One of Edwin Hubble's discoveries is that the known universe is expanding.This means that
A)most all observable galaxies are moving away from each other.
B)light rays bend as they near the event horizon of a black hole.
C)light rays undergo acceleration as they travel vast distances.
D)the mass of the universe is slowly dissipating.

Question

Quizplus · Accepted Answer

Edwin Hubble discovered that the galaxies are moving away from each other, which means the universe is expanding. This observation led to the development of the Big Bang Theory, which suggests that the universe began as a singularity and has been expanding ever since.

One of Edwin Hubble's Discoveries Is That the Known Universe