Suppose the universe contained only "normal" matter, like hydrogen, helium, etc. How would the expansion rate of the universe change with time?
A) It would speed up.
B) It would slow down initially but then speed up when the matter pressure became high enough.
C) It would slow down.
D) It is impossible to tell, because it depends on the density of the matter.

Question

Quizplus · Accepted Answer

The expansion rate of the universe would slow down over time if it contained only "normal" matter like hydrogen and helium. This is because the gravitational attraction between the masses would work against the expansion, causing it to decelerate.

Suppose the Universe Contained Only "Normal" Matter, Like Hydrogen, Helium