In the ten years since its publication in 1988, Stephen Hawking's
classic work has become a landmark volume in scientific writing, with
more than nine million copies in forty languages sold worldwide. That
edition was on the cutting edge of what was then known about the origins
and nature of the universe. But the intervening years have seen
extraordinary advances in the technology of observing both the micro-
and the macrocosmic worlds. These observations have confirmed many of
Professor Hawking's theoretical predictions in the first edition of his
book, including the recent discoveries of the Cosmic Background Explorer
satellite (COBE), which probed back in time to within 300,000 years of
the universe's beginning and revealed wrinkles in the fabric of
space-time that he had projected. Eager to bring to his original text
the new knowledge revealed by these observations, as well as his own
recent research, Professor Hawking has prepared a new introduction to
the book, written an entirely new chapter on wormholes and time travel,
and updated the chapters throughout.