Terrific paper by @johncarlosbaez and Ted Emory, explaining the meaning of the Einstein field equations for general relativity: http://math.ucr.edu/home/baez/einstein/einstein.pdf …pic.twitter.com/65fMVQR2tH
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Nice! I never got that far with the Cartan formulation of Newtonian gravity. But since pressure's contribution is suppressed by a factor of c squared, it must go away in the Newtonian limit.
Yes, exactly. In fact, if you write the Einstein equation as "Ricci curvature = 8*pi*G*(trace-reversed stress-energy)," then both sides have a smooth Newtonian limit, which is the Poisson equation. (Pressures don't matter, because the metric degenerates in the Newtonian limit.)
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.