8.962 | Spring 2020 | Graduate

General Relativity

Video Lectures

Lecture 23: Black Holes II

Description: Motion near black holes. Taking advantage of the symmetries of a black hole spacetime, we develop simple equations that describe orbits near black holes. We deduce the existence of an innermost stable orbit—any orbit that is set up inside this radius will either fall into the black hole or rocket out to infinity if slightly disturbed. We also examine the motion of light near these objects, showing that a “light ring” exists where light is bent into a circular orbit. This is closely related to black hole shadow that was observed by the Event Horizon Telescope.

Instructor: Prof. Scott Hughes

Course Info

As Taught In
Spring 2020
Learning Resource Types
Lecture Videos
Problem Sets