Preferred Frame Theory indistinguishable from SR
in [Math]
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From: Daryl McCullough on 6 Jul 2010 11:18 harald says... >The twin scenario was presented by Langevin in 1911 to show that >physical acceleration is "absolute", even more so with SRT than with >Newton's mechanics. What does that mean? As I said, proper acceleration (as measured by an accelerometer) is absolute, but coordinate acceleration is certainly not. >He argued that these absolute effects detect the ether (what you call >a "preferred frame"). If that's what he argued, then he was wrong. The fact that acceleration is measurable does not imply the existence of a preferred rest frame. Here's an analogy: A flat Euclidean plane has no notion of a preferred direction. Any direction is as good as any other. But it certainly has a notion of a *change* of direction. If you draw a path on the Euclidean plane, then you can unambiguously determine whether the line is straight or curved, because a straight line connecting two points is shorter than any curved line connecting the same two points. If you measure the lengths of two curves, you can determine which one is straight. A rest frame in Einstein's spacetime is analogous to a direction in Euclidean space. There is no preferred rest frame in spacetime any more than is a preferred direction in the Euclidean plane. But a *change* of rest frames is certainly detectable, in the same way that a change in direction is detectable in the Euclidean plane. >However, Einstein (1916) considered that the PoR of SRT has an >"epistemological defect", since it relates to a privileged group of >"spaces" that cannot be observed. And what he could not observe, he >called 'factitious'. In other words, he rediscovered Newtons' argument >but he found it unacceptable. He preferred to go the opposite route >and extended the PoR as follows: > >"The laws of physics must be of such a nature that they apply to >systems of reference in any kind of motion". >As a result, physical acceleration is, according to Einstein's GRT, >*relative* - which is just the contrary of what Langevin argued based >on his "twins" example of SRT. As I said, proper acceleration is definitely *not* relative, but coordinate acceleration trivially *is*. But proper acceleration is measuring acceleration relative to *freefall*. >It should not be surprising that this was not only very confusing for >bystanders (who already hardly understood the difference between the >two theories), but that it even looked like a contradiction I would like to hear any coherent explanation of why it looks like a contradiction. The bare statement "The laws of physics must be of such a nature that they apply to systems of reference in any kind of motion" is not a contradiction---on the contrary, it is nearly a tautology. You can always write the laws of physics so that you can use an arbitrary coordinate system. To derive a paradox from the twin thought experiment, you need to reason something like this: 1. There exists two coordinate systems, C1 and C2, such that the path of the traveling twin, as described in C1, is the same as the path of the stay-at-home twin, as described in C2. 2. Therefore, the predicted age of the traveling twin, computed using C1, must be the same as the predicted age of the stay-at-home twin, computed using C2. I don't see how 2 follows from the general principle of relativity, as expressed in the sentence "The laws of physics must be of such a nature, blah, blah, blah." From the latter, it follows that one can use either C1 or C2 to compute the ages of the two twins, but it *doesn't* imply that the ages will be the same. To be able to conclude that, you need to assume a very specific form for the laws of physics. -- Daryl McCullough Ithaca, NY
From: colp on 6 Jul 2010 16:03 On Jul 7, 3:07 am, PD <thedraperfam...(a)gmail.com> wrote: > > > I don't have any idea > > > how you conclude from his postulate about no preferred frame that time > > > for both systems cannot be dilated with respect to each other. > > > That isn't what I am saying. I'm saying that for time for both systems > > to be dilated with respect to each other constitutes a paradox, > > No, it does not. Yes it does. If a clock in a moving frame runs slow, then a clock in a stationary frame runs fast when viewed from the moving frame. If that were not the case then you would get paradoxical outcomes. > > I suspect that you believe that it is because you believe the > statement made by relativity is that "moving clocks run slow". Relativity makes a statement that means exactly the same thing. "If at the points A and B of K there are stationary clocks which, viewed in the stationary system, are synchronous; and if the clock at A is moved with the velocity v along the line AB to B, then on its arrival at B the two clocks no longer synchronize, but the clock moved from A to B lags behind the other which has remained at B ..." Einstien, Electrodynamics of Moving Bodies > You > hear this to mean that "Clock A is running slower than clock B, and > clock B is running slower than clock A." No, B only runs slower than A if there is no preferred frame of reference. > You furthermore believe that, > logically, "Clock A is running slower than clock B" necessarily > implies that "Clock B is running faster than clock A" and hence the > paradox arises with the combination of sentences "Clock B is running > faster than clock A" and "Clock B is running slower than clock A." O.K. > The problem, you see, is that the comic-book statement you are using > as your launching point belongs in COLP's Oversimplified Relativity. It's not a comic book statement any more than Einstein's statement that a moving clock lags behind a stationary clock is a comic book statement. > > Relativity doesn't make that statement as carelessly and loosely as > you're using it. There is nothing careless or loose about my statement. > > Instead, it makes a more precise statement about what it MEANS to say > that Clock B is running slower than Clock A. And here is where > identification of particular *events* comes into play. And this makes > all the difference. So why can't you say what the difference is if it exists? Some vague reference to "events" doesn't cut it.
