Ever since Albert Einstein's general theory of relativity burