Speed of Light: A universal Constant?
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From: kenseto on 28 Mar 2005 08:57 "Jerry" <Cephalobus_alienus(a)comcast.net> wrote in message news:1112017049.679112.184630(a)o13g2000cwo.googlegroups.com... > kenseto wrote: > > "Tom Roberts" <tjroberts(a)lucent.com> wrote in message > > news:_KL1e.15294$DW.3498(a)newssvr17.news.prodigy.com... > > > > ... I can say that there have been no reliable and reproducible > > > experiments or observations that contradict SR within its > > > domain of applicability. > > > > That's because mainstream physicists refuse to do experiments > > that could potentially contradict SR. For example: > > > 1. Test for OWLS with two same frame spatially separated and > > synchronized clocks. > > One-way light speed from moving sources has been measured many > times. The results are quite unambiguous. The speed is always c. > > Alvaeger, Farley, Kjellman and Wallin, > Physics Letters 12, 260 (1964) > > Babcock and Bergmann, > Journal Opt. Soc. Amer. Vol. 54, p. 147 (1964) > > Beckmann and Mandies, > Radio. Sci. 69D (1965), p623. > > Brecher, > Phys. Rev. Lett. 39 1051-1054, 1236(E) (1977) > > Filipas and Fox, > Phys. Rev. 135, 1071 B (1964) > > Sadeh, > Phys. Rev. Lett. 10 no. 7 (1963) I think these are one-way isotropy experiments. OWLS is isotropic but the value of OWLS is not c. Ken Seto
From: PD on 28 Mar 2005 09:04 kenseto wrote: > "PD" <pdraper(a)yahoo.com> wrote in message > news:1111961159.929557.184000(a)f14g2000cwb.googlegroups.com... > > > > kenseto wrote: > > > "PD" <pdraper(a)yahoo.com> wrote in message > > > news:1111770058.196421.21200(a)l41g2000cwc.googlegroups.com... > > > > > > > > kenseto wrote: > > > > > "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message > > > > > news:Xns96217F0FC3412WQAHBGMXSZHVspammote(a)130.39.198.139... > > > > > > "kenseto" <kenseto(a)erinet.com> wrote in > > > > > > news:24Z%d.14316$cC6.10056(a)fe2.columbus.rr.com: > > > > > > > > > > > > > What you said is hogwash. If we define that the wave length > > of a > > > > > > > specific light source remains constant in all frames then the > > > > observed > > > > > > > Doppler shift is due to the varying speed of light from these > > > > different > > > > > > > sources. > > > > > > > > > > > > > > > > > > > Are you going to say that doppler shift of sound is ALSO due to > > > > varying > > > > > > the speed of sound? A car drops a fire cracker on the ground > > and > > > > sets off > > > > > > a fire cracker on the hood of the car at the same time. The > > 'bang' > > > > from > > > > > > the fire cracker on the ground and the one on the hood of the > > car > > > > reach me > > > > > > at the same time. The bang from the one on the hood of the car > > is > > > > dopplar > > > > > > shifted, the one on the ground is not. They both travel through > > the > > > > same > > > > > > air. Why should one travel at a different speed than the other? > > > > > > > > > > I assume that you mean that the fire cracker is at rest wrt the > > > > ground when > > > > > it goes off. In that case there is no Doppler shift. The fire > > cracker > > > > on the > > > > > car would be Doppler shifted. The sound generated by that fire > > > > cracker would > > > > > be closer to the detector with the passage of incremental time > > and > > > > this is > > > > > the cause of the doppler shift. There is no valid way to measure > > the > > > > speed > > > > > of sound from a moving fire cracker because there is no valid way > > to > > > > measure > > > > > the distance between the fire cracker and the detector at rest > > when > > > > the fire > > > > > cracker generate the first sound wave. > > > > > > > > Oh, good Lord. I can't believe you said such a thing. Never mind > > light. > > > > First pick up a book and learn what causes the Doppler effect in > > sound. > > > > Jiminy. Whoowhee. > > > > > > Hey idiot....what do you think that causes Doppler shift?? Hint: > > Changing > > > distance with time between the source and the detector. Therefore the > > > observed Doppler shift can be interpreted as that the speed of sound > > (or > > > light) arriving from a moving source is different than that if the > > source > > > and the detector are at rest wrt each other. This conclusion is based > > on the > > > assumption that the wave length remain constant whether the sound (or > > light) > > > wave is generated by a stationary source or a moving source wrt the > > > detector. > > > > > > Ken Seto > > > > No, what causes Doppler shift is that successive wavefronts are closer > > together because the source is