The critical density of the universe is the
A)average density the universe would need for gravity to someday halt the current expansion if dark energy did not exist.
B)actual average density of the universe.
C)density of dark matter in the universe.
D)density of water.

Question

Quizplus · Accepted Answer

The critical density is defined as the average density the universe would need for gravity to someday bring the current expansion to a halt if dark energy did not exist. This is important because it helps us understand the ultimate fate of the universe. If the density of the universe is less than the critical density, the expansion will continue forever. If it is greater than the critical density, the universe will eventually collapse in a "Big Crunch."

The Critical Density of the Universe Is the