[net.sci] Doppler Shift of Photons related to Gravitational Intensity

randy@utcsri.UUCP (Randall S. Becker) (11/10/85)

I am looking for the (a) formula which relates the gravitational intensity
about a photon emitting object with the shift in the photons' frequency.

Randy

-- 
		Randall S. Becker
		Usenet:	..!utcsri!randy
		CSNET:	randy@toronto

gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (11/15/85)

> I am looking for the (a) formula which relates the gravitational intensity
> about a photon emitting object with the shift in the photons' frequency.

Last I heard, the frequency of an emitted photon is
independent of the gravitational field at the site
of emission, so long as it does not affect the
structure of the emitting material, etc.  Perhaps
you are really interested in the "gravitational
red shift"?  This describes how the frequency of
light that a distant observer sees is affected by
the lights travel through an extended gravitational
field.  That depends very much on the situation.
For a very distant observer of light emitted at
the surface of, say, a star of radius R and mass m,
the observed frequency will be
	emitted_frequency * sqrt( 1 - 2*k*m/R ),
where k is the Newtonian gravtitational constant
divided by the square of the speed of light.