Multiple choice

The redshift of light from distant galaxies provides evidence that the universe is

  1. imploding

  2. shrinking

  3. expanding

  4. static

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The redshift of light from distant galaxies provides evidence that the universe is expanding. In an expanding universe such as the one we inhabit, the scale factor is monotonically increasing as time passes, thereby distant galaxies appear redshifted.