A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: BURT on 6 Mar 2010 14:50 On Mar 6, 9:45 am, "G. L. Bradford" <glbra...(a)insightbb.com> wrote: > "waldofj" <wald...(a)verizon.net> wrote in message > > news:91cf20f2-735c-4ba2-b961-e0337f9d257f(a)q23g2000yqd.googlegroups.com... > > >> > In SR there is no c+v or c-v, because there is no fixed absolute aether > >> > frame in which light really travels at c. > > >> Then why did Einstein say that M' is runshing toward the light front > >> from the front (c+v) and receding away from the light front from the > >> rear (c-v)?? > > >> Ken Seto > > that is from the point of view of the observer on the ground and it's > > called closing speed (c + v) and separating speed (c - v). > > Why is that so difficult to understand? > > ===================== > > In both going away and closing, 'c' always forces the view that the > traveler is located, positioned, somewhere between the real-time traveler > and the real-time observer. A false position always apparently closer in > space than the real, always apparently earlier in time than the real, always > apparently slower in velocity than the real. > > In going away not only does the real-time space traveler distance itself > from the observer, but distances itself from what will be apparent to the > observer. Distancing itself from what is apparent to the observer > (distancing itself from the virtual of itself being observed by the > observer). An expansion. At apparently one light second's distance from the > observer, the real-time traveler will be one light second plus one second in > distance from the observer. At apparently ten light seconds in distance from > the observer, the real-time traveler will be ten light seconds plus ten > seconds in distance from the observer. And so on, gaining distance in both > space and time (at once) from both the observer and the virtual of itself > being carried by the speed of light to the observer. > > In closing, not only does the (unobserved) real traveler close upon the > observer, but closes upon the apparent traveler (only apparent to the > observer) situated between them until it closes up to the virtual of itself > and a merger of the real traveler and the apparent traveler occurs [dead at > the observer in the merged frame of all three]. A contraction. At apparently > ten light seconds from the observer (apparent coordinate position) the > real-time -older- traveler will be ten light seconds plus ten seconds in > distance from the observer. At apparently one light second from the observer > the real-time -older- traveler will be one light second plus one second from > the observer....and closing fast upon that light-time -younger- virtual of > itself -- apparently gaining in age ever more quickly -- being observed; > closing fast upon the light-time -younger- virtual of the observer -- also > apparently gaining in age ever more quickly -- it is observing; closing fast > upon the (unobserved) -older- real-time observer. > > At [apparently] one light micro-second from the observer, as pointed out > above WHETHER IN CLOSING OR OPENING DISTANCE, the real-time traveler will be > one light micro-second plus one micro-second in [actual] distance from the > observer. > > At [apparently] one light year from the observer, as pointed out above > WHETHER IN CLOSING OR OPENING DISTANCE, the real-time traveler will be one > light year plus one year in [actual] distance from the observer. Thus in > either direction, contracting or expanding distance in space-time, the > unobserved -faster- real always gains on the observed -slower- apparent > [always] located between itself and the observer. Yet!.....in closing to any > observer....it, the light speed carried -younger- apparent, or -younger- > virtual version, of the -older- traveler, did get there "between" reals > (getting there first! only -- and always -- to be tied by the real at the > finish line: every finish line)! > > GLB > > ====================== Light travels through space at C in the space frame. Mitch Raemsch
From: Bruce Richmond on 6 Mar 2010 15:56 On Mar 6, 5:21 am, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > On Mar 5, 10:43 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > > > On Mar 5, 12:08 am, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > > > On Mar 4, 10:33 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > The author is kind enough to point out problems in some similar > > > > experiments, while failing to notice any in his own. > > > > > 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. > > > > Do you understand the principle of Gagnon's experiment? Do you > > > understand the inverse relationship between group velocity and > > > phase velocity that exists in a wave guide? Do you understand > > > that length contraction would