Strong evidence that the Universe is expanding comes from the fact that the light emitted from nearly all distant galaxies appears to be
A) red-shifted.
B) blue-shifted.
C) green-shifted.
D) yellow-shifted.

Question

Quizplus · Accepted Answer

The red-shifted light indicates that the galaxies are moving away from us, as the wavelength of the light is increasing due to the Doppler effect. This observation is consistent with the expansion of the Universe.

Strong Evidence That the Universe Is Expanding Comes from the Fact