# Susskind Lectures on General Relativity

Via Dmitry Podolsky, a series of YouTube videos from Stanford encompassing an entire course by Lenny Susskind on general relativity. I didn’t look closely enough to figure out exactly what level the lectures are pitched at, but it looks like a fairly standard advanced-undergrad or beginning-grad introduction to the subject. (For which I could recommend an excellent textbook, if you’re interested.) This is the first lecture; there are more.

It’s fantastic that Stanford is giving this away. I don’t worry that it will replace the conventional university. The right distinction is not “people who would physically go to the lectures” vs. “people who will just watch the videos”; it’s between “people who can watch the videos” and “people who have no access to lectures like this.” And Susskind is a great lecturer.

### 28 Responses to Susskind Lectures on General Relativity

1. Brian Mingus says:

This is a really boring lecture.

You might try these lectures on quantum computation by David Deutsch: http://www.quiprocone.org/Protected/DD_lectures.htm

They are very well produced but also very technical. I wasn’t able to truly follow them, but I probably could have had I come armed with pen and paper.

2. Count Iblis says:

Uncle sam, in your problem General Relativity is not important, the Newtonian treatment of gravity yields almost the exact answer. The reason why a naive appication of the equivalence principle gives you the wrong answer, is because if the equivalence principle were to apply, the boundary conditions for the fields at infinity would necessarily have to be different.

So, if you consider an electron at rest in some inertial frame and then you switch to an accelerating frame, then in that accelerating frame, the electron is accelerating in the opposite direction, but it is not emitting any radiation. Now, compare the electromagnetic fields of this accelerating electron in the non-inertial accelerating frame to the electromagnetic fields of an electron that is accelerated in an inertial frame which we know will radiate electromagnetic waves.

In the latter case, you know that the fields are given as an integral over the charge and current densities at the retarded time, which then gives you radiation fields that fall of as 1/r at large distances. But in the former case, you simply have the Coulomb field that falls off as 1/r^2 at large distances which remains the case if you switch to the accelerating frame.