be a second order phenomenon, while > > > Gagnon's experiment should be sensitive to first order, assuming > > > an anisotropy exists? Do you understand that Gagnon's experiment > > > is a true one-clock measurement of OWLS anisotropy? Do you > > > understand the difference between an attempt to detect OWLS > > > anisotropy versus an attempt to perform a one way light speed > > > measurement? > > > I know what OWLS is, and I know what assume means. > > > > On the negative side, I probably know a lot more about defects > > > in Gagnon's experiment than you have ever dreamed of. Gagnon > > > drove the wave guides near cutoff. What does that imply about > > > heating? Take a good look at the test theory that they used to > > > analyze their results. Do you notice something about its internal > > > consistency in terms of an important criterion that I shall not > > > name, but which you ought to be aware of? Is the fact that the > > > test theory does not meet this standard of internal consistency > > > important in their analysis? Can you guess what this problem is? > > > Can you guess why I consider Gagnon et al. to be an important > > > experiment, despite some problems in analysis? > > > > Start with the basics. I've given you important clues. How does > > > Gagnon et al's xperiment work? > > > I haven't looked it over that closely but off hand I would say it is a > > gussied up MMX. > > No, their experiment was very different from MMX.http://mysite.verizon.net/cephalobus_alienus/papers/Gagnon_et_al_1988... > > There is a reciprocal relationship between group velocity and > phase velocity in a waveguide. Depending on the frequency, a > typical waveguide transmits microwave signals at 70% of the speed > of light. However, the phase velocity would be 140% of the speed > of light (the product of group velocity and phase velocity is c^2). > > Gagnon et al. used two parallel waveguides with different cutoff > frequencies, one close to the oscillator frequency, the other > widely different from the oscillator frequency. At the cutoff > frequency, the wavelength in an ideal waveguide would become > infinite,and there would no longitudinal position dependence for > the electrical phase of the wave along the waveguide. At the far > end of the waveguides, Gagnon et al. situated a phase comparator. > > The signal was injected at one end of the two waveguides. The > phase difference was measured at the other end of the two > waveguides. Here is an ascii art representation of their setup: > > --------------------------------------------------- > --------------------------------------------------- > @ > > =================================================== > > The top parallel set of hyphens represents the first waveguide. > The equal signs represents the second waveguide. > The @ represents the oscillator at one end. > The > represent the phase comparator at the other end. > > In the first waveguide (operating at close to cutoff frequency), > the phase of the RF exiting the waveguide would be essentially > identical to the phase of the RF entering the waveguide. In the > second waveguide, variation in OWLS would alter the phase of the > RF exiting the waveguide as a first-order effect. So DEPENDING ON > THE THEORY BEING TESTED, the setup should be highly sensitive to > anisotropies in the one way speed of light (OWLS). > > if you wish to measure OWLS, you need synced clocks at different > points. The hidden assumption in most measurements of OWLS is > that the synchronization procedure for the clocks either involves > two-way signaling (as for instance in Einstein synchronization), > or can be shown to be equivalent to the Einstein sync procedure. > > Gagnon et al. didn't measure OWLS. Rather, they measured > DELTA OWLS. That's a -very- different measurement, and hence > they were able to use a single clock. > > If Tim Lincecum simultaneously throws a baseball and a paper > airplane to you against the wind, you do not need a clock > synchronized to Lincecum's watch to determine that they arrive > at your location at different times. > > Gagnon et al. "threw" two continuous RF beams simultaneously in > the same direction, one, like the baseball, relatively > insensitive to any hypothetical aether wind, the other, like the > paper airplane, sensitive to a classical aether wind. Thank you for taking the time to explain this to me. I didn't even know what group velocity was till I looked it up last night. Still need to look the experiment over more to fully understand it. > There are no hidden assumptions concerning clock synchronization > in their experiment. They did make assumptions, however, about > their "test theory" that turn out to have been unwarranted. > Gagnon et al. believed that their setup was capable of > distinguishing between between LET and SR. In other