Why does the expansion of space cause redshifts of distant galaxies?
A) The amount of space in between the galaxies is increasing.
B) All galaxies are moving away from us because we are at the center of the universe.
C) All galaxies are moving toward us because we are at the center of the universe.
D) Galaxies do not show redshifts.

Question

Quizplus · Accepted Answer

As space expands, the wavelength of light traveling through that space also expands, causing the light to become redshifted. This is known as cosmological redshift and is one of the key pieces of evidence for the expansion of the universe. It should be noted that there is no center of the universe, so choices B and C are incorrect, and choice D is incorrect because galaxies do, in fact, show redshifts due to the expansion of space.

Why Does the Expansion of Space Cause Redshifts of Distant