The redshift of galaxies in the Universe is correctly interpreted as (in Einstein's general theory of relativi?

a. a Doppler shift due to the motions of the galaxies through expanding space. b. an "aging" of the light. c. space itself is expanding with time; the wavelengths of photons are stretched while they travel through the expanding space. d. the difference in temperatures of distant and nearby... show more a. a Doppler shift due to the motions of the galaxies through expanding space.
b. an "aging" of the light.
c. space itself is expanding with time; the wavelengths of photons are stretched while they travel through the expanding space.
d. the difference in temperatures of distant and nearby galaxies.
4 answers 4