Joan-Claude van Dirk Helps to Trivialize Special Relativity
in [Relativity]
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From: Daryl McCullough on 19 Mar 2005 15:03 cadwgan_gedrych(a)yahoo.com says... > > >Daryl McCullough wrote: >> cadwgan_gedrych(a)yahoo.com says... >[snip] >> Okay, let's get very specific. Suppose we have two identical >> atomic clocks. Each clock produces a periodic signal, which >> we will call a "tick" of the clock. > >Not nearly specific enough. > >Cut it down to just one atomic clock and then tell >us if this clock is intrinsically slowed or not. That is not an observable. Your original complaint was that Special Relativity did not make any empirical predictions. Predicting the result of comparing two clocks that take different paths is an empirical prediction. Saying whether a clock is intrinsically slowed or not is not an empirical prediction, because there is no experiment that can tell whether you are right or not. -- Daryl McCullough Ithaca, NY
From: Bilge on 19 Mar 2005 18:59 Harry: >"Bilge" <dubious(a)radioactivex.lebesque-al.net> wrote in message >> >> And the aforementioned experiment shows that there is no >> ``correct choice.'' Events which are simultaneous in one frame >> are simultaneous in _every_ frame. > >You mean, they are *out of sync* according to the calibration of *every >other* frame - or your experiment is different from this one of PD. Exactly. What you fail to understand is that any to events connected by a signal which propagates with less than infinite velocity are not simultaneous in that case. [...] >> ought to be able to >> grasp the reason why. Anything which can have any effect on anything >> in this universe, has to be measureable in principle, since by definition, >> an effect is the outcome of an experiment. > >Now that's too the point. There is a difference between measuring something >with our toolbox, and inferring cause and effect. >And it seems that you agree that what we measure are effects, from which we >infer causes. The existence of an effect is not sufficient to infer a cause. In order to infer a cause, you first need a theory which quantifies the effect and tells you what parameters of an experiment can be manipulated in such a way that the effect is correlated with changing those parameters. Finally, you need data that demonstrates that correlation. That is why it is so difficult to do any experiment which provides evidence for new physics. You first have to eliminate any possibility that existing physics doesn't already contain the explanation. You can't simply attribute a physical effect to a lack of desire to perform a difficult calculation or to a cause which cannot be quantified physically. Anything which is physical can, in principle, be manipilated by physical means through an experiment and quantified. If you can't affect some physical quantity, it can't affect you, since those are one and the same. >But necessarily the causes of what we can measure can logically not be >measured, except if they themselves are effects. >In the end we may expect that causes exist that can't be measured, but that >can be inferred. Only if you believe it's turtles all the way down, in which case, you might as throw your hands up in despair, declare science to have no point and go to work for a pr firm. >> Explain how something can affect physical objects, yet conspire to not >> affect the physical objects of an experiment. > >See above. Nothing is suggested to exist and that is useful for physics but >that has no effect. You are suggesting exactly that. You are trying to avoid quantifying the elements that make up the ontology of a theory by removing the cause to the cause of a cause which is unquantifiable. That simply adds a literal ``nothing'' to the theory. >> >> 3. No test has been able to distinguish which choice is correct. >> > >> >Correct, AFAIK. >> >> Incorrect. The article below reports an experiment that demonstrates >> quantum correlations over a spacelike interval using moving beam >> splitters, are completely independent of any time ordering assigned >> to the measurements over that spacelike interval. > >"Incorrect" would imply, if I read him well, that an absolute reference >frame has be measured. As usual, you do your best to read anything but what has been written. ``Incorrect'' means that a test has been performed to determine which choice is correct and what it determined is that no choice for an absolute frame is correct. By the way, the outcome was exactly the opposite of what the author had proposed.
From: Bilge on 19 Mar 2005 19:17 Harry: >"PD" <pdraper(a)yahoo.com> wrote in message >news:1111081433.010734.73380(a)o13g2000cwo.googlegroups.com... >> I don't think anyone worries too much about whether it is measurable >> with existing instruments. Certainly, Einstein proposed some >> measurements to test the theory that involved experimental apparatus >> not yet developed, but he DID suggest some ways to test it *in >> principle*. > >My objection was against your argument that all that exist must be >measurable by us, as if we are gods who can measure all that exists. That's exactly the opposite, since presumably gods would not be subject to the laws of physics in this universe. By contrast, humans _are_ subject to the same laws of physics as everything else in the universe, so there is no reason that humans cannot exploit that fact. [...] > >OK, we agree that that is an optionally choice. OTOH, what do you think of >neutrinos? Likely a theory can be divised in which they don't exist, but >instead we just introduce a correction factor in calculations. IMO, Okham's >razor is easily misapplied. You should read something about neutrinos before speculating on what possibilities exist to eliminate them. The same possibilities exist for the electron, the proton, atoms and everything else. The evidence for the existence of neutrinos is just as solid as the evidence for the existence of any other particle. How do you think steinberger, et al were able to distinguish between the \nu_e and the \nu_mu back in 1962? How do you think physicists were able to create neutrino beams at accelerators? >> Similarly here, if absolute simultaneity is a property of two events >> but is completely and by nature undetectable, even in principle, then >> for the purpose of physics, absolute simultaneity is not a needed >> concept. > >Right - except maybe if physics is based on the premise that its purpose is >to investigate nature by observations, and not just observations. >AFAIK, such used to be its purpose. That is what physicists do. They are simply less naive about separating observations about nature from nature itself. While you've been boning up on 19th century physics, physicists have been exploring the underlying assumptions about what it means to observe something. For example, the neutral kaons cannot be separated uniquely into a K0 and its anti-particle the K0bar, because they are linear combinations of K_long and K_short, which in turn are linear combinations of K0 and K0bars. They are only uniquely identified by the interaction through which they are observed. Look up ``neutral kaons'' and ``regeneration.''
