Science stars Leonard Susskind and Stephen Hawking squabbled for years over whether or not energy is destroyed in a black hole. At stake in this nerd war: our very understanding of the universe. Susskind’s new book describes the fundamental workings of black holes, drawing analogies to grade-school-level geometry, tidal pulls, and tadpoles—and it comes with handy illustrations, too. All to prove that, well, Hawking was wrong.