words, they > believed their experiment capable of detecting a LORENTZIAN > aether wind. This turns out to have been wrong. That is why in my response to PD I asked if assumptions were made about contraction of the equipment. I had noticed that after pointing out the distinction between SR and LET he didn't use LET but GGT instead. > Despite defects in their test theory that led them to erroneous > conclusions concerning their ability to distinguish between LET > and SR, the experiment of Gagnon et al. is important because it > represents a true one-clock measurement of OWLS anisotropy. > > Jerry- Hide quoted text - > > - Show quoted text - Just as some background, when I first studied EM waves in high school the teacher told us that the speed of light was always c. If you were standing on the ground it was c, and it was c for those in an airplane flying by you. I asked how that could be? Why wasn't it c+v like it would be for a sound wave or a bullet. His answer was "That's just the way nature made things." When I didn't buy that answer he told me "Thousands of scientists say it works that way. Who should I believe, them or you." Whe I didn't accept that as an explaination I was told that I could work the problems out my way and have them marked wrong, or I could work them out his way and get them marked right. It was a bitter pill to swollow but I just let it go at that. Never gave it much thought again until I got on line and found this group. When I took the SATs I got a 730 in math and a combined score of 1425. Just for fun I took the physics SAT and got a 700 on it. That was over 40 years ago, but I don't think I have lost too many marbles since then ;) Bruce
From: Bruce Richmond on 6 Mar 2010 19:09 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? ;) > More generally, you are missing the difference between LET and SR. LET > compared to SR is a bit like Kepler's laws of planetary motion compared to > Newton's laws of gravity. Mathematically, inverse square laws imply > elliptical orbits (and Kepler's equal area formula), and Kepler's laws > require inverse square forces for gravity. You could say that Kepler is > mathematically identical to Newton for calculating planetary motion, because > you could derive the inverse square law purely from Kepler. Just as you can > derive time dilation purely from LET. > > What Newton did, in a sense, is create a model of the solar system which > obeys the same physical laws as Kepler, but did so using a completely > different starting point and framework. Newton and Kepler predict exactly > the same kinds of orbits, but Kepler's laws of planetary movement are not > the same as Newton's law of gravity, even though mathematically they produce > exactly the same orbits. > > A very similar relationship exists between SR and LET. SR in a sense > "explains" LET, just as Newton "explained" Kepler. > > Kepler's laws were statements about what is observed, Newton explains why > these observations occurred. LET was statements about what was observed, SR > explains why these observations occur. > > When Newton's law of gravity came out, it did not invalidate Kepler, and nor > did it even make any new predictions concerning elliptical orbits. It did > explain however why Kepler's laws were in a sense correct. Physicists did > not say immediately after Newton that Kepler was wrong, or his equations > were wrong (and indeed they produce mathematically identical elliptical > orbits). Newton just told a whole lot more of the story a lot more clearly, > and Newton's laws were immediately taken as more fundamental and useful than > Kepler. > > When SR came out, it did not invalidate LET, and nor did it even make any > new predictions concerning time dilation. It did explain however why LET's > equations were in a sense correct. Physicists did not say immediately after > SR that LET was wrong, or its equations are wrong (and indeed they produce > mathematically identical time dilation). SR just told a whole lot more of > the story a lot more clearly, and SR was immediately taken as more > fundamental and useful than LET. Nice analogy, and for the most part I can buy that. > Had Kepler known calculus, he could have worked out that the acceleration of > a planet is proportional to the inverse square of the distance, and > eventually got Newton's law of gravity, which is implicit in elliptical > orbits. He didn't. More to the point, he had no explanation of why his laws > held; they were empirical and not theoretical in that they described the > results of experiments, but provided no theoretical framework. > > 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. 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. 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. > 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.
