Have you ever wondered why the sky is blue? Neil deGrasse Tyson is here to help you answer that question alongside comic co-host Chuck Nice. And, you’re about to find out why the answer is easy to understand, but not that simple. You’ll learn how the white light from the sun interacts with the atmosphere through a process called “Rayleigh scattering” that makes the sky blue. Neil tells us why the sky turns different shades as the day goes on, and why the sunset changes from blue to amber. Discover why the reason we have a blue sky is the same reason you can’t see stars during the daytime. And, how this lead to the discovery of the operational definition of where the atmosphere ends and space begins. Neil explains why he thinks space should be defined by gravity and not by the circumstances of our atmosphere. Lastly, Neil gives us a lesson on the frailty of our atmosphere and our delicate place among the stars. Support us on Patreon: https://www.patreon.com/startalkradio Subscribe to StarTalk: null Follow StarTalk: Twitter: http://twitter.com/startalkradio Facebook: https://www.facebook.com/StarTalk Instagram: https://www.instagram.com/startalkradio/ 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 0:00 - Introduction 1:13 - The Composition Of The Atmosphere 1:44 - The 7 Colors Of The Spectrum 3:52 - How The Atmosphere Creates A Blue Sky 4:35 - Rayleigh Scattering 5:30 - Why Sunsets Are Red 6:18 - Why Can’t We See Stars During The Daytime? 7:11 - Where Is The Edge Of The Atmosphere? 9:38 - Neil’s Operational Definition Of Space