Eager to bring to his original text the new knowledge revealed by these many observations, as well as his recent research, for this expanded edition Professor Hawking has prepared a new introduction to the book, written an entirely new chapter on the fascinating subject of wormholes and time travel, and updated the original chapters. In addition, to heighten understanding of complex concepts that readers may have found difficult to grasp despite the clarity and wit of Professor Hawking's writing, this edition is enhanced throughout with more than 240 full-color illustrations, including satellite images, photographs made made possible by spectacular technological advance such as the Hubble Space Telescope, and computer generated images of three and four-dimensional realities. Detailed captions clarify these illustrations, enable readers to experience the vastness of intergalactic space, the nature of black holes, and the microcosmic world of particle physics in which matters and antimatter collide.