtonian dynamics – and it applies no less in the special theory of relativity. For the purposes of dynamical analysis, motion must be referred to a particular class of rectilinear inertial coordinate systems, rather than simply to the relations between material bodies, or even to classical fields.
Thus, according to Newton, we can not infer everything important about an object's state of motion simply from its distances to other objects (at least not to nearby objects). In this sense, both Newtonian and relativistic physics find it necessary to invoke a non-relational aspect of the spatio-temporal behavior of objects. The most natural way of representing this aspect seemed (to Newton) to be in terms of absolute space and time.
Well, this will be my last response for a week or so. Try not to go overboard.
What does Hogg say about it? First he says what one "sees" can be quite different that what one "observes."
When Hogg describes how what you see and what you observe are different, he gives explanations, as in physical things that create the effect, for them. He doesn't just say "WRONG", he says *why* the wrong thing is seen in, for example, Doppler shifts.
I'm still waiting for your "why". All these people you link not, and not one of them has answered the question? It's a very big hole in the theory.
He would simple use the Lorentz transformation to show the relative difference in clocks, and then apply them to HIS clock (since his is the moving clock) and NOT to my clock (as SR says he "must" do because he "must" always assume he is stationary, even if he knows he aint).
So, you want the "really moving" person to apply the inverse Lorentz transformations. That's been clear for a couple of pages of comments now, but I suppose it doesn't hurt to say it explicitly. It still does not answer the question of why what the person sees is a Lorentz transformation, even though the inverse Lorentz transformation is the "proper" one.
I've been through all this several times, at least.
Yet, every time you duck the question about the difference between what you maintain is correct and what a person sees, rather than even pretend to explain it. By comparison, true SR does actually explain such differences.
The term "absolute" must therefore be understood here to characterize anything which is defined, or measured, relative to the universe.
Presumably, this means "relative to the assumption that the universe as a whole is at rest" or, if there is a difference, "the center of gravity for the universe is at rest" or "the total momentum of the universe is zero". An absolute rest frame, as I said. I don't have a problem with it, it just doesn't have any more relevance than any other inertial frame when actually doing physics. Despite his intent, the preference is philosophical.
Building seems to believe that "inertia" (as a concept, not as state of motion or a "frame of reference") and "fictitious" inertial forces must play some part in the fact that motion has an affect on the measuring instruments of moving observers.
So, Building thinks that a concept and a fictitious force have an effect on measuring instruments, and you are accusing me of overt subjectivity because I I ascribe changes in answers to the physical difference in the motions of the objects being measured and the observers. Got it.
If I bash a baseball, it moves.
I agree. How does that relate the supposed inconsistency?
"In any inertial state these is one correct answer."
This is the inconsistency which to continue to flagrantly flount, all while denying you adhere to it.
There is ONE, and only one, "correct'" answer to the question of which clock slows down under SR. It is, always is, and always will be, the MOVING clock.
After you have chosen the rest state, usually one of the clocks will be moving faster, and within that state the clock moving faster will move through less time. All your doing is pretending that the rest state is not a choice, but decded perforce. Again, where's the contradiction, besides being more flexible with my choice of rest states?
The theory does not hold that inertial frames dictate clock retardation. Acceleration does, nothing else.
We both know that acceleration is not the cause of clock retardation. Even if the acceleration is near-instantaneous, the retardation is largely unaffected. The amount of retardation is directly proportional to the time spent in a different inertial state.
Mach and the relationalists dispute this claim.
Yawn.
The stationary twin thinks that, relative to him, the travelling twin has been accelerated, and hence that it is the clocks of the traveller which are the MOVING clocks (relative to his), and hence it is those clocks that have slowed down. The stationary twin is correct. His answer is correct. His answer is the ONLY correct answer. Anyone who comes to a different conclusion, whether based on the mistaken assumption that the earth has been accelerated relative to the twin sitting in the ship, or based on any other assumption whatsoever is WRONG. Their answer is "incorrect."
Unless they have better knowledge than the stationary twin. Let's use Builder's absolute rest frame as an example. We (and the twins) don't know what it is, but some other alien species might. If both twins are actually moving at .6c relative to the universal rest frame, but beleive they are at rest because they have no way of knowing better, and the traveling (aka accelerated) twin accelerates to the universal rest frame (according to the aliens), while the stationary (aka "unaccelerated"),
1) Do either of them see something different than when you assumed the stationary twin was at rest?
2) Whose clock is actually moving faster now?
3) What difference does this change in the assumptions make that is meaningful to assessing the part of the physics that is not tied to the choice of rest frame?
Answers (according to your point of view, from what I can tell):
1) No, they don't see anything different
2) The traveling twins clock is not MOVING, and it therefore faster, according to you. The stationary twin is WRONG.
3) Nothing truly meaningful in assessing the physics of the situation has changed, expect for the parts specific to the rest frame.
I'll say it one more time. The predictions of SR do NOT vary from frame to frame, observer to observer. It is AlWAYS the moving clock which gets retarded.
However, since you've already acknowledged that to be a moving clock, it must be moving according to some rest frame, you have built the choice fo a rest frame into your statement. All your complaints of subjectivity ring hollow when you keep insisting that I have to agree with your rest frame as the One True Frame.
Hence this claim misunderstands and misrepresents SR: "SR predictions on the differening ages of the twins will be different in different inertial frames,"
As a consequence, one frame is ALWAYS superior. It is the frame in which the actual motion is correctly perceived and explained
One frame to rule them all, one frame for measure,
One frame to bring about knowledge and pleasure.
(for example, the "heliocentric frame" is superior to the "geocentric" one).
According to you, both of these frames are WRONG. If they are both WRONG, why is one superior?
As for your last challenge, you have already conceded this. Time dilation for B does not occur because Twins A and B are travelling "relative to each other." It occurs for B because he has been accelerated relative to A (and/or A's "frame of reference," if you prefer).
If acceleration cause time dilation directly, that the amount of dilation would be dependent on the acceleration, not the amount of time in inertial motion. If I accelerate to .6c and a millionth of a second later decelerate back to 0, in a thousandth of a second total, despite the huge acceleration, there will be almost no time dilation. If I undergo the exact same acceleration and deceleration, but the difference between them was a week rather than a microsecond, there would be easily visible delay. The delay is caused by the time spent in a different inertial movement, not by the acceleration.
If it was due to merely relative motion (rather than absolute acceleration) then the effects would be symmetrical (neither would be slower than the other, irrespective of any possible deceptive appearances to the contrary).
I agree the effects of relative motion will be symmetrical over symmetrical phenomena. In the traveling twin scenario, the twins are not in symmetrical phenomena? Why should the effects of relative motion be symmetrical over phenomena which are not symmetrical?
I'm sorry, but your response completelhy fails to answer my challenge, unless you can explain why the effects of relative motion have to be symmetrical even when the phenomena are not.
One more quote (same source) on relationalism versus (true) relativism:
Yawn. I am not a realtionalist, and have not be advocating such.
I'm still waiting for your "why". All these people you link not, and not one of them has answered the question? It's a very big hole in the theory.
Why what? I have no clue what your question is any more. I don't think there is a problem beyond one created by your own confusion.Can you carefully state the question in terms of what physical phenomena (not mental conclusions), if any, that you think are creating an insoluble problem? I don't get it.
Hole in what theory? SR, or some other theory? Are you agreeing with Dingle? Are you saying the circumstance are symmetrical, so therefore the effects must be?
After you have chosen the rest state, usually one of the clocks will be moving faster,
Thanks for telling me what happens AFTER you choose a rest state. My question is about what is happening before YOU make your choice. Which is it:
1. All motion in the universe is suspended, with every object and observer waiting, with bated breath, for Eric to make his choice so they can commence moving again?
2. They keep moving, but each moves faster than the other pending your choice?
"We both know that acceleration is not the cause of clock retardation. Even if the acceleration is near-instantaneous, the retardation is largely unaffected. The amount of retardation is directly proportional to the time spent in a different inertial state."
Yeah, I spoke loosely, but I'm sure you know what I'm saying. Acceleration is a necessary contributing cause, but not the most direct cause. Acceleration (at some time past or present) leads to a higher rate of speed. Acceleration, while not ADDING anything to the affect, causes the affect in that sense, If it were possible for an object to accelerate forever, then its clocks would such keep slowing down more and more every second, even if it never levelled off to maintain a uniform speed. It is, however, the instantaneous rate of speed, not the acceleration per se, which causes this.
Based upon a postulated acceleration of one twin, One Brow asked:
1) Do either of them see something different than when you assumed the stationary twin was at rest?
2) Whose clock is actually moving faster now?
3) What difference does this change in the assumptions make that is meaningful to assessing the part of the physics that is not tied to the choice of rest frame?
1) Of course, they both see something different (than they saw before, when they were travelling side by side). They each see each other separating from the other now, among other things.
2. The travelling twin's clock is moving slower (than it was), the stay at home's clock remains the same. Therefore the travelling twin's clock is moving slower (the stay at home's faster--than his twin's).
3. I don't understand your question. What is supposed to be "meaningful," You started out by stating the aliens KNEW more. Now you're back to talking about assumptions. To me it is meaningful, as a matter of phsyical fact, that one clock is moving at a different rate than the other.
I will say this, and maybe it will answer what you're trying to ask, maybe not.
Prior to the acceleration of one twin, both of their clocks would have been distorted relative to the clocks "absolutely" at rest. Their clocks would have been running slower, in that respect. Once the twin is accelerated, his clocks slow down even more, and are slower than BOTH (1) his twin's and (2) the clocks in the rest frame. Before his acceleration, only (2) was true, while (1) was not.
Please respond to this post, already made above, or else point out to me where you already have (in which case I missed it.
=====
One Brow said: "There very existence of the motion itself implies the rest frame."
Yeah, so what? Why bring that up 5,000 in a conversation. That is true of EVERYTHING, EVERWHERE, AT ALL TIMES. It is nothing unique to motion, SR, GR or unique to anything else. Why keep saying it, as though it relates to motion itself?
Tell me anything coherent about anything...your kids, the state you were born in, evolution, your favorite color, your ethics...anything, and I will show you that there is an implicit constrast in everything you say. I could, of course, say it after each sentence. Or I could interrupt all your sentences several times to say it. But that would be pointless.
No word or concept has any meaning without a contrasting background. Not tall, taller, or tallest, or any other concept. "White" means nothing unless there is some other color to contrast it with, and so on down the line.
Why act as though the "frame of reference" for motion is some highly revealing and significant revelation of metaphysical truth only when it comes to the concept of "motion." Every concept has a "frame of reference."
There is a (historical) answer to that, but I doubt that you realize what it is.
===
So what? What is the deep metaphysical significance of this simple tautology, which applies to all possible subjects of discourse?
Why do you bring it up 10,000 times in a conversation?
One Brow said: "According to you, both of these frames are WRONG. If they are both WRONG, why is one superior?
Within the context of our solar system, which statement is correct?"
1. All planets, and the sun, orbit the earth, or
2. All planets, and the sun, orbit the center of gravity of the solar system, which is at, or very near to, the sun at all times.
3. Both are true, depending on what inertial frame Eric happens to choose as being "at rest' today?
I'm sorry, but your response completelhy fails to answer my challenge, unless you can explain why the effects of relative motion have to be symmetrical even when the phenomena are not.
It's been explained, over and over, by many I have quoted. The effects are NOT symmetrical, because absolute acceleration is asymmetrical. We agree on that. The asymmetry is CAUSED by an ABSOLUTE, not a relative effect. We agree.
That answers the question you asked. Let me quote the math guy one more time, since you apparently did not read him the first time:
"The absolute significance of spacetime in the theory of relativity was already obvious from trivial considerations of the special theory. The twins paradox is a good illustration of why relativity cannot be a relational (and local) theory, because the relation between the twins is perfectly symmetrical, i.e., the spatial distance between them starts at zero, increases to some maximum value, and then decreases back to zero. The distinction between the twins cannot be expressed in terms of their mutual relations to each other..."
You ARE a strict relationist in some of your claims, whether you deny it or not, sorry. Ted Bundy said he was not a murderer, but....
I probably quoted too much in my last post. Now I suspect you may stop at first (or second, or third) sentence of my last quote, object, and then move on to your next post.
Let me just quote the last sentence, in isolation. First, the issue:
I said: Motion that is "merely relative" (relational) cannot cause absolute effects.
You asked: Why not?
I said: All attempts to deny this conclusion are doomed to failure.
You offered: Feel free to prove that, any time.
Math guy: The distinction between the twins cannot be expressed in terms of their mutual relations to each other..."
Nobody said there was no distinction. The question is what type of motion (ontology) can explain the distinction.
Your failure to comprehend an explanation does not establish the truth of your insistence that nothing has been explained.
One Brow said: "... unless you can explain why the effects of relative motion have to be symmetrical even when the phenomena are not."
They most certainly do NOT have to be symmetical, that's the whole point. How can this be? Pretty simple, actually. Again, to quote the math guy:
"Early in his career, Einstein was sympathetic to the idea of relationism, and entertained hopes of banishing absolute space from physics but, like Newton before him, he was forced to abandon this hope in order to produce a theory that satisfactorily represents our observations...special relativity is arguably a strongly absolute theory, even more so than was the relativity of Galileo and Newton."
"The absolute significance of spacetime in the theory of relativity was already obvious from trivial considerations of the special theory. The twins paradox is a good illustration of why relativity cannot be a relational (and local) theory..."
Like Newton, Einstein developed a theory which upheld the relativity principle (the laws of phsyics are the same in all inertial frames) by RESORTING to a theory of absolute motion and absolute spacetime.
Motion is SR is absolute. It is not called a theory of "relativity" because "motion" is relative. It is called that only because Gallieo's principle of relativity is upheld, and extended to electro-magnetic phenomena.
Once again, motion is NOT relative in SR. Any claim that "all motion is relative" is NOT compatible with SR.
I said: "If I bash a baseball, it moves."
One Brow said: I agree. How does that relate the supposed inconsistency?
Over and over, and over, and over, and over, and over (ad infinitum) you make the same implicit assertion.
You suggest that it is only once I posit a rest state that "actual motion" can be determined. The clear implication is that if, in this case, I happen to choose the "rest frame" of the baseball, THEN I, and the earth with me, are "actually moving," not the baseball.
You've said it 10,000 times. It doesn't get more correct with each re-assertion, sorry.
One Brow asked: If both twins are actually moving at .6c relative to the universal rest frame, but beleive they are at rest because they have no way of knowing better, and the traveling (aka accelerated) twin accelerates to the universal rest frame (according to the aliens), while the stationary (aka "unaccelerated"),"
This question is very poorly worded. It hit me that you might be trying to suggest that, if you loaded up a ship with rocket fuel and blasted it off, then, by doing that, you could make it "slow down" relative to the rest frame (which it is ALREADY moving faster than).
Is that what you are trying to somehow suggest? If so, your assumptions are absurd and your question is meaningless. How do I make a baseball reduce it's (absolute) speed by speeding it up even more?
If
1. an object is going .6 relative to a massive object,
2. That massive object happens to be at absolute rest, and
3. The object going .6c smashes into the massive object and comes to a complete stop, now what?
In those circumstances, the object is no longer going .6c, it is going 0. Assuming it's clocks could survive such a collision, they would now run faster than they did before the collision.
If the ship could somehow be reassembled, and blasted off from the motionless object, then its clock would slow down.
Because he was so strongly committed to relationalism prior to 1920, Einstein, like Dingle, rejected SR as an acceptable theory of motion. He [Al] used the example of two globes [one rotating, one not] to decry the "epistemological defect" of SR, but as many have noted, this is just a variant of the twins situtation. As one author puts it:
"The Newtonian explanation—that the globe’s
rotation with respect to (the set of inertial frames of) Newton’s absolute space rather
that its rotation relative to the other globe is what causes it to bulge out—is unsatisfactory, because the purported cause is not an “observable empirical fact” (“beobachtbare Tatsache;” Einstein 1916a, 771). Special relativity, Einstein claims, inherits this “epistemological defect” (“erkenntnistheoretische[n] Mangel;” ibid.), to which he had been sensitized by Ernst Mach...
Imagine attaching ideal clocks to both globes somewhere on their equators. Use these clocks to measure how long one revolution of the other globe takes. The point of introducing these clocks is to show that the situation of the two globes in relative rotation to one another is not symmetric, not even at the purely kinematical level. It therefore need not surprise us that it is not symmetric at the dynamical level either."
http://philsci-archive.pitt.edu/2123/1/annalen.pdf
Al did not like the fact that SR presupposed absolute spacetime and absolute motion, as he reluctantly admitted it did. This spurred him to (unsuccessfully) attempt to achieve a theory of truly "relative" (read "relational") motion with GR.
Dingle and Al were both right. If SR gave a different result for the twins, then it could NOT be a relational theory. In light of the extensive claims that SR was a truly relational theory, Dingle said the theory was inconsistent. Al ultimately knew better. He knew SR was consistent, but that it simply not a relational theory, as he had hoped.
There's a bright side though, as this same author notes:
"If we take Einstein at his word in 1916—that preferred frames of reference are objectionable because they lead to violations of the principle of sufficient reason—we must conclude that Einstein was worried about a problem he had already solved with special relativity...For the further development of physics it was a good thing that Einstein did not fully appreciate what he had accomplished with special relativity. In trying to solve a problem that, unbeknownst to himself, he had already solved, Einstein produced a spectacular new theory of gravity."
One must distinguish what SR actually is, as a theory, from what relationalists insist it "must" be (in order to satisfy their subjectivist philosophical demands). You fail to consistently make this distinction. You parrot all the disproven claims of the relationalist about what SR "holds" or "implies" or "teaches us" about motion. In their minds, "relative motion" is simply a synonym for "relational motion."
