Marcelo Gleiser on the multiverse hypothesis: "It's not science."

Can we possibly know everything about our world? Marcelo Gleiser, a professor of Physics and Astronomy at Dartmouth College, explores the limits of human knowledge in his new book, The Island of Knowledge. Gleiser spoke with guest host Helen Mann about the controversial multiverse theory - where our universe is just one of many - and how, despite advancements in science, we have to realize how much we still don't know.