Even if a black hole emitted no light, we can still detect it
A) from sound waves produced by material falling onto the black hole.
B) by tides produced on Earth's oceans.
C) through its Hawking radiation.
D) through its gravitational effect on surrounding gas or stars.
E) by looking for dark patches on the sky where the black hole swallows background light.

Question

Quizplus · Accepted Answer

Black holes can be detected by observing the gravitational effects they have on nearby gas or stars, such as the motion of stars orbiting an invisible mass.

Even If a Black Hole Emitted No Light, We Can