Like I said, SR is not called a theory of relativity because it posits that all motion is "relative" (relational). And that is true despite claims of the tens of thousands of relationalists who, over the years, have denied it.
I don't really expect that you will EVER realize this. You have been irremediably indoctrinated with the relationalist claims, and you now think that just HAVE to be a part of SR.
One Brow said: "All your complaints of subjectivity ring hollow when you keep insisting that I have to agree with your rest frame as the One True Frame..."
You don't have to agree with anything, Mr. Subjectist. Your agreement is totally irrelevant. Choose any rest frame you want, I don't care. Choose the frame of reference of a mouse who is chewing his way through the moon in a corkscrew pattern, but who thinks he's motionless, I don't care.
It will NEVER make me and the entire earth move away from a baseball I just bashed, instead of vice versa. Again, your agreement, your personal choice, of a "rest frame" is totally irrelevant to establishing objective physical reality as it pertains to motion.
As usual, you seem to think that your agreement is what makes something true or false. So long as you agree, it's true. So long as you don't, it's false. End of story.
I should point out that it doesn't matter what I think, or agree with, either. I happen to be convinced that the baseball moves when I lay some bigtime wood on it, but I could be wrong. If I am, then I am, it won't matter if I agree or not.
In short, I start with the premise that there exists, totally independent of me, an objective world consisting of "matter" (whatever that is), motion, etc. Not all people do. Some (like Berkeley, the empiricist) think there is, and can be, no such objective world and that all is subjective. Some, like Parmenides, think that all motion, all change, all perception, is strict illusion. Who knows, they could be right. If so, then I am wrong in the "initial premise" that I just stated (and you are right in your premises to the contrary).
But anyone who doesn't adopt my starting point must reject the discipline of physics as mere metaphysical speculation (as Berkeley and Parmenides do). They should not pretend that it has any credibility or status as a legitimate subject at all. At least not if they want to be consistent, ya know?
Each to his own. If you want to wallow in subjectivism, help yourself. It's not my business to tell you what to believe. I just resist the notion that someone can have it both ways, and insist that he is an objectivist while he advocates strictly subjectivist doctrines, that's all.
1. SR and LR both predict exactly the same thing, i.e. that, with increased speed, rods contract and clocks are retarded. Really. Not just as an appearance, not as an illusion. There are actual physical changes in rods and clocks.
2. Why? Good question. Many theories, more or less plausible, have been advanced to explain why, usually having to do with phenomena at the quantum level which deform the physical object and the rate of physical processes at the macrocosmic level.
3. SR, as such, makes no attempt whatsover to explain it, which, Al admitted, was a definite weakness of the theory (it is merely a "principle" theory, and not a "constructive" theory).
4. LR says we "measure" the speed of light to be constant in all inertial frames, with the emphasis on "measure." SR advocates, strongly influenced by the logical positivist dictum that empirical measurement the ONLY possible way to give meaning to a word, and that the accompanying claim that the meaning is identical to the measurement, "try" to say that the speed of light "really is" constant in all frames. But they are just fooling themselves, and attempting to fool others by being faithful to their own misguided definition.
5. Why is it constant? Al immediately points out that it is because rods contract, and clocks slow down with speed. This is just another way of saying we merely "measure" the speed to be the same and that is only because different observers are using rods and clocks which have changed with respect to each other.
6. Take a light beam that we bounce off of Jupiter and back to us, and that is seen by millions of observers, all in different frames moving at different rates of speed. All agree that the light beam leaves earth, hits Jupiter and returns. There are NOT one million different light beams, only one. The light beam leaves earth when it does, and returns to earth when it does. That is totally independent of, and irrespective of, how any particular observer might "see" it (measure it). The light leaves earth when it does (whenever that is) and returns to earth when it does (whenever that is.) The events are concommitent. There is no question of "distant simulaneity" for anyone who is "on the spot."
7. The only reason that I can measure the same football field to be 100 yards long, and you can measure it to be 50 yards long is because you are using a yardstick that is twice as long as mine. Not because the football field physically changes dimensions the second you get a distorted yardstick slapped in your hands. Al makes this quite clear. Positing the constancy (as measured) of the speed of light implies the strict necessity of changed measuring instruments. There is nothing earth-shaking, mysterious, or particularly complicated about it. The only complications arise when some people (positivists) try to erroneously insist that the same football really does "shrink" to 50 yards the second you are handed an oversized yardstick. It's stupid, really.
Why do I say it's stupid? Because it is, that's why. Looky here:
Suppose you go out and measure a standard football field to be 50 yards with your 2-foot long "ruler." I measure it myself with my 12 inch ruler, and tell you you're wrong. Just to check, you measure it again, and still get 50 yards. I go out and measure it again, and still get 100 yards.
So, we sit down for weeks trying to figure out how this mysterious circumstance could occur. If we are mystically inclined, we might discuss under what circumstances the very same football field can magically shrink to 50 yards when you're present, and grow back to 100 yards when I'm present. Could it be the shoes you're wearing that cause it to shrink as you approach?
All of this speculation is stupid enough, standing alone, but that's not even why I say it's stupid. What makes it stupid is that you and I both know full well that you're ruler is twice as long as mine. We compared them, before you left, remember? There is, and we both knew there was, a simple, an obvious explanation before we ever set out on our detective-playing quest to solve the "mystery."
Al tells everyone, right up front, that for the speed of light to "be" constant, clocks must slow down, and lengths must contract with increased speed. That's the only way it can be MEASURED to by 186,000 mps by two different observers moving relative to each other.
The very same light beam, going between two points and back, does not "actually" have one million different speeds if there are one million different observers in one million different states of relative motion. It makes the trip in the time it takes (which is only one time, not one millions times, however measured).
Why try to deny what SR (via Al) specifically tells you? Why say the rods and clocks don't change, and it's all an illusion? Do you think SR is about the "science" of illusion, rather than physics? If all the clock and rod deformation were illusory, then the constant speed of light would HAVE to be illusory too.
That's another reason I say you're a complete subjectivist. You actually want to argue (well, endlessly assert, really, since you don't attempt to delineate your position in a systematic, coherent manner) that if 1 million different observers, all with differently-calibrated rulers and clocks, measure one and the same light beam to have the same speed, then there are 1 million different "truths" about "time" and "distance" as they relate to that single light beam.
Without analyzing this claim any further, it is clear from the outset that you identify "truth" with the mental conclusions of observers, not with objective reality.
I said" Without analyzing this claim any further, it is clear from the outset that you identify "truth" with the mental conclusions of observers, not with objective reality."
Realizing this, the logical positivists tried to place the existence of "truth" in the rod, and in the clock. Consistent with their utterly discredied philosophy, for them distance is, and can only be, what your particular rod tells you it is. Such a position falls to pieces upon analysis, as I have already quoted Al himself as telling you. Despite his earlier eagerness to advocate such a view, he came to know better. Others, like yourself can (in theory at least) too.
A few (later) comments Al made about Mach and his philosophy:
"[to Besso]: "“I do not inveigh against Mach’s little horse; but you know what I think about it. It cannot give birth to anything living, it can only stamp out harmful vermin.”
“…in fact what Mach has done is to make a catalog, not a system.” Paris, 1922)
[to Besso, 1948]: "I see his weakness in this, that he more or less believed science to consist in a mere “ordering” of empirical “material”...He even went so far that he regarded “sensations” not only as material which has to be investigated, but, as it were, as the building blocks of the real world; thereby, he believed, he could overcome the difference between psychology and physics. If he
had drawn the full consequences, he would have had to reject not only atomism but also the idea of a physical reality."
http://philsci-archive.pitt.edu/2149/1/Norton.pdf
Al made these statements even though he had been a devoted disciple of Mach's for many years. Of special significance, with respect to what I've been saying, are the following excerpts:
1. "...he believed, he could overcome the difference between psychology and physics.
2. "If he had drawn the full consequences, he would have had to reject...the idea of a physical reality."
In a prior quote, recall that Al said positivism reduced to Berkeley's dictum that "to be is to be perceived," a dictum which Al rejected.
Do you have any idea of what Al is saying here?
Eric, a couple of posts got dumped in the spam box, not sure why. I'll just quit posting and see if you care to read, think about (I hope) and respond to anything I've said since your last post.
aintnuthin,
I have not yet had a good opportunity to read your comments. I'll do so as soon as is reasonable.
Eric: Very sorry to hear about your Mom. She sounds like she was a wonderful person.
I decided to add a couple of posts with excerpts from modern philosophers of space and time that I came across. There's a couple of points I'm trying convey, and I thought you might be more open to them if you didn't just think it was me, saying anything I could think up, just to be contrary.
This first one is from Dieks. To see the whole article, go to this cite, then click on the "The adolescence of Relativity: Einstein, Minkowski, and the Philosophy of Space and Time." It will then bring up the article as a word document: http://philpapers.org/rec/STEOES
Dieks is basically making an argument about the conventionality of simultaniety, but in the process he somewhat chronicles the way the positivists misinterpret Al.
"Einstein’s statements in these pages have had an enormous influence in twentieth century philosophy of science...Among logical positivists it was one of the motivations for developing the doctrine of ‘coordinative definitions’, according to which physical concepts (like ‘time’) should be coordinated to concrete physical things and procedures...Percy Bridgman, the founder of operationalism, took his inspiration from Einstein’s analysis as well. In his contribution to Albert Einstein: Philosopher-Scientist (Schilpp, 1949), Bridgman (1949) wrote: “Let us examine what Einstein did in his special theory. In the first place, he recognized that the meaning of a term is to be sought in the operations employed in making application of the term."...Bridgman must have been disillusioned by the reply Einstein gave to his admonitions...Einstein squarely rejected operationalism, both in the context of special and general relativity.
The first point that consistently emerges from these statements [by Einstein[ is that the unit of length may only be supposed to be realized by a ‘theoretical’ object, an ideal rod, which can merely be approximated by concrete objects...Putting all this evidence into one coherent whole, it is natural to conclude that Einstein’s reference to ‘definitions’, in his discussion of relativistic concepts, should not be taken as embodying a systematic operationalist or logical empiricist philosophy...Einstein’s special theory of relativity served as a beacon for many twentieth-century philosophers of science; but many of them misinterpreted the philosophical implications of the theory...As Howard (2007) points out, it was only with the downfall of logical empiricism that philosophy of science caught up with Einstein’s thinking about the status of physical concepts. In the philosophy of physics the notion that at the fundamental level it is basic physical theory that is important for the status of space and time, has only rather recently gained substantial ground (cf. Brown, 2005; Dieks, 1984).
We have seen that Einstein introduced his rule for establishing simultaneity with the term definition; this has been seized upon by many later philosophers of physics, to invoke Einstein’s authority...For the logical empiricists this accorded with central tenets in their philosophy of science, because such local facts are paradigmatic of what is directly accessible to the senses...it follows that neither from Einstein’s nor from Minkowski’s work support can be derived for the existence of the ‘epistemological revolution’ that the logical empiricists perceived in relativity theory. In particular, the notorious conventionality thesis that was so ardently defended by many philosophical commentators on Einstein’s revolution appears as a consequence of philosophical prejudices rather than as a part of relativity theory."
This second excerpt is from John Norton's article entitled "What Can We Learn about the Ontology of Space and Timefrom the Theory of Relativity?" http://www.pitt.edu/~jdnorton/papers/OntologyOUP_TimesNR.pdf
What energized philosophical analysis into the deeper import of Einstein's theories was that he explicitly based his theorizing on philosophical reflections. New viewpoints soon multiplied, all supposedly vindicated by Einstein’s theories, be they new findings on methods of discovery, on the nature of scientific theories, on the essence of space and time, on matter and cause, on being and bunkum.
We could choose to be fictionalists. Then we would judge the ontological pronouncements of relativity theory, whatever they might be, as useful mythmaking, devoid of insight into that which exists...In so far as is possible, we must take the theory to mean literally what it
says...
“Time is the fourth dimension” is a mischievous slogan. It inevitably misleads novices seeking to distill the essence of relativity...Is the tacit claim that time is not just a dimension of spacetime but one that is just like the three spatial dimensions? That is a falsehood. The temporal aspects of spacetime always remain distinct from its spatial aspects.
“All is Relative.” Need I warn anyone with a modicum of philosophical sophistication that this weary slogan gains no support from relativity theory? The relativity Einstein found in his theories is a relativity of measured quantity to observer. So the length of a measuring rod or the time of a process alters with the motion of the observer.
Einstein presented his theories of relativity as a part of the relational tradition in theories of space and time...There is
a flourishing tradition in Machian theories, but since it generally seeks to augment Einstein’s theories in order to realize its brand of relationism...To extract a relationist moral from relativity theory still seems to extract more that can be read uncontroversially in the theory.
We do not learn [from Einstien's theories] that all is relative, that time in the fourth dimension in any non-trivial sense, that coordinate systems and even geometry are conventional or that spacetime should be reduced ontologically to causal, spatio-temporal or other relations."
I think Norton and many others advance a good case for concluding that many unsupported (and unsupportable) philosophical claims have traditionally been "scabbed on" to relativity by those with an independent agenda who don't mind disregarding the actual content of the theory if to do so suits their polemical goals.
I decided to post one more set of excerpts from Norton, eh? They really just elaborate on what's already been quoted, but I can't resist because they express my sentiments exactly, know what I'm sayin?:
"Almost everyone with some foundational axe to grind finds a way to argue that what Einstein did vindicates their view... Some independent understanding of Einstein's physics is needed to separate the real insights from the never-ending hogwash that seems to rain down on us all...
"It is not true in relativity theory that "everything is relativity". Only certain quantities are, albeit more that in classical physics. Some quantities are not relative. The simplest examples are the so-called "rest" quantities: rest mass, rest length etc. These are by definition the masses and lengths measured by a co-moving observer. They are characteristic properties of bodies and are of fundamental physical importance; (obviously) all observers must agree on their values. They are an absolute. In the more mathematical approach to the theory, what draws most attention is what is not relative, the so-called "invariants." So early in the history Einstein agreed with the great mathematician Felix Klein that a better name for the theory would have been "theory of invariants."
"The power of the slogan comes from it suggests but does not say. The slogan "time is the fourth dimension" is used, as far as I can tell, to intimidate novices. They are supposed to be awed by the apparent profundity of the claim while at the same time never being able quite to grasp its content at the insightful depth apparently accessible to the mischief making sloganeer. If you meet such a sloganeer, you should ask "what precisely do you mean?" Keep in mind the confusion favored by sloganeers sketched below and insist on a precise answer!"
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/index.html
It's new-age, touchy-feely, woo kinda stuff, I tellya!: "They are supposed to be awed by the apparent profundity of the claim while at the same time never being able quite to grasp its content at the insightful depth apparently accessible to the mischief making sloganeer."
I was sitting at the 50-yard line at Soldier Field watching a Bears game a couple months back, except I was in the nosebleed section. I could see both goal posts without moving my head. During the whole game, they never moved; the uprights always stayed 100 yards apart. Kinda what I expected, of course--I aint never seen goal posts move all by they own damn self.
Suppose 1000 observers had flown over Soldier Field, at varying speeds, and each observer measured a different distance between the goalposts. One guy only measures 1 yard, one guy 50 yards, etc.
What happened? Did "space" change? Did, unbeknownst to me, the goalposts "really" move toward each other to where they were only 1 yard apart when that guy passed over, and again to be only 50 yards apart when that guy flew over, etc.?
Of course not. Not a single observer thought they moved either, at least not relative to each other. If an observer, erroneously assuming he was motionless as he flew over Soldier Field at the near the speed of light, saw the goalposts "moving" he only saw them moving in tandem, and not as approaching each other as he passed.
The distance between the goalposts never changed, as far as each and every observer is concerned. It is baffling to me how some people can get the notion that "space" changes with speed in their heads. Even more baffling is that, once in their head, it seems impossible to get the new-age notion out of their head. Just too much inherent mysterious appeal to the notion, I guess.
aintnuthin said...
Eric: Very sorry to hear about your Mom. She sounds like she was a wonderful person.
Thank you.
Why what? I have no clue what your question is any more.
According to your interpretatiion of the theory, there is an observer O1 who is moving, whose clock C1 is really slowed. There is an observer O2 whose clock is stationary, whose clock C2 is moving at normal speed, much faster than moving clock C1. The stationary observer O2 measures the moving clock C1 correctly as moving slower. The moving observer O1 measures the stationary clock C2 incorrectly as moving slower, but he is WRONG.
My question is: why does the moving observer O1 see the stationary clock C2 the WRONG way? What effect allows O2 to observe C1 correctly, and but prevents O1 from observing C2 correctly?
Thanks for telling me what happens AFTER you choose a rest state. My question is about what is happening before YOU make your choice. Which is it:
1. All motion in the universe is suspended, with every object and observer waiting, with bated breath, for Eric to make his choice so they can commence moving again?
No.
2. They keep moving, but each moves faster than the other pending your choice?
No.
Acceleration (at some time past or present) leads to a higher rate of speed.
Acceleration can also lead to a lower rate of speed, or no change in speed. Any change in speed/velocity is acceleration.
Acceleration, while not ADDING anything to the affect, causes the affect in that sense,
Acceleration causes a change in inertial states, and this change leads to relativistic effects. I agree.
One Brow said: "There very existence of the motion itself implies the rest frame."
Yeah, so what? Why bring that up 5,000 in a conversation.
It means when you say something is in motion, you are already saying that relative to something itself. Motion, as defined by a velocity or speed, is not an absolute.
Why act as though the "frame of reference" for motion is some highly revealing and significant revelation of metaphysical truth ...
I didn't.
Within the context of our solar system, which statement is correct?"
