Strong evidence that the Universe is expanding comes from the fact that the light emitted from distant galaxies appears to be ____________.
A)red shifted
B)blue shifted
C)green shifted
D)None of the above are correct.

Question

Quizplus · Accepted Answer

The red shift of light from distant galaxies is caused by the Doppler effect, which occurs when an object is moving away from the observer. The longer wavelengths of light are stretched as they travel through expanding space, causing them to shift towards the red end of the spectrum. This red shift of light from distant galaxies is strong evidence that the Universe is expanding.

Strong Evidence That the Universe Is Expanding Comes from the Fact