Stephen Hawkings worldwide bestseller A Brief History of Time has been a landmark volume in scientific writing. Its authors engaging voice is one reason & the compelling subjects he addresses is another: the nature of space & time the role of God in creation the history & future of the universe. But it is also true that in the years since its publication readers have repeatedly told Professor Hawking of their great difficulty in understanding some of the books most important concepts. This is the origin of & the reason for A Briefer History of Time: its authors wish to make its content accessible to readers -- as well as to bring it up-to-date with the latest scientific observations & findings. Although this book is literally somewhat briefer it actually expands on the great subjects of the original. Purely technical concepts such as the mathematics of chaotic boundary conditions are gone. Conversely subjects of wide interest that were difficult to follow because they were interspersed throughout the book have now been given entire chapters of their own including relativity curved space & quantum theory. This reorganization has allowed the authors to expand areas of special interest & recent progress from the latest developments in string theory to exciting developments in the search for a complete unified theory of all the forces of physics. Like prior editions of the book--but even more so -- A Briefer History of Time will guide nonscientists everywhere in the ongoing search for the tantalizing secrets at the heart of time & space. Thirty-eight full-colour illustrations enhance the text & make A Briefer History of Time an exhilarating addition in its own right to the literature of science.