How Curved Spacetime Works | Gravity & Relativity Explainer

Einstein’s relativity, and how it relates to gravity, explained in less than 10 minutes. This video uses a type of spacetime diagram invented by the physics author Lewis Carroll Epstein in his book "Relativity Visualized," with proper time on the y-axis (also representing the null geodesic that light takes in a vacuum). Epstein diagrams are more intuitive for the layperson than Minkowski diagrams, where the null geodesics are at 45° angles. Epstein's book is available at many libraries, as well as online at https://archive.org/details/L.EpsteinRelativityVisualizedelemTxt1994Insight/page/n9/mode/2up?view=theater . The GPS & Relativity article referenced in the video is here: https://www.astronomy.ohio-state.edu/pogge.1/Ast162/Unit5/gps.html A different article, by NASA, is here: https://www.nasa.gov/mission_pages/chandra/images/einstein-s-theory-of-relativity-critical-for-gps-seen-in-distant-stars.html Questions are welcome, but fringe-science comments — like insisting that gravity can be explained as the Earth expanding, or buoyancy, or Earth being bombarded by massive photons, or "electric universe" etc. — are not (sorry). General relativity is one of the most battle-tested theories in physics, for over 100 years now. If you think you have a better theory, go ahead and make your own video, and in your video please include how the math in your theory makes better quantitative predictions than GR. I guarantee that you will win a Nobel Prize. Thank you to my Patreon supporters https://www.patreon.com/edwardcurrent