While traveling the galaxy in a spacecraft,you and a colleague set out to investigate the 10⁶ M_$\bigodot$ 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 his/her results back to you using a green laser.What would you see?

Question

Quizplus · Accepted Answer

The event horizon is the point of no return, beyond which not even light can escape the gravitational pull of the black hole. Since your colleague is maintaining a distance of 1 AU from the black hole and orbiting well outside the event horizon, his/her signals can escape and reach your spacecraft. The wavelength of the signal would not be shifted to a much redder wavelength because your colleague is not close enough to the event horizon to experience significant gravitational redshift.

While Traveling the Galaxy in a Spacecraft,you and a Colleague ⨀\bigodot⨀

While Traveling the Galaxy in a Spacecraft,you and a Colleague $\bigodot$