1. All planets, and the sun, orbit the earth, or
2. All planets, and the sun, orbit the center of gravity of the solar system, which is at, or very near to, the sun at all times.
3. Both are true, depending on what inertial frame Eric happens to choose as being "at rest' today?
In any inertial state, 2 in much closer to the truth (I believe that technically, it is the center of gravity of that planet and the sun, not the solar system as a whole). Thus, 3 is nonesensical, since it never holds that the choice of an inertial frame can make 1. true.
It's been explained, over and over, by many I have quoted. The effects are NOT symmetrical, because absolute acceleration is asymmetrical. We agree on that. The asymmetry is CAUSED by an ABSOLUTE, not a relative effect. We agree.
Acceleration did cause the difference in inertial states. It does not cause a difference in the measured lengths of rods or speeds of clocks. That is caused by a suymmetrical difference in motion.
You ARE a strict relationist in some of your claims,
Yawn. A strict relationist holds that even acceleration is relative. I don't.
I said: Motion that is "merely relative" (relational) cannot cause absolute effects.
You asked: Why not?
I said: All attempts to deny this conclusion are doomed to failure.
You offered: Feel free to prove that, any time.
Math guy: The distinction between the twins cannot be expressed in terms of their mutual relations to each other..."
So, I ask you to prove that relative motion can't cause absolute effects, and you respond by refuting a relational interpretation of motion? Yawn.
Prove the statements you offered about relative motion, not similar statements about relational motion. Any time.
Once again, motion is NOT relative in SR. Any claim that "all motion is relative" is NOT compatible with SR.
I agree, not all motion is relative in SR. Only some types of motion are relative in SR. That's why it's not a relational theory.
The clear implication is that if, in this case, I happen to choose the "rest frame" of the baseball, THEN I, and the earth with me, are "actually moving," not the baseball.
The baseball doesn't have a unique rest frame. It accelerated.
You've said it 10,000 times. It doesn't get more correct with each re-assertion, sorry.
When you misinterpret something 10,000 times, your misinterpretations do not get more correct.
This question is very poorly worded. It hit me that you might be trying to suggest that, if you loaded up a ship with rocket fuel and blasted it off, then, by doing that, you could make it "slow down" relative to the rest frame (which it is ALREADY moving faster than).
Is that what you are trying to somehow suggest? If so, your assumptions are absurd and your question is meaningless. How do I make a baseball reduce it's (absolute) speed by speeding it up even more?
Spaceships actually do this every mission upon re-entry. If your understanding is so meager that it truly eludes you something can accelerate from moving to being at rest, I see no point in continuing the conversation on relativity.
In those circumstances, the object is no longer going .6c, it is going 0. Assuming it's clocks could survive such a collision, they would now run faster than they did before the collision.
So, if the non-accelerated twin and the traveling twin are both moving at .6c, and the traveling twin decelerates to 0, his clock is moving faster, not slower. Now, he's the one who correctly see the non-accelerated twin's clock as moving slower, while the non-accelerated twin incorrectly sees the traveling twins clock as moving slower, and the non-accelerated twin is WRONG. What causes this effect? It can't be acceleration, but the non-accelerated twin is the one that is wrong.
Al did not like the fact that SR presupposed absolute spacetime and absolute motion, as he reluctantly admitted it did.
Please post such a quote. You have not so far. Saying there are aboslute effects is not saying there is absolute motion.
In short, I start with the premise that there exists, totally independent of me, an objective world consisting of "matter" (whatever that is), motion, etc. Not all people do. Some (like Berkeley, the empiricist) think there is, and can be, no such objective world and that all is subjective. Some, like Parmenides, think that all motion, all change, all perception, is strict illusion.
On the other hand, some just disagree on the list of entities that are objective.
1. SR and LR both predict exactly the same thing, i.e. that, with increased speed, rods contract and clocks are retarded. Really. Not just as an appearance, not as an illusion. There are actual physical changes in rods and clocks.
Incorrect. LR predicts this through physical changes. SR predicts the contraction of rods and slowing of clocks without physical changes in the rods and clocks.
3. SR, as such, makes no attempt whatsover to explain it, which, Al admitted, was a definite weakness of the theory (it is merely a "principle" theory, and not a "constructive" theory).
I've already given you one possible explanation: the path of the object moving in a different inertial frame points away from us in spacetime. There are others.
The only complications arise when some people (positivists) try to erroneously insist that the same football really does "shrink" to 50 yards the second you are handed an oversized yardstick. It's stupid, really.
I think the stupid part is taking a claim that is assuming there is no preferred intertial state, and interpreting it within a frame that insists on a preferred inertial state.
Suppose you go out and measure a standard football field to be 50 yards with your 2-foot long "ruler." I measure it myself with my 12 inch ruler, and tell you you're wrong.
The thing is, we are using the same ruler. However, one of us is measuring at an angle compared to the sidelines, the other is measuring parallel to the sidelines.
Why try to deny what SR (via Al) specifically tells you? Why say the rods and clocks don't change, and it's all an illusion?
I don't. It's a real, physical effect.
... if 1 million different observers, ... then there are 1 million different "truths" ...
Yawn. There is one truth, and a million different, equally valid means of stating it.
Do you have any idea of what Al is saying here?
Yes, I agree with them.
I decided to add a couple of posts with excerpts from modern philosophers of space and time that I came across.
I read them. They seem to be refuting views I don't hold to.
In relational physics, every aspect of motion is relative: position, veliecity, acceleration, jump (change in acceleration, change in jump, etc. In LET, every aspect of motion is absolute. There is a true center of the universe; every inertial state has a specific, unique velocity; there is a true difference between different inertial states (acceleration), etc. In SR, position and velicity are relative, the rest are absolute. As long as you keep arguing against the first position, you are ingnoring my positon. It's really that simple.
The distance between the goalposts never changed, as far as each and every observer is concerned.
I agree.
It is baffling to me how some people can get the notion that "space" changes with speed in their heads.
Space doesn't change, but how we interact with other things in space changes.
I said: "Yeah, so what? Why bring that up 5,000 in a conversation."
You responded: "It means when you say something is in motion, you are already saying that relative to something itself. It means when you say something is in motion, you are already saying that relative to something itself."
Right, all motion is relative in that sense, which makes the term "relative motion" totallly redundant. It's like saying someone is an "unmarried bachelor." Why not just say "motion," or "bachelor." What does the redundancy add? Why do keep stressing this redundancy? What is the significance? What point are you trying to make that isn't already completely obvious to everyone?
One Brow said: "Prove the statements you offered about relative motion, not similar statements about relational motion. Any time...I agree, not all motion is relative in SR. Only some types of motion are relative in SR."
Once again, it looks like vaguely-specified definitions are causing a problem in our communications.
Please define "relational motion," as you understand it.
Please define "relative motion," as you understand it.
What is the difference? Once again, is "relative motion" just a way of saying "motion" twice for you?
I said: Motion that is "merely relative" (relational) cannot cause absolute effects.
You asked: Why not? Feel free to prove that, any time.
===
You said: "So, I ask you to prove that relative motion can't cause absolute effects, and you respond by refuting a relational interpretation of motion? Yawn."
Read the statement you were questioning, and asking me to prove again, eh? It IS about relational motion ["merely relative" (relational)].
I responded to the question you asked. Here again, until I get some understanding of what you think the difference between "relative motion" and "relational motion" is, I don't think we can communicate.
One Brow said:
'The stationary observer O2 measures the moving clock C1 correctly as moving slower. The moving observer O1 measures the stationary clock C2 incorrectly as moving slower, but he is WRONG.
My question is: why does the moving observer O1 see the stationary clock C2 the WRONG way? What effect allows O2 to My question is: why does the moving observer O1 see the stationary clock C2 the WRONG way? What effect allows O2 to observe C1 correctly, and but prevents O1 from observing C2 correctly?"
OK, I'll try this one more time. To begin with, neither observer really "sees" the other's clock. Armed with knowledge of the applicability of the Lorentz transformations, each DEDUCES how time is passing in the other's frame.
But let's leave that aside for now, and pretend they actually "see" the other's clocks. What do they see? They "see" that the other clock is running at a different rate than their own. They do not "see" it running slower, they just see that it is different than their own.
Now, SR says the MOVING (accelerated) clock will be slowed down, so the answer to the question about whose clock is running slower reduces to is who is moving (faster).
Those with a relational philosophy, who want to claim that SR proves their views, say, in effect, that each observer MUST assume he is motionless. Given those assumptions, and only because of those artificial and senseless constraints on what each observer must assume, THEN (and only then), each will "see" the other's clock as moving slower than theirs.
So to answer your question (again): NOTHING prevents both from seeing the situation correctly, other than the erroneous assumptions that relationalists say the MUST make. Our physicist friend, you will recall, said that the train-ticket-buying, acceleraton-experiencing, "observer" thought he was motionless (and that all objects attached to the earth were moving past him) and, the physicicst said, HE WAS CORRECT.
He was not correct. Any sensible person would conclude that he and the train were moving relative to the earth. Under those circumstances, he would NOT "see" (deduce that) the earth clocks had slowed down. He would realize that his clocks (being the moving clocks in his case) had slowed down. The guy on earth would see it the same way.
They both "see" a difference in clocks. Which clock is "correct" is a matter of logical conclusion from assumptions. Wrong assumptions give wrong conclusions.
Is there something I've left out?
One Brow said: "Spaceships actually do this every mission upon re-entry. If your understanding is so meager that it truly eludes you something can accelerate from moving to being at rest, I see no point in continuing the conversation on relativity."
Eric, if your understanding of physics is so meager as to think any ship can escape the earth's gravitational field without first speeding up, then I see no point in us discussing anything about physics at all. You didn't say a single word about speeding up and THEN slowing down at some later time.
In every day useage, "accelerate" generally means to "speed up" (with "decelerate" used to differentiate "speeding up" from "slowing down"). I understand, of course, that phsyics uses accelerate to mean any change in speed or direction, but, again, you miss the point, and I hope you don't think your "technical" correction has the least bit of bearing on what I said.
Again, you cannot not make a ship slow down by blasting it out of earth's gravitational field. It could, of course, decelerate on its own, later, but not in order to leave earth.
Although Al says "moving" clocks slow down, he really means accelerated (in the everyday sense of speeded up) clocks slow down. The clock running at the higher rate of speed slows down. If you want to scream that nobody can ever know who is speeding up or slowing down, go tell it to Al, or, if you want "understanding," rather than a pre-emptive dismissal, go tell it to Mach.
If we speed up a ship, it is going faster than us. If it later slows down, it's clocks will speed up, at which point they may be going faster of slower than ours, depending on the degree of slowing.
If a spaceship can "slow down" (and I agree that it can), then why can't it slow down to absolute rest? If you brake a car, once it stops, hitting the brake will have no further effect. Hitting the brake on a stopped car doesn't make it go backwards, ya know?
So, there ya have it then. All we gotta do is blast a ship into space, then make it slow down until it stops. From then on, we will have a definite object which is motionless, and from which absolute velocities can be determined, see? Why aint some genius done thought of that, I wonder?
One Brow said: "Incorrect. LR predicts this through physical changes. SR predicts the contraction of rods and slowing of clocks without physical changes in the rods and clocks."
SR makes no such prediction. I've already quoted Hogg, Einstein, and others, and could (and in fact repeatedly have, already) further cite dozens of respectable, accomplished physicists to the same end.
But what good would it do? You never hear a word of it. You just continue to parrot, senselessly, the relationalist philosophy and new age slogans you have been thoroughly indoctrinated with.
Prove this: "SR predicts the contraction of rods and slowing of clocks without physical changes in the rods and clocks."
I know you can't prove it, but just try to even explain the "reasoning" you base it on and explain why Hogg, Al, and others don't get it, eh? I mean, you would think that at least Al would know what his own theory "predicts," eh? But that's apparently not what your guru predicts. Did he tell you why he doesn't predict that?
One Brow said: "In LET, every aspect of motion is absolute. There is a true center of the universe..."
Nobody, not Newton, not Lorentz, and not Al ever said this. Newton never claimed that motion was "absolute" in the sense you seem to be using the term. You just have some erroneously definitions. Newton said the whole solar system could well be moving, he said that the "theoretical" rest point (the center of gravity of the entire universe) could never be detected, and therefore that "true" or "right" motion could never be ascertained. He simply used inertial frames of reference (like SR does). For Newton, the center of gravity of the solar system provided a "motionless" point with respect to which, within the system, planetary motion could be determined.
I have already quoted Al as saying that Newton's "absolute space," the "ether," and "spacetime" in SR all boiled down to being the same thing: A necessary contextual background without which all physics would be impossible.
It is true, that, early in his career, Al boasted that he had eliminated the ether and "absolute space" (as Mach insisted should be done) He later clearly said he had been mistaken in doing so, and that he misunderstood the nature of the concept.
It is so like you to decide all issues, summarily and without further reflection, based upon some vague, ill-defined significance you give to the meaning of a single word (such as "absolute").
One Brow said: It's a real, physical effect.
One Brow said: SR predicts the contraction of rods and slowing of clocks without physical changes in the rods and clocks."
Of course you NEVER contradict yourself. All is perfectly consistent and coherent in your mind, it's just that you can't explain it. But, hey, why should that stop you from authoritatively declaring it without cessation.
The difference between LR and SR has nothing to do with preferred frames (both use them). The difference is that SR posits the speed of light to be invariable, and LR doesn't.
Speed is a function of time and distance. For the speed of something to be constant (like the rate of 60 mph to go from Chicago to New Orleans), then time and or distance must change for each traveller who leaves Chicago at the same time as others, but who does not arrive in New Orleans at the same time.
LR posits time to be constant between frames (not ABSOLUTE, in all caps, but "absolute" simply in terms of not varying). If you keep time constant, you can't keep speed constant (unless you rely exclusively on length changes). Time, being a mere concept, is constant. LR does not try to artifically distort familiar, necessary concepts in order to achieve a polemical end.
Clocks are retarded and rods are contracted with increased speed in both SR and LR. LR simply converts the mistakenly measured time arrived at by moving observers back to "standard time."
Both work the same, as far as predictions and calculated results are concerned. But LR avoids the senseless explanations that SR must resort to when improperly coupled with a relationalist philosophy. One need only look at the physical non-sensableness of the time slippage "explanation" (which we have gone over many times in the past) which geometricians using Minkowski diagrams pretend "explain" the difference of time found in the twin paradox. They make no physical sense to anybody, and only a formalist would find them to be a satisfactory explanation (just like they think a vague reference to a "change of inertial frames" provides a physical explanation of objective phenomena). Just like the guy who says gravity is caused by "time pointing downwards." Sounds like something an Indian guru would come up with as an "explanation," eh?
Unlike SR, LR does not generate the inconsistencies that invariably arise when one tries to have it both ways (as relationalist advocates of SR do when insisting that there is no preferred frame and that SR is therefore "correct," all while SR relies on preferred frames for all it's predictions and explanations--which they ignore, falsely deny, or simply do not understand. They ignore the content of the theory is order to promote their philosophical agenda.
In LR, one would simply say that a person who travelled 600 miles in 10 hours averaged a rate of 60 mph while one who made the same trip in 12 hours averaged 50 mph.
SR says both MUST travel at the rate of 60 mph, and that, therefore, the distance increased, and time slowed down, for the guy who might otherwise "appear" to have only travelled at the rate of 50 mph.
LR is similar in this respect: If the guy who averaged 50 mph swears that he calculated himself as averaging 60, LR says: Yeah, that's what you measured because your watch and your odometer were miscalibrated. Your calculations are correct, based upon your information, but your information is wrong.
One last time:
1. SR says the speed of light is invariable, therefore time must change.
2. LR says time is invariable, therefore speed must change.
One can achieve the same mathematical results either way. But one makes sense, and one doesn't, at least not when one (improperly) claims on behalf of SR, that "time" really changes. Time is not a thing. It is not a physical "dimension," like space, that you can move around in, and take "paths" in. Time doesn't change, although measurements of it can certainly vary, as anyone who ever had a watch with a bad battery can attest to.
One Brow said: "I believe that technically, it is the center of gravity of that planet and the sun, not the solar system as a whole)."
My understanding is different, although it's not a major issue, by any means, and I could easily be wrong (I never claimed to be a physicist).
Both the earth and the moon orbit their common "center of mass," as I understand it, although that center of mass is always well-within the earth and not outside of it.
Likewise, the Sun, and all planets, actually orbit the center of mass of the solar system (not always within the diameter of the sun (or so I've been told, as I recall).
"This article has been concerned with tracing the history and philosophy of ‘absolute’ and ‘relative’ theories of space and motion...There is the question of whether all motions and all possible descriptions of motions are equal, or whether some are ‘real’ — what we have called, in Seventeenth Century parlance, ‘true’. There is a natural temptation for those who hold that there is ‘nothing but the relative positions and motions between bodies' (and more so for their readers) to add ‘and all such motions are equal’, thus denying the existence of true motion"
Heh, I like the parenthetical "and more so for their readers" part, eh? One Brow said: "There is one truth, and a million different, equally valid means of stating it." What do these platitudes of yours really mean, Eric? What are the physical (not psychological) implications of your "equally valid" claim? Are heliocentric and geocentric descriptions of planetary motion "equally valid," as Mach claimed, in a PHYSICAL sense?
One reason this author treats participants in the absolute/relative debate as distinct from their readers is because, he claims:
"However, arguably — perhaps surprisingly — no one we have discussed [Descartes, Liebniz, Mach, Einstien, etc.] has unreservedly held this view (at least not consistently)"
http://plato.stanford.edu/entries/spacetime-theories/#1
Whose side are you on, Eric? Is there, or is there aint, any such thing as "true" motion?"
One Brow said: "I've already given you one possible explanation: the path of the object moving in a different inertial frame points away from us in spacetime. There are others."
