Thursday, January 21, 2016


I'm extremely dubious of string theory. It sounds nice and logical, but for decades really smart people have been trying to make it predict something, without success. Supersymmetry is a natural consequence, and a delight to the theorists, but there's no trace of it in our experiments (unless dark matter turns out to be related--but we haven't detected that directly either).

I figured I should learn about it anyway--if for no other reason than to try to keep the wits sharp. One of the big names in string theory is Leonard Susskind, and Stanford published several sets of his lectures on youtube. As I write this I'm done with lecture 6 of this 10-lecture playlist. I suspect that this is something like a survey course, since he goes into a lot of quite elementary detail--or perhaps he was reacting to his audience, since some things are shown on the fly. I hadn't appreciated the historical motivations, and there are some things I'd not seen before.

Without some introduction to special relativity and to quantum mechanics, you won't understand exactly what he's saying--but you might get some feel for the subject anyway. Be warned: the lectures are typically over 1 1/2 hours long.

UPDATE: By lecture 7 Susskind is starting to review some math the layman isn't likely to have been acquainted with.

1 comment:

Unknown said...

Depending upon the speaker, I find that I can often go to the little gear icon in the lower right of the youtube window and change the playback speed to 1.5x or 2x. There is something about a lecture that is more engaging than reading a transcript of a lecture, but for most academic classroom lectures I find it even more engaging if the information comes at me a little faster than normal presentaion speed.

Now, is the speaker is in the habit of pacing back and forth as he talks, that can become really distracting at double-speed...