Which of the following is not consistent with observations of the cosmic microwave background?
A) The universe is geometrically "flat" (in the four dimensions of spacetime).
B) The matter density (both luminous and dark matter combined) in the universe is only about one-fourth of the critical density.
C) Dark energy, whatever it is, represents the majority of the energy content of the universe.
D) The universe is at least 20 billion years old.

Question

Quizplus · Accepted Answer

Observations of the cosmic microwave background suggest that the universe is roughly 13.8 billion years old, so choice D is not consistent with those observations. The other choices are consistent with observations.

Which of the Following Is Not Consistent with Observations of the Cosmic