This week’s videos are all about gravity. However, before embarking on the main videos about the four forces of nature, I decided I needed to make Noether’s Theorem seem plausible. Noether’s theorem tells us that, for every continuous symmetry in nature, there is a conserved quantity. It’s so central to what follows that I think you have to have some confidence in the truth of the theorem. So that’s where I’ll begin.
Now we can examine the first of the four forces: gravity.
There’s a very nice demonstration of how curvature creates forces, and that I reference in the above video. You can see it on YouTube.
Finally, for those who want something a bit more detailed, I’ve put together a 10 minute summary of General Relativity. It took me several years to boil GR down to the absolute essentials so that I could remind myself, on a single sheet of paper, how it all hangs together. so here is the result.
Warning – this one, and the ones that follow, are all maths.
If you would like something a bit more leisurely, then the following video (not by me) does the same thing in about two hours (phew, what a slouch!).
And if you really want to learn GR, then Leonard Susskind’s videos can’t be beaten.
http://theoreticalminimum.com/courses/general-relativity/2012/fall
The only book on General Relativity that ever made the slightest bit of sense to me was this one. (And it makes a LOT of sense.)
Cheng: Relativity, Gravitation and Cosmology A Basic Introduction
Platitude of the Day 