Speed of Light: A universal Constant?
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From: bz on 22 Jun 2005 10:19 "Arthur Dent" <jp006t2227(a)blueyonder.co.uk> wrote in news:1119446666.314323.27450(a)o13g2000cwo.googlegroups.com: Arthur, Show me ANY wave phenomina in any real venue with a wave phenomina that shows a v=c wrt source and supports a c'=c+v for wave propagation THROUGH the medium. [where c is a 'critical' velocity that appears to be 'constantant'] -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: bz on 22 Jun 2005 10:11 "Arthur Dent" <jp006t2227(a)blueyonder.co.uk> wrote in news:1119446666.314323.27450(a)o13g2000cwo.googlegroups.com: >> bz wrote: >> Arthur, >> I am afraid I am not sure what your point is. >> Are you arguing against what I said or supporting it? >> Are you claiming c'=c+v is correct? >> If so, what about all the experiments that have demonstrated that for >> c'=c+vk k must be a very small number? >> If not, what point are you trying to make? > >> I'm agreeing with your philosophical viewpoint: >> "An assertion is a claim unsupported by evidence." > > > bz: > That is the meaning of the word 'assertion' as it is used in law. > > A.D. > so what are you arguing about? I am not arguing with that, just wanted to clarify the fact that it isn't a philosophical viewpoint. > > > >> I've asked you to look at Einstein's assertion concerning time that is >> a claim unsupported by evidence. Consider the following: > > bz: > Einstein bases his SR on two POSTULATES. A postulate is a clearly > stated > assumption. It is not an assertion. > > A.D. > What's the difference between a postulate and a definition, then? > As far as I can see, both are "assertions" as used in law. > When both litigants agree, that is then called a stipulation - in law. If I say that there is no evidence that there is an absolute aether, that is an assertion. I have offered no evidence to back up my statement. If I say that mmx invalidated the concept of an absolute aether to within the experimental errors of their experiment, I am testifying to my knowledge of a fact and offering some evidence for my statement. If I say 'for the purposes of this paper we postulate that light travels at c', then I am setting forth a specific explicitly stated 'assumption' that all my conclusions must be consistent with. If YOU say 'The accident happened at 12:14 pm. Your client was driving the car that struck my client'. I could say 'prove it' or I could say 'we so stipulate'. > A.D. >> A wave source emits one crest every second, and the crest travels away >> from the source a distance of one meter in one second. > > > bz: > This is clearly not light we are talking about. As light does not travel at 1 meter per second, I felt I needed to make clear the fact that you were not talking about light waves. If you say that it WAS light you were talking about, then you must support the velocity of 1 meter per second. > > A.D. > I'm not going to argue with you for the sake of argument, and I'm > certainly not going to debate semantics, in law or otherwise. Arguing semantics is a waste of time. Making sure we are using the same words in the same way is a good way to SAVE time. > If you do > not accept that light has wave properties, we are not going to agree on > anything. Where have I said anything that makes you think that I do not believe light has wave properties? > > bz: > c'=c+v is wrong because it REQUIRES k to be '1'(one). > > 2 = 1 + 1*k is wrong because it requires k to be '1' (one). A wonderful > piece of logic. Have a nice day. In the above case, k being 1 produces no contradiction with experimental data. In the case of light, experimental data shows that in any c'=c+vk, k is less than 400 parts per million or more. http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html [quote] If the light emitted from a source moving with velocity v toward the observer has a speed c+kv in the observer's frame, then these experiments place a limit on k. Experiments Using Cosmological Sources Comstock, Phys. Rev. 10 (1910), p267. DeSitter, Koninklijke Akademie van Wetenschappen, vol 15, part 2, pg 1297- 1298 (1913); DeSitter, Koninklijke Akademie van Wetenschappen, vol 16, part 1, pg 395-- 396 (1913). Zurhellen, Astr. Nachr. 198 (1914), p1. Observations of binary stars. k < 10-6. K. Brecher, "Is the Speed of Light Independent of the Velocity of the Source?", Phys. Rev. Lett. 39 1051-1054, 1236(E) (1977). Uses observations of binary pulsars to put a limit on the source-6 velocity dependence of the speed of light. k < 2*10-9. Heckmann, Ann. D'. Astrophys. 