Ep. 4: When The Stars Turned On

"Is free will still in the equation?"In this episode, the universe begins to become visible to itself. Dr. Katie Mack teaches John Green about the moment the stars turned on, while John seeks to answer one question... do humans matter to the universe? Head to https://policygenius.com/crashcourse to get your free life insurance quotes and see how much you could save.This show is a production of Complexly. If you want to help keep Crash Course free for everyone, forever, you can join our community on Patreon at  http://www.patreon.com/crashcourse  See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.