Quiz 4: String Theory and Black Holes

. Check how much you've learned so far about the topics we've presented here with this self-scoring quiz.

Question 1: What is the escape velocity at the event horizon of a black hole?
The speed of light
The speed of sound
Warp six

Question 2: Black holes can be formed by the gravitational collapse of which astronomical objects?
Large planets like Jupiter
Stars about the size of our Sun
Stars much heavier than our Sun

Question 3: How do astronomers know when they are observing a black hole?
When they see the light emitted from nearby dust and gas being sucked into the black hole
When they hear the screams of people falling into the black hole
When everything in that region of space is completely black

Question 4: Which statement below is true as far as the theory of black holes is concerned?
In classical theory black holes always decay but in quantum theory they never decay.
In classical theory black holes always decay and in quantum theory they decay even faster.
In classical theory black holes never decay but in quantum theory they always decay.