13. The Einstein field equation (variant derivation).

MIT General Relativity, Spring 2020 Instructor: Scott Hughes View the complete course: YouTube Playlist: A second route to the Einstein field equation, using a variational principle.  (Note, this lecture is due for an overhaul; we were unable to do so as planned in Spring 2020 due to the outbreak of the COVID-19 pandemic.) License: Creative Commons BY-NC-SA More information at More courses at Support OCW at We encourage constructive comments and discussion on OCW’s YouTube and other social media channels. Personal attacks, hate speech, trolling, and inappropriate comments are not allowed and may be removed. More details at