From: PD on 6 Jul 2010 16:52 On Jul 6, 3:03 pm, colp <c...(a)solder.ath.cx> wrote: > On Jul 7, 3:07 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > I don't have any idea > > > > how you conclude from his postulate about no preferred frame that time > > > > for both systems cannot be dilated with respect to each other. > > > > That isn't what I am saying. I'm saying that for time for both systems > > > to be dilated with respect to each other constitutes a paradox, > > > No, it does not. > > Yes it does. If a clock in a moving frame runs slow, then a clock in a > stationary frame runs fast when viewed from the moving frame. If that > were not the case then you would get paradoxical outcomes. See below. It'd be a good idea to read my whole post before opening your yap. > > > > > I suspect that you believe that it is because you believe the > > statement made by relativity is that "moving clocks run slow". > > Relativity makes a statement that means exactly the same thing. No, it does not. See below. > > "If at the points A and B of K there are stationary clocks which, > viewed in the stationary system, are synchronous; and if the clock at > A is moved with the velocity v along the line AB to B, then on its > arrival at B the two clocks no longer synchronize, but the clock moved > from A to B lags behind the other which has remained at B ..." > > Einstien, Electrodynamics of Moving Bodies > > > You > > hear this to mean that "Clock A is running slower than clock B, and > > clock B is running slower than clock A." > > No, B only runs slower than A if there is no preferred frame of > reference. > > > You furthermore believe that, > > logically, "Clock A is running slower than clock B" necessarily > > implies that "Clock B is running faster than clock A" and hence the > > paradox arises with the combination of sentences "Clock B is running > > faster than clock A" and "Clock B is running slower than clock A." > > O.K. And this is part of your problem. > > > The problem, you see, is that the comic-book statement you are using > > as your launching point belongs in COLP's Oversimplified Relativity. > > It's not a comic book statement any more than Einstein's statement > that a moving clock lags behind a stationary clock is a comic book > statement. Not so. Einstein's statement included things that you have discounted. For example, he makes note of specific events, rather than just making the general statement that "moving clocks" run slow. Furthermore, he makes EXPLICIT mention of the statement that the clocks at points A and B are initially synchronized IN THE K FRAME. A contradiction would arise by making the clock at B the moving clock only if the clocks are claimed to be intially synchronized also in the K' frame -- but they are NOT, and this is the essential detail that you have missed. Yes, in the K' frame, the B clock runs slower than the A clock, but when A arrives at B, it is STILL behind the B clock because in the K' frame the clocks are not initially synchronized. There is no contradiction. The observation that when the clock from A arrives at B, the former is behind the latter is a completely consistent observation in both frames. > > > > > Relativity doesn't make that statement as carelessly and loosely as > > you're using it. > > There is nothing careless or loose about my statement. Yes, there is, and I've pointed it out to you repeatedly, and you are ignoring it, preferring to stick to your guns with COLPs Oversimplified Relativity. I agree that COLPs Oversimplified Relativity is contradictory and should be chucked. But relativity does not suffer from that problem. > > > > > Instead, it makes a more precise statement about what it MEANS to say > > that Clock B is running slower than Clock A. And here is where > > identification of particular *events* comes into play. And this makes > > all the difference. > > So why can't you say what the difference is if it exists? Some vague > reference to "events" doesn't cut it. And again, it would help if you would actually READ what relativity says in a book designed to TEACH relativity, rather than just sticking to COLPs Oversimplified Relativity and demanding that people have COR make sense to you. I've already told you what the statement about time dilation is in regard to events. If you've forgotten it, then please reread that. If you don't know what an "event" is to a physicist, then I suggest you look it up, and preferably someplace other than the Internut. PD
From: PD on 6 Jul 2010 16:56 On Jul 5, 12:04 am, colp <c...(a)solder.ath.cx> wrote: > On Jul 5, 7:31 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Jul 3, 6:06 pm, colp <c...(a)solder.ath.cx> wrote: > > > > On Jul 4, 2:14 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jul 3, 1:06 am, colp <c...(a)solder.ath.cx> wrote: > > > > > > On Jul 3, 3:03 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Jul 1, 7:56 pm, colp <c...(a)solder.ath.cx> wrote: > > > > > > > > On Jul 2, 2:21 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > On Jun 30, 5:47 pm, colp <c...