Preferred Frame Theory indistinguishable from SR
in [Math]
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From: colp on 3 Jul 2010 02:04 On Jul 3, 2:57 am, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 1, 6:25 pm, colp <c...(a)solder.ath.cx> wrote: > > > > > On Jul 2, 2:26 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jul 1, 12:53 am, colp <c...(a)solder.ath.cx> wrote: > > > > > On Jul 1, 11:37 am, Koobee Wublee <koobee.wub...(a)gmail.com> wrote: > > > > > > On Jun 30, 4:20 pm, artful wrote: > > > > > > > On Jul 1, 8:47 am, colp wrote: > > > > > > > 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 over simplification. There is more to SR than just clocks > > > > > > running slow. > > > > > > Nonsense and mysticism. <shrug> > > > > > A postulate is just an assumption with better table manners. > > > > Yes, indeed. By DEFINITION, a postulate is something that is ASSUMED. > > > > In science, the test of a postulate is based on experimental check of > > > the *consequences* of postulates. A direct test of the postulate is > > > not required. > > > One such test is the test for paradoxes arising from one or more > > postulates. For example, the following two postulates lead to a > > paradox, meaning that not all the postulates are correct: > > > 1. Statement 2 is true. > > 2. Statement 1 is false. > > > The paradox that arises from the postulates of Einstein's > > "Electrodynamics of Moving Bodies" can be described as follows: > > > "Examples of this sort, together with the unsuccessful attempts to > > discover > > any motion of the earth relatively to the light medium, suggest that > > the > > phenomena of electrodynamics as well as of mechanics possess no > > properties > > corresponding to the idea of absolute rest. They suggest rather that, > > as has > > already been shown to the first order of small quantities, the same > > laws of > > electrodynamics and optics will be valid for all frames of reference > > for which the > > equations of mechanics hold good.1 We will raise this conjecture (the > > purport > > of which will hereafter be called the Principle of Relativity) to > > the status > > of a postulate, and also introduce another postulate, which is only > > apparently > > irreconcilable with the former, namely, that light is always > > propagated in empty > > space with a definite velocity c which is independent of the state of > > motion of the > > emitting body." > > > Einstien, Electrodynamics of Moving Bodies (Introduction) > > > This text describes Einstein's postulate that there is no preferred > > inertial frame of reference. > > > "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 (Section 4) > > > The text describes the time dilation of a clock that moves from point > > A to point B. If there is no preferred frame of reference then it is > > just as true to say that > > the clock is viewed as part of a stationary system and the points A > > and B are in a moving system which moves at velocity -v. The > > conclusion that time for both systems can be dilated with respect to > > the other system is paradoxical. > > No, it's not paradoxical at all. It is paradoxical because time for both systems cannot be dilated with respect to each other. > > In the moving frame, the clocks at A and B were never synchronous. There aren't multiple clocks in the moving system in Einstein's example.
From: colp on 3 Jul 2010 02:06 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.
From: Daryl McCullough on 3 Jul 2010 07:02 harald says... >If you google search, you will find me explaining that Einstein >claimed to have solved GRT's clock paradox. ;-) The use of GR to explain the results of the twin paradox is a little perverse, because GR is a generalization of SR. In the case of empty space far from any large gravitating bodies, GR reduces to SR, so any GR solution to the twin paradox would have to have already been a solution in SR. Which is exactly the case: GR solves the twin paradox in the exact way that SR does. Many people are confused by the equivalence principle into thinking that Einstein's theory of gravity is necessary in order to describe physics from the point of view of an accelerating coordinate system. That's exactly backwards. The reasoning goes the other way around: 1. We already understand SR as described in standard inertial coordinates (the type of coordinate systems related by the Lorentz Transformations). 2. We use ordinary calculus to figure out what SR looks like in other coordinate systems. This is not a different *physical* theory than SR, any more than using spherical coordinates to do Newtonian mechanics means we are no longer doing Newtonian mechanics. 3. Using calculus, we can figure out what SR looks like in an accelerated coordinate system (a coordinate system in which an accelerated observer is "at rest". What we find is that, as measured in such a coordinate system, a clock shows an elapsed time T such that dT/dt is position dependent: Clocks that are "higher" (in the direction of the acceleration) run faster, and clocks that are "lower" run slower. 4. Now, we invoke the equivalence principle, and assume that the situation of being at rest in a uniform gravitational field is approximately the same as being at rest in an accelerated coordinate system in SR. 5. We conclude from 4 that clocks that are stationary and "higher" in a gravitational field run faster than clocks that are stationary and "lower". So a clock high on a mountain runs faster than a clock at sea level (after accounting for the SR effect of velocity due to the rotating Earth). The equivalence principle allows us to *approximately* solve problems involving gravity by using SR. That's what it's useful for. The other way around, using GR to solve problems that involve acceleration in flat spacetime, makes little sense, because you don't need GR. You just need SR + calculus. -- Daryl McCullough Ithaca, NY
