Speed of Light: A universal Constant?
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From: Sue... on 3 Apr 2005 17:33 What if we use three Harrison chronometers and slower than slow transport ? http://www.illinoisleader.com/content/img/f5680/SZ200_shellgame.jpg Sue...
From: kenseto on 3 Apr 2005 18:10 "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message news:Xns962D919A05F12WQAHBGMXSZHVspammote(a)130.39.198.139... > "kenseto" <kenseto(a)erinet.com> wrote in > news:DxW3e.4691$tI6.525(a)fe2.columbus.rr.com: > > > > > "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message > > news:Xns962D6C5EFCC74WQAHBGMXSZHVspammote(a)130.39.198.139... > >> "kenseto" <kenseto(a)erinet.com> wrote in > >> news:vLS3e.8442$Fh4.4410(a)fe2.columbus.rr.com: > >> > >> > > >> > "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message > >> > news:Xns962B878445D4CWQAHBGMXSZHVspammote(a)130.39.198.139... > >> >> "kenseto" <kenseto(a)erinet.com> wrote in news:HFg3e.1282$Fh4.780 > >> >> @fe2.columbus.rr.com: > >> >> > >> >> > > >> >> > >> .... > >> >> Here is an experiment similar in some ways to part of mine > >> >> experiment. > >> > >>>http://artemis.austincollege.edu/acad/physics/lrobin/lightspeed%20exp.pd > >>>f > >> >> > >> .... > >> >> The difference is the time interval needed for the PHOTONS to move > >> >> from one detector to the other. > >> >> > >> >> There is nothing else moving from one detector to the other. > >> > > >> > The signals are moving in oppsite directions and you assumed that the > >> > signals will take the same time moving in these opposite directions. > >> > This is the same as Eintein's TWLS thought experiment in which he > >> > assumed that (tB-tA1)=(tA2-tB). > >> >> > >> >> The photon travel time is the "signal" that I am measuring. > >> > > >> > The proper one-way measurement is to have a clock at each detector's > >> > location. Using a cable will only complicate things. The clocks can > >> > be synchronized by slow clock transport of two touching and > >> > synchronized clocks in the opposite directions. > ... > > > > But you are measuring the two way time difference. > > I disagree. > But even if I were, since the distance traveled by the photons is constant, > and both detectors and the cables are at relative rest with respect to each > other, the motion of my source is the only variable. If your doppler shift > changes the photons speed, it will show up. Since my doppler shift has no > effect on the speed of the photons, I predict no change in the speed of the > photons, no matter how fast I spin the disk that carries the source. The doppler shift is the result of the source and the detectors are in different states of absolute motion. This means that doppler shift is detecting a different speed of light. Ken Seto
From: bz on 3 Apr 2005 18:36 "kenseto" <kenseto(a)erinet.com> wrote in news:rRZ3e.8545$Fh4.3309(a)fe2.columbus.rr.com: > > "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message > news:Xns962D919A05F12WQAHBGMXSZHVspammote(a)130.39.198.139... >> "kenseto" <kenseto(a)erinet.com> wrote in >> news:DxW3e.4691$tI6.525(a)fe2.columbus.rr.com: >> >> > >> > "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message >> > news:Xns962D6C5EFCC74WQAHBGMXSZHVspammote(a)130.39.198.139... >> >> "kenseto" <kenseto(a)erinet.com> wrote in >> >> news:vLS3e.8442$Fh4.4410(a)fe2.columbus.rr.com: >> >> >> >> > ..... >> > But you are measuring the two way time difference. >> >> I disagree. >> But even if I were, since the distance traveled by the photons is >> constant, and both detectors and the cables are at relative rest with >> respect to each other, the motion of my source is the only variable. If >> your doppler shift changes the photons speed, it will show up. Since my >> doppler shift has no effect on the speed of the photons, I predict no >> change in the speed of the photons, no matter how fast I spin the disk >> that carries the source. > > The doppler shift is the result of the source and the detectors are in > different states of absolute motion. This means that doppler shift is > detecting a different speed of light. Does that mean you predict that "whatever it is" I am going to measure is going to change as the speed of the source changes? -- 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: The Ghost In The Machine on 3 Apr 2005 19:00 In sci.physics, H@..(Henri Wilson) <H@> wrote on Sun, 03 Apr 2005 08:45:18 GMT <16bv4112a99gjs54gmro5c0hrsb9rtfak2(a)4ax.com>: > On Sun, 03 Apr 2005 01:00:07 GMT, The Ghost In The Machine > <ewill(a)sirius.athghost7038suus.net> wrote: > >>In sci.physics.relativity, H@..(Henri Wilson) >><H@> >> wrote >>on Sat, 02 Apr 2005 23:21:50 GMT >><f5au41p1m4h5pjacaresa5e6082hcuro8q(a)4ax.com>: [crunch] >>Optical fibre would suffer the same signal-speed anisotropy >>as electrical cabling. That is not a solution. >> >>Of course, it turns out signal-speed anisotropy is not >>really a problem, either. :-) OLWS lightspeed is isotropic >>to a few parts per billion, if my memory is correct >>regarding certain experiments thereon. (My memory also >>tells me that the experiments did not measure OLWS directly.) > > Well Ghost, I was trying to keep that a secret > > It is true because light speed is source dependent. And what experiments show this source dependency? Color me curious. [.sigsnip] -- #191, ewill3(a)earthlink.net It's still legal to go .sigless.
