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: kenseto on 23 Mar 2005 09:19 "The Ghost In The Machine" <ewill(a)sirius.athghost7038suus.net> wrote in message news:7a87h2-gbu.ln1(a)sirius.athghost7038suus.net... > In sci.physics, kenseto > <kenseto(a)erinet.com> > wrote > on Tue, 22 Mar 2005 17:57:56 GMT > <E0Z%d.116$nC.112(a)fe1.columbus.rr.com>: > > > > "robert j. kolker" <nowhere(a)nowhere.net> wrote in message > > news:3ab1ntF66i2odU3(a)individual.net... > >> > >> > >> kenseto wrote: > >> > >> > > >> > The speed of light is measured to be constant because we arbitrarily > > assumed > >> > that the Doppler shift is due to wave length change. If wave length is > >> > assumed to be contant then the speed of light is different from > > different > >> > sources. > >> > >> The speed of light is that same for all frequencies of light. > > > > Not if you assume that the wave length of the incoming light > > is the same as that of the source at rest with the observer. > > In SR, that is a highly unwarranted assumption. So what is your point? BTW, such an assumption is not incompatible with SR as you seem to think. All we need to do is to re-define the speed of light as a constant math ratio in all frames as follows: Light path length of ruler (299,792,458m)/the absolute time content for a clock second co-moving with the ruler. Ken Seto
From: kenseto on 23 Mar 2005 09:43 "The Ghost In The Machine" <ewill(a)sirius.athghost7038suus.net> wrote in message news:q887h2-gbu.ln1(a)sirius.athghost7038suus.net... > In sci.physics, kenseto > <kenseto(a)erinet.com> > wrote > on Tue, 22 Mar 2005 14:31:56 GMT > <w%V%d.6496$rL3.4855(a)fe2.columbus.rr.com>: > > > > "robert j. kolker" <nowhere(a)nowhere.net> wrote in message > > news:3aamtkF6bbkreU2(a)individual.net... > >> > >> > >> kenseto wrote: > >> > >> > That's becasue you failed to recognize that Doppler shift > >> > is due to varying speed of light. > >> > >> The speed of light in vacuo relative to any inertial frame is a well > >> measured constant. It has been shown experimentally again and again and > >> has yet to be falsified. The speed of light in vacuo is independent of > >> th motion of the source or the observer. > > > > The speed of light is measured to be constant because we arbitrarily assumed > > that the Doppler shift is due to wave length change. If wave length is > > assumed to be contant then the speed of light is different from different > > sources. > > > > Ken Seto > > > > Assume two orbiting stars, far away, with barycenter > motionless with respect to Earth. This assumption is already wrong. There is no object in the universe that is motionless wrt the Earth. The Earth itself is in a constant state of absolute motion. >Assume they orbit with > speed of approximately 10^-4 c = 30 km/s (which is about > Earth's orbital speed), to make the math easy, and that > the nominal radiation is 588 nm (which happens to coincide, > or at least be close to, a sodium line). > > Emissive: delta-lambda = 58.8 pm > > SR: delta-lambda = 2.94 fm I think you are missing the point. What I said is that any observed Doppler shift from a distant source moving wrt the observer is due to different speed of light and not due to the changing of the wave length. Ken Seto > > I'd say that's darned obvious, assuming one can in > fact determine that the velocity is 10^-4 c (which is > a problem). This is admittedly a hypothetical example > but real-world examples abound -- the most cited one > around here appears to be PSR B1913+16, which has a nice > elliptical precessing orbit and goes 15 times faster at > periastron than Earth. > > -- > #191, ewill3(a)earthlink.net > It's still legal to go .sigless.
From: kenseto on 23 Mar 2005 10:10 "The Ghost In The Machine" <ewill(a)sirius.athghost7038suus.net> wrote in message news:3k77h2-gbu.ln1(a)sirius.athghost7038suus.net... > In sci.physics, PDraper > <pdraper(a)yahoo.com> > wrote > on Tue, 22 Mar 2005 11:37:19 -0500 > <BE65B3EF.3114%pdraper(a)yahoo.com>: > > On 3/22/05 8:21 AM, in article oZU%d.6488$rL3.5018(a)fe2.columbus.rr.com, > > "kenseto" <kenseto(a)erinet.com> wrote: > > > >> > >> "Mark Fergerson" <nunya(a)biz.ness> wrote in message > >> news:LaF%d.149857$FM3.86220(a)fed1read02... > >>> kenseto wrote: > >>>> SR says that the speed of light is a universal constant. > >>>> > >>>> Questions: > >>>> Why a clock second used to define the speed of light is > >>>> not an interval of universal time?? > >>> > >>> Nobody else even uses the term "universal time". > >> > >> So what?? Everybody knows what the term universal time means. > >> > >> Ken Seto > >> > >> > > > > I don't. > > I for one would think that a "universal second" is a clock > tick of 1 second duration from the natural absolute origin > of the Universe, as measured in one's own reference frame. The observer's clock second can be defined as a "universal second". To determine the clock time value for a defined "universal second" in any observed frame the observer uses SR/GR or IRT. The reason why we need to do such calculations is that there is no "universal clock" exist that keeps the same rate of passage of "universal second" in all frames of reference. > > The catch is: there is no such natural origin. Oh, one can > create an artificial one (I hereby decree the origin to be > at Greenwich, England! So there! :-) ), but SR never needed > one, and Newton can be rewritten to function without one, > leading to a variant of ballistic/emissive light theory. > > Also, AFAICT, Kenseto's error is in not recognizing that > a 1-second tick in the "absolute" reference frame > may differ in length from a 1-second tick in the > observer's. He is not the only one to err in that fashion. You don't know what you are talking about. A clock second will contain a different amount of "universal time (absolute time)" in different frames (different states of absolute motion). A clock second in the absolute reference frame contains the least amount of "universal time". All clock seconds (in all frames) will give the same math ratio for light speed as follows: Light path length of ruler (299,792,458m)/the universal time content for a clock second co-moving with the ruler. Ken Seto Ken Seto >
From: bz on 23 Mar 2005 10:18 "kenseto" <kenseto(a)erinet.com> wrote in news:QVe0e.9440$rL3.8762 @fe2.columbus.rr.com: > > Light path length of ruler (299,792,458m)/the absolute time content for a > clock second co-moving with the ruler. > > how do you get different photons to move at different speeds with respect to a single frame of reference? Why, when we measure the speed of those photons, do the photons seem to move at the same speed? In a recent post you say: > What I said is that any observed Doppler > shift from a distant source moving wrt the observer is due to different > speed of light and not due to the changing of the wave length. > How distant must the source be? Why must it be distant? I can't see any reason that photons from a distance source should be different from those from a nearby source. In my mind, 5 feet is distant compared to the wavelength of light. Will you allow me to call 5 feet 'distant'? In another article, which you may have missed, I said: "kenseto" <kenseto(a)erinet.com> wrote in news:24Z%d.14316$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. > ..... Why do you think that the sound/light bouncing off of a moving object changes speed? I know that the waves do NOT change speed. How do I know that they don't? I can measure their speed between two points AFTER they have bounced off of something and come back to me. Their transit between the two points will be at the speed of light. Their energy is changed by bouncing off of a moving object, their frequency has changed, but their speed is not changed. This would seem to disprove your idea. Go buy a police doppler lidar and bounce the laser beam off of the blades of a turning fan if you don't believe me. Measure the beam velocity as it goes past two points at different distances from the fan. It will still be moving at c, but the frequency will have changed by the doppler shift. -- 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: PD on 23 Mar 2005 13:50
kenseto wrote: > "The Ghost In The Machine" <ewill(a)sirius.athghost7038suus.net> wrote in > message news:q887h2-gbu.ln1(a)sirius.athghost7038suus.net... > > In sci.physics, kenseto > > <kenseto(a)erinet.com> > > wrote > > on Tue, 22 Mar 2005 14:31:56 GMT > > <w%V%d.6496$rL3.4855(a)fe2.columbus.rr.com>: > > > > > > "robert j. kolker" <nowhere(a)nowhere.net> wrote in message > > > news:3aamtkF6bbkreU2(a)individual.net... > > >> > > >> > > >> kenseto wrote: > > >> > > >> > That's becasue you failed to recognize that Doppler shift > > >> > is due to varying speed of light. > > >> > > >> The speed of light in vacuo relative to any inertial frame is a well > > >> measured constant. It has been shown experimentally again and again and > > >> has yet to be falsified. The speed of light in vacuo is independent of > > >> th motion of the source or the observer. > > > > > > The speed of light is measured to be constant because we arbitrarily > assumed > > > that the Doppler shift is due to wave length change. If wave length is > > > assumed to be contant then the speed of light is different from > different > > > sources. > > > > > > Ken Seto > > > > > > > Assume two orbiting stars, far away, with barycenter > > motionless with respect to Earth. > > This assumption is already wrong. There is no object in the universe that is > motionless wrt the Earth. The Earth itself is in a constant state of > absolute motion. The Earth itself is in a constant state of motion. You cannot state one way or the other whether that motion is absolute. If it were, you would be able to rank objects in the universe according to their absolute motion, and you would be able to calculate or measure the absolute velocity of the Earth. PD > > >Assume they orbit with > > speed of approximately 10^-4 c = 30 km/s (which is about > > Earth's orbital speed), to make the math easy, and that > > the nominal radiation is 588 nm (which happens to coincide, > > or at least be close to, a sodium line). > > > > Emissive: delta-lambda = 58.8 pm > > > > SR: delta-lambda = 2.94 fm > > I think you are missing the point. What I said is that any observed Doppler > shift from a distant source moving wrt the observer is due to different > speed of light and not due to the changing of the wave length. > > Ken Seto > > > > > I'd say that's darned obvious, assuming one can in > > fact determine that the velocity is 10^-4 c (which is > > a problem). This is admittedly a hypothetical example > > but real-world examples abound -- the most cited one > > around here appears to be PSR B1913+16, which has a nice > > elliptical precessing orbit and goes 15 times faster at > > periastron than Earth. > > > > -- > > #191, ewill3(a)earthlink.net > > It's still legal to go .sigless. |