From: harald on 3 Jul 2010 07:47 On Jul 3, 1:02 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > harald says... > > >If you google search, you will find me explaining that Einstein > >claimed to have solved GRT's clock paradox. ;-) > > The use of GR to explain the results of the twin paradox is a little perverse, Sorry but no, you missed the point (how is that possible after all these years?). The original clock or twin paradox is NOT the SRT exercise of textbooks at all, despite the fact that most confused commentators parrot that error. Instead, it is a challenge to GRT's postulate that an accelerated reference system may be considered to be "in rest". SRT does NOT pretend such a thing. On that point I therefore fully agree with Einstein. > because GR is a generalization of SR. In the case of empty space far from any > large gravitating bodies, GR reduces to SR, so any GR solution to the twin paradox would have to have already been a solution in SR. Irrelevant. > Which is exactly the > case: GR solves the twin paradox in the exact way that SR does. Impossible: according to Einstein and myself, there *was* no "twin paradox" in SRT. [..] > The equivalence principle allows us to *approximately* solve problems involving > gravity by using SR. That's what it's useful for. The other way around, using GR > to solve problems that involve acceleration in flat spacetime, makes little > sense, because you don't need GR. You just need SR + calculus. Sure. That never was an issue, except (again) for later confused commentators. Regards, Harald
From: PD on 3 Jul 2010 10:10
On Jul 3, 1:04 am, colp <c...(a)solder.ath.cx> wrote: > On Jul 3, 2:57 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Jul 1, 6:25 pm, colp <c...(a)solder.ath.cx> wrote: > > > > On Jul 2, 2:26 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jul 1, 12:53 am, colp <c...(a)solder.ath.cx> wrote: > > > > > > On Jul 1, 11:37 am, Koobee Wublee <koobee.wub...(a)gmail.com> wrote: > > > > > > > On Jun 30, 4:20 pm, artful wrote: > > > > > > > > On Jul 1, 8:47 am, colp wrote: > > > > > > > > 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 over simplification. There is more to SR than just clocks > > > > > > > running slow. > > > > > > > Nonsense and mysticism. <shrug> > > > > > > A postulate is just an assumption with better table manners. > > > > > Yes, indeed. By DEFINITION, a postulate is something that is ASSUMED. > > > > > In science, the test of a postulate is based on experimental check of > > > > the *consequences* of postulates. A direct test of the postulate is > > > > not required. > > > > One such test is the test for paradoxes arising from one or more > > > postulates. For example, the following two postulates lead to a > > > paradox, meaning that not all the postulates are correct: > > > > 1. Statement 2 is true. > > > 2. Statement 1 is false. > > > > The paradox that arises from the postulates of Einstein's > > > "Electrodynamics of Moving Bodies" can be described as follows: > > > > "Examples of this sort, together with the unsuccessful attempts to > > > discover > > > any motion of the earth relatively to the light medium, suggest that > > > the > > > phenomena of electrodynamics as well as of mechanics possess no > > > properties > > > corresponding to the idea of absolute rest. They suggest rather that, > > > as has > > > already been shown to the first order of small quantities, the same > > > laws of > > > electrodynamics and optics will be valid for all frames of reference > > > for which the > > > equations of mechanics hold good.1 We will raise this conjecture (the > > > purport > > > of which will hereafter be called the Principle of Relativity) to > > > the status > > > of a postulate, and also introduce another postulate, which is only > > > apparently > > > irreconcilable with the former, namely, that light is always > > > propagated in empty > > > space with a definite velocity c which is independent of the state of > > > motion of the > > > emitting body." > > > > Einstien, Electrodynamics of Moving Bodies (Introduction) > > > > This text describes Einstein's postulate that there is no preferred > > > inertial frame of reference. > > > > "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 (Section 4) > > > > The text describes the time dilation of a clock that moves from point > > > A to point B. If there is no preferred frame of reference then it is > > > just as true to say that > > > the clock is viewed as part of a stationary system and the points A > > > and B are in a moving system which moves at velocity -v. The > > > conclusion that time for both systems can be dilated with respect to > > > the other system is paradoxical. > > > No, it's not paradoxical at all. > > It is paradoxical because time for both systems cannot be dilated with > respect to each other. This is your assumption about what can and cannot be. > > > > > In the moving frame, the clocks at A and B were never synchronous. > > There aren't multiple clocks in the moving system in Einstein's > example. There are at least two clocks. There is one at point A and there is one at point B. One of them moves from A to B, and the other remains at B. In the reference frame K where A and B are at rest, then the clocks are synchronized initially. In the reference frame K' where A and B are moving, the clocks are NOT synchronized initially. When the clock at A ends up next to clock B and we discover that the reading on A is behind the reading on B, the account in the K frame is that the clocks were initially synchronized but that A ran slower than B. The account in the K' frame is that the clocks are NOT initially synchronized, and so even though B ran slower than A, it is STILL true that the reading on A is behind the reading on B when they are next to each other. As I said, colp, it would help if you would learn what special relativity ACTUALLY SAYS, rather than what your superficial COR says, then you will see that there are no contradictions in SR. PD |