What is fire? How do gravitational waves ripple through space-time? Neil deGrasse Tyson and comedian Harrison Greenbaum answer grab bag questions about why supernovae form black holes, photons, the singularity, and more! First up, where do photons come from? What are they? Neil gives us a crash course on photons, potential energy, and why falling out of a window is bad news. He explains how energy can be stored in atoms and how photons are born when electrons move between energy levels. Neil even shares some candle-making tips from his personal experiences. We explore gravitational waves, the groundbreaking discovery in 2015 that confirmed Einstein's century-old prediction. Neil breaks down how space and time are like a stretchy fabric, and what happens when two black holes collide, sending ripples across the cosmos. We discuss the "Big Rip," black holes, and the very fabric of space itself. Why does a star going supernova form a black hole? We explore dark matter, tidal energy from the moon, and whether osmium is really heavier than gold. They even touch on the ultimate nuclear furnace—our Sun—and how energy from it powers almost everything on Earth, from fossil fuels to fish in the ocean. Timestamps: 00:00 - Introduction: Grab Bag 01:57 - What is Fire? 12:50 - Detecting Gravitational Waves 21:00 - What is the Fabric of Space? 24:16 - Did the Big Bang make a “Bang!”? 27:33 - Why Does A Supernova Cause a Black Hole? 29:03 - Does Infinite Curvature of A Black Hole Mean Infinite Time? 32:16 - Travelling at a Planck Length 33:50 - Why Black Holes Are Not Dark Matter 35:58 - Solar & Tidal Energy 48:41 - Is Osmium Heavier Than Gold? 51:50 - Closing Check out our second channel, @StarTalkPlus Get the NEW StarTalk book, 'To Infinity and Beyond: A Journey of Cosmic Discovery' on Amazon: https://amzn.to/3PL0NFn Support us on Patreon: https://www.patreon.com/startalkradio FOLLOW or SUBSCRIBE to StarTalk: Twitter: http://twitter.com/startalkradio Facebook: https://www.facebook.com/StarTalk Instagram: https://www.instagram.com/startalk About StarTalk: Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up! #StarTalk #NeildeGrasseTyson