sci.physics.particle

On Mar 26, 1:34 pm, "kens...@erinet.com" wrote:
> On Mar 26, 8:30 am, PD wrote:
>
>
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> > On Mar 26, 7:54 am, "kens...@erinet.com" wrote:
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> > > On Mar 25, 8:33 am, PD wrote:
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> > > > On Mar 25, 8:07 am, kenseto wrote:
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> > > > > On Mar 24, 3:43 pm, PD wrote:
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> > > > > > On Mar 24, 3:34 pm, kenseto wrote:
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> > > > > > > On Mar 24, 12:12 pm, PD wrote:
>

> > idea that spectroscopists look at a spectrum and say, "If it has a
> > line at 589 nm it is sodium, and if it doesn't have a line at 589 nm
> > it is not sodium."
This will be a real surprise to radio astronomers. A radio
astronomer can look at a Doppler shifted spectrum of radio waves,
correct it with a relativistic formula, and say "this spectrum came
from a rapidly moving sodium atom." However, to collect that light,
they have to use a radio antennae that is hundreds of meters wide.
Maybe kilometers wide. This is so the wavelength matches the length of
the antennae to a certain fraction. The wavelength is long. Your
grating won't work on the "light" emitted from the sodium atom. The
wavelength is much longer in the rest frame of the antennae then it
would be in the rest frame of the sodium atom.
>
> That's correct.....the grating defines a universal wavelength for
> every light source at rest wrt it. The incoming light is a new light
> source at rest wrt it.
The term "universal wavelength" doesn't mean anything. There are no
"universal wavelengths" or "universal frequencies" in the sense you
are talking about. If there were, how could radio telescopes work?
> >This is a mistake on your part, born out of
> > ignorance of how spectroscopy is done.
What you are describing isn't spectroscopy. It is voodoo. And not
even the fun kind, which at least has dancing and music.