You seem to think this abstract gobblety-gook says something about physical reality (rather than about Minkowski diagrams on graph paper), but I don't see it. In any event, it is NOT a part of SR as a physical theory. It is a philosophical reinterpretation of that theory, at best. Al specifically says that rods contract and clocks are retarded, not that motion causes a false appearance of change due to the angle of perspective.
One Brow said: "The thing is, we are using the same ruler. However, one of us is measuring at an angle compared to the sidelines, the other is measuring parallel to the sidelines."
Same comment here. I have no clue what you're really trying to say. According to Al, they are NOT using the "same ruler." One has contracted. I've seen a lot of physical explanations of length contraction and time dilation from physicists, but never this one.
Here's a typical explanation. A guy throws a ball straight up (for him) about 20 feet, and catches it when it comes straight down (total travel distance is 40 feet).
How does a moving observer see this? Well, he sees the ball leave the guys hand and return to it at the same time(s) the guy throwing the ball does. But he might "see" the ball travelling 40 miles instead of just 40 feet. Why? Because in addition to going 20 feet up and 20 feet down, he also sees it as going 40 miles to the west (for example) between the time it left the guy's hand and returns to it. How can it travel 40 miles in that short of a time AND have the speed of light to be the same in all inertial frames? Well, time and distance have to change relative to each observer.
What do "angles" have to do with anything? If you could actually explain why, rather than simply assert, your assertion makes sense, maybe it could be evaluated. Absent that, it's just a curious statement.
It does appear, however, that you want make the observer's perspective the cause of what Al says is a physical change. Changes in viewpoints do NOT cause physical changes. They may well cause changes in subjective perception, but.....
One Brow said: "I think the stupid part is taking a claim that is assuming there is no preferred intertial state, and interpreting it within a frame that insists on a preferred inertial state."
Exactly. Despite the unwarranted, mistaken, and loud braying of the relationalists that "there is no preferred frame in SR," SR relies on a preferred frame to make predictions and to say anything meaningful whatsoever. Why try to interpret SR within the framework of a Machian relationalist theory?
One Brow said: "The baseball doesn't have a unique rest frame. It accelerated."
1. Just because the laws of physics, in their simplest (i.e., without needing to account for forces caused by acceleration) form are not the same in accelerating reference frames as in inertial ones does not mean such a frame cannot be a reference. It can be, the principle of relativity simply won't apply to it.
2. A perfect example of putting your desired conclusion into your premises. If I'm a baseball, I can insist that I'm at rest and that the bat, the batter, and the whole earth is accelerating away from me. Zeno's old paradox still holds for accelerating objects: A flying arrow never moves (relative to itself).
Before you claimed there can be no "actual motion" until a physicist chose a rest frame. As if a deer running across route 64 and getting smashed by a semi at this very moment didn't, and couldn't, actually move until someone chose to designate a "rest frame" for it to move relative to. Now, you say the baseball "can't" have a rest frame because it accelerated, which presupposes a rest frame already chosen, which determines, in advance, what can't even be chosen be a frame of reference.
I asked: "Do you have any idea of what Al is saying here?"
You replied: "Yes, I agree with them."
===
If you understand Al, and if you agree, then you would have to agree that the modern physicist quoted below is trying to impute the same Machian, logical positivistic views to Al that Al upbraided Percy Bridgman (quoted above) for trying to impute to him. This is the Machian view which Al rejects and which does NOT reflect the physical content of SR:
"Q. Do you have a favorite definition of time?
A. [from William Phillips] "Yes. The one I like best is the one given by Einstein which is “time is what a clock measures."...By taking seriously the idea that time is what a clock measures Einstein was able to come up with a deeper understanding of the nature of time than had been the case before....Taking the idea seriously, that time is what a clock measures, you come to the conclusion that time is running more slowly for the person who is moving from the observer’s point of view."
http://www.electricalfun.com/ElectronCafe/William_Phillips_interview.aspx
The Machian/logical positivist philosophy was so strongly drummed into physicists in the 20's and 30's that it sometimes still seems as persistent among physicists as ever, even though completely discredited. More from William Phillips:
"Time is relative to the reference frame in which you are measuring it. So if I am sitting at rest in my laboratory and I see somebody who is moving with respect to me and I look at their clock I’m going to conclude that their clock is running slower than my clock – even though the two clocks are completely identical in every other respect. Now that observer, in his moving laboratory is looking at me – motion is just relative – he’s going to come to the same conclusion, that my clock is running slower than his. This sounds paradoxical but it is completely consistent with everything we know about the way the world works."
At least after that misleading spiel, he acknowledges that SR does NOT predict that both clocks are running slower than the other. But somehow, he doesn't see that fact as inconsistent the the foul philosophical spew he just regurgitated ("This sounds paradoxical but it is completely consistent with everything we know about the way the world works").
The "world" does not "work" that way, evem if the human mind, relying on incorrect assumptions, does "work" that way.
Even when he acknowledges that the moving clock is the one which slows down he (1) reveals no insight as to why, and (2) immediately tries to effectively deny it:
"Well, whose clock is slower? The person who goes and comes back is the one whose clock is slower. In order to go away and come back you have to turn around, and there is no ambiguity about turning around. There is ambiguity about who is moving and who is not moving, because motion is relative."
If there is "ambiguity about who is moving and who is not moving" then how in the hell could he conclude that it was the one who "goes and comes back" whose clock is slower to begin with? He says there is "no ambiguity" about that. But how could he know who is going, and who is coming back if the question of who is moving motion cannot be answered to begin with? He doesn't appear to have any sense of the internal contradiction he just offered up as "the way the world works."
I'm re-quoting Dieks to reinforce the point:
"As Howard (2007) points out, it was only with the downfall of logical empiricism that philosophy of science caught up with Einstein’s thinking about the status of physical concepts. In the philosophy of physics the notion that at the fundamental level it is basic physical theory that is important for the status of space and time, has only rather recently gained substantial ground (cf. Brown, 2005; Dieks, 1984)."
One Brow said: "Only some types of motion are relative in SR."
1. What types of motion are "relative" in SR?
2. Once again, what do you intend to convey by the use of the word "relative" here? I think you intend to say "strictly relational."
3. Einstien said there was nothing "epistemologically new" in SR. In what way does SR, as a physical theory, say anything about what motion is "relative?" I contrast "as a physical theory" (it's physical concepts and the corresponding math) from "epistemological philosophy" (such as the epistemological philosophy that if I don't know the answer to something, there is, and can be, no answer, because I am the measure of all things).
aintnuthin said...
Please define "relational motion," as you understand it.
Please define "relative motion," as you understand it.
In relational motion, no aspect of motion is absolute.
In relative motion (that is, the version used by SR/GR), acceleration and higher aspects are absolute, velocity and position are relative.
In absolute motion, all aspects of motion are absolute.
Nobody, not Newton, not Lorentz, and not Al ever said this. Newton never claimed that motion was "absolute" in the sense you seem to be using the term.
At the very least, LET proposes absolute velocity (regardless of what Newton, Lorentz, or Einstein proposed). Without it, you have no way of saying one interpretation is WRONG about which clock is slower, because you can accelerate to a lower speed.
What is the difference? Once again, is "relative motion" just a way of saying "motion" twice for you?
"Motion" technically describes all aspects of moving, not just velocity/speed. Relative motion is a specific statement about specific aspects of motion.
Read the statement you were questioning, and asking me to prove again, eh? It IS about relational motion ["merely relative" (relational)].
Careless of me, sorry. You were not referring to relative motion, got it.
OK, I'll try this one more time. To begin with, neither observer really "sees" the other's clock.
Why not? What prevents the light from traveling from C1 to O2?
Armed with knowledge of the applicability of the Lorentz transformations, each DEDUCES how time is passing in the other's frame.
I understand this is your interpretation, but that does not answer the question of why only one person see the other's clock incorrectly.
But let's leave that aside for now, and pretend they actually "see" the other's clocks. What do they see? They "see" that the other clock is running at a different rate than their own. They do not "see" it running slower, they just see that it is different than their own.
What sort of difference do they see? Faster? Reversed direction?
Now, SR says the MOVING (accelerated) clock will be slowed down, so the answer to the question about whose clock is running slower reduces to is who is moving (faster).
Again, does not explain what the observers see. According to SR, each sees the other's clock as moving more slowly. Again, not "observe", but "see", using Hogg's terrminology.
Those with a relational philosophy,
Not relevant.
So to answer your question (again): NOTHING prevents both from seeing the situation correctly,
Yet, one sees it incorrectly.
Is there something I've left out?
Yes, you left out the actual difference each person sees between their clock and the other clock, a very straightforward thing in SR.
SR makes no such prediction. I've already quoted Hogg, Einstein, and others, and could (and in fact repeatedly have, already) further cite dozens of respectable, accomplished physicists to the same end.
They would all agree that the physical contraction occurs without physical changes to the rods and clocks themselves, if you pose the questions that precisely.
You just continue to parrot, senselessly, the relationalist philosophy ...
Why should I parrot an interrpreation that I do not hold to?
One Brow said: It's a real, physical effect.
One Brow said: SR predicts the contraction of rods and slowing of clocks without physical changes in the rods and clocks."
Of course you NEVER contradict yourself.
In thisparticular case, there is no contradiction.
... it's just that you can't explain it.
I can't seem to explain it in a way that makes sense to you.
Likewise, the Sun, and all planets, actually orbit the center of mass of the solar system (not always within the diameter of the sun (or so I've been told, as I recall).
I did some reading up, and it might just be different ways of saying the same thing anyhow.
Heh, I like the parenthetical "and more so for their readers" part, eh? One Brow said: "There is one truth, and a million different, equally valid means of stating it." What do these platitudes of yours really mean, Eric? What are the physical (not psychological) implications of your "equally valid" claim?
I'm not aware of anyphysical implications to having a million equally valid descriptions of a phenomena, outside of the notion they exist.
Are heliocentric and geocentric descriptions of planetary motion "equally valid," as Mach claimed, in a PHYSICAL sense?
No, that would be a relational motion position, denying the absluteness of acceleration (and the conservation of energy).
Whose side are you on, Eric? Is there, or is there aint, any such thing as "true" motion?"
Define it more specfically first, since you don't like my understandings of it.
Al specifically says that rods contract and clocks are retarded, not that motion causes a false appearance of change due to the angle of perspective.
Nor was I talking about a false appearance of change based upon perspective.
Let's go back to the example of the yardstick in the sunlight. We agreed it could cast a different shadow depending upon it's positon, did we not? We agreed this was a real, physical, measurable effect, and not an illusion, did we not? We agreed this is true even though the yardstick itself did not contract/expand, did we not?
If you want to call that "perspective", as I initially did, fine. That doesn't make it just an appearance. There is a real effect on the shadow. You can see the effect even if you can't manipulate the yardstick.
One Brow said: "The thing is, we are using the same ruler. However, one of us is measuring at an angle compared to the sidelines, the other is measuring parallel to the sidelines."
Same comment here. I have no clue what you're really trying to say.
It's like using the shadows to make the measurement, not the yardsticks themselves, and one yardstick is pointed partially away from the sidelines.
According to Al, they are NOT using the "same ruler." One has contracted. I've seen a lot of physical explanations of length contraction and time dilation from physicists, but never this one.
I don't think many people phrase their questions like you do.
Exactly. Despite the unwarranted, mistaken, and loud braying of the relationalists that "there is no preferred frame in SR," SR relies on a preferred frame to make predictions and to say anything meaningful whatsoever.
I agree. Our difference is that you say there can only be one preferred (inertial rest) frame, and I don't.
1. Just because the laws of physics, in their simplest (i.e., without needing to account for forces caused by acceleration) form are not the same in accelerating reference frames as in inertial ones does not mean such a frame cannot be a reference.
It can be a reference, but not a *rest frame*, because rest frames do not undergo acceleration, and acceleration is an absolute.
Before you claimed there can be no "actual motion" until a physicist chose a rest frame.
No, I did not. You misinterpreted such.
If you understand Al, and if you agree, then you would have to agree that the modern physicist quoted below is trying to impute the same Machian, logical positivistic views to Al that Al upbraided Percy Bridgman
Unless I think you have misinterpreted the physicist below. If youare inferring a machian view from him, you have.
"Well, whose clock is slower? The person who goes and comes back is the one whose clock is slower. In order to go away and come back you have to turn around, and there is no ambiguity about turning around. There is ambiguity about who is moving and who is not moving, because motion is relative."
If there is "ambiguity about who is moving and who is not moving" then how in the hell could he conclude that it was the one who "goes and comes back" whose clock is slower to begin with?
He is speaking imprecisely, not separating "motion" from "velocity", but using the same term for both.
A better way to put it:
Well, whose clock is slower? The person who goes and comes back is the one whose clock is slower. In order to go away and come back you have to turn around, and there is no ambiguity about turning around. There is ambiguity about when a person has non-zero velocity and when a person does not, because velocity is relative.
Rescued some additional comments from the spam filter.
Eric, if your understanding of physics is so meager as to think any ship can escape the earth's gravitational field without first speeding up,
Speeding up relative to the surface of the earth, or the center of gravity of the galaxy? You can certainly escape the earth's graviational field while slowing down compared to the latter.
then I see no point in us discussing anything about physics at all. You didn't say a single word about speeding up and THEN slowing down at some later time.
Yet, your whole position rests on some knowledge that people have not sped up.
Although Al says "moving" clocks slow down, he really means accelerated (in the everyday sense of speeded up) clocks slow down. The clock running at the higher rate of speed slows down. If you want to scream that nobody can ever know who is speeding up or slowing down, go tell it to Al,
The funny think is you think Einstein agree with you.
If a spaceship can "slow down" (and I agree that it can), then why can't it slow down to absolute rest?
It can slow down complete rest. Absolute rest requires an absolute rest frame.
Exactly. Despite the unwarranted, mistaken, and loud braying of the relationalists that "there is no preferred frame in SR," SR relies on a preferred frame to make predictions and to say anything meaningful whatsoever.
Not "Despite", "In addition to". There is no preferred rest frame in SR; SR relies on a preferred rest frame to make predictions.
Why try to interpret SR within the framework of a Machian relationalist theory?
No one is, except your strawman.
One Brow said: "It can be a reference, but not a *rest frame*, because rest frames do not undergo acceleration, and acceleration is an absolute"
Well, I agree that acceleration is absolute, but there is still the question of which object is accelerating. I recall your former (mistaken) position was that acceleration been rendered "relative" by GR.
One Brow said: "At the very least, LET proposes absolute velocity (regardless of what Newton, Lorentz, or Einstein proposed). Without it, you have no way of saying one interpretation is WRONG about which clock is slower..."
Well, if that's the case, then SR proposes "absolute velocity," because they twin paradox resolution says both observers conclude that the other's clock is moving more slowly (ask yourself why--it is not because of what they see), but that one is wrong.
One Brow said: "At the very least, LET proposes absolute velocity..."
Per Van Flandern: "Einstein’s innovation in SR was to abolish the need for aether, or more specifically, the need for a preferred frame, by making all inertial frames equivalent, with each having the same speed of light. LR went in the opposite direction, specifying that the generalized, amorphous, universal aether of LET should in fact be identified with the local gravitational potential field, which is of course a different frame from place to place."
http://www.metaresearch.org/cosmology/gravity/lr.asp
A "different frame from place to place" is a preferred frame, but not an absolute one. LR does NOT require a motionless ether, as authors I have already quoted make clear. It so happens that virtually every physicist used to believe that there had to be a luminiferous ether as a medium to propogate light waves, but that was not based on considerations about motion, per se.
I notice that you now attempt to define "relative" by contrasting it with the term "absolute." I have already told you that neither I, nor most people I'm aware of, use "absolute" in that sense in this context.
One Brow said: "Again, does not explain what the observers see. According to SR, each sees the other's clock as moving more slowly."
Where does "SR" say that, straightforwardingly, or otherwise? In any explanation that is at all comprehensive, it is always made clear (explicitly or implicitly) that the mental conclusion that the other clock is slower is based upon the assumption that the observer drawing that conclusion is "at rest." Re-read what Phillips (who I just quoted) says, just for one example.
One Brow said: "They would all agree that the physical contraction occurs without physical changes to the rods and clocks themselves, if you pose the questions that precisely."
Hogg was very clear in what he was trying to stress, without anybody asking. Eric, you have to be far and away the most bigoted person I've ever had any extended conversations with. Hogg could scream at you 50 times that his car is black, but if you had already concluded that he had a white car, you would insist that he was saying it was white.
How can "physical contraction" occur WITHOUT "physical changes?" Your claim does even make the least bit of sense. A contraction is a change. You seem capable of convincing yourself that whatever you believe has to be true, all while remaining totally oblivious to all your own internal contradictions.
One Brow said: "Yet, your whole position rests on some knowledge that people have not sped up."
No, it doesn't. My knowledge (and yours) of any particular circumstance has NOTHING to do with it. SR predicts what it predicts, and it's predictions do NOT depend on who knows what about any particular object or objects. If it predicts that only one of two clocks "really" slows down, then only one of two really do (according to the theory).
What is your point? That nothing can be known? That "knowledge" is an illusion? What are you trying to say? You think physics depends on your knowledge. I don't.
Why do you think physics depends on what you, personally, think you know?
One Brow said: "Let's go back to the example of the yardstick in the sunlight. We agreed it could cast a different shadow depending upon it's positon, did we not? We agreed this was a real, physical, measurable effect, and not an illusion, did we not?"
To begin with, your analogies, standing alone, say nothing about rods and clocks, unless you can show the connection. We are not talking about measuring "shadows." Shadows are NOT solid, three-dimensional physical objects like rigid rods are. Shadows are merely an object of perception, with no tangible physical substance. As always, you want to equate perception with physical reality, it seems, just like Einstein complained about Mach trying to do.
