If a galaxy contains a great deal of "dark matter," what will that do the galaxy's mass-to-light ratio?
A) increase it a small amount
B) decrease it a small amount
C) increase it quite a bit
D) decrease it quite a bit
E) not affect it in any way (since it's dark matter)

Question

Quizplus · Accepted Answer

Dark matter does not emit, absorb, or reflect light, making it invisible and undetectable by electromagnetic means. However, it exerts gravitational effects on visible matter, radiation, and the large-scale structure of the universe. Therefore, a galaxy containing a great deal of dark matter will have a significantly higher mass than what is suggested by its visible light alone, thus increasing its mass-to-light ratio quite a bit.

If a Galaxy Contains a Great Deal of "Dark Matter