The concept of multiple unperceived dimensions in the universe is one of the hottest topics in contemporary physics. It is essential to current attempts to explain gravity and the underlying structure of the universe. The Great Beyond begins with Einstein's famous quarrel with Heisenberg and Bohr, whose theories of uncertainty threatened the order Einstein believed was essential to the universe, and it was his rejection of uncertainty that drove him to ponder the existence of a fifth dimension. Beginning with this famous disagreement and culminating with an explanation of the newest ""brane"" approach, author Paul Halpern shows how current debates about the nature of reality began as age-old controversies, and addresses how the possibility of higher dimensions has influenced culture over the past one hundred years.