From: Bruce Richmond on 6 Mar 2010 19:14 On Mar 6, 9:29 am, kenseto <kens...(a)erinet.com> wrote: > On Mar 5, 12:12 am, "Inertial" <relativ...(a)rest.com> wrote: > > > > > > > "Bruce Richmond" <bsr3...(a)my-deja.com> wrote in message > > >news:7806715d-93d2-49ff-ad67-6dac8ea64d8c(a)e7g2000yqf.googlegroups.com... > > > > 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. > > > > 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. > > > > Provide a link to an experiment and I'll take a look. > > > >> > > Then the determination of simultaneity or nonsimultaneity of the > > >> > > original events is completely unambiguous: If the observer receives > > >> > > both signals at the same time, then (because the propagation delays > > >> > > are the same) the original events were simultaneous; if the observer > > >> > > receives both signals at different times, then (because the > > >> > > propagation delays are the same) the original events were > > >> > > nonsimultaneous. > > > >> > > Then the frame-dependence of simultaneity follows directly from the > > >> > > experimental *observation* that for the same pair of events, one > > >> > > observer correctly and unambiguously concludes the events were > > >> > > simultaneous, and the other observer correctly and unambiguously > > >> > > concludes the events were nonsimultaneous. > > > >> > > You've mentioned in the past that you found your disbelief in > > >> > > relativity stems from being unable to find a good, understandable > > >> > > explanation of it. I invite you to read back on this thread where I > > >> > > was trying to explain to Ste (who has a similar complaint) how this > > >> > > comes about. > > > >> > No need. Lorentz showed how all frames could measure the speed of > > >> > light to be c. That in effect confirms the second postulate, which is > > >> > the stumbling block for many. > > > >> Well then, you are just *choosing* what you would like to believe. In > > >> this case, lodging a complaint against relativity that it is not well > > >> explained, when you are not interested in pursuing a better > > >> explanation, having settled on LET instead, is a bit on the > > >> disingenuous side. > > > > You are reading more into that than what I wrote. I am not choosing > > > LET over SR. They use the same math > > > Yes > > > > and I consider them two > > > interpertations of the same thing. > > > Not at all. Very different as far as how they explain reality > > > LET has and required a fixed (theoretically undetectable) aether in a fixed > > absolute frame. > > SR does not specify nor require anything about an aether > > > LET has objects physically compressed due to absolute motion thru the aether > > SR has no absolute motion, so objects are not affected by such motion > > > LET has processes physically slowed due to absolute motion thru the aether > > SR has no absolute motion, so processes are not affected by such motion > > > LET has a side-effect of the speed of light being measured as the same in > > all frames of reference, due to measuring with compressed rulers and slowed > > clocks, even though its only really has that speed relative to the aether, > > SR has no absolute compression and slowing, and the speed of light really is > > c > > > LET has a side-effect of an appearance of the lorentz transforms holding on > > measured values, due to measuring with compressed rulers and slowed clocks. > > SR has no absolute compression and slowing, so the lorentz transform hold > > > > The LET interpertation had the > > > advantage, for me, of showing how c + or - v could end up being > > > measured c in all frames. > > > In SR there is no c+v or c-v, because there is no fixed absolute aether > > frame in which light really travels at c. > > Then why did Einstein say that M' is runshing toward the light front > from the front (c+v) and receding away from the light front from the > rear (c-v)?? > > Ken Seto > Just to confuse you. Seriously, each frame has its own perspective. Anything moving relative to the frame you consider to be at rest will have a closing speed with light. In its own rest frame light it sees things differently. > > > > > > Given that was possible I no longer had any > > > problem accepting the second postulate. Eventually I became aware > > > that the second postulate wasn't so much an assumption as a > > > stipulation. We will consider the speed of light to be our standard. > > > No .. it is an observed fact. Not a stipulation > > > > Recently I have been going back and re-reading some of the books I > > > have bought over the years to see if I can come to grips with some of > > > the modern interpertations of SR. After thinking about it for awhile > > > I have realized that my objections about the changing definition of c > > > were petty/anal. > > > :) Always a good conclusion to reach .. it shows you really are thinking > > and learning and advancing. > > > > An analogy would be that there used to be 24 hours > > > in a day, 60 minutes in an hour, and 60 seconds in a minute. Now we > > > have defined a second as so many transitions of an atom, and can > > > measure the variation in the length of a day. The new way is better. > > > That it is not in perfect agreement with the old doesn't change much. > > > There was nothing sacred about the old. So yes, an old dog can be > > > taught new tricks :) > > > > Bruce > > > And several points up my estimation ladder for doing so and admitting it > > :):)- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text -- Hide quoted text - > > - Show quoted text -
From: Dono. on 6 Mar 2010 21:09
On Mar 5, 8:43 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > Start with the basics. I've given you important clues. How does > > Gagnon et al's xperiment work? > > I haven't looked it over that closely but off hand I would say it is a > gussied up MMX. > Not even close. Mind you, since Gagnon there have been a lot more experiments that did a fantastic job in constraining one way light speed anisotropy. |