Which of the following provides direct evidence for the existence of dark matter?
A) the rotation curves of spiral galaxies
B) the motions of galaxies in clusters
C) the temperature of the diffuse intergalactic gas within clusters
D) the gravitational lensing produced by galaxy clusters
E) all of these

Question

Quizplus · Accepted Answer

All of these phenomena provide direct evidence for dark matter, as they all show gravitational effects that cannot be explained by visible matter alone.

Which of the Following Provides Direct Evidence for the Existence