From: The Ghost In The Machine on 3 Apr 2005 19:00
In sci.physics, bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote on Sun, 3 Apr 2005 15:39:12 +0000 (UTC) <Xns962D6C5EFCC74WQAHBGMXSZHVspammote(a)130.39.198.139>: > "kenseto" <kenseto(a)erinet.com> wrote in > news:vLS3e.8442$Fh4.4410(a)fe2.columbus.rr.com: > >> >> "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message >> news:Xns962B878445D4CWQAHBGMXSZHVspammote(a)130.39.198.139... >>> "kenseto" <kenseto(a)erinet.com> wrote in news:HFg3e.1282$Fh4.780 >>> @fe2.columbus.rr.com: >>> >>> > >>> > .... >>> Here is an experiment similar in some ways to part of mine experiment. >>>http://artemis.austincollege.edu/acad/physics/lrobin/lightspeed%20exp.pdf >>> > .... >>> The difference is the time interval needed for the PHOTONS to move from >>> one detector to the other. >>> >>> There is nothing else moving from one detector to the other. >> >> The signals are moving in oppsite directions and you assumed that the >> signals will take the same time moving in these opposite directions. >> This is the same as Eintein's TWLS thought experiment in which he >> assumed that (tB-tA1)=(tA2-tB). >>> >>> The photon travel time is the "signal" that I am measuring. >> >> The proper one-way measurement is to have a clock at each detector's >> location. Using a cable will only complicate things. The clocks can be >> synchronized by slow clock transport of two touching and synchronized >> clocks in the opposite directions. >>> >>> Have you ever used an oscilliscope? >> >> Yes I have. So what is your point? > > That it is easy to measure time differences with an oscilliscope. Though it might take some work to do it correctly, given certain conditions. I can't remember the character's name but he claimed to have FTL cables and "proof" that the cables were in fact FTL, since he had mismeasured the time it took a periodic signal to propagate through his cable. > > All I need to establish is that the travel time of the photon does not > change as the speed of the source is changed. > > I just want to establish that the doppler effect is NOT due to a change in > the velocity of the photon. > Hmmm...well, here's a thought. I'll assume that we have a set of mirrors mounted on the edge of a rapidly rotating disc, and that the stationary light source is firing *away* from the destination into the disc, and that the destination will pick up the reflected signal. What would be the predicted frequency of the received lightsignal, assuming a certain edge velocity v towards the destination and a laser source of 500 nm (pea-green), or 600 THz or 1.67 fs? Emissive: From the mirror's perspective, the light hits at c + v and reflects at c + v. Since the mirror is moving towards the light the incident and reflected frequency will be 600 THz * (c+v) / c. Since the receiver is also moving towards the mirror the receiver will see a frequency of 600 THz * (c+v)^2 / c^2. Delta frequency would be 600 THz * (2*v/c+v^2/c^2). Emissive Alternate 1: The receiver will instead see a frequency of 600 THz * (c+2*v)/c. Delta is therefore 600 THz * 2*v/c. SR: From the mirror's perspective the second light wave (we assume the first is at (0,0)) will transform as follows, assuming t = 1.67 fs: (0, t) => (-g*v*t, g*t) or an observed delta time of g*t-g*v*t/c = g*t*(1 - v/c), where g = 1/sqrt(1-v^2/c^2). The mirror faithfully reflects this pulse and since the receiver is also moving in the exact same fashion to the mirror as the mirror was to the source, the receiver will see a time interval of g^2*(1-v/c)^2, and therefore a frequency shift of (1 - v^2/c^2) / (1-v/c)^2. Delta frequency is therefore (1 - v^2/c^2 - 1 + 2*v/c - v^2/c^2) / (1-v/c)^2 = (2*v/c - 2*v^2/c^2) / (1-v/c)^2 = (2*v/c)/(1-v/c). If one assumes a carefully knurled disc where the "knurls" are reflective, and it is of size 5" = 12.7 cm in diameter with a rate of 10,000 RPM (perfectly possible in light of modern disk drives), one gets an edge velocity of 10000 revs/minute * 1/60 min/sec * Pi*0.127 m/rev = 66.5 m/s. 66.5 m/s = 2.2 * 10^-7 c. Emissive Delta: 265988207.48 SR Delta: 265988236.96 Delta of Deltas: -29.48 Alt 1 Delta: 265988178.00 Delta of Deltas: -58.96 This looks doable but the faster the mirrors, the better, and one would have to establish the precise velocity thereof. Of course one other possibility is to do the experiment both ways, with the knurls splitting the beam. One subbeam would go towards the detector and the other to either another detector or to a mirror arrangement which would eventually interfere with the first beam. There's the issue of vibration, as well. -- #191, ewill3(a)earthlink.net It's still legal to go .sigless. |