23 (1960), p410. Differential aberration, galaxies versus stars. These experiments are all subject to criticism due to extinction effects in the interstellar gas; see for instance J.G. Fox Am. J. Phys. 30, p297 (1962); AJP 33, 1 (1964). The standard reference for optical extinction is Born and Wolf, Principles of Optics. -------------- Experiments Using Terrestrial Sources Beckmann and Mandies, Radio. Sci. 69D (1965), p623. A moving mirror experiment. Alvaeger F.J.M. Farley, J. Kjellman and I Wallin, Physics Letters 12, 260 (1964). Measured the speed of gamma rays from the decay of fast pi0 (~0.99975 c) to be c with a resolution of 400 parts per million. Sadeh, Phys. Rev. Lett. 10 no. 7 (1963), p271. Measured the speed of the gammas emitted from e+e- annihilation (with center-of-mass v/c ~ 0.5) to be c within 10%. Babcock and Bergmann, Journal Opt. Soc. Amer. Vol. 54, pg 147 (1964). - Filipas and Fox, Phys. Rev. 135 no. 4B (1964), p B1071. Measured the speed of gamma rays from the decay of fast pi0 (~0.2 c) in an experiment specifically designed to avoid extinction effects. Their results are in complete disagreement with the assumption c + v, and are consistent with SR. Because of the high energies of the gammas in Alvaeger, extinction is not a problem for it; Filipas and Fox specifically designed their experiment to avoid extinction. [unquote] In order to support your assertion that c'=c+vk where k=1, you must produce valid arguments that explain how the above experimental data may be consistent with your theory. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: Arthur Dent on 22 Jun 2005 11:52 bz wrote: "If you can follow my 'slinky' waves, you may change your mind." Not a hailstone's chance in the core of the sun. I simply move your slinky toward or away from me at v, or walk toward it or away from it, and the speed of the slinky wave is c+v in my frame of reference if it is c in the slinky's frame of reference. Perhaps you do not understand the meaning of relative motion, but I do not see a way to pardon it or discuss such simple concepts further with you. A.D.
From: bz on 22 Jun 2005 12:17 "Arthur Dent" <jp006t2227(a)blueyonder.co.uk> wrote in news:1119455576.127223.290020(a)g43g2000cwa.googlegroups.com: > bz wrote: > > "If you can follow my 'slinky' waves, you may change your mind." > > Not a hailstone's chance in the core of the sun. > > I simply move your slinky toward or away from me at v I said transverse waves. Side to side. However, if you look closely at waves along the axis, you will see that they, also, will NOT follow c'=c+v [unless you compress all the space out from in between the turns. >, or walk toward > it or away from it, > and the speed of the slinky wave is c+v in my frame of reference if it > is c in the slinky's frame > of reference. Perhaps you do not understand the meaning of relative > motion, Perhaps I don't understand what YOU mean by relative motion. > but I do not see a way > to pardon it or discuss such simple concepts further with you. That is a pity. I have never found someone who didn't know something I didn't know. I could always learn something from anyone. I have also never met anyone that knew so much that they couldn't learn something worthwhile from me. You appear to be an exception to the rule. So long and thanks for the fish. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: Arthur Dent on 22 Jun 2005 17:31
bz wrote: If I say that there is no evidence that there is an absolute aether, that is an assertion. I have offered no evidence to back up my statement. A.D. I'm not discussing your "ifs", I'm discussing real statements made by Einstein. Einstein asserted: "also introduce another postulate, which is only apparently irreconcilable with the former, namely, that light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body" and he also asserted "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." Reference: http://www.fourmilab.ch/etexts/einstein/specrel/www/ Putting these two together, we have a constant speed of light in all frames of reference. Now what, in you view, makes these two assertions one a postulate and the other a definition, if as you claim he had only two postulates? As far as I'm concerned his definition of time is just another postulate, and one I do not accept. Neither do I accept his second postulate. Einstein offered no evidence to back up his statements, they are unsupported assertions. Actually his first postulate he states by way of example: "Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relatively to the ``light medium,'' suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest. " That is of course a reference to MMX, for those that think he never heard of it and the first postulate is a formal declaration of Galilean relativity extended to optics and electrodynamics. > A.D. >> A wave source emits one crest every second, and the crest travels away >> from the source a distance of one meter in one second. > bz: > This is clearly not light we are talking about. As light does not travel at 1 meter per second, I felt I needed to make clear the fact that you were not talking about light waves. A.D. It is if I change the unit of 1 meter to 1 