How does the observed total amount of matter in the universe,including dark matter,compare with the amount of matter required to just close the universe?
A) The observed total amount of matter equals the amount needed, to within observational uncertainty.
B) The observed total amount of matter is about 1/3 of the amount needed.
C) The observed total amount of matter is about twice the amount needed.
D) The observed total amount of matter is about 1/200 of the amount needed.

Question

Quizplus · Accepted Answer

Multiple lines of evidence (such as Cosmic Microwave Background radiation and large scale structure) suggest that about 1/3 of the total matter density needed to close the universe is visible matter (such as stars and gas), with the remaining 2/3 being dark matter. Therefore, the observed amount of matter (visible + dark) is about 1/3 of what is needed to close the universe.

How Does the Observed Total Amount of Matter in the Universe,including