"Part of me was there?" Dr. Katie Mack teaches John Green about the beginning of the Universe - including that we are not just made of stardust; we are also made of Big Bang stuff, with pieces of us directly born in the vast, first cacophony. 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