The property of the universe that primarily determines whether the universe will expand forever or eventually stop its expansion and contract is
A)its average abundance of heavy elements.
B)how much of its gas has been converted into stars.
C)its average temperature.
D)its total mass.
E)dependent on the amount of helium in the universe.

Question

Quizplus · Accepted Answer

The total mass of the universe, including both matter and dark matter, is what primarily determines whether the universe will continue to expand forever or eventually slow down and contract. If the total mass of the universe is greater than a critical value, known as the "critical density," then the gravitational attraction between all the matter in the universe will eventually overcome the expansion and cause the universe to contract. If the total mass is less than the critical density, then the expansion will continue indefinitely.

The Property of the Universe That Primarily Determines Whether the Universe