(a)solder.ath.cx> wrote: > > > > > > > > > > <quote> > > > > > > > > > > > > At best, all you've done is show the > > > > > > > > > > > fallacies or assumptions inherent in COLP's Oversimplified Relativity. > > > > > > > > > > What specific fallacies or assumptions? Quotes, please. > > > > > > > > > > Sure. You've used the statement from COLP's Oversimplified Relativity > > > > > > > > > that moving clocks run slow (which you've said is true even for blue- > > > > > > > > > shifted clocks), and you've used the statement that COLP's > > > > > > > > > Oversimplified Relativity makes no provision whatsoever for a > > > > > > > > > compression of time for a clock turning around. This immediately leads > > > > > > > > > to several paradoxes, and this is ample reason to chuck Colp's > > > > > > > > > Oversimplified Relativity. > > > > > > > > > </quote> > > > > > > > > > > The statement that "moving clocks run slow" isn't an > > > > > > > > > oversimplification, it is directly inferred from Einstein's > > > > > > > > > "Electrodynamics of Moving Bodies". > > > > > > > > > It IS an oversimplification. If you've inferred this from his 1905 > > > > > > > > paper, then you've oversimplified. > > > > > > > > No, inferring something from a paper does not constitute an > > > > > > > oversimplification. > > > > > > > It does if it's an oversimplification of what's presented in the > > > > > > paper! > > > > > > It isn't. Claiming that it is without showing why is of no value. > > > > > You aren't owed an education on a newsgroup, despite your taunts to > > > > the contrary. > > > > I'm not asking for an education, I'm pointing out that all you have to > > > defend you beliefs are hollow claims. > > > No, they are fully supportable claims. > > Wrong. The burden of proof is yours. You can't support them because no > such support exists. I'm sorry, but both sentences are wrong. Since it's been pointed out to you that your understanding of relativity is shallow and oversimplified, and since resources to correct that have been explicitly pointed at for you, then the burden is on YOU to correct that. If you have an erroneous understanding of something, you do NOT have the right to insist, "My presentation of it is correct, unless someone steps in and proves that it's wrong." No one owes you a convincing. The facts are not hidden. They are at your disposal. You either CHOOSE to correct your erroneous understanding or you CHOOSE not to. PD
From: Paul Stowe on 6 Jul 2010 20:47
On Jul 6, 12:25 am, harald <h...(a)swissonline.ch> wrote: > On Jul 5, 8:26 pm, PaulStowe<theaether...(a)gmail.com> wrote: > > > > > > > On Jul 5, 10:00 am, harald <h...(a)swissonline.ch> wrote: > > > > On Jul 5, 2:46 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > > > > > harald says... > > > > > >Acceleration effects are not identified as gravitational fields in > > > > >Newtonian physics (which, as you now know, you didn't know); and > > > > >neither is that the case in SRT. In those theories acceleration is > > > > >"absolute", and no gravitational fields are caused by acceleration.. > > > > > This is a topic for another discussion, but I'm talking about > > > > "pseudo-gravitational" fields, which crop up in both SR and Newtonian > > > > physics if you use accelerated coordinates. > > > > We agree on "pseudo", while Einstein rejected that. > > > > > >> I think it is because you have not made it very well. I still > > > > >> have no idea what your point is. > > > > > >Just study Einstein's paper carefully, > > > > > I want to know what *YOUR* point is. State it in your own words. > > > > I did, also in the part of my sentence that you exactly here snipped: > > > > *you'll know what theory the paradox challenges*. > > > > THAT (and only that) was my point: the clock paradox challenges the > > > General PoR. > > > > You certainly are aware that, despite Einstein's *suggestion* to that > > > effect in the introduction of his 1905 paper, SRT is *not* based on > > > the General PoR. > > > Strictly speaking the 'domain' of the 'special' theory of relativity > > is limited to inertial states. The original principle of relativity > > as expressed in Einstein's 1905 work covered only that domain. So > > Harald is correct, the paradox is confined to the situation where, you > > have identical twins one remain in the original inertial frame, the > > other accelerated rapidly (nearly instantaneously) to speed ~c travels > > for x time wrt the original FOR, reverses comes to an equally rapid > > stop (wrt the original FOR) then returns the same way. Since SRT is > > based upon v^2 effects (second order quantities) the directionality of > > any asymmetry is lost in the expressions that quantify changes. > > However, there is NO! paradox, either in nature, or SRT, once one > > understands that limitation. The traveling twin, not the stay at home > > twin will be physically younger. On a one-way trip however, we can't > > say which one would be for an equal physical duration. That would > > depend upon the speeds of both FOR relative to the CMBR... > > Directionality does matter. > > I don't follow your last sentence. Perhaps you mean, as Langevin put > it, that a change of direction of speed does matter for the asymmetry. > > Regards, > Harald According to LR the rate at which time passes is related to the absolute speed wrt to the aether frame. For any round trip direction is irrelevant, the total travel necessary to complete the circuit will guarantee the total time will be relative to the delta velocity between the systems. However!, if, for example you are traveling at 600,000 Kps in some direction as measured by the CMBR Doppler and accelerate in a direction as to bring your speed to zero wrt to the CMBR, LR predicts that your rate of time passage is now proceeding faster than your stay at home twin. That twin is now receding from you at 600,000 Kps and to EVER! hope to get back to him you must catch up to him. Doing so requires you to go faster, longer, than ANY outbound track, making the total elapsed time still less when you get back than his. However, if you don't go back, LR say your time passes faster. Note however that for the outbound one-way trip your clock rate depends upon whether you're increasing or decreasing your speed relative to the CMBR. Definitely direction dependent. Paul Stowe |