From: PD on 20 Mar 2005 08:53 cadwgan_gedrych(a)yahoo.com wrote: > From: "" <cadwgan_gedrych(a)yahoo.com> > Newsgroups: sci.physics.relativity > Subject: Re: Joan-Claude van Dirk Helps to Trivialize Special > Relativity > Date: Sat, 19 Mar 2005 08:39:36 -0800 > > PD wrote: > > Reread the paper. He cites it as a "postulate". A postulate is > > something that is assumed to be true, not something that is proven > > to be true. > > [Here is the posting history:] > > [Cadman wrote] > > > > SR sez: > > > > "If we manually force all clocks in all frames to > > > > obtain the same one-way light speed, then, by George, > > > > all clocks in all frames will obtain the same one-way > > > > light speed." > > [PD responded] > > > You confuse a conclusion with an assumption. Read the 1905 paper. > > As anyone can plainly see, I was talking about something very > specific, namely, light's one-way speed per two clocks in two > or more frames. > > And the specific word for that is "invariance." And that invariance is ASSUMED in SR. It is taken as an (informed) postulate. > > [repeating PD's above] > > Reread the paper. He cites it as a "postulate". A postulate is > > something that is assumed to be true, not something that is proven > > to be true. > > Question: > How can one assume invariance to be true when one *gives it* > via definition (*prior to* any experimentation)? I say again, read the paper. You do not comprehend what he said, or you never read it. > > As even Daryl had to admit, Einstein's "invariance" is merely > a silly convention (or definition), and such things have nothing > to do with physics. > > [snip] > > [Cadman wrote] > > > And, ironically, Einstein himself told us exactly how to have > > > one-way variance. In his little popular book "Relativity," he > > > stated mathematically that if the assumed-to-be-absolutely- > > > synchronous clock of classical physics were used, then light's > > > one-way speed would be c +/- v in all frames. > > [PD wrote] > > Which conflicts with observation, which is why the synchronous > > clock of classical physics is a poor assumption. > > What, precisely, is wrong with correctly synchronized clocks? > Enquiring minds would like to know. There is a difference between "assumed-to-be-absolutely-synchronous clock of classical physics" and the synchronized clocks at rest in a particular observers frame. You assume that synchronicity is an inherent property of two clocks. It's not. > > > > But I do not need such clocks to answer your challenge to > > > provide experimental evidence that the speed of light is NOT > > > constant [sic] for all inertial frames because all I need is > > > the following simple experiment: > > [snip body of world's simplest physics experiment] > > > > The observers can now compare one-way light speeds. (Having no > > > rulers or clocks, they must do this qualitatively.) Here are > > > their extremely simple results: > > > > > > Light's speed wrt Oa = X/Ta > > > > > > Light's speed wrt Ob = X/Tb > > > > And they know their clocks are synchronized with respect to each > > other how? > > > > PD > > Uhhh... what clocks? See above. No clocks were used & no rulers, > either. Only by clearing away that which is irrelevant can the > truth be shown. Uhhh... how do they measure Ta and Tb without clocks? How do they measure X without rulers? > > -------------------------------------------------------------------- > start separate-but-related PD post > -------------------------------------------------------------------- > > [Cadman wrote] > > > The only "physics" that one-way invariance would "blow away" > > > would be SR. > > [PD wrote] > > Forgot to respond to that little tidbit. You are perhaps unaware > > that GR is based on and consistent with SR, .... > > Upon which part of SR, specifically and physically, is GR based? Ummm....Lorentz invariance. > > In fact, why don't you just go ahead and forget about all of that > irrelevant stuff (GR, Dirac equations, etc. etc.) and simply tell > us what SR itself says physically and specifically about any part > of physics? Umm... that every law of physics must obey Lorentz invariance. Note that this is sort of a metalaw, a law about physical laws. Nevertheless, it's a profound statement. > > Could it be that you have *nothing* to say about that (because SR > says absolutely nothing physically about any part of physics?) > (At least SR says nothing that is nontrivial, noncircular, and/or > correct, as I have repeatedly-yet-irrefutably stated)
From: cadwgan_gedrych on 21 Mar 2005 13:38
Daryl McCullough wrote: > cadwgan_gedrych(a)yahoo.com says... [snip] > >Cut it down to just one atomic clock and then tell > >us if this clock is intrinsically slowed or not. > > That is not an observable. Your original complaint > was that Special Relativity did not make any empirical > predictions. Predicting the result of comparing two > clocks that take different paths is an empirical prediction. > Saying whether a clock is intrinsically slowed or not > is not an empirical prediction, because there is no > experiment that can tell whether you are right or not. You are now repeating your errors. As I noted, you have not proved that SR pertains to intrinsic clock rhythms. (I physically defined intrinsic clock rhythm in a prior post, so don't re-complain about _that_.) Only if it does can you say that it makes predictions about intrinsic clock rhythms. (Any other "rhythms" are not a part of empirical physics). And your other repeated error is your claim that there is no experiment which can tell if a clock is intrinsically slowed. This was taken care of by my very simple 3-clock "paradox" experiment. Here are some burden-of-proof items for you to consider: [1] Prove that SR says anything predictive about intrinsic or physical clock rhythms. [2] If it does, then tell us what it says. [3] Tell us the physical SR explanation for the MMx. [4] Tell us the physical SR explanation for the 3-clock "paradox" result. [5] Prove that SR can correctly measure any relative speeds, clock times, or ruler distances. |