On Mar 26, 3:43=A0pm, Randy Poe
> On Mar 26, 4:18 pm, kenseto
> Ken says:
>
> > Assertion is not a valid arguement.
>
> And then immediately asserts:
>
> > The grating does define a
> > universal wavelength for every light source at rest in its own frame.
>
> Assertion is not a valid argument, Ken. No matter how
> many times you say this, it is not going to cause anybody
> using diffraction gratings to actually use them this way.
What I said is not assertion.The grating defines a universal
wavelength for every light source at rest wrt it. The incoming light
becomes a new light source in the grating's frame and a new universal
length is defined for it by the grating.