Product Description

Einstein said that the most incomprehensible thing about the universe is that it is comprehensible. But was he right? Can the quantum theory of fields and Einstein's general theory of relativity, the two most accurate and successful theories in all of physics, be united in a single quantum theory of gravity? Can quantum and cosmos ever be combined? On this issue, two of the world's most famous physicists - Stephen Hawking ("A Brief History of Time") and Roger Penrose ("The Emperor's New Mind" and "Shadows of the Mind") - disagree. Here they explain their positions in a work based on six lectures with a final debate, all originally presented at the Isaac Newton Institute for Mathematical Sciences at the University of Cambridge. How could quantum gravity, a theory that could explain the earlier moments of the big bang and the physics of the enigmatic objects known as black holes, be constructed? Why does our patch of the universe look just as Einstein predicted, with no hint of quantum effects in sight? What strange quantum processes can cause black holes to evaporate, and what happens to all the information that they swallow? Why does time go forward, not backward? In this book, the two opponents touch on all these questions. Penrose, like Einstein, refuses to believe that quantum mechanics is a final theory. Hawking thinks otherwise, and argues that general relativity simply cannot account for how the universe began. Only a quantum theory of gravity, coupled with the no-boundary hypothesis, can ever hope to explain adequately what little we can observe about our universe. Penrose, playing the realist to Hawking's positivist, thinks that the universe is unbounded and will expand forever. The universe can be understood, he argues, in terms of the geometry of light cones, the compression and distortion of spacetime, and by the use of twistor theory. With the final debate, the reader will come to realise how much Hawking and Penrose diverge in their opinions of the ultimate quest to combine quantum mechanics and relativity, and how differently they have tried to comprehend the incomprehensible.

Product Details

• Amazon Sales Rank: #379408 in Books
• Published on: 1996-05-01
• Format: Illustrated
• Original language: English
• Number of items: 1
• Binding: Hardcover
• 150 pages

Amazon.co.uk Review
Who doesn't love a good argument? When physics heavyweights Stephen Hawking and Roger Penrose delivered three sets of back-and-forth lectures capped by a final debate at Cambridge's Isaac Newton Institute, the course of modern cosmological thinking was at stake. As it happens, The Nature of Space and Time, which collects these remarks, suggests that little has changed from the days when Einstein challenged Bohr by refusing to believe that God plays dice. The maths is more abstruse, the arguments more refined, but the argument still hinges on whether our physical theories should be expected to model reality or merely predict measurements.

Hawking, clever and playful as usual, sides with Bohr and the Copenhagen interpretation, and builds a strong case for quantum gravity. Penrose, inevitably a bit dry in comparison, shares Einstein's horror at such intuition-blasting thought experiments as Schrödinger's long-suffering cat--and scores just as many points for general relativity. The maths is tough going for lay readers, but a few leaps of faith will carry them through to some deeply thought-provoking rhetoric. Though no questions find final answers in The Nature of Space and Time, the quality of discourse should be enough to satisfy the scientifically curious. --Rob Lightner

Review
Over the past thirty years, Stephen Hawking and Roger Penrose have done more than anyone to further our understanding of the nature of gravitation and cosmology... The Nature of Space and Time is the result of their attempt to stage a structured dialogue about these problems, to isolate points of disagreement, and stimulate further investigation of these problems... The debate between Hawking and Penrose is a live one between brilliant scientists... This elegant little volume provides a clear account of two approaches to some of the greatest unsolved problems of gravitation and cosmology. -- John Barrow New Scientist A debate between Hawking and Penrose ... raises the reader's expectations of a lively interaction, and this is fully borne out in the transcribed discussion... Hawking's effervescent sense of humour frequently enlivens the text. -- Joseph Silk The Times Higher Education Supplement If there were such a thing as the World Professional Heavyweight Theory Debating Society, this would be the title bout. -- Christopher Dornan Toronto Globe & Mail This is an interesting book to read now, but it promises to become an even more interesting book for future generations of physicists. -- Robert M. Wald Science I found great satisfaction and not inconsiderable benefit from my efforts... The clarity and brilliance of Hawking's logic would break through in simple straightforward terms... This provided a real thrill. -- Lucy Horwitz Boston Book Review As well as providing an accurate scientific record of the lectures, the text has lost none of the drama of the original occasion, which stemmed from the almost antithetical views of the two protagonists on almost everything except the classical theory of general relativity. -- Gary Gibbons Physics World This is a very courteous and intellectually stimulating exchange between two first-rate minds. Library Journal

Customer Reviews

A possibly interesting debate, spoilt by inaccuracies.
Any popular science book MUST be accurate and not hide serious scientific controversies; if this rule is not followed the book-buying public is being misled. Apart from the elementary, undergraduate level errors in thermodynamics,(e.g. the first law of thermodynamics on page 24 is NOT the first law, nor is it a combination of the first and second laws due to a sign error; the Helmholtz free energy on page 50 is NOT the Helmholtz free energy again due to a sign error),the statement on page 135 that all Einstein needed not to go fishing after 1925 was 'Stephen's discovery, fifty-five years later, of black hole radiation', might be felt by some offensive! Hawking's great surprise, on page 43, that black hole radiation emission was exactly thermal with a temperature derived from the Bekenstein-Hawking expression for black hole entropy in terms of the area of the horizon is dubious because it has to correspond to the entropy of black body radiation, which it doesn't. It should be noted also that, as has been pointed out on several occasions, the above-mentioned Bekenstein-Hawking entropy expression is itself dubious because it leads to possible violations of the second law of thermodynamics. The above are merely examples which certainly raise grave doubts concerning the worth of this book as a serious contribution to popular scientific literature.

Well worth reading
...This book strives to answer "unanswerable" questions, and succeeds admirably. This is NOT a textbook, but fascinating fodder for the intelligent layman. I enjoyed it thoroughly, and would recommend it highly.

Very difficult to read
The introduction to each of the chapters have some very interesting ideas. However, this book would be very difficult for even an intelligent layman who has not had a background in Physics. Therefore, not really for the general reader.