Is There a Gravitational red Shift of Light From a Star?

Most recent answer: 09/30/2018

Q:
Can the gravitational force of a star cause any red shift of its own light as it begins its journey into space?
- Dawn (age 84)
Dallas, TX
A:

Yes indeed.  In fact it's measurement is one of the significant tests of Einstein's theory of general relativity.  One can see it's effect here on earth with careful experiments .   In 1960 Robert Pound and Glen Rebka of Harvard University succeed in testing this crucial prediction.   See https://physics.aps.org/story/v16/st1

Todays GPS clocks traveling in orbit around the earth must be corrected from time to time in order to compensate for this gravitational shift. 

LeeH

 


(published on 09/30/2018)