light-second, I'm now discussing light. Actually I'm discussing a wave in general, and I see no reason to nit-pick over a triviality, a unit of distance. bz: If you say that it WAS light you were talking about, then you must support the velocity of 1 meter per second. A.D. I'm changing the unit "one meter" and calling it "one light-second". You are nitpicking my choice of units. > A.D. > I'm not going to argue with you for the sake of argument, and I'm > certainly not going to debate semantics, in law or otherwise. bz: Arguing semantics is a waste of time. Making sure we are using the same words in the same way is a good way to SAVE time. A.D. Correct, so why did you assert "Einstein bases his SR on two POSTULATES. A postulate is a clearly stated assumption. It is not an assertion." (your capitals) if you are not arguing semantics? > If you do > not accept that light has wave properties, we are not going to agree on > anything. bz: Where have I said anything that makes you think that I do not believe light has wave properties? AD: Right here: "This is clearly not light we are talking about." - bz. BTW, your slinky doesn't have a constant wavelength :-) > bz: > c'=c+v is wrong because it REQUIRES k to be '1'(one). > 2 = 1 + 1*k is wrong because it requires k to be '1' (one). A wonderful > piece of logic. Have a nice day. bz: In the above case, k being 1 produces no contradiction with experimental data. A.D. c' = c+v has no contradiction with empirical data. Experimental data is subject to interpretation. bz: In the case of light, experimental data shows that in any c'=c+vk, k is less than 400 parts per million or more. http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html [quote] If the light emitted from a source moving with velocity v toward the observer has a speed c+kv in the observer's frame, then these experiments place a limit on k. Experiments Using Cosmological Sources Comstock, Phys. Rev. 10 (1910), p267. DeSitter, Koninklijke Akademie van Wetenschappen, vol 15, part 2, pg 1297- 1298 (1913); DeSitter, Koninklijke Akademie van Wetenschappen, vol 16, part 1, pg 395-- 396 (1913). Zurhellen, Astr. Nachr. 198 (1914), p1. Observations of binary stars. k < 10-6. K. Brecher, "Is the Speed of Light Independent of the Velocity of the Source?", Phys. Rev. Lett. 39 1051-1054, 1236(E) (1977). Uses observations of binary pulsars to put a limit on the source-6 velocity dependence of the speed of light. k < 2*10-9. Heckmann, Ann. D'. Astrophys. 23 (1960), p410. Differential aberration, galaxies versus stars. These experiments are all subject to criticism due to extinction effects in the interstellar gas; see for instance J.G. Fox Am. J. Phys. 30, p297 (1962); AJP 33, 1 (1964). The standard reference for optical extinction is Born and Wolf, Principles of Optics. -------------- Experiments Using Terrestrial Sources Beckmann and Mandies, Radio. Sci. 69D (1965), p623. A moving mirror experiment. Alvaeger F.J.M. Farley, J. Kjellman and I Wallin, Physics Letters 12, 260 (1964). Measured the speed of gamma rays from the decay of fast pi0 (~0.99975 c) to be c with a resolution of 400 parts per million. Sadeh, Phys. Rev. Lett. 10 no. 7 (1963), p271. Measured the speed of the gammas emitted from e+e- annihilation (with center-of-mass v/c ~ 0.5) to be c within 10%. Babcock and Bergmann, Journal Opt. Soc. Amer. Vol. 54, pg 147 (1964). - Filipas and Fox, Phys. Rev. 135 no. 4B (1964), p B1071. Measured the speed of gamma rays from the decay of fast pi0 (~0.2 c) in an experiment specifically designed to avoid extinction effects. Their results are in complete disagreement with the assumption c + v, and are consistent with SR. Because of the high energies of the gammas in Alvaeger, extinction is not a problem for it; Filipas and Fox specifically designed their experiment to avoid extinction. [unquote] In order to support your assertion that c'=c+vk where k=1, you must produce valid arguments that explain how the above experimental data may be consistent with your theory. A.D. I don't have time to answer ever single experiment you refer to, so let's take just one. Alvaeger et. al. bombarded a beryllium block to produce pions which then decayed to gamma photons. What they omitted to mention was that they didn't measure the speed of the pions, although they did state their lifetime. it turns out that even at the speed of light, the lifetime of the pions was so short that they didn't get out of the beryllium. Now, you might consider a block of beryllium to be a vacuum, but I do not. So their ~0.99975c is an estimate at best, certainly not a measurement, and would be irrelevant even if it was. There is one more point I need to mention. I have never claimed to have a theory. All theory I'm using belongs to others, great men like Galileo, Newton, Huyghens, Kepler and Doppler. I have modelled c+v, and it is consistent with the light curve of Algol. A.D. |