While you read these words, the universe is splitting into countless copies. New realities, all with a version of you, exactly like you are now, but journeying off into their own branch of the multiverse. Maybe. Sean Carroll is a theoretical physicist at CalTech, the host of the Mindscape podcast, and author of, among other books, Something Deeply Hidden, which blew my mind a bit. He is also a believer in, and defender of, the “many-worlds” interpretation of quantum mechanics, which has to be one of the five most fun things in the world to think about. Science! This is a conversation where I get to do something I’ve always wanted to do: Ask a real quantum physicist all of my questions about quantum physics. And then ask again, when I don’t understand the answer, which I usually don’t. And then again, when I sort of understand, but there’s still a part tripping me up. Carroll is wonderfully patient and beautifully clear, and the result is a conversation I haven’t stopped telling friends about since I had it. This world sucks right now. Let’s think about some other ones. References: The Biggest Ideas in the Universe! YouTube series Book recommendations: How Physics Makes Us Free by J. T. Ismael How the Universe Got Its Spots by Janna Levin The Calculus Diaries by Jennifer Ouellette Want to contact the show? Reach out at ezrakleinshow@vox.com Please consider making a contribution to Vox to support this show: bit.ly/givepodcasts Your support will help us keep having ambitious conversations about big ideas. New to the show? Want to check out Ezra’s favorite episodes? Check out the Ezra Klein Show beginner’s guide (http://bit.ly/EKSbeginhere) Credits: Producer/Editor - Jeff Geld Researcher - Roge Karma Learn more about your ad choices. Visit podcastchoices.com/adchoices