The total number of people who have ever been born is about 100 billion. Yet the genetic code that generates viable versions of us is capable of at least 10 to the 30 variations. So far, our branch of the tree of life has produced no more than point. Most people who could exist will never exist. Each of us for all practical purposes is unique in the universe now and forever.
Neil deGrasse Tyson—world-renowned astrophysicist, Emmy-nominated host, and author—is one of the most popular and influential figures in modern science. He joins to discuss his cosmic career and new book, “Starry Messenger: Cosmic Perspectives on Civilization.”