Preferred Frame Theory indistinguishable from SR
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From: Tom Roberts on 29 Jun 2010 22:14 Paul Stowe wrote: > On Jun 27, 10:03 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >> PaulStowewrote: >>> On Jun 27, 5:14 pm, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: >>>> PaulStowewrote: >>>>> There is SOMETHING in SR that gives rise to the second postulate. >>>> Axiomatic systems do not need to justify their axioms. >>> Yeah, 'taken for granted systems' do not need to justify their >>> 'statements which are taken for granted'. >> SR is not really an "axiomatic system". Nor a 'taken for granted system'. > > Look up the definition of axiomatic... Look at my reply to eric gisse. >> SR is a physical theory with testable predictions and a well-defined domain of >> applicability. Within that domain, literally hundreds of experiments have >> confirmed the predictions of SR, and NONE have been significantly different from >> the corresponding prediction of SR. >> >> Actually, zillions more experiments have confirmed SR, in the >> portion of its domain shared with Newtonian mechanics. > > Millions Tom? READ WHAT I WROTE! Until you learn to read accurately, you will remain mystified. > Come on, get real! There is N-O-T-H-I-N-G! special in > SR and Lorentz and Poincare pointed out... Who said or implied that SR is "special" (in the sense you apparently mean here, which is not at all the usual sense in this context)? Note I explicitly mentioned another theory indistinguishable from SR within a limited domain common to both theories. >> THAT is what makes SR a valid and viable theory. And why it is one of the >> foundations of modern physics. > > Since SR has no uniqueness one can say the very same thing about LR. In one sense yes, in several other senses, no: Yes: * LR (LET) is experimentally indistinguishable from SR. So LET is every bit as valid as SR within their common domain of applicability. No: * they don't have the same domain of applicability -- SR is considerably more general than LET (LR) * the theoretical underpinning of LET (LR) borders on a reductio ad absurdum (the supposedly unique ether frame is not unique) * because it does not obey the PoR, and thus is not based on symmetry considerations at all, LET (LR) could not have led to most of the major theoretical advances in the 20th century, which are based on symmetries -- SR taught us A LOT about this * physicists are understandably reluctant to embrace a theory based on an inherently unobservable medium (such as the ether of LET/LR); moreover it is continuous, and no continuous object or medium has ever been observed It is those differences that make SR a foundation of modern physics, and LR (LET) a historical anecdote unknown by most. [Do not deceive yourself into thinking that the speed of light is part of the theoretical underpinning of SR. Historically it was important; not today, or for the past half-century or so.] Note, please, that uniqueness is not important for physical theories. For instance, Newtonian mechanics, Lagrangian mechanics, Hamiltonian mechanics, and Hamilton-Jacobi theory are all experimentally indistinguishable within the same domain (classical mechanics), yet all are taught in good physics curricula. The difference between this example and SR vs LET is that in the former case the four different theories each bring a new perspective and new theoretical concepts to the student, which have been found to be essential in the development of theoretical physics during the past century; on the other hand, LET (LR) brings nothing new that has been found to be useful. I suspect there are additional theories indistinguishable from Newtonian mechanics, but like LET (LR) they have been lost, most likely because they brought nothing new that is useful. I believe there is also a quaternion-based theory equivalent to SR that has also been lost. Tom Roberts
From: Daryl McCullough on 29 Jun 2010 23:06 Surfer says... >But for spacecraft earth flybys viewed from an earth centered frame, >Newtonian mechanics requires the asymptotic speed of the departure to >be equal to that of the approach. > >This provides a very accurate way to test the radar Doppler formula, >because if all known perturbations are allowed for and the speed data >gained using the formula does not result in approach and departure >speeds that are sufficiently similar, then something is wrong. > >Interestingly, this is often the case. The subject of this thread is actually a theory that is *indistinguishable* from SR. So there cannot be an experiment that confirms this theory and which disconfirms SR. If you use different coordinate systems than is typically used in SR, you will get a different formula for Doppler shift, but there is no physical difference between this formula and the usual SR prediction. It's analogous to this: You can use Cartesian coordinates to compute areas, and you get A = Integral of dx dy. You can also use polar coordinates to compute areas, and you get A = Integral of r dr dtheta. These are different formulas for area. But it would make no sense to believe that you empirically decide which formula is "correct". They are both correct for their respective coordinate systems. To get a physically different theory, you have to come up with a coordinate-free calculation that gives different predictions for the different theories. Changing coordinates cannot change a physical prediction. -- Daryl McCullough Ithaca, NY
From: Inertial on 29 Jun 2010 23:20 "Daryl McCullough" wrote in message news:i0ecb30157q(a)drn.newsguy.com... [snip] >To get a physically different theory, you have to come up with >a coordinate-free calculation that gives different predictions >for the different theories. Changing coordinates cannot change >a physical prediction. Unless, of course, the 'theory' is self-contradictory and/or wrong :):)
From: eric gisse on 29 Jun 2010 23:30 Surfer wrote: [...] > This provides a very accurate way to test the radar Doppler formula, Atomic measurements are more precise. > because if all known perturbations are allowed for [...] Why would you think they are, when the 'accounting' for the perturbations are order-of-magnitude guesses?
From: Tom Roberts on 29 Jun 2010 23:54
Paul Stowe wrote: > Tell us where LR fails to comply > with the PoR. LET (LR) starts out with an implicit postulate: there is a unique inertial frame in which the ether is at rest. So the (also implicit) law of ether motion is DIFFERENT in different inertial frames, violating the PoR. LET (LR) has an amazing and unexpected cancellation that makes the ether frame completely unobservable FOR PHYSICAL MEASUREMENTS. But its transform equations were all derived starting from that unique inertial frame. Tom Roberts |