Debunking Nimtz
in [Relativity]
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From: Dono on 22 Aug 2007 10:09 On Aug 22, 6:31 am, Ben Rudiak-Gould <br276delet...(a)cam.ac.uk> wrote: > Dono wrote: > > From your paper one > > gathers that you call "Lorentzian theory" the one governed by the > > Selleri-Tangherlini transforms, right? > > > x'=gamma*(x-vt) > > t'=t/gamma > > Can someone explain to me once and for all what the heck these are supposed > to mean? You can't use them as a plug-in alternative to the Lorentz > transforms, because they don't define a symmetry. Any time you have a set of > transforms that leave your equations unchanged, it must be true (for obvious > reasons) that > > 1. If T is one of them, then its inverse T^-1 is one of them. > 2. If T and U are two of them, then the combination T-then-U is one of > them. > > The transforms above don't satisfy either of these. So what on earth can > they possibly mean? The only reason the Lorentz transformations are > interesting is that they define a symmetry, and that symmetry is a > physically meaningful constraint on possible physical laws. Can someone show > me a physical theory that's "consistent" with the Selleri-Tangherlini > transforms, and one that isn't, and what exactly the difference is? > > -- Ben Ben, The Selleri-Tangherlini theory satisfies the so called H.P.Robertson "canonical experiments" : MMX, KTX and Ives-Stilwell. Surprisingly. They are the rallying point of what Tom Robets calls the "class of theories indistinguishable from SR". But Tom can be wrong at times, there is a class of experiments that falsify the Tangherlini theory. I cannot tell ou more about it since I am trying to nail Tom van Vlandern. Stay tuned to the exchange :-)
From: Ben Rudiak-Gould on 22 Aug 2007 11:38 Dono wrote: > The Selleri-Tangherlini theory satisfies the so called H.P.Robertson > "canonical experiments" : MMX, KTX and Ives-Stilwell. Surprisingly. There's nothing surprising about this. It's meaningless. Saying that empirical data is consistent with the Selleri-Tangherlini transforms is like saying it's consistent with metric units. I gather that a Selleri-Tangherlini transform t' = t/gamma x' = gamma (x - vt) is supposed to be a Lorentz transform t'' = gamma (t - vx) x'' = gamma (x - vt) followed by a clock resynchronization t' = t'' + v x'' x' = x'' This is not a theory. It's a convention. It says, "instead of using Einstein synchronization, let's synchronize our clocks in a certain way with respect to an agreed-upon common intertial frame." People do this sort of thing all the time. In practice, clocks are not Einstein-synchronized; they're synchronized with respect to the time coordinate of a standardized reference frame. UTC and TAI and cosmological time are examples of such coordinate times. Atomic clocks count coordinate time, not proper time; their proper tick rate has to be tweaked based on altitude and latitude in order to count coordinate time correctly. This kind of synchronization is far more useful than Einstein synchronization, because the real point of synchronizing clocks is to ensure that /everyone agrees/ on what time something happens. If your clocks are synchronized based on some personal state of motion, then they don't agree with anyone else's clocks, which makes them virtually useless. None of this has anything to do with physics. The universe doesn't care how you synchronize your clocks. That's not what Lorentz invariance is about. -- Ben
From: Tom Roberts on 22 Aug 2007 14:00 Tom Van Flandern wrote: > The Nimtz claim may or may not be correct, but it certainly is not > ridiculous. Sure. "Naive" would be a more accurate characterization. > It has now been solidly established that Lorentzian > relativity (with no speed limit) is just as viable a physical model as > special relativity (with speed limit c) because both theories agree with > all 11 independent experiments testing the relativity of motion. Hmmm. It is not at all obvious that Lorentzian relativity has no speed limit. Certainly Lorentz himself did not think so (c.f. the title of his 1904 paper that is the cornerstone of this theory). But yes, Lorentz's theory is experimentally indistinguishable from SR, because they use the same transforms and math; only the interpretation of quantities differs, and that is not involved in comparing theory to experiments. > It is also the prevailing opinion at present that > gravitational force propagates faster than light in forward time because > all six experiments sensitive to that speed agree that it propagates > faster than c. This is a gross, self-serving statement not supported by the facts. This may "prevail" in the circles you frequent, but it is most definitely not the case for the physics community at large. > Several early challenges to that conclusion between 1998 > and 2001 were answered to the satisfaction of neutral parties, and no > further challenges have appeared since the 2002 comprehensive review > paper on this subject. Hmmm. That is not how science works (that is a literary approach, not a SCIENTIFIC one). What really matters is that the predictions of GR agree with all those experiments. And they do. In GR: