Which of these statements correctly describes cosmologists' current state of knowledge about the future expansion of the universe?
A) The amount of matter (both visible and dark) is only 1/3 the amount needed to halt expansion, so the expansion will continue to slow down but will never stop.
B) The amount of matter (both visible and dark) is only 1/3 the amount needed to halt expansion, and there is strong evidence of a previously unknown form of energy that acts to accelerate the expansion.
C) The amount of matter (both visible and dark) is exactly the right amount needed to halt expansion after an infinite amount of time has gone by.
D) The amount of matter (both visible and dark) is 3 times the amount needed to halt expansion, so the expansion will eventually stop and the universe will begin to collapse.

Question

Quizplus · Accepted Answer

The correct statement is B because current cosmological models and observations, including the study of the cosmic microwave background radiation and supernovae, suggest that the universe contains a form of energy, known as dark energy, which is causing the expansion of the universe to accelerate. This is despite the fact that the amount of matter, both visible and dark, is not enough to halt the expansion on its own.

Which of These Statements Correctly Describes Cosmologists' Current State of Knowledge