Re: SR Postulate on Speed of Light


harry wrote:
> Curious schrieb:
> > Harry wrote:
> >
> > > Quite, the second formulation encompasses the first:
> > > If the measured vacuum speed of light is the constant c in any
> > inertial
> > > frame, it is by definition independent of the motion of objects
in
> > that
> > > frame and that includes light sources.
> >
> > 'Scuse me for asking dumb questions:
> > 1. So the measured vacuum speed of light is a constant in an
inertial
> > frame independent of the speed of BOTH the source AND the observer,
> > correct?
>
> Not dumb at all! According to SRT, yes. And there is a quite some
> experimental support in forward and backward directions. But be
careful
> with the word "observer", as here you obviously mean detector, while
> the same label is commonly used in relativity to sloppily mean
inertial
> frame of reference! Thus your correct use of that word can lead to
> misunderstanding if you don't make sure to be understood.
>
> > 2. Does it follow that the ACTUAL vacuum speed of light in an
> inertial
> > frame is also constant, or can't we tell?
>
> If you mean with "actual" "real", such as in a model of propagation,
> than you just hit the heart of a century old and never ended debate
> (meanwhile largely removed from journals) that is still continuing in
> this group!
> The diplomatic answer is that physics is about measurements, it's not
> intended to cover such "philosophical" matters.
> Still, you can find papers in physics journals that cover that
subject:
> some concluded that the answer on your question is Yes, and others
such
> as Ives and Builder concluded that the answer is No.
>
> I also found an example on the web of a reasoning that supports the
No:
>
> http://www.twow.net/ObjText/OtkCaLbStrC.htm
>
> No doubt other participants can provide more links that support each
> pov.
>
> Best regards,
> Harald

Wow - thanks Harry - that web page has a powerful argument! At this
stage it seems to me to be unarguable. I'mn left thinking, "that's it!
Why isn't everyone else onto this answer already?" But I'm sure there's
plenty of debatable things I've missed!

.

Relevant Pages

  • Re: SR Postulate on Speed of Light
    ... >> Harry wrote: ... >>> frame and that includes light sources. ... >than you just hit the heart of a century old and never ended debate ... you can find papers in physics journals that cover that subject: ...
    (sci.physics.relativity)
  • Re: SR Postulate on Speed of Light
    ... >> frame and that includes light sources. ... > frame independent of the speed of BOTH the source AND the observer, ... experimental support in forward and backward directions. ... you can find papers in physics journals that cover that subject: ...
    (sci.physics.relativity)
  • Re: A little challenge for relativists.
    ... SNIP ... > contingent, Harry? ... > (or the observers reference frame). ... GPS works fine with SRT. ...
    (sci.physics.relativity)
  • Re: On The Irrelevance Of The Absolute Rest Frame In Special Relativity
    ... harry wrote: ... At this point I *will* postulate an absolute rest frame, ... Lorentz at least within that subcase. ...
    (sci.physics.relativity)
  • Re: SR fundamental contradiction
    ... Dirk Van de moortel wrote: ... Any object measures shorter in terms of a frame relative to ... Tell that to Van de Moortel, ... With his SNIP Harry missed the first line of my reply. ...
    (sci.physics.relativity)
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