a) no energy or signal can propagate with a local speed > c. b) there is no "gravitational force", that appears only in an APPROXIMATION to GR. c) the mathematics of that approximation makes it clear how "gravitational force" propagates essentially instantaneously while still obeying the local speed limit of c: no energy or signal is "propagated >>c from the source's current position to the detector", but rather, it propagated with speed c from a previous position of the source. In essence the equations for "gravitational force" depend not only on the position of the source, but also on its velocity and acceleration -- they in effect _extrapolate_ the position of the source and make the detected "force" point right to the position of the source right now (as long as higher derivatives are negligible, and for all the experiments this is so [#]). [BTW this is no different from Coulomb force in classical electrodynamics, except that depends only on position and velocity, not acceleration.] [#] There's a hint: to really test this you should find a situation for which those higher derivatives are large enough to distinguish between the GR prediction and your model of ">>c propagation". Perhaps the binary pulsar will do. Note that "speed of propagation" depends ONLY on the position of the source, so is inadequate to accurately capture the subtleties of GR in this particular APPROXIMATION (which also involve its velocity and acceleration). This has been shown in several peer-reviewed papers (by Carlip and by Low). > Here are the citations:[...] Note he omits references that show agreement with GR; his basic claim is merely playing with the meanings of words and does not refute GR as he seems to think. > These are peer-reviewed, published in major physics journals, and the > last of them is unchallenged and therefore stands as the last word on > the subject to date. That is not how science works. The papers by Low and Carlip show this is all consistent with GR. Until and unless you can impeach them, there is no need for further papers. This is not a high-school debating society. > This means that propagation and communication at > unlimited speeds in forward time (no causality violations) is not just > possible, but an inevitable development in our future. Nonsense. You consider your personal hopes, dreams, and INTERPRETATIONS OF WORDS to be some sort of binding contract on the world we inhabit. That is not how science works. The fact that in GR no energy or signal can travel with local speed > c puts a strong limit on this: one must either impeach that conclusion of GR, or show that GR is not valid here. Both of those appear HUGELY unlikely. > It also means > SETI is a waste of time because no technologically advanced civilization > would communicate over interstellar distances using electromagnetic > waves when they could use classical gravitons instead and communicate in > seconds instead of centuries. <giggle> That's a conclusion that is completely and utterly unwarranted by current knowledge or experiments. It's also self-contradictory ("classical gravitons" (:-)). James ("The Amazing" Randi said "Extraordinary claims require extraordinary proof." That applies here: any experiment that claims to overthrow the foundations of modern physics MUST be bulletproof or nobody will believe it. Neither Nimtz's claims nor van Flandern's come anywhere close. Tom Roberts
From: eugene_stefanovich on 22 Aug 2007 14:56 On Aug 22, 11:00 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > What really matters is that the predictions of GR agree with all those experiments. But one can construct an alternative theory http://www.arxiv.org/abs/physics/0612019 in which gravity propagates instantaneously, and still all classical gravitational observations (precession of the Mercury's perihelion, light bending, Shapiro time delay, gravitational time diolation and red shift) are well reproduced. So, the agreement of GR with experiment (which is, undeniably, a remarkable achievement) is not a proof of the retarded character of gravity. I think that the inconsistency between GR and QM is a serious warning sign. Eugene.
From: Dono on 22 Aug 2007 15:02
On Aug 22, 11:56 am, eugene_stefanov...(a)usa.net wrote: > On Aug 22, 11:00 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > What really matters is that the predictions of GR agree with all those experiments. > > But one can construct an alternative theoryhttp://www.arxiv.org/abs/physics/0612019 > in which gravity propagates instantaneously, and still all classical > gravitational observations (precession of the Mercury's perihelion, > light bending, Shapiro time delay, gravitational time diolation and > red shift) are well reproduced. So, the agreement of GR with > experiment (which is, undeniably, a remarkable achievement) is not a > proof of the retarded character of gravity. I think that the > inconsistency between GR and QM is a serious warning sign. > > Eugene. But , you didn't construct anything valid , Eugene. Your starting premise is a fake (the Hamiltonian that mixes in Newtonian potential) , so the conclusion of your paper follows the principle GiGo ("Garbage in, Garbage out"). |