As a writer for "Scientific American", the author routinely interviews contemporary scientists such as Richard Dawkins, Murray Gell-Mann, Stephen Hawking, Karl Popper, Richard Feynmann and Noam Chomsky. In this book he discusses with them whether all the big scientific questions have been answered and all the knowledge worth knowing become known. Will there eventually be a "theory of everything" that signals the end? At a time when scientific rationality is under fire from many quarters, Horgan provides an overview of current scientific enterprise as he discusses God, Star Trek, superstrings, quarks, consciousness and many other topics.