red shift: doppler or einstein?

Sam Wormley wrote:
I don't think this answers the question.
This is just 2 equations to describe how a wavelength shift can be related
to two different causes.

Question .. how can we distinguish a red shift due to a moving object from a
red shift due to a gravitational field.

md wrote:
relativity predicts a red-shift for light traveling "up" in a gravity
field. Doppler predicts a red-shift for light emitted from an object
moving away from us.

How can we distinguish the two? When we measure the red-shift of a
distant object, how can we conclude that it moves away from us? It might
also be that it is not moving away, but it is very heavy instead?


Relativistic Redshift
http://scienceworld.wolfram.com/phys...cRedshift.html

Gravitational Redshift
http://scienceworld.wolfram.com/phys...lRedshift.html

Doppler Effect
http://scienceworld.wolfram.com/phys...lerEffect.html

These three sources of redshift can usually be sorted by the context
of other data made in the measurement process.