One Brow said: In relational motion, no aspect of motion is absolute."
Eric, you are presenting an "all or nothing" explanation. If a particular motion is relational, then it is, whether or not every other concievable motion is or not. This doesn't address the question.
One Brow said: "In relative motion (that is, the version used by SR/GR), acceleration and higher aspects are absolute, velocity and position are relative."
I take you to be saying that, in SR, inertial motion is "relative." The question remains, what do you mean by "relative" is this context?
One Brow said: "Yet, one sees it incorrectly."
I've said this probably at least 100 times, Eric:
1. SR, itself, (not me, not "my interpretaion," not my philosophical preference, but the mathematics of SR) says ONLY ONE clock (at most) really runs slower. It therefore indisputably follows that:
2. If both think the other's clock is running slower that at least one of them MUST be wrong.
Al never insisted that "both see the other's clock as running slower." That is the insistence of the Machian, logical positivists who jumped in to use SR as a vehicle for their propaganda.
Both can only "see" the other's clock as being slower if BOTH assume they are motionless. But, of course, they can't be in motion with respect to each other and both also be motionless. The contradiction is readily apparent to anyone who has not been brainwashed by the relationalists.
I asked: "Whose side are you on, Eric? Is there, or is there aint, any such thing as "true" motion?"
You responded: "Define it more specfically first, since you don't like my understandings of it."
I wasn't the one defining it, the author I was quoting was. Here it is again:
"There is a natural temptation for those who hold that there is ‘nothing but the relative positions and motions between bodies' (and more so for their readers) to add ‘and all such motions are equal’, thus denying the existence of true motion"
You deny "true motion" if you assert that "all such motions are equal."
Which side are you on?
To expound on the last post a little:
For clarification purposes (i.e., to avoid the ambiguities that can arise from the word "absolute"), this author replaced one particuar useage of the term "absolute" (as traditionally used) with the adjective "true" (as used by Newton and others of his time). In the context of the historical debate, absolute motion is "true motion." Relative motion is merely "apparent" motion, and no "truth" of the matter can ever be ascertained if one asks which of two (or more) objects is "truly" moving. The whole question of "which one" is moving is senseless, meaningless, and simply asking for metaphysical speculation in this view.
aintnuthin said...
Well, I agree that acceleration is absolute, but there is still the question of which object is accelerating. I recall your former (mistaken) position was that acceleration been rendered "relative" by GR.
Yes, rotational acceleration is not not relative at all, even within GR. Within GR, lienar acceleration can be treated relatively.
Well, if that's the case, then SR proposes "absolute velocity," because they twin paradox resolution says both observers conclude that the other's clock is moving more slowly (ask yourself why--it is not because of what they see), but that one is wrong.
There is no absolute velocity needed within SR to resolve the twin paradox. You can assume the unaccelerated twin is stationary. You can assume the traveling twin is stationary after decelerating to 0, while the unacceleragted twin is moving away from him, and the traveling twin subsequently moves to catch up to him. You can assume the unaccelerated twin moves at a constant velocity, while the traveling twin at first moves faster, and then pulls to a complete stop. In each case, you get the same resolution. Since SR can use any of those three (and an infinite number in addition), in what way does it "propose" an absolute velocity?
Per Van Flandern: "Einstein’s innovation in SR was to abolish the need for aether, or more specifically, the need for a preferred frame, by making all inertial frames equivalent, with each having the same speed of light. LR went in the opposite direction, specifying that the generalized, amorphous, universal aether of LET should in fact be identified with the local gravitational potential field, which is of course a different frame from place to place."
A "different frame from place to place" is a preferred frame, but not an absolute one.
A locally absolute frame, but still absolute.
LR does NOT require a motionless ether,
The ether is basically motionless within the gravitational field.
I notice that you now attempt to define "relative" by contrasting it with the term "absolute." I have already told you that neither I, nor most people I'm aware of, use "absolute" in that sense in this context.
Except, if you don't, then your only complaint boils down to terminiology.
One Brow said: "Again, does not explain what the observers see. According to SR, each sees the other's clock as moving more slowly."
Where does "SR" say that, straightforwardingly, or otherwise?
As you mention above, each twin sees the other's clock as moving slower (while they are separating).
In any explanation that is at all comprehensive, it is always made clear (explicitly or implicitly) that the mental conclusion that the other clock is slower is based upon the assumption that the observer drawing that conclusion is "at rest."
How does assuming you are at rest change what you see?
One Brow said: "They would all agree that the physical contraction occurs without physical changes to the rods and clocks themselves, if you pose the questions that precisely."
Hogg was very clear in what he was trying to stress, without anybody asking.
Yes, and his explanation fits mine precisely.
Hogg could scream at you 50 times that his car is black, but if you had already concluded that he had a white car, you would insist that he was saying it was white.
Except, Hogg would agree with me here.
How can "physical contraction" occur WITHOUT "physical changes?"
There are physical changes, but not to the rods and clocks themselves.
SR predicts what it predicts, and it's predictions do NOT depend on who knows what about any particular object or objects. If it predicts that only one of two clocks "really" slows down, then only one of two really do (according to the theory).
If you don't choose a reference frame before making the determination, SR makes no specfic predictions.
One Brow said: "Let's go back to the example of the yardstick in the sunlight. We agreed it could cast a different shadow depending upon it's positon, did we not? We agreed this was a real, physical, measurable effect, and not an illusion, did we not?"
To begin with, your analogies, standing alone, say nothing about rods and clocks, unless you can show the connection.
You can't see the analogy? You find it false for some reason? Which reason?
We are not talking about measuring "shadows." Shadows are NOT solid, three-dimensional physical objects like rigid rods are. Shadows are merely an object of perception, with no tangible physical substance.
Incorrect. Shadows have different light absorption rates than non-shadowed areas, leading to many physical effects. Shadows are darker and cooler. You can verify them with a thermometer, for example. They are not merely perception, unless you think light and temperature are merely perception.
As always, you want to equate perception with physical reality,
Yet here, you deny physical reality.
Eric, you are presenting an "all or nothing" explanation. If a particular motion is relational, then it is, whether or not every other concievable motion is or not. This doesn't address the question.
I said "every aspect of motion", not "every motion". Every phenomenon of motion has various aspects (position, velocity, acceleration, jump, etc.). In relational motion, all of these aspects are considered relative.
I take you to be saying that, in SR, inertial motion is "relative." The question remains, what do you mean by "relative" is this context?
It has to be defined relative to an arbitrary choice of an inertial frame, no inertial frame is priviledged as being best.
I've said this probably at least 100 times, Eric:
1. SR, itself, (not me, not "my interpretaion," not my philosophical preference, but the mathematics of SR) says ONLY ONE clock (at most) really runs slower.
SR only says this after you decide on the preferred intertial frame.
It therefore indisputably follows that:
2. If both think the other's clock is running slower that at least one of them MUST be wrong.
Yes, the one not in the preferred inertial frame is wrong.
But, of course, they can't be in motion with respect to each other and both also be motionless.
Of course not. Once you know which state represents motionlessness, they will not both be motionless.
I wasn't the one defining it, the author I was quoting was. Here it is again:
"There is a natural temptation for those who hold that there is ‘nothing but the relative positions and motions between bodies' (and more so for their readers) to add ‘and all such motions are equal’, thus denying the existence of true motion"
You deny "true motion" if you assert that "all such motions are equal."
Which side are you on?
Obviously things can have different motions, so motions can be unequal. Does anyone really think all motions are equal?
I think your definition is poorly worded.
aintnuthin said...
To expound on the last post a little:
I saw this after my most recent posts.
For clarification purposes (i.e., to avoid the ambiguities that can arise from the word "absolute"), this author replaced one particuar useage of the term "absolute" (as traditionally used) with the adjective "true" (as used by Newton and others of his time). In the context of the historical debate, absolute motion is "true motion." Relative motion is merely "apparent" motion, and no "truth" of the matter can ever be ascertained if one asks which of two (or more) objects is "truly" moving. The whole question of "which one" is moving is senseless, meaningless, and simply asking for metaphysical speculation in this view.
So, the author is claiming there is a "true" motion that can be "ascertained"? HOw does one "ascertain" the "true" motion?
I said: "Al never insisted that "both see the other's clock as running slower." That is the insistence of the Machian, logical positivists who jumped in to use SR as a vehicle for their propaganda."
Let me try to break this down a little. First, let's clarify what is meant by an "inertial frame of reference."
I will first note that you often seem to speak of an "inertial frame" as though it is something tangible and physically existing. You often speak as though "tilting" or "changing" inertial frames can cause differences is physical reality.
But an "inertial frame of reference" is simply a matter of a particular perspective, taken or held by one or more individuals. It is, at bottom, merely a subjective, mental "thing" and any corresponding physical concomittants are merely contingent. If I happen to be standing on the corner of 12th street and Vine, looking east, then that is my frame of reference. I will not see things to the west of me, but that doesn't mean they don't exist.
Now, you will hear the relationalists, when arguing for their particular brand of "truth" constantly shift back and forth between frames of reference. First they will talk about observer A, and then quickly contrast A's "frame of reference" with observer B's "frame of reference."
Alway implicit is that in A's "frame of reference" A is motionless and in B's "frame of reference" B is motionless. And, of course, they will tell you that both A and B's "frame of reference" are "equally valid," and that "both are correct."
It is an obvious truism that one will see different things looking east than he does looking west. But, the claims of Berkeley and his ilk notwithstanding, the things to the west don't disappear when I look east. They are still existing. To say you will see different things looking east than you will looking west tells you NOTHING about what is "true," what is "real" or what is (or is not) absolute.
But, the relationalists favorite form of "arguing" aside, A and B cannot BOTH be motionless if they are moving with respect to each other. The whole style of argument is ultimately based on a false premise.
One Brow said: "You can't see the analogy? You find it false for some reason? Which reason?"
Analogies are neither true nor false. They are either applicable and useful for comparative purposes or not. Your analogy is NOT for the very reasons I've already stated and won't bother to repeat here.
One Brow said: "Incorrect. Shadows have different light absorption rates than non-shadowed areas, leading to many physical effects. Shadows are darker and cooler. You can verify them with a thermometer, for example. They are not merely perception, unless you think light and temperature are merely perception."
OK, I guess I will say it again. A "shadow" is not cooler, darker, or anything else, even if the the air, the grass, or the car behind it is. A shadow is NOT a tangible, solid, three dimensional object like a rigid rod. The sun is a physical object, an object blocking sunlight (say a house) is a physical object, and the objects in the area where the sunlight is blocked by the house are too. The shadow is not. A shadow is not "cooler," or anything else. Many conditions, qualities, and concepts which apply to physical objects simply do not apply to it. Next thing I know, you'll be telling me that "nightime" is a physical object, too, eh?
One Brow said: "So, the author is claiming there is a "true" motion that can be "ascertained"? HOw does one "ascertain" the "true" motion?"
No, the author is making no claims whatsoever; he is merely summarizing the issues and arguments that have been made on each side of the debate.
Which side are you on?
One Brow said: "If you don't choose a reference frame before making the determination, SR makes no specfic predictions."
Now, for the 10,001st time, you have made this assertion as though it has some special significance that "changes" everything. But, of course, you never did respond to my specific questions:
I asked: "It's like saying someone is an "unmarried bachelor." Why not just say "motion," or "bachelor." What does the redundancy add? Why do keep stressing this redundancy? What is the significance? What point are you trying to make that isn't already completely obvious to everyone?"
Suppose I say to you: "You cannot draw any logical conclusions without a premise." Let's say you agree. OK, fine, we've established that. But if I just keep on saying it, over, and over, and over, I must be trying to imply something further.
What are you trying to imply?
I meant to also say this in the last post:
One Brow said: One Brow said: "If you don't choose a reference frame before making the determination, SR makes no specfic predictions."
SR makes predictions either way. It's predictions do not depend on you choosing a reference frame. The clock which is moving will be slower WHICHEVER frame of reference you happen to pick.
I said: "SR makes predictions either way."
Here's an analogy. Let's say that I "predict" (state an obvious fact, really) that if you hold a loaded 45 magnum to a guy's temple and pull the trigger, then he will suffer great bodily injury.
Now suppose I do hold a 45 Magnum to your head and tell you I'm going to pull the trigger. You don't know if the gun is loaded. Does your knowledge of that change my prediction in any way?
Of course not. My prediction was itself conditional, dependent on a "if." It is just as valid whether any particular 45 is, or is known to be, loaded or not.
As stated, the prediction is, and will always be, valid.
One Brow said: "There is no absolute velocity needed within SR to resolve the twin paradox. You can assume the unaccelerated twin is stationary. You can assume the traveling twin is stationary after decelerating to 0, while the unacceleragted twin is moving away from him, and the traveling twin subsequently moves to catch up to him. You can assume the unaccelerated twin moves at a constant velocity, while the traveling twin at first moves faster, and then pulls to a complete stop. In each case, you get the same resolution. Since SR can use any of those three (and an infinite number in addition), in what way does it "propose" an absolute velocity?"
In what way is LR the least bit different? None of these theories (Newton's, Lorentz's, or Al's) are in the least bit dependent upon establishing "absolute velocity." We have talked about this many times before, but you just can't seem to shake this misconception.
Suppose I'm sitting on my lazy ass, watching two horses running around a racetrack.
Assume that, among other things, all three of us are rotating at the rate of about 20,000 mph, while orbiting the sun at a high rate of speed all while the sun and us are revolving in the galaxy all while the whole galaxy itself is moving toward the Constellation Leo at an extremely high rate of speed. OK, so, now what?
Does that mean the horses are standing still, and I'm moving? Of course not. In ADDITION to all that other motion, the horses are also moving around the track, and I'm not. And, whatever their "absolute velocity" one horse also happens to be moving faster than the other.
What's the problem? How do I need to determine "absolute velocity" to know that?
One Brow said: "It has to be defined relative to an arbitrary choice of an inertial frame, no inertial frame is priviledged as being best."
1. What do you mean by "arbitrary?" Is is "arbitrary" to claim that the earth "really" (truly, absolutely) rotates on it's axis while orbiting the sun? Is there no non-arbitrary reason to "prefer" this view to one which holds that the earth is motionless?
2. Everything has to be defined relative to something. That's the way definitions work, ya know. Everything (certainly not just "motion) works that way. We've been through this many times. Your point is..... What?
Look, Eric, we can at least imagine a motionless state, even if you can't say with God-like certainty, what objects, if any, are in that state.
We can imagine that if an object, let's say it's an eight-ball, were in a motionless state, and some fast(er)-moving object, like, say, a cue ball, came along and bashed into it then it would start moving and no longer be "motionless," right?
Let's say that it now has a constant speed of 50 mph compared to it's former rest state, and settles into a uniform state of motion at that speed.
Now say another fast-moving cue ball bashes into it. How fast would it be going now? Well, faster than it was, we know that. Let's say that, once again, it is now going 50 mph faster than it was before. That would be true if it started out going an "absolute" speed of 50 mph, or 500,000 mph. Either way, it is now going 50 mph faster than it was. We know it is moving, and moving faster than it was before, regardless.
If acceleration is "absolute" then an object which has been accelerated, but then stablizes at into uniform motion, is still moving at an accelerated rate of speed compared to its former rate of speed, and, we believe, it will remain at that (new) rate of speed until it is once again acted upon by an external force.
All that is true whether we know it's entire history of accelerations or not. Our speed does not retroactively determine how often, and how much, that object has been accelerated in the past. The fact that we might not know it's history does not mean it has no history.
Assume every particle in the universe started out "motionless" in the "cosmic egg" prior to the big bang. If they are now going different rates of speed, then it is because they have been more or less accelerated in the past. This would be true of each and every such particle, and the motion of any other particle would have no current bearing on it's current rate of speed. The speed of one object does not "determine" the speed of another unless perhaps they collide. Nor would my choice of a "frame of reference" in any way re-write their histories of acceleration and inertial motion. The two things are simply totally unrelated. Unless, maybe, you are a Berkeleyite.
Of all the objects in the universe, some have, in the past, been accelerated to higher rates of speed than others. If they hadn't been, they would all be going the exact same speed now. According to SR, in each and every case, the faster the speed of the object, the more it's clocks slow down. Whether we know which ones are faster, or not. Whether we "like it," or not. All that's irrelevant to what SR predicts.
Since you want to reject all "absolutes," Eric, why don't you reject SR? According to the Stanford University Gravity Probe B astronomers:
"In 1918, Einstein described Mach's principle as a philosophical pillar of general relativity, along with the physical principle of equivalence and the mathematical pillar of general covariance. This characterization is now widely regarded as wishful thinking. Einstein was undoubtedly inspired by Mach's relational views, and he hoped that his new theory of gravitation would "secure the relativization of inertia"...The theory does not make spacetime more relative than it was in special relativity. Just the opposite is true: the absolute space and time of Newton are retained."
http://einstein.stanford.edu/SPACETIME/spacetime2.html
I keep asking you: Why don't you reject SR? You want to reject all it's tenets.
====
Let's forget about 2 clocks for a minute, and just talk about 1. Al didn't seem to like the concept of absolute rest, but he certainly had no problem with absolute top-ends. In SR, the speed of light is ABSOLUTELY ABSOLUTE. And what does SR tell us about rods and clocks, as they relate to this absolute measure?
Simple: the closer a rod and a clock get to the speed of light, the more the rod contracts, and the more the clock is retarded. As it slows down from this top end, the rod gets longer, and the clock gets faster. This is not "relative" to any other object whatsoever. It is ABSOLUTE (within SR). This prediction applies to any object, totally independent of that's object's relation to the sun, the earth, the fixed stars, or any other material thing. At least that's the prediction.
