In cosmology,the phrase "critical density" refers to the
A) smallest density that will produce inflation of the universe.
B) density below which stars will never form.
C) density above which the universe is opaque to radiation.
D) density needed to produce precisely flat space,on average,throughout the universe.

Question

Quizplus · Accepted Answer

The critical density is the density needed to produce precisely flat space, on average, throughout the universe. If the actual density of the universe is less than the critical density, then the universe is open and will expand forever. If the actual density is greater than the critical density, then the universe is closed and will eventually collapse in on itself.

In Cosmology,the Phrase "Critical Density" Refers to the