Schwarzschild metric - part 1
This video is the first part of a three-part series that looks at how the form of the Schwarzschild metric is determined using symmetry arguments. In this first video it shows how the metric takes a diagonal form using arguments involving the invariance of the line interval.
Note: At time stamp 5:51 there should be a "c" multiplied to the "dt" term there. Also, earlier on in the video there are some other places where "c" has been left out for the sake of visual simplicity. An updated version of this video has been made in which the "c's" are put back in.