As an observer is investigating a black hole from a safe distance, a rivet pops out of the tailfin on their spaceship and falls toward the black hole. Will the observer ever see the rivet enter the event horizon?
A) Yes. However, it will be so blueshifted that the observer would need X-ray eyes to see it.
B) No. It will be compressed to zero size and disappear from sight before it reaches the event horizon.
C) Yes. The observer will see it fall faster and faster until it disappears as it falls through the event horizon.
D) No. It will appear to stop and hover forever before entering the event horizon.

Question

Quizplus · Accepted Answer

The observer will never see the rivet enter the event horizon due to the extreme gravitational time dilation effects near the event horizon. From the observer's perspective, the rivet will appear to slow down and asymptotically approach the event horizon, but never actually cross it.

As an Observer Is Investigating a Black Hole from a Safe