A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: Dono. on 10 Mar 2010 14:13 On Mar 10, 11:10 am, "Dono." <sa...(a)comcast.net> wrote: > On Mar 10, 10:56 am, harald <h...(a)swissonline.ch> wrote: > > > > > > > On Mar 5, 5:33 am, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > On Mar 4, 10:48 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 3, 10:59 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > > On Mar 3, 11:21 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Mar 2, 8:12 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > > > > > It is not a function of finite propagation speeds, this we know, > > > > > > > > because we took into account the finite propagation speeds in our > > > > > > > > procedure for determining simultaneity/nonsimultaneity. Do you not > > > > > > > > remember that? > > > > > > > > I beg to differ. It is not a "mere" or "simple" function of finite > > > > > > > propagation speed, but it *is* a function of it IMO. RoS only took it > > > > > > > into account by allowing us to use different time coordinates in each > > > > > > > frame. If the speed of light was infinite there would be no RoS. > > > > > > > I disagree. All that is needed in relativity of simultaneity is a > > > > > > signal speed that can be VERIFIED to be the same from both events by > > > > > > either observer. > > > > > > Well you are going to have problems with that. There is no way to > > > > > *know* that the speed is the same both ways. > > > > > Yes, there is. That's what isotropy experiments have determined. I'm > > > > surprised you weren't aware of this. > > > > Do you mean like this one? > > > >http://mysite.verizon.net/cephalobus_alienus/papers/Gagnon_et_al_1988.... > > > > The author is kind enough to point out problems in some similar > > > experiments, while failing to notice any in his own. > > > Yes that paper is amazing - shocking, what a blunder of Physical > > Review! > > In a nutshell, although they claim to haves obtained results that are > > "consistent with the special theory of relativity", they claim in fact > > (but unwittingly) to have disproved SRT's postulates: > > > 1. "A clear null result is obtained for a hypothesis in which > > anisotropy of the cosmic background radiation is used to define a > > preferred reference frame [...] in which light propagates > > isotropically at a fixed speed." -> according to SRT, one may pretend > > ANY inertial reference to be such a "rest frame"; and contrary to > > their assertions, according to SRT such a claim cannot be disproved > > with measurements. > > > > For example, has he made any assumption about contraction of his > > > equipment in the direction of motion? Tom Roberts has written posts > > > in this group showing where some of these experiments are in effect > > > two way measurements. > > > > > > That is why Einstein > > > > > wrote, "But it is not possible without further assumption to compare, > > > > > in respect of time, an event at A with an event at B. We have so far > > > > > defined only an ``A time'' and a ``B time.'' We have not defined a > > > > > common ``time'' for A and B, for the latter cannot be defined at all > > > > > unless we establish by definition that the ``time'' required by light > > > > > to travel from A to B equals the ``time'' it requires to travel from B > > > > > to A." > > > > > > > Since the distance from the events to the observer is > > > > > > equal, as verifiable at any time by each observer, we learn from this > > > > > > that each observer KNOWS the propagation delays from each event to the > > > > > > observer are equal. This acknowledges the propagation delays > > > > > > completely, but simply allows for verification that they are the same. > > > > > > Assuming the speed of light is the same in both directions. > > > > > Which is an experimentally confirmed fact. Done well after Einstein's > > > > comments on the matter, by the way. > > > That would contradict SRT - people who are discussing here for years > > SHOULD know better! > > Check this out: > > http://groups.google.com/group/sci.physics.relativity/browse_thread/t...- Hide quoted text - > ...and here is the link to the published paper: http://arxiv.org/abs/0910.5658
From: Jerry on 10 Mar 2010 15:21 On Mar 10, 12:56 pm, harald <h...(a)swissonline.ch> wrote: > Some experiments show smart attempts to sidestep that problem by > basing themselves on physical effects that are consistent with > "Einstein synchronization"; and some less smart experiments (such as > by Gagnon et al) are based on faulty reasoning. Gagnon et al. performed a smart experiment that bypassed the issue of clock synchronization in the measurement of OWLS anisotropy. What wasn't smart was their ANALYSIS, which relied on a defective test theory. Gagnon et al. thought their experiment was able to distinguish between LET and SR. It couldn't, although it should have been able to detect a classical (i.e. pre-MMX) aether if one existed. Jerry
From: harald on 10 Mar 2010 15:25 On Mar 7, 1:09 am, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > On Mar 6, 7:26 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > "Bruce Richmond" <bsr3...(a)my-deja.com> wrote in message > > >news:26e68f86-9827-4534-9390-31137fb9853e(a)q15g2000yqj.googlegroups.com.... > > On Mar 5, 1:04 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > > You are reading more into that than what I wrote. I am not choosing > > > > LET over SR. They use the same math > > > > ================================================== > > > > Well, e = mc^2 is maths. It appears in SR, but not LET. > > > > So I guess you were wrong, and they don't use the same maths. > > > It can be derived using LET. SR wasn't the first place it showed up, > > so it doesn't own it any more than LET does. > > > Others here say they use the same math, so I guess you are wrong :)~ > > > _________________________________ > > You said that SR uses the same maths. > > > 1. e=mc^2 is maths > > 2. It appears in SR > > 3. It does not appear in LET > > 4. Therefore the maths in LET is not the same as the maths in SR > > > Which part of this do you disagree with? > > Like I said, it can be derived from LET just as easily as SR. How > many books on LET have you read? ;) :-)) I doubt that there ARE any books on "LET", which is based on (erroneous) revisionist history. According to Lorentz and Einstein there was Lorentz's electrodynamics theory of before 1904, and SRT which is based on Lorentz 1904 and Einstein 1905 - see Einstein's 1907 paper as well as the collection "The Principle of Relativity" by Lorentz et al (funny enough, recently it was subtly changed it into "Einstein et al!). [snip nice arguments against a non-existing "LET") > > Similarly, if Lorentz and the others had considered the relationships > > between energy and momentum in the right way, they would have got e=mc^2. > > They didn't. More to the point, Lorentz had no explanation of why the > > various transforms worked, they were empirical and not theoretical in that > > described the results of experiments, but provided no theoretical framework. > > Not sure what you mean by that. The Lorentz-FitzGerald contraction > was proposed to explain experimental results, but there was definitely > a theory about how it was arrived at. Correct. As a matter of fact, Lorentz predicted the correct equation of electron acceleration in 1904, based on the PoR. > It's not like some oddball > equation was picked out of the air to match the data points recorded > in the MMX. He was aware that in order to measure the speed of light > as c in all frames, which what experimental results showed, he had to > use "local time" that was different from absolute time. And again he > made a pretty good guess at what that "local time" had to be. In fact he was a bit inconsistent in that, and Poincare corrected that. However, he first learned about that correction from reading Einstein. > I do agree that in a way SR shows how LET arrives at it's results, but > at the same time I see LET explaining how to get from a single > absolute frame to the second postulate. SR doesn't attempt to explain > that, it just postulates it. Indeed, that's also what Lorentz stressed. And in his introduction, Einstein made no secret of the fact that the second postulate stems from Maxwell's theory. However, Lorentz came to adopt the derivation of Einstein as that approach is easier (simpler) for students. > > You can use LET to calculate time dilation, just as you can use Kepler to > > calculate orbits. But that doesn't mean that Kepler's theories are the same > > as Newton's, or that LET is the same as SR. > > > HTH > > I see your point, but it doesn't change the fact that the theories > make the same predictions. The point can be made in different ways, giving inverse impressions. For example: You can use SRT without physical model to calculate time dilation, just as you can use Kepler's theory to calculate orbits. But that doesn't mean that Kepler's mathematical theory is the same as Newton's theory (which includes a physical model), or that Einstein's principle theory is the same as Lorentz's theory (which similarly includes a physical model). Note: as the one includes the other, Langevin promoted SRT using Minkowski mathematics but with Lorentz's physical model. Cheers, Harald
From: harald on 10 Mar 2010 15:36 On Mar 8, 3:15 am, "Inertial" <relativ...(a)rest.com> wrote: > "Paul Stowe" <theaether...(a)gmail.com> wrote in message [..] > > LET is as possibly valid as SR .. Neither is refuted experimentally. I just > don't think it is the correct physical explanation. LET is not compatible > AFAIK with GR .. so is a bit of a dead end .. and has the assumption of an > undetectable aether with properties that don't make sense. AFAIK, Lorentz and Einstein didn't notice such an incompatibility... and what DO you think may be "the correct" physical explanation? So far I have not seen another feasible one, so that I have little choice but to use it as a working model (and with success as it helps to quickly detect erroneous papers such as by Gagnon et al). Harald
From: harald on 10 Mar 2010 16:19
On Mar 9, 3:06 am, "Inertial" <relativ...(a)rest.com> wrote: > "Paul Stowe" <theaether...(a)gmail.com> wrote in message [..] > > I'm sorry about these questions but, what does privileged mean? There > > is certainly physical consequences of the medium (such as field > > profile alterations due to motion) but there is certainly nothing > > priveleged as in having different properties about it. > > In LET the speed of light is only isotropically c in the aether frame. > > In all other frames of reference, the compression of rulers and the slowing > and change of sync in processes means we *measure* the speed incorrectly and > get a value of isotropic c .. when *really* the speed is not isotropic c in > that frame at all. > > If we could have a ruler and clock immune to the effects of movement through > the aether (ie that stayed its correct length and kepy correct time) then we > would see that. According to LET (Lorentz Electrodynamics Theory), rulers and clocks are made up of "electrons" (an concept not yet developed into our more precise concepts), so that no such immune materials can exist. > Perhaps we can find a way to make a region of space aether-free (though that > would involve knowing the properties of aether and finding a way to stop it > getting into a given region, or extracting it from there). Then putting our > clocks and rulers in that space. According to Lorentz's pre-SRT theory, it makes as much sense to "put clocks and rulers" in ether-less space as putting water waves in water- less space... > That would then give correct measurements > and show that the aether frame is indeed privileged (as LET claims it to > be). In this context, the word "privileged" is rather inappropriate... > But due to the nature of the effects of movement through the aether, we are > destined to never be able to measure correct speeds or distances with our > compressed rulers and slowed out-of-sync clocks. And worse, as that means > we cannot really know which is the aether frame, we cannot even calculate > the correct adjustments. > > How sad. But that's how things are according to LET. Indeed. Still, it's less sad to have a sloppy model that can only be indirectly tested (like the atomic model of the Greeks) than to be clueless altogether. Harald |