Tonight we explore the strange reality of Einstein's General Theory of Relativity and what it means for 3 dimensional beings born into a 4 dimensional Universe. It predicts our birth from a singularity in an expanding Universe, the contraction of space at the speed of light, and both black holes and the infinite time dilation at their horizon. It's bizarre that space truly compresses and time actually slows down deep inside gravitational wells and near the speed of light. We literally observe supernovae billions of light years away exploding at half their normal speed. So let's find out about the history and basics of relativity.   ▸ Want to leave a tip or connect?:    Video credits: Carrol and Ostlie (textbook I used): https://amzn.to/3QtiABm TNG Simulations https://www.tng-project.org/media/ NASA/STSci/ESA Davis and Lineweaver (2003) https://arxiv.org/abs/astro-ph/0310808 Nolan, C. (2014). Interstellar. Paramount Pictures. The Eagle Simulation, Durham University https://youtu.be/Fim6dWJhxz4 Doppler Shifts, Prof. Richard Pogge, The Ohio State University https://youtu.be/xCTUgpwuP0I  2 Hour Jupiter time lapse with Io transit, https://youtu.be/EBBhvY8ZRwE Relativity 110d: Cosmology - FLRW Geodesics, Cosmological Redshift, Horizons, Comoving Coordinates, https://youtu.be/OxkY4Wqdpp8 Relativity 103a: Galilean Relativity - Spacetime Diagrams, https://youtu.be/powCBsDOa8U How Fast Is It - 03 - Special Relativity (4K), https://youtu.be/IyxX8LAvkdQ Dr. David Bradstreet (Eastern University), Ole Roemer and the Speed of Light, https://youtu.be/XNJw0B1o8cQ Mythbusters, Soccer ball shot from a truck Time Stamps: 0:00 Relativity and the expanding Universe (intro) 5:54 Galileo and Roemer discover light isn't infinitely fast (1600's) 19:55 The mystery of the constant speed of electromagnetic field waves 32:17 Galileo discovered relativity 50:26 Einstein discovers Special Relativity 1:11:39 Time dilation and space contraction 1:33:08 Galaxy redshifts and expansion 2:16:24 General Relativity (gravity now explained by relativity) 2:57:41 Light cones (future and past causality) 3:12:21 Relativity in Cosmology: discovery of expanding spacetime  #educational #letsfindout #ASMR #relaxing #space #science