Going back to my "loaded gun" prediction, it was not that pulling the trigger of a loaded would cause harm, BUT ONLY IF YOU KNOW THE GUN IS LOADED. If that were the prediction, it would in fact be laughable. A loaded gun will cause harm when you pull the trigger, whether you believe, or know, it's loaded. or not. Your subjective state of knowledge has absolutely zero affect on the consequences.
Hence, the claims you just keep on making to the effect that, as you just said again for about the 50th time,: "Once you know which state represents motionlessness, they will not both be motionless" is nonsensical.
The clear implications of this claim are that:
1. Until you "know" which state represents motionless they WILL both be motionless, and
2. That their state of motion is determined by your knowledge.
Can it get any more subjective, I ax ya? I mean, like, would that be possible, ya think?
aintnuthin said...
I will first note that you often seem to speak of an "inertial frame" as though it is something tangible and physically existing.
Inertial states are real. Inertial frames are abstractions of them. I am somewhat careless at the distinction, sometimes.
You often speak as though "tilting" or "changing" inertial frames can cause differences is physical reality.
When you change something's inertial state (aka, accelerate it), I think you do change reality. Don't you?
... And, of course, they will tell you that both A and B's "frame of reference" are "equally valid," and that "both are correct."...
The alternative is that one frame of reference is the preferred frame for reasons of physics/philosophy. However, there are no good physical reasons to say that, only philosophical reasons.
...Berkeley and his ilk notwithstanding, ...
Yawn.
But, the relationalists favorite form of "arguing" aside, A and B cannot BOTH be motionless if they are moving with respect to each other.
You keep repeating this over and over, as if it is making some sort of point. What's the point? In neither frame of reference are A and B both motionless. So, how does your point negate the notion both frames are valid?
The whole style of argument is ultimately based on a false premise.
What's the false premise? Be precise. It can't be that "A and B are both motionless", because that statement does not appear in any frame.
Your analogy is NOT for the very reasons I've already stated and won't bother to repeat here.
As you wish. Incorrectly citing the work of physicists you don't understand, and whom you are criticizing for their position above even while citing them, makes for poor reasons, though. It's kind of funny to watch you say they are relationist fools who can't be right, and then use them to say that my understanding can't be right.
OK, I guess I will say it again. A "shadow" is not cooler, darker, or anything else, even if the the air, the grass, or the car behind it is. A shadow is NOT a tangible, solid, three dimensional object like a rigid rod.
Insufficient precision again. Either way, we agree the angle of the yardstick, compared to the sunlight, has real, physical effects, even though the yardstick is not changed.
No, the author is making no claims whatsoever; he is merely summarizing the issues and arguments that have been made on each side of the debate.
Which side are you on?
Sorry, I didn't mean to disparage the author. Still, while the author is no necessarily endorsing this position, is "true motion" something that can be "ascertained"? How does one "ascertain" it? I can hardly say if I agree or disagree with "true motion" if you can't define it with a third of the precision you expect from me.
I asked: "It's like saying someone is an "unmarried bachelor." Why not just say "motion," or "bachelor." What does the redundancy add? Why do keep stressing this redundancy? What is the significance? What point are you trying to make that isn't already completely obvious to everyone?"
That the answer you seek depends upon hidden assumptions, which you deny exist.
SR makes predictions either way. It's predictions do not depend on you choosing a reference frame. The clock which is moving will be slower WHICHEVER frame of reference you happen to pick.
I said "specific predictions". Responding wtih generic predicitons is not a valid response, and very imprecise. "The clock which is moving" is entirely generic if you don't identify which clock is moving slower.
In what way is LR the least bit different?
LET creates a locally absolute rest state of wich matches the motion of the source of local gravitational field.
And, whatever their "absolute velocity" one horse also happens to be moving faster than the other.
After you set the reference frame of "the track", one horse is moving faster. No question about that. We agree.
1. What do you mean by "arbitrary?" Is is "arbitrary" to claim that the earth "really" (truly, absolutely) rotates on it's axis while orbiting the sun?
In any inertial reference frame, the earth rotates.
Is there no non-arbitrary reason to "prefer" this view to one which holds that the earth is motionless?
There is no inertial reference frame with a rotationless earth, so the question is moot.
Assume every particle in the universe started out "motionless" in the "cosmic egg" prior to the big bang.
That is, adopt a particular inertial reference frame. The two paragraphs you followed this with is something I agree follows after the preferred frame has been determined.
Your trying to convince me that you don't need to choose the reference frame first, aren't you?
Since you want to reject all "absolutes," Eric,
Yawn.
Simple: the closer a rod and a clock get to the speed of light,
You can only get closer to the speed of light in the view of some other inertial state than the one you are in. You never actually get closer to the speed of light, you always observe light as traveling at approximately 186,000mps. Outside of that, I agree with your statements.
Hence, the claims you just keep on making to the effect that, as you just said again for about the 50th time,: "Once you know which state represents motionlessness, they will not both be motionless" is nonsensical.
The clear implications of this claim are that:
1. Until you "know" which state represents motionless they WILL both be motionless, and
Why?
2. That their state of motion is determined by your knowledge.
Why? If that is a clear implication, derive it. Demonstrate the chain of logic.
One Brow said: "Your trying to convince me that you don't need to choose the reference frame first, aren't you?"
The dinosaurs got wiped out by moving meteorites whether they chose a frame of reference by which they could fashion some understanding of what was happening to them and why, or not. Physical occurrences do not depend on YOUR understanding (which you are demonstrating to be more and more minimal with every post you make). Your understanding depends on choosing rest frames, in the same way that no logical conclusion can ever be reached without a premise. But physics do not depend on you, or your understanding, your presumptions to the contrary notwithstanding.
One Brow said: ""Once you know which state represents motionlessness, "Once you know which state represents motionlessness, they will not both be motionless
What are the qualifications and conditions stated in your introductory phrase supposed to add and convey to you meaning and your statement? Why not just say "they will not both be motionless?" Your are using "once" in the sense of "when" or "not until." Like, "Once you're 21, you can legally drink."
Once YOU KNOW (as if that has a damn thing to do with physical objects in the world) which is motionless, THEN, they will not both be motionless. But, until that time....
It's simply impossible to have a rational discussion with you Eric, because your solipistic interpretations and tendencies make objective discussions irrelevant and and inconsequential to you.
One Brow said: "What's the false premise? Be precise. It can't be that "A and B are both motionless", because that statement does not appear in any frame."
I've said it a million times, Eric, but the most rudimentary and obvious logic always gets totally ignored by you. I will say this one more time.
Let's start with basics, like your initial premise. At least two contrasting initial premises have been advanced by philosophers in the past, viz:
1. Change is impossible and change does not occur. Any perception to the contrary is strictly an illusion, a false appearance. NOTHING EVER moves, in reality, because motion is impossible (Parmenides)
2. Change does occur in the world, independently of our perceptions. True (not merely apparent) motion does occur (most people)
If position 1 is correct, then what I'm saying is necessarily wrong, and you are right. I start with the presumption that if 2 people appear to moving with respect to each other, then at least one of them is really (not just apparently moving).
Given that, if:
1. Two people are in motion relative to each other, and
2. Both assume that they are not moving, then
Both CANNOT be correct. Their respective claims cannot be "equally valid." At least one of them is wrong.
On the other hand, both are absolutely correct under the Parmenidean view. There is no motion to begin with.
Now, can both "believe" they are correct, even if there is "true motion?" Sure, but subjective belief is not, and does not determine, objective physical reality.
I said:
"1. Two people are in motion relative to each other, and
2. Both assume that they are not moving, then
Both CANNOT be correct. Their respective claims cannot be "equally valid." At least one of them is wrong."
I guess I need to add what is (to me) obvious. The above is true no matter who is really moving. The conclusion is in no way dependent upon me knowing that particular, contigent circumstance.
One Brow said: "You never actually get closer to the speed of light..."
Your utter inability to distinguish the subjective from the objective never ceases to display itself. Objectively speaking, if you can never get closer to the speed of light, then you simply can never move faster. How do you finish your claims?
One Brow said: "...you always observe light as traveling at approximately 186,000mps."
Your observations ARE objective reality for you. There is no distinction between "objective reality" and "subjective reality" to be made, because, a la Berkeley, all reality is of one, and only one, kind--subjective.
That's why you are a Berkelean Relationalist. What you "observe" is what is. A strictly Machian position, one which Al denounced, when he said: "He even went so far that he regarded “sensations” not only as material which has to be investigated, but, as it were, as the building blocks of the real world"
Al already told you will "observe" the speed of light to be 186,000 mph when you speed up ONLY BECAUSE your rods have contracted and your clocks have slowed down. Like the logical positivists, you believe that "truth" lies in the rods and clocks, another claim which Al strongly rejected.
The speed of light is, for you, "whatever I measure it to be." What I "observe" is what is true, and only what I observe can be true. "To be is to be perceived" (by ME).
Only one with such premises could conclude that a shadow (or nightime) is a "physical object." You, for example, impute your pereception of color (of a shadow) to the "thing" where you "see" it and conclude it must be a "physical thing." The wind (not your pecerception of it) is hot (or cold), for you. Why? Because that's the way YOU sense it.
aintnuthin said...
The dinosaurs got wiped out by moving meteorites whether they chose a frame of reference by which they could fashion some understanding of what was happening to them and why, or not. Physical occurrences do not depend on YOUR understanding (which you are demonstrating to be more and more minimal with every post you make).
You say this like it is some sort of revelation or in opposition to something I believe. As far as I can tell, it's not particularly profound nor in opposition to what I believe, and has nothing to do with the need to choose a reference frame to get an specific answer.
Why not just say "they will not both be motionless?"
Calling an inertial state motionless is meaningless unless you identify a comparison against which you can say motion does not exist.
It's simply impossible to have a rational discussion with you Eric, because your solipistic interpretations and tendencies make objective discussions irrelevant and and inconsequential to you.
I apologize for not glibly swallowing all the hidden assumption you make without mentioning they exist. That must indeed be frustrating for you.
Let's start with basics, like your initial premise. At least two contrasting initial premises have been advanced by philosophers in the past, viz:
1. Change is impossible and change does not occur. Any perception to the contrary is strictly an illusion, a false appearance. NOTHING EVER moves, in reality, because motion is impossible (Parmenides)
2. Change does occur in the world, independently of our perceptions. True (not merely apparent) motion does occur (most people)
Let's go with 2.
I start with the presumption that if 2 people appear to moving with respect to each other, then at least one of them is really (not just apparently moving).
Define "really moving" in a way that is meaningful, and I might agree. So far, you've ducked. Is "true motion" (or "real motion") something that can be "ascertained"? How does one "ascertain" it? If not, what do you mean by it?
Given that, if:
1. Two people are in motion relative to each other, and
2. Both assume that they are not moving, then
Both CANNOT be correct.
This has what to do with the choice of inertial rest frame being arbitrary?
Their respective claims cannot be "equally valid."
I suggest you consider the difference between and valid and a sound logical argument more carefully, and then come back to what it means when we say both claims are valid.
At least one of them is wrong.
Again, how does this affect the initial choice of the inertial rest frame being arbitrary?
Now, can both "believe" they are correct, even if there is "true motion?" Sure, but subjective belief is not, and does not determine, objective physical reality.
What does determine "objective physical reality"?
One Brow said: You can only get closer to the speed of light in the view of some other inertial state than the one you are in. You never actually get closer to the speed of light"
1. Do "inertial states" also have a "view?"
2. You can't speed up, you can only be falsely "seen" to speed up (but never "actually" do so), by someone else, that the idea?
3. You know this how?
4. Why couldn't you see yourself increasing speed, like when you get on a jet, for example?
5. Did you come to this conclusion before or after choosing a frame of reference?
6. Does this conclusion presuppose the validity of a theory which relies on absolute space and time, like SR does?
One Brow asked: "Again, how does this affect the initial choice of the inertial rest frame being arbitrary?"
It doesn't have a fucking thing to do with anything I've said. Why do you think that is the only topic here? And since you do think it is, why don't you say, just once, why it's significant to any of these questions.
I go out of my way to state the obvious and you still can't read or understand it"
I said: "I guess I need to add what is (to me) obvious. The above is true no matter who is really moving. The conclusion is in no way dependent upon me knowing that particular, contigent circumstance."<---the choice of a frame of reference is totally irrelevant, get it?
I will say this again. Your ability to concieve of things, as a human being, may (and does) require that you making certain stipulations to establish a starting point.
That said, my position is that the earth, the sun, the galaxy, etc. were all here, and all "really moving" long before any human being was ever born. Their existence, and their motion, in NO WAY depends whether YOU, or any other human being, ever "choose" anything, arbitrarily or not. The objective physical world does NOT depend on YOU, get it?
Do you have a different position about that? If so, state it. If not, then don't keep repeating the obvious 20,000 times and keep pretending that's the issue we're discussing.
I am NOT discussing epistemology right now. I'm discussing physics. You're discussing what you think you know and how you think you know it. You also repeatedly imply that your knowledge, and your personal means of arriving at it, are what determines what happens in objective reality. Fraid not.
One Brow said: "I apologize for not glibly swallowing all the hidden assumption you make without mentioning they exist. That must indeed be frustrating for you."
Since you are far too clever to fail discern anything that would be "hidden" from most people. Tell me the "hidden assumptions" you have detected and tell me why you can't "swallow" them, eh?
I really want to hear it.
Let's quit shifting frames, and stay with one, and let's quit quibbling about who could possibly be moving by explictly choosing the earth as the "rest frame." Since we have made an arbitrary choice, now (and only now) there can be "actual motion," right?
Now, we earthlings blast ship into space and keep accelerating it until it reaches a speed where FROM OUR VIEW ONLY, his clocks and rods have been deformed by a factor of 10 (not sure that's possible, but let's use it for easy calculation purposes). He then settles into a unform rate of speed.
Now, lets assume that, halfway between us there are two stars which are (by our measurements) 10 light years apart. These two stars happen to be moving away from us, and toward him at a rate which keeps them equidistant from both us and the spacehip we blasted off at all times. So we both see those stars as moving away from us, but the distance remains the same (not that that is important).
Now we see a beam of light leave one of these stars and arrive at the other 10 years later. He sees the beam leave at the same time we do, and arrive at the other at the same time we do (after adjusting for the travel time of his signals, as we do).
What does he see (from our viewpoint)? Well, from our viewpoint, he sees the 2 stars as being 100 lightyears (as we measure them) apart. Can the same light beam go both 10 lightyears and 100 light years in the same time? Of course not. But since his time has slowed down, he sees the beam as taking 100 (of our) years to make the trip.
So, as it all conveniently happens to work out, we both agree on the speed of this beam. As expected, it goes exactly 1 lightyear per year, for both of us.
Both we and the ship agree that the light left one star and arrived at the other at the same instant(s). We also agree on the rate of speed (distance traveled/time elapsed) at which the lightbeam travelled. We just don't agree on the distance the lightbeam travelled or the time it took to do it. Why? Because his measuring instruments were deformed, that's why.
According to SR, since he (as per our stipulation which of course has nothing whatsover to do with him being accelerated to beat all hell) is the "moving" one, it is HIS, not our, clocks and rods which have really been deformed, right?
Remember, I said I am keeping this whole analysis in only one frame, ours. All measurements I have given for both parties is from OUR perspective only. I don't care in the least, right now, what his perspective might be, I'm just trying to understand how SR relates to OUR perspective. From our perspective his instruments have been deformed, and SR says they really have, so....
Now, I can understand why, if he has a ruler that is only 1.2 inches long, he can measure 1 foot to be 10 feet, and, why, if his clock has slowed down by a factor of 10, he can measure 6 minutes to be one hour.
What I don't understand is how we could reach the same conclusions about the speed of light if neither his rods or clocks are really distorted. This all has something to do with shadows and perspectives, not actual physical shrinkage of his rod, and actual physical slowing of his clock, you say?
1. How does that work, exactly?
2. Why, if it's all illusory, are the lorentz contractions even a part of the theory? You don't need mathematical formulas to explain an optical illusion. You just leave the math adjustments out, and explain why we mistakenly think his rods have contracted and his clocks have slowed down. Then everything is clear: For him it "really is" only 10 years and 10 lightyears, just like it is for us.
4. If it's that simple, why would Al insist that his rods and clocks must become deformed, and why does SR predict that a travelling twin really will be younger when he returns?
5. There is a reason why Al says they must actually shrink. What is it?
It occurred to me that the spaceship would also see the 2 stars being only 10 lightyears apart, since the "shinkage" in his rods is ONLY in the direction of his travel, and my example supposes that the 2 stars in question are aligned perpendicularly to both us and the ship. So I answered my own example wrong.
But how about time? Does it only dilate in one direction? I don't think so.
So how does this work from OUR perspective? Is his clock running slower? If so, then it would take 100 of our years for him to him to see the beam going between the two points and we would therefore see light to only be travelling at 1/10th of the speed for him as it does for us, since the distance is only 10 lightyears for him also. At first blush, that doesn't sound right, given Al's idea of what the "principle of relativity" requires.
Do only 10 of ours years pass for him too while the light makes it's trip? If that's the case he won't come back younger, because time is the same for both of us too.
It seems that the answer is that the speed of light is NOT the same for him by our standards. And since time really has slowed for him, per SR, the speed of light has also slowed for him, as we measure it. So how is the principle of relativity upheld? It isn't, really, at least not in the sense that the speed of light MUST be the same in all inertial frames. Of course, SR never really says it "is" the same, only that it is "measured to be" the same.
Since time has slowed down by a factor of 10 for him, the speed of light has also slowed down for him (by our standards). Of course, that's what LR says--that the speed of light varies from frame to frame. In LR, the relativty principle still holds, it's just that it works according to Gallilean transformations.