moving in the same direction as the > > wavefronts. However, the wavefronts are still traveling at the same > > speed as they would for a stationary source. The speed is the same, but > > the wavelength (the distance between wavefronts) is smaller, and > > therefore the frequency is higher. > > No, successive wave crests remains the same distance apart in the ether. The > absolute motion of the detector moving toward the wave crests or away from > the wave crests is what causes the Doppler shift. > All observers measure the same speed of light because the speed of light is > a constant math ratio as follows: > Light path length of rod (299,792,458m)/the absolute time content for a > clock second co-moving with the rod. > You made this same claim about sound waves (the firecracker on the car) -- that successive wave crests remain the same distance apart in the medium -- which is what I was correcting, as it is demonstrably wrong. Note that a diffraction grating works because of the matching between light's wavelength and the physical distance between artifacts in the grating. If what you were saying were true, then Doppler-shifted light (say, shifted from blue to green) would be scattered at the same angle as unshifted light. This is empirically hooey. PD
From: Sam Wormley on 28 Mar 2005 09:11 Henri Wilson wrote: > However nobody has ever measured the OW light speed from a moving source. > Henri Wilson forgets that the speed of light is a *defined* constant http://scienceworld.wolfram.com/physics/SpeedofLight.html And that that the constancy of the speed of light (even one way) is constantly being verified by the global positioning system (GPS) 24/7--Moving sources, Henri! And historically there is a body of OWLS experiments Ref: http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way%20tests 3.2 One-Way Tests of Light-Speed Isotropy Note that while these experiments clearly use a one-way light path and find isotropy, they are inherently unable to rule out a large class of theories in which the one-way speed of light is anisotropic.These theories share the property that the round-trip speed of light is isotropic in any inertial frame, but the one-way speed is isotropic only in an ether frame. In all of these theories the effects of slow clock transport exactly offset the effects of the anisotropic one-way speed of light (in any inertial frame), and all are experimentally indistinguishable from SR. All of these theories predict null results for these experiments. See Test Theories above, especially Zhang (in which these theories are called "Edwards frames"). Cialdea, Lett. Nuovo Cimento 4 (1972), p821. Uses two multi-mode lasers mounted on a rotating table to look for variations in their interference pattern as the table is rotated. Places an upper limit on any one-way anisotropy of 0.9 m/s. Krisher et al., Phys. Rev. D, 42, No. 2, pp. 731-734, (1990). Uses two hydrogen masers fixed to the earth and separated by a 21 km fiber-optic link to look for variations in the phase between them. They put an upper limit on the one-way linear anisotropy of 100 m/s. Champeny et al, Phys. Lett. 7 (1963), p241. Champeney, Isaak and Khan, Proc. Physical Soc. 85, p583 (1965). Isaak et al, Phys. Bull. 21 (1970), p255. Uses a rotating Moessbauer absorber and fixed detector to place an upper limit on any one-way anisotropy of 3 m/s. [one part in 10^8]
From: Tom Roberts on 28 Mar 2005 09:14 kenseto wrote: > I think these are one-way isotropy experiments. OWLS is isotropic but the > value of OWLS is not c. It is not mathematically possible for OWLS to be isotropic and have a value different from TWLS, which is known to be c for any locally-inertial measurement (including numerous highly-accurate laboratory measurements). kenseto, you _REALLY_ need to learn the basics. Tom Roberts tjroberts(a)lucent.com
From: Sam Wormley on 28 Mar 2005 09:44
kenseto wrote: Sam Wormley wrote: > Until there is credible evidence that they are wrong, they remain > the tools of choice in their domains. To find something wrong and > understanding the reason will be very exciting! > > > That's because mainstream physicists refuse to do experiments that could > potentially contradict SR. That not true--there have been tens of thousands of experiment that could have knocked of SR, but didn't! Crank Seto forgets that the has *never* been a prediction of SR that was contradicted by and observation. And that SR and GTR are continually used by the global positioning system (GPS) 24/7. We thank Seto for registering at crank dot net. http://www.google.com/search?q=%22Ken+H.+Seto%22+site%3Awww.crank.net |