Consider four different regimes of space in which distances between objects might be changing as a result of the general expansion of the universe: (1) distances between different parts of Earth; (2) distance between planets in the solar system; (3) distances between stars in the Milky Way; (4) distances between clusters of galaxies. In which of these regimes are the distances changing because of the universe's expansion?
A) 4, 3, 2, 1
B) 4
C) 4, 3, 2
D) 4, 3

Question

Quizplus · Accepted Answer

The expansion of the universe primarily affects the distances between clusters of galaxies. Gravitational forces within smaller structures like solar systems, galaxies, and certainly between parts of Earth, are strong enough to overcome the effects of cosmic expansion.

Consider Four Different Regimes of Space in Which Distances Between