It won't change anything to say "he sees it as taking only 10 years" because that's only 10 years according to his distorted (per SR) sense of a "year," and it's still 100 earth years. It is non-sensical to simultaneously hold that:
1. His clocks have slowed down by a factor of 10, and yet
2. A year is still a year.
In such a case, the word "year" is being used equivocally. If the earth makes 10 revolutions around the sun, that is the standard for 10 years, not what some guy with a slow-running timepiece says 10 years is.
One Brow asked: "What does determine "objective physical reality"?"
To get an answer to that, you would have to ask someone who pretends to know. It could be physcial "laws," known or unknown, it could be utterly chaotic and lawless forces at work, or anything in between, as far as I know. Whatever I know, or think I know, stuff is happening all over the universe, regardless of my "reflections" on the matter, and it doesn't require my acknowledgement or assent in order to happen.
I merely said that I have a convicton about what does NOT determine objective reality, to wit: Your subjective choices, perceptions, conclusions, presumed knowledge, etc.
If you say you "chose" to designate the sun as motionless, fine. It may be motionless, and your choice may be right, Or it may be moving, and in that case your choice is wrong. But, either way, the sun either is, or is not, moving, TOTALLY irrespective of your perceptions. Your perceptions do NOT determine whether or not the sun is moving. It does not idle in suspended animation until such time as you think you know enough, or arbitrarily choose, to label it as either moving or motionless.
Do you have a different view of the matter? If so, say so, and we can talk about that.
I said: "5. There is a reason why Al says they must actually shrink. What is it?"
I'll answer this one for us (again). You can go to virtually any university website, Harvard, Stanford, MIT, whatever, and get the same basic reason, accompanied by the same basic examples to illustrate the claim.
This pattern is always this:
1. We KNOW (absolutely and without doubt, because Einstein told us so, that the speed of light is invariable in all inertial frames.
"How long does he think that blip takes to make a round trip? The one thing he’s sure of is that it must be moving at c = 186,300 miles per second, relative to him—that’s what Einstein tells him."
2. Knowing that, one need not even bother to mess with measuring time and distance, in order to determine speed. Knowing either one or the other is quite sufficient to deduce the other.
"So to find the round trip time, all he needs is the round trip distance."
3. So just do the simple algebraic calculation to deduce what the time HAS to be in order to fulfill Einstein's demands.
"...the length of the “zig” from the bottom mirror to the top mirror is necessarily ct, since that is the distance covered by any blip of light in time t." [Once again the presumed constancy of the speed of light is appealed to.]
So, what is the consequence?
"This means that Jack sees Jill’s light clock to be going slow—a longer time between clicks—compared to his own identical clock."
Why is time dilation and clock retardation required? So they can both "measure" the speed of light to be the same, that's why. That's why her clock MUST NECESSARILY be going slower. It's all a matter of deduction from necessary implication--you don't even have to measure time and distance to get the speed, because you already know it.
Then, of course, it order to strictly maintain the NO PREFERRED FRAME mantra (even though SR itself relies on a preferred frame) comes the obligatory "equal validity of all inertial frames of reference (once again, by postulate):
"But this isn’t the whole story—we must now turn everything around and look at it from Jill’s point of view. Her inertial frame of reference is just as good as Jack’s. She sees his light clock to be moving at speed v (backwards) so from her point of view his light blip takes the longer zigzag path, which means his clock runs slower than hers."
In this example, Jill is, as usual, on a moving train and, as aways, she MUST assume that the earth, not her, is moving to achieve the required "reciprocity" of "observation" (deduction).
http://galileo.phys.virginia.edu/classes/252/srelwhat.html
The explicit announcement, made here (and italicized in the original) that: "Her inertial frame of reference is just as good as Jack’s" is tantamount to the denial of "true motion" that the author was talking about. If you want more details, go read the 10 pages of comments by him that I referred you to.
The suggestion is, as always, that it is just as reasonable, just as correct, just as valid, and "just as good" for her you insist that the earth is moving relative to her while she remains motionless as it is for Jack to insist on the opposite.
Without that assertion, the "requirement" for "reciprocity" of transformations falls apart. As I've already said many times, this is the "false premise" of the relationalist SR advocates.
Since SR tells us that only the moving object "truly" has contracted lengths and retarded clocks, it is utter bullshit for a physicist to simultaneously claim and imply that:
1. Both are correct, and
2. SR tells us they are both correct.
What's interesting, and quite instructive, about the presentation made by the UV professor is that it is artfully contrived to give the impression that a guy is measuring the speed of light. The setup is this:
"Let us now consider two observers, Jack and Jill, each equipped with a calibrated inertial frame of reference, and a light clock. To be specific, imagine Jack standing on the ground with his light clock next to a straight railroad line, while Jill and her clock are on a large flatbed railroad wagon which is moving down the track at a constant speed v. Jack now decides to check Jill’s light clock against his own."
OK, then, both have clocks and he decides to "to check Jill’s light clock against his own." But, if this were done it would create a problem for SR. Why? Because Jack would look at his own clock to get the time, and then use the distance travelled to obtain the speed of light. But if he actually did this, he would not obtain a speed of 186,000 mps. The duration of time between the two events would be the same, but the speed of light would not come out to be 186,000 mps if he actually read the time, instead of deducing it. But he must ALWAYS measure that speed in his inertial frame, per SR. So, what now?
So, after this big-ass setup to check one clock against another, guess what happens? This:
"Imagine it to be a slightly misty day, so with binoculars he can actually see the blip of light bouncing between the mirrors of Jill’s clock."
Tough luck, eh? Misty day...must use binoculars...can't see own clock while looking through binoculars. Not to worry, he can just "deduce," rather than actually measure, the time elapsed, which he proceeds to do, based on what he already knows the speed of light to be.
This has to be an intentional and deceitful way of giving the false impression that Jack "measured" the light. Why all the talk about having, and comparing clocks, only to have a "misty day" suddenly come along? Heh.
aintnuthin said...
1. Do "inertial states" also have a "view?"
Observers within them do.
2. You can't speed up, you can only be falsely "seen" to speed up (but never "actually" do so), by someone else, that the idea?
No.
3. You know this how?
Moot.
4. Why couldn't you see yourself increasing speed, like when you get on a jet, for example?
You see the groung moving, and interpret that as you increasing speed. Not the same thing as seeing yor own speed increase.
So, you'll have to answer this one positively: how do you see yourself moving at a higher rate of speed previously, without making reference to something else?
5. Did you come to this conclusion before or after choosing a frame of reference?
Moot.
6. Does this conclusion presuppose the validity of a theory which relies on absolute space and time, like SR does?
Moot. Also, I thought you said SR did not rely on absolute space and time, that I was misunderstanding you there. You'll really need to clarify what you mean here.
It doesn't have a fucking thing to do with anything I've said.
Then why are you complainging abotu statements that are equivalent to saying the choice of the inertial rest frame is arbitrary, if that has nothing to do with what you are saying?
Why do you think that is the only topic here?
I'm just trying to get tot he root of your position. I've offered what I could, but you seem to think you understand this better than I. So, I'm starting to expect you to exhibit the precision an actual theory needs.
And since you do think it is, why don't you say, just once, why it's significant to any of these questions.
The notion that the observations of Alice on the ground and Bob on the train are equally valid is based on the notion of the choice of inertial rest frame being arbitrary. If you aren't prepared to argue that, you have no real argument with "equally valid".
I go out of my way to state the obvious and you still can't read or understand it"
Throwing up vague notions isn't going to cut it anymore. You want me to take your position more seriously, you need to get serious.
<---the choice of a frame of reference is totally irrelevant, get it?
Then you have no problem with the choices of Alice and Bob being equally valid.
The objective physical world does NOT depend on YOU, get it?
I agreed with that a few pages of comments ago.
I am NOT discussing epistemology right now. I'm discussing physics.
Well, we might get you there.
Since you are far too clever to fail discern anything that would be "hidden" from most people. Tell me the "hidden assumptions" you have detected and tell me why you can't "swallow" them, eh?
I really want to hear it.
Very simply, you are trying to sneak an absoluteness into motion with the notion of real motion, without making the concession you are doing so. That's why you still can't come up with a definition of what it means to be "really moving".
Let's quit shifting frames, and stay with one, and let's quit quibbling about who could possibly be moving by explictly choosing the earth as the "rest frame." Since we have made an arbitrary choice, now (and only now) there can be "actual motion," right?
Assuming that "actual motion" is synonymous to "real motion", how should I know? You still haven't defined the term. If there not synonymous, you haven't defined two terms.
Now, we earthlings blast ship into space and keep accelerating it until it reaches a speed where FROM OUR VIEW ONLY, his clocks and rods have been deformed by a factor of 10 (not sure that's possible, but let's use it for easy calculation purposes). He then settles into a unform rate of speed.
The actual speed would be sqrt(.99)*c, by our frame.
Now we see a beam of light leave one of these stars and arrive at the other 10 years later. He sees the beam leave at the same time we do, and arrive at the other at the same time we do (after adjusting for the travel time of his signals, as we do).
What does it mean to say "He sees ... at the same time we do"? Please give a precise, physical definition to this. On that works whether he has been traveling at .99c (relative to us) for a day, a week, or a year. Without such a defintion, your example is not sensible. It's certainly not a phrase you will find in the work of Einstein, Hogg's book, etc. Once you have that defined that, we can come back to this example.
This all has something to do with shadows and perspectives, not actual physical shrinkage of his rod, and actual physical slowing of his clock, you say?
1. How does that work, exactly?
Because when moving in a different inertial states, objects basically are pointing away from each other.
2. Why, if it's all illusory,
It's not illusory, any more than the angle of a yardstick in sunlight is illusory. It's a real phenomenon with real effects.
are the lorentz contractions even a part of the theory?
They predict the rectangular projection back into the observer's inertial frame, similar to the way you can use trigonometry to predict the length of the shadow cast by a yardstick when you know the angles of the yardstick and the sun to the ground.
Then everything is clear: For him it "really is" only 10 years and 10 lightyears, just like it is for us.
No, it really is 100 years for him (assuming the light between the stars is parallel to his direction of travel. A real effect of the change in angle.
It occurred to me that the spaceship would also see the 2 stars being only 10 lightyears apart, since the "shinkage" in his rods is ONLY in the direction of his travel, and my example supposes that the 2 stars in question are aligned perpendicularly to both us and the ship. So I answered my own example wrong.
I missed the part where they were perpendicular. You are correct, it would be 10 years, 10 light years.
So how does this work from OUR perspective? Is his clock running slower? If so, then it would take 100 of our years for him to him to see the beam going between the two points and we would therefore see light to only be travelling at 1/10th of the speed for him as it does for us, since the distance is only 10 lightyears for him also. At first blush, that doesn't sound right, given Al's idea of what the "principle of relativity" requires.
I have no idea what it means when you say "we would therefore see light to only be travelling at 1/10th of the speed for him as it does for us". How would we see what he sees?
Do only 10 of ours years pass for him too while the light makes it's trip?
I'm not sure what it means to say "10 of ours years pass for him". Please give a detailed explanation of that.
My recollection is that if the direction of travel of the light is perpendicular to the relative direction of travel that we see, then he sees ten years pass, just as we see ten years pass. If you a source or a mathematical justification to say otherwise, I'd like to see it.
Since time has slowed down by a factor of 10 for him, the speed of light has also slowed down for him (by our standards).
Again, I'll need to see a defintion of what it means for the speed of light to be "slowed down for him (by our standards)".
My recollection is that if the direction of travel of the light is perpendicular to the relative direction of travel that we see, then he sees ten years pass, just as we see ten years pass. If you a source or a mathematical justification to say otherwise, I'd like to see it.
Of course, that's what LR says--that the speed of light varies from frame to frame. In LR, the relativty principle still holds, it's just that it works according to Gallilean transformations.
The Galilean and Lorentz velocity equaitons are not the same. If LET uses Galilean velocity tranformations, it's not using LR.
It won't change anything to say "he sees it as taking only 10 years" because that's only 10 years according to his distorted (per SR) sense of a "year," and it's still 100 earth years. It is non-sensical to simultaneously hold that:
1. His clocks have slowed down by a factor of 10, and yet
2. A year is still a year.
I agree, what you said makes no sense at all.
In such a case, the word "year" is being used equivocally. If the earth makes 10 revolutions around the sun, that is the standard for 10 years, not what some guy with a slow-running timepiece says 10 years is.
If the earth makes ten revolutions according to whom? You need to be more precise here.
To get an answer to that, you would have to ask someone who pretends to know. ... I merely said that I have a convicton about what does NOT determine objective reality, to wit: Your subjective choices, perceptions, conclusions, presumed knowledge, etc.
OK. You have no method for determining what is objective reality.
If you say you "chose" to designate the sun as motionless, fine. It may be motionless, and your choice may be right, Or it may be moving, and in that case your choice is wrong. But, either way, the sun either is, or is not, moving, TOTALLY irrespective of your perceptions.
What does it mean for the sun to be moving? Be precise.
One Brow said: "Moot. Also, I thought you said SR did not rely on absolute space and time, that I was misunderstanding you there. You'll really need to clarify what you mean here."
Moot? What does that mean. I see that you are intentionally being evasive with virtually every post you make now. You claim imprecision, "mootness." reply with non sequiturs and red herrings rather than addressing the questions. What does "moot" mean, and why can't you understand what I've already made clear? Because you don't read it to begin with?
With respect to SR and absolute space and time, I have quoted MANY authorities to this effect, which you apparently never read either, eh? Just a view posts up I quoted a Stanford U. webpage which said, for example: "[GR]does not make spacetime more relative than it was in special relativity. Just the opposite is true: the absolute space and time of Newton are retained."
One Brow said: "So, you'll have to answer this one positively: how do you see yourself moving at a higher rate of speed previously, without making reference to something else?"
Whatever gave you the idea that I ever said that? By it terms it would be impossible to "see yourself moving at a higher rate of speed previously, without making reference to something else?"
You really seem to have no clue what this (attempt at a) discussion is even about.
One Brow said: "The notion that the observations of Alice on the ground and Bob on the train are equally valid is based on the notion of the choice of inertial rest frame being arbitrary. If you aren't prepared to argue that, you have no real argument with "equally valid".
I not just "prepared" to, I do utterly deny, and have been so arguing for over a year now, that all frames are "equally valid" and that any choice of a frame is simply "arbitrary."
One Brow said: "Very simply, you are trying to sneak an absoluteness into motion with the notion of real motion, without making the concession you are doing so. That's why you still can't come up with a definition of what it means to be "really moving".
To begin with, I have said repeatedly that I am of the persuasion that there is an objective reality that is independent of us, our knowledge, or lack thereof, many times. I'm not "hiding" that or pretending otherwise. As far as the Stanford author, and defintions go:
1. I quoted you his exact words.
2. I supplemented that with an explanation of how the "absolute vs relative" debate about motion had gone that issue
3. And already told you it's not "my" definiton. If you have any uncertainties about what this author means, and actually want to know, go read his entire 10 page article for yourself. I imagine you will find the precise details you are lookiing for there, or at least enough detail to answer (rather than evade) the question, which was:
"Which side are you on?"
One Brow said: "Assuming that "actual motion" is synonymous to "real motion", how should I know? You still haven't defined the term."
I put "actual motion" in quotes because those are your words, not mine. What to they mean to you? You claimed there could be no "actual" motion between two things until someone specified a frame or reference.
One Brow said: "Because when moving in a different inertial states, objects basically are pointing away from each other."
I have no idea what this means...go on.
Suppose I'm driving straight at you, while you're standing on the corner, motionless, at a constant rate of 120 mph. Am I then "pointing away" from you? If so, how does the direction I point serve to cause a "physical" change in your (or my own) rods and clocks, and/or the readings we get from these instruments?
One Brow said: "are the lorentz contractions even a part of the theory?
They predict the rectangular projection back into the observer's inertial frame, similar to the way you can use trigonometry to predict the length of the shadow cast by a yardstick when you know the angles of the yardstick and the sun to the ground."
Says who? Not Lorentz. Not Al. Not the content of the math (which specifies the amount by which a rigid rod contracts with motion). Just about every "example" I've seen used to illustrate the physical interpretation of the math says nothing about "rectangular projection back into the observer's inital frame," as far as I can discern. The idea always seems to be along the lines that an observer will see a moving physical object which passes him at relativistic speeds as highly deformed (flattened out) in the direction of it's motion.
Other "illustrations" of the concept I've seen basically reduce it to a side effect of time dilation, and treat it as just another variable (of two possible ones in the speed formula, i.e,, time elapsed and distance travelled) which can be manipulated to ensure that the measure speed of light is seen to be 186,000 mps.
I just cited a website from the University of Virginia which contained such an example, but it's apparently in the spam filter.
One Brow said: "I missed the part where they were perpendicular. You are correct, it would be 10 years, 10 light years."
That's not what I said. I said 100 years, 10 light years (after rejecting the possiblity of it being 10). Unlike length contraction, time dilation in no way varies due to direction of motion. It is a strict function of increased speed (see, e.g., the GPS).
One Brow said: "I have no idea what it means when you say "we would therefore see light to only be travelling at 1/10th of the speed for him as it does for us". How would we see what he sees?"
As far as this, and all your other comments exhibiting lack of comprehension goes, I deliberately stressed, several times, that I am not, in this analysis, the least bit concerned with how "he" sees things. I said I'm staying in one frame, and stressed that ALL measurements I was using were based on our perceptions, not his.
From our perspective, 100 years pass for him to see light go 10 lightyears (we BOTH see that distance as 10 lightyears). So, from our perspective (which is also the perspective which SR says is "real" in this case--he is the moving party), light is only going 18,600 mph for him.
