While traveling the galaxy in a spacecraft,you and a colleague set out to investigate the 10⁶-M¤ black hole at the center of our galaxy.Your colleague hops aboard an escape pod and drops into a circular orbit around the black hole,maintaining a distance of 1 AU,while you remain much farther away in the spacecraft but from which you can easily monitor your colleague.After doing some experiments to measure the strength of gravity,your colleague signals the results back to you using a green laser.What would you see?

Question

Quizplus · Accepted Answer

Since your colleague is maintaining a distance of 1 AU from the black hole, they are well outside the event horizon and able to send signals back to you with a green laser. The signals won't be shifted to a redder wavelength as he or she is not close enough to the event horizon for that to happen, and it is also assumed that he or she has not crossed the event horizon yet. Finally, option D is incorrect as your colleague is close enough to you and outside the event horizon to be able to send signals back to you.

While Traveling the Galaxy in a Spacecraft,you and a Colleague