Speed of Light: A universal Constant?
in [Relativity]
|
Prev: Joan-Claude van Dirk Helps to Trivialize Special Relativity
Next: GOD=G_uv Measure your IQ in 30 seconds
From: Henri Wilson on 19 Apr 2005 03:05 On Mon, 18 Apr 2005 23:29:39 +0100, "George Dishman" <george(a)briar.demon.co.uk> wrote: > >"Henri Wilson" <H@..> wrote in message >news:ep9861dp7ghqsoldq7bhajko5okj3t53ul(a)4ax.com... >> On Mon, 18 Apr 2005 21:33:08 +0100, "George Dishman" >> <george(a)briar.demon.co.uk> >> wrote: ><snip> >>>Some of the more advanced stuff perhaps but the >>>fundamentals are well known. Probably the only >>>significant refinement is the use of modulation >>>as outlined here: >>> >>> http://www.physik.fu-berlin.de/~bauer/habil_online/node11.html >> >> I assume the modulating increases the sensitivity. > >Since the non-rotating state has both path >lengths and speeds equal, you get constructive >interference a maximum intensity. It falls off >symmetrically either side and the general form >is I_0 * cos(phase). The modulation breaks the >symmetry. > >>>That's the technique KVH use and I have seen a >>>number of other sites discussing it. However, >>>this isn't really too important from the point >>>of view of your animation. >> >> One of my main concerns is that in steady rotation, there can be no change >> in >> the output pattern, whatever that may be. So to obtain a reading for >> actual >> rotation from the starting zero, a continuous integration must be carried >> out. > >That's why I pointed out the choice of formats >in the spec. The primary output from all these >devices is rotation rate, not orientation. Yes, >you are right that integration is needed in >inertial navigation applications (and the box >does that too) but for fly-by-wire applications >the rate information is adequate to stabilise >the control system. GPS will take care of >longer term guidance. > >> That applies to my ballistic concept as well as your standard treatment. > >That's right, I am not disagreeing with that, >but first you need an output. The conventional >analysis of the ballistic model says there will >be none. That's the challenge. I have spent all day on it. It ain't easy. > >George > HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: G on 19 Apr 2005 03:55 Dear Henri I especially like your demo "Vertical.exe", and agree 100% "This is an upgrade of 'vertical.exe. It shows conclusively why the second postulate cannot be correct " Do you realize that at least one textbook is in error in presenting this as a reason for space contraction etc? Do you also realize that you are saying Einstein was wrong... Ah yes "The most useful thing I have ever done is prove Einstein wrong " But specifically can you see an error the train thought experiment which he used to derive SRT? What do you mean that the one way speed of light has never been measured? I will answer the crossing the street problem later. First shown on TV in Jame Burke "The day the world changed :or was it Carl Sagan's "Cosmos"? BTW the colors came out fine G
From: Paul B. Andersen on 19 Apr 2005 04:46 Henri Wilson wrote: > On Mon, 18 Apr 2005 16:16:22 +0200, "Paul B. Andersen" > <paul.b.andersen(a)deletethishia.no> wrote: > > >>Henri Wilson wrote: >> >>>On Thu, 14 Apr 2005 00:30:42 +0100, "George Dishman" <george(a)briar.demon.co.uk> >>>wrote: >>> >>> >>>>"Henri Wilson" <H@..> wrote in message >>>>news:s03r51d3gmd6qick1ffuuiebr31gljr9lk(a)4ax.com... >>>> >>>>>What I have realised is that the standard SR explanation doesn't work!! >>>>> >>>>>FOR A CONSTANT RATE OF ROTATION, THERE WOULD BE NO FRINGE MOVEMENT. >>>>> >>>>>The pattern would remain fixed. And that is not what happens, surely. >>>>>Your version of Sagnac would be sensitive to angular acceleration only. >>>> >>>>Why? The animation shows that there is a >>>>clear time difference produced in the SR >>>>version. What you say is inconflict with >>>>what it shows yet you just make that bald >>>>statement without giving any reason. >>> >>> >>>Think about it George. >>>For constant rotation (incuding zero), there is a constant relationship between >>>the two path lengths. The fringes should remain static. >>>That is not what happens. >> >>Of course that's what happens, and of course that's >>what SR say should happen. >> >>The term "fringe shift" refers to the shift of the fringes >>when the interferometer is rotating compared to when it is not. >> >>What did YOU think "fringe shift" meant? >>That the fringes are moving? >>They are not in a Sagnac interferometer rotating >>at a constant rate. >> >>Ring lasers are quite different, though. >>That's why ring lasers rather than Sagnac rings >>are used in inertial navigational systems. >> >>Sagnac rings and ring lasers both falsifies the ballistic theory. >>Obviously. >> >>Paul > > > You are not being at all helpful for the purpose of this discussion. You are claiming that the fringes in a Sagnac interferometer are moving when the interferometer is rotating at a constant rate. That is wrong. So you don't know what is happening in the Sagnac experiment. I think it would be very helpful for the purpose of this discussion to know what is actually happening in the real world. But maybe you prefer your fantasy world were what actually happens surely isn't what happens? Paul
From: Paul B. Andersen on 19 Apr 2005 05:09 Henri Wilson wrote: > > Paul, here is a simple question, Please answer. > > S________r________c----------------------------------------------A > > S is a light source connected to a clock by a long rod r, which point towards > Andromeda. > > S emits a light pulse towards A. > > Clock c intercepts the pulse and indicates ONE single travel time from S. It > also observes that the length of the pulse is the same as when emitted by S. All what can be read off clock c when the pulse is intercepted is the reading of the clock at that instant. To find the travel time, you must read off the clock c when the pulse is emitted. Please specify exactly how that's done. No hand-waving. Specify a method which actually is possible to use. I think we can agree that c would measure the length (duration) of the pulse to be the same as measured by a clock at S. > How can you claim that the pulse is traveling at 'c' wrt all the moving objects > in Andromeda? It clearly has only one speed, not an infinite number. So let's introduce a "moving object" - a second clock d. Let's suppose that this clock is adjacent to c when the pulse is intercepted by both clocks at the same instant. (Coinciding events.) d -> v S________r________c All what can be read off clock d when the pulse is intercepted is the reading of the clock at that instant. To find the travel time, you must read off the clock d when the pulse is emitted. Please specify exactly how that's done. No hand-waving. Specify a method which actually is possible to use. I think we can agree that d would measure the length (duration) of the pulse to be different from what is measured by a clock at S. > > Note: the ballistic theory, as applied to brightness curves, is in no way > dependent on how the speed of light might be measured by any observers. > As we know, the aether (and pseudo-aether) concept is that all observers will > measure OWLS as being 'c' because their clocks and rods will miraculously > change in order to make it so. Even if that were true, (haha) it would not > affect the BaT's predictions concerning variable stars. You sure are right about the latter. :-) Every time we - you and I - have checked what the BaT predicts for concrete binaries, the predictions have proven to be wrong. Paul
From: Jim Greenfield on 19 Apr 2005 06:05
"George Dishman" <george(a)briar.demon.co.uk> wrote in message news:<d3tfer$icb$1(a)news.freedom2surf.net>... > "Jim Greenfield" <jgreen(a)seol.net.au> wrote in message > news:e7b5cc5d.0504161506.76630d7c(a)posting.google.com... > > "George Dishman" <george(a)briar.demon.co.uk> wrote in message > > news:<d3qkqn$luu$1(a)news.freedom2surf.net>... > >> "Henri Wilson" <H@..> wrote in message > >> news:748161p3j4p7o776a6q3uq1ddlf7adi1l8(a)4ax.com... > >> > On Fri, 15 Apr 2005 15:32:14 +0100, "George Dishman" > >> > <george(a)briar.demon.co.uk> > >> > wrote: > > > >> >>1879 and 1926, Michelson > > > > In the famous experiment where Michelson measured the speed of light, > > his source was stationary, and frequency or wave lengths were not > > considered at all. > > Henri asked if an experiment had ever been done > with light bouncing off a moving mirror and of > course that was one of the first methods used > to measure the speed of light. It wasn't exactly > what Henri was looking for but it was the obvious > answer to his question. It is a bit of an aside > from the real topic, though related. > > > A similar experiment, using the exact same principals, but with the > > source moving, has NEVER been done (vacuum). > > Yes it has Jim, the Sagnac experiment uses a > moving source which is why Henri and I are > discussing it. Henri understands the question > and so did you a few months ago when we were > discussing it by email. > > It has even been done in vacuum but in fact > the version in a fibre is a better test since > it removes possible concerns about remnant > atmosphere. > > > And until it is, c'=c+v > > will NOT be falsified (or afterwards) > > That seems to sum up some people's attitude, > even AFTER it has been falsified, they will > not admit it is false. > > > (for Henri) > > I tried to email you privately, but am blocked. George and I have > > discussed his sagnac at length, and I arrived at position as follows: > > My understanding of George's arguement is that the point of > > interference changes, which is the basis on which the machine works, > > due to a change of time for the photons to complete their circuit(s), > > which is produced by the rotation of the plane. (OK so far, G?) > > But velocity is ALSO a factor of time, so it is a matter of > > INTERPRETATION only, as to whether time changes, or velocity does! > > That is not correct. SR says the speed is c > in the lab frame while Ritz says the light > is launched ballistically at c relative to > the source so the velocity is defined by the > theory in both cases. This part is not in > dispute. > > > I > > think that if G wishes to argue otherwise, he is defacto introducing > > the assumption that the DISTANCE factor in velocity altered also. > > We know that the distance in the lab frame > is altered because the detector moves during > the time of flight, and since we know the > rate of rotation, we know how much it moves. > The current discussion relates to how to > calculate the exact path length using Ritz > and whether any additional time delay effects > are predicted other than distance/speed. > > > That > > would be an unacceptable assumption to make George- to use postulates > > of SR to show SR correct ;-( > > You still don't seem to follow the method Jim, > we use the postulates of SR to make the SR > prediction, we use the postulates of ballistic > light theory to make its prediction. Then we > see which one matches reality. Each theory > can only use its own postulates to make its > prediction. Here's the rub! SR uses TWO postulates; that distance AND time BOTH alter inversely due to the same velocity (particle). c'=c+v has only the one. as the formula for light velocity is 3 part algebraic, since 2 postulates of SR are operating (magically) to compensate, SR can NEVER fail! (by definitiion) > > The question we are discussing is what > prediction you get using ballistic theory. The > launch speed is well defined but that together > with conventional model of reflection gives a > prediction of dt = 0 falsifying the theory. > Henri and I are looking at the only poorly > defined aspect, the reflection process, to see > if an alternative model could resolve the > problem. I don't think it can but that is the > challenge. "launch speed well defined"? No way! We say c is rel to source, while SR says it is what an observer sees (whether he misunderstands doppler or not) > > > So sleep tight, Henri, and leave G some free time to work on his > > animation which will show how time dilation occurs! > > It might have to do one to illustrate how > Huygens wavefront construction determines the > angle of reflection in the case where the > speed of the light is affected by bouncing off > the mirror. Henri has your sagnac animation ? Apply a stop-watch to the actual angular motion, and refer to both a spot on the screen, and the angle increase rate. Have you not 'assumed' that there would be none G, and built the animation accordingly? :-) (my lab so poorly equipped, I can't even find my old stopper :-( ) Cheers Jim G c'=c+v |