That's how WE see it, because we (accurately) see his clock slowed down by a factor of 10.
One Brow said: If the earth makes ten revolutions according to whom? You need to be more precise here.
According to the relationship between the earth and the sun, in this case. If we see 100 revolutions, how many do you think the traveler would see? Only 10? Something in between?
Edit: Meant to say: According to the relationship between the earth and the sun AS SEEN BY US, in this case.
aintnuthin said:
1. We KNOW (absolutely and without doubt, because Einstein told us so, that the speed of light is invariable in all inertial frames.
Change the to "all experiements indicate that the speed of light in invariable to all inertial oberservers", and I would agree.
2. Knowing that, one need not even bother to mess with measuring time and distance, in order to determine speed. Knowing either one or the other is quite sufficient to deduce the other.
A common caluculation to make.
In this example, Jill is, as usual, on a moving train and, as aways, she MUST assume that the earth, not her, is moving to achieve the required "reciprocity" of "observation" (deduction).
Why? She can make calcuations based the earth moving without assuming the earth is moving.
The explicit announcement, made here (and italicized in the original) that: "Her inertial frame of reference is just as good as Jack’s" is tantamount to the denial of "true motion" that the author was talking about.
But, since you don't own up to that definition of motion, that's not really relevant.
The suggestion is, as always, that it is just as reasonable, just as correct, just as valid, and "just as good" for her you insist that the earth is moving relative to her while she remains motionless as it is for Jack to insist on the opposite.
Why is it unreasonable?
Without that assertion, the "requirement" for "reciprocity" of transformations falls apart.
There is no "requirement" for reciprocity. It exists, required or otherwise. What we do or not not require does not affect reality.
Since SR tells us that only the moving object "truly" has contracted lengths and retarded clocks, it is utter bullshit for a physicist to simultaneously claim and imply that:
1. Both are correct, and
2. SR tells us they are both correct.
You keep saying that, but can't quite put your finger on the wrong part of it.
OK, then, both have clocks and he decides to "to check Jill’s light clock against his own." But, if this were done it would create a problem for SR. Why? Because Jack would look at his own clock to get the time, and then use the distance travelled to obtain the speed of light. But if he actually did this, he would not obtain a speed of 186,000 mps. The duration of time between the two events would be the same, but the speed of light would not come out to be 186,000 mps if he actually read the time, instead of deducing it. But he must ALWAYS measure that speed in his inertial frame, per SR. So, what now?
This is very confusingly written. What are supposed two events that Jack does not get a duration for that equates to the speed of light being see? What causes him to see his own clock incorrectly? You made no sense here, at all. Why can't Jack just read his own clock?
This has to be an intentional and deceitful way of giving the false impression that Jack "measured" the light. Why all the talk about having, and comparing clocks, only to have a "misty day" suddenly come along? Heh.
The mist allows jack to see the path of the light pulse in Jill's clock. It's doesn't block anything.
Moot? What does that mean.
In this case, a question based on a false premise. You asked a question assuming an answer to a previous question was "yes", when the answer was actually "no", redenring the latter question without the foundation upon which it was built.
I see that you are intentionally being evasive with virtually every post you make now.
I've decided that it's time to nail the jello.
With respect to SR and absolute space and time, I have quoted MANY authorities to this effect, which you apparently never read either, eh? Just a view posts up I quoted a Stanford U. webpage which said, for example: "[GR]does not make spacetime more relative than it was in special relativity. Just the opposite is true: the absolute space and time of Newton are retained."
I agree that GR does not use a more relative model of space than SR. It is incorrect to say that it makes space closer to absolute. The choice of an inertial rest frame is just as arbitrary in Gr as in SR.
Of course, none of that answers what you mean by "true motion" or "real motion".
One Brow said: "So, you'll have to answer this one positively: how do you see yourself moving at a higher rate of speed previously, without making reference to something else?"
Whatever gave you the idea that I ever said that?
You asked: "4. Why couldn't you see yourself increasing speed, like when you get on a jet, for example?" Since we agree acceleration is detectable, the question only made sense if you meant you were traveling inertially at a higher rate of speed than previously. My response is that you do so by reference to something else, that is you don't see yourself going faster, you see the background going by faster. If you think there is a way to see yourself going faster than you did previously, you'll have to say how. I don't know of a way.
You really seem to have no clue what this (attempt at a) discussion is even about.
Hence the jello nailing.
I not just "prepared" to, I do utterly deny, and have been so arguing for over a year now, that all frames are "equally valid" and that any choice of a frame is simply "arbitrary."
Then you should get started explaining the invalidity, rather than whine about whether both can be "motionless". Because the fact that they are not both motionless (in whatever sense you mean, you won't define it) does not alter the validilty.
To begin with, I have said repeatedly that I am of the persuasion that there is an objective reality that is independent of us, our knowledge, or lack thereof, many times.
That's somethihg we agree upon.
I'm not "hiding" that or pretending otherwise. As far as the Stanford author, and defintions go:
1. I quoted you his exact words.
So, when you say "really moving", you are referring to absolute motion in the sense that Newton meant it?
2. I supplemented that with an explanation of how the "absolute vs relative" debate about motion had gone that issue
While denying that you are referring to absolute motion.
3. And already told you it's not "my" definiton.
Then give me yours. I'm not interested in discussing your secondhand opinions of a Stanford author. What do you mean by "real moton"?
"Which side are you on?"
Define the sides, as you see them, with a definition you endorse.
You claimed there could be no "actual" motion between two things until someone specified a frame or reference.
Incorrect. I have made no such claim, assuming by "motion between two things" you mean two things in motion with respect to each other.
One Brow said: "Because when moving in a different inertial states, objects basically are pointing away from each other."
I have no idea what this means...go on.
I assume you know what it means to point away from something, so I gather from this that you don't have a physical interpretation for objects in different inertial states pointing away from each other. I wish I had a better illustration for it, but I don't at the time. It's a very high-level summary of what I recall of the situation from mathematical models.
Well, I shouldn't assume that. By pointing away from each other, I mean in the sense that if we are sitting on a yardstick, looking perpendicular to the side of the yardstick, while the yardsticks are skew instead of parallel. Each of us would see a shorter yardstick on one side, and a longer end, than for an equivalently ecentered, parallel yardstick. This would be a real effect of the real property of being skew.
Suppose I'm driving straight at you, while you're standing on the corner, motionless, at a constant rate of 120 mph. Am I then "pointing away" from you?
As long as you have motion relative to me, yes, but not in any manner that would change your spatial path.
If so, how does the direction I point serve to cause a "physical" change in your (or my own) rods and clocks, and/or the readings we get from these instruments?
It doesn't cause a physical change for you in the clocks and rods with you, or the readings you get from them, because they are not pointed away from you. I see less of your rod in the direction of travel, and more of your clock.
Says who? Not Lorentz. Not Al. Not the content of the math (which specifies the amount by which a rigid rod contracts with motion).
Actually, it's a geometric description of precisely what Lorentx, Einstein, and the math says. Your denial does not change this.
Just about every "example" I've seen used to illustrate the physical interpretation of the math says nothing about "rectangular projection back into the observer's inital frame," as far as I can discern.
Then ask a physicist whether or not this is a viable interpretation. That an interpretation appears rarely does not make it invalid.
The idea always seems to be along the lines that an observer will see a moving physical object which passes him at relativistic speeds as highly deformed (flattened out) in the direction of it's motion.
Which is in agreement with what I just explained.
That's not what I said. I said 100 years, 10 light years (after rejecting the possiblity of it being 10).
Which makes no sense. No one sees it taking 100 years. The traveler sees the light going from star to start in 10 years. The non-traveler see the light going from star to star in ten years.
As far as this, and all your other comments exhibiting lack of comprehension goes, I deliberately stressed, several times, that I am not, in this analysis, the least bit concerned with how "he" sees things. I said I'm staying in one frame, and stressed that ALL measurements I was using were based on our perceptions, not his.
So, we see the light going from start to star in ten years. Again, no reason to invoke some 100 years.
From our perspective, 100 years pass for him to see light go 10 lightyears (we BOTH see that distance as 10 lightyears).
How does time pass for him from our perspective? Time passes for him from his perspective. Why would our perspective control his perception of time?
So, from our perspective (which is also the perspective which SR says is "real" in this case--he is the moving party), light is only going 18,600 mph for him.
Except, light is moving at 186,000mph for him. All this talk about how you hate submitting reality to a subjective point of view, but now you're suddenly saying the traveler must submit reality as he expderiences it to your point of view?
That's how WE see it, because we (accurately) see his clock slowed down by a factor of 10.
We don't see it that way at all.
One thing you've forgotten: in those ten years, the traveler will move another 90 light-years away from the stars, from our perspective, and will see the light reach the second star from a further distance that the light leaving the first star. He sees the ten years it takes for the light to go from star to star spread out over a long period of time, and has to account for that in his calculations.
According to the relationship between the earth and the sun, in this case. If we see 100 revolutions, how many do you think the traveler would see? Only 10? Something in between?
I don't think there any way to say that we and the traveler are starting and stopping at the same time in the first place, so there is no way for us to count revolutions simultaneously. This is espcially true when he is in a new location after every revolution.
One Brow said: "What does it mean for the sun to be moving? Be precise."
It hardly matters what it means in this context. I merely said the sun is moving or not moving, which seems to cover all bases, whatever it means. Let it mean whatever you want and/or that the sun is/is not moving with respect to whatever you choose--the earth, the milky way, absolute space, the center of gravity of the entire universe, my candyass neighbor, Charlie, whatever---the point is the same:
Whatever state of motion the sun may have now, may have had in the past, or may have in the future is completely independent of what you or I know, understand, believe, desire, perceive, etc.
One point is simple: Our state of knowledge has nothing to do with what is (although what is may well influence our conclusions about what bwe believe is). The two questions are ENTIRELY separate. What "is" may well influence what we think we know (or don't know), but what we think does not influence what "is" in the general realm of physical objects (excluding thought processes which lead to inventions or other manipulations of physical things). If you can't separate the two issues, then it's hard to communicate with you.
Another "point" (which I only address repeatedly because you keep bringing it up) is that choosing a reference frame is a simple and absolutely necessary prerequisite for discussing anything. We understand that. That is a necessary condition (limitation, if you prefer) of all human understanding. Making that assertion does NOT explain some other point you're trying to drive at.
For example, it's possible you're trying to suggest something along the lines of:
1. Because all theories and statements of any kind start with some (necessarily) unproven assumptions, all knowledge is suspect, and in fact impossible so, therefore...
2. All discussion of physics or any other thing is simply meaningless speculation based on less than absolute knowledge.
3. Knowledge is either (1) absolute, perfect, eternally true, absolutely immutable and indisputable or else it is (2) not knowledge at all, and there is no sense in discussing anything that does not consist of true knowledge.
Is that your point? What is your point?
One Brow said: "You keep saying that, but can't quite put your finger on the wrong part of it."
Wrong, I have said quite specifically why it is wrong dozens of times, but every time I do you still come up with some non-sequitur which demonstrates that you can't comprehend or respond to simple logic, for example (your most recent "response"):
"This has what to do with the choice of inertial rest frame being arbitrary?
1. It is a fucking logical contradiction easily identified by any high school kid with no knowledge of SR whatsoever (because none is required), and
2. It contradicts the express content and conclusions of SR.
That's how I "put my finger on it' dozens of times. You don't hear, consider, or even attempt to respond to anything I say--you just ask how it "relates" to some completely irrelevant point.
One Brow said: "The Galilean and Lorentz velocity equaitons are not the same. If LET uses Galilean velocity tranformations, it's not using LR."
No, this does not follow, and is not the case. LR does not "use" the transformations in an attempt to establish a relativity principle, as Al does. Within LR, the relativity principle is upheld via the usual invariant gallilean transformations. That said,it also predicts, and deals with, the consequences of the LR transformations because they exist and must be considered and accounted for in any theory of motion.
One Brow said: "There is no "requirement" for reciprocity. It exists, required or otherwise. What we do or not not require does not affect reality."
While on the topic of LR, let me address this claim too. The demand for reciprocal transformations comes from relationalists, and "exists" only to that extent. Reciprocal transformations are NOT required by, and are in fact rejected by, LR.
One Brow said: "Change the to "all experiements indicate that the speed of light in invariable to all inertial oberservers", and I would agree."
Experiments which indicate the invariable (as measured) speed of light also "indicate" the truth of LR. But LR does NOT, like Al, insist that the speed of light must be the same in all reference frames (which is the observation you were responding to).
One Brow said: "This is very confusingly written. What are supposed two events that Jack does not get a duration for that equates to the speed of light being see? What causes him to see his own clock incorrectly? You made no sense here, at all. Why can't Jack just read his own clock?"
Did you read the webpage it came from? No real use in my trying to respond if you didn't, because I didn't attempt to go into all the details, figuring the webpage could speak for itself on that matter.
One Brow said: "The mist allows jack to see the path of the light pulse in Jill's clock. It's doesn't block anything."
He can see that without mist. But the mist prevents him from seeing it without binculars, and, Golly Gee, looking through the binoculars prevent him from referring to his own light clock, which he supposedly brought for the purpose of "comparing clocks"
One Brow said: "the question only made sense if you meant you were traveling inertially at a higher rate of speed than previously."
Yeah, you got my meaning perfectly. Why should I add a bunch of obvious, inconsequential stuff to a simple question?
One Brow said: "the question only made sense if you meant you were traveling inertially at a higher rate of speed than previously."
Yeah, you got my meaning perfectly. Why should I add a bunch of obvious, inconsequential stuff to a simple question?
You had suggested that a traveller could ONLY move closer to the speed of light in the eyes of some other party but could never "actually" get closer to that speed. Again, you cannot distinguish what is measured from what is.
Let me give you an example. Suppose we blast a guy off into space, and accelerate him, all day long, with him experiencing tremendous g-forces for weeks on end, at which time the acceleration stops and he "coasts." Via radio contact we tell him that, according our calculations, he is now going at .99c. He knows all about SR predicts and all about it's claims that a "moving" clock (i.e, his clock now, not the "stationary" clock he saw on earth) is the one where time dilates etc.
Would he have any reason to believe that he was now going "closer to the speed of light" than he was when he left earth, ya figure? What would prevent him from reasonably beleiving that? I mean even if his ship had no speedometers, no acceleration detectors, or any other sophisticated instruments.
I'll come back to the "true motion" questions, which I am skipping over for now.
One Brow said: "The idea always seems to be along the lines that an observer will see a moving physical object which passes him at relativistic speeds as highly deformed (flattened out) in the direction of it's motion.
Which is in agreement with what I just explained.
Well, at least that gives me some physical idea of the effects you are talking about. Let me ask this: Is this "flattened appearance" just an illusory appearance, or do physical objects actually get foreshorteden in the direction of motion as the image clearly suggests?
One Brow said: "It doesn't cause a physical change for you in the clocks and rods with you, or the readings you get from them, because they are not pointed away from you. I see less of your rod in the direction of travel, and more of your clock."
So "seeing more of my clock" makes you think time runs slower for me, how? Do my clocks actually slow down, as Hafele-Keating et al, claim?
aintnuthin said...
Whatever state of motion the sun may have now, may have had in the past, or may have in the future is completely independent of what you or I know, understand, believe, desire, perceive, etc.
One point is simple: Our state of knowledge has nothing to do with what is (although what is may well influence our conclusions about what bwe believe is). The two questions are ENTIRELY separate. What "is" may well influence what we think we know (or don't know), but what we think does not influence what "is" in the general realm of physical objects (excluding thought processes which lead to inventions or other manipulations of physical things). If you can't separate the two issues, then it's hard to communicate with you.
How can one object have a state of motion?
Outside of that, I have been agreeing with this for some time. I'm sure that won't stop you from bringing it up again.
Is that your point?
No.
What is your point?
You keep talking about things having inertial motion as if it was a property of that one object. As far as I can tell, it isn't.
1. It is a fucking logical contradiction easily identified by any high school kid with no knowledge of SR whatsoever (because none is required), and
A contradiction is a statement of the form A & ~A. So, I assume you want to start with a statement such as "The viewpoints of Alice on the ground and Bob on the train are equally valid." Derive an actual contradiction, step by step. If you skip a step, I'll notice.
I don't think you can do it, frankly.
2. It contradicts the express content and conclusions of SR.
Except, it doesn't.
You don't hear, consider, or even attempt to respond to anything I say--
I admit I wasn't treating your position seriously. I am now. Can you treat your own position seriously? If so, do the work. Deive the contradiction, step by step, not skipping anything or glossing over anything.
Within LR, the relativity principle is upheld via the usual invariant gallilean transformations.
Then it is wrong, experiementally. If a light source is moving at v with respect to a laboratory, the light from the light source does not proceed at v + c in the laboratory, it only proceeds at c.
While on the topic of LR, let me address this claim too. The demand for reciprocal transformations comes from relationalists, and "exists" only to that extent.
Then you have discovered an experiemntal way to verify LET over SR (as understood by the vast mahjority of physicists). Mention this to a few LET-friendly physicists, have one of them get grant money, and test it.
Experiments which indicate the invariable (as measured) speed of light also "indicate" the truth of LR.
Not if LET uses Galilean velocity transformations.
Did you read the webpage it came from?
Yes. I went back and read it again. There is no hint of Jack not being able to see his own clock, nor of getting a speed of light ther than the usual. That was you.
He can see that without mist.
A light pulse is unidirectional. The mist scatters it a bit, allowing Jack to see it.
But the mist prevents him from seeing it without binculars, and, Golly Gee, looking through the binoculars prevent him from referring to his own light clock, which he supposedly brought for the purpose of "comparing clocks"
He need binoculars because Jill is moving so quickly that she spends very little time in Jack's normal visual field.
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