Re: Speed of Light: A universal Constant?

From: kenseto (kenseto_at_erinet.com)
Date: 03/23/05 

Date: Wed, 23 Mar 2005 14:43:35 GMT

"The Ghost In The Machine" <ewill@sirius.athghost7038suus.net> wrote in
message news:q887h2-gbu.ln1@sirius.athghost7038suus.net...
> In sci.physics, kenseto
> <kenseto@erinet.com>
> wrote
> on Tue, 22 Mar 2005 14:31:56 GMT
> <w%V%d.6496$rL3.4855@fe2.columbus.rr.com>:
> >
> > "robert j. kolker" <nowhere@nowhere.net> wrote in message
> > news:3aamtkF6bbkreU2@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@earthlink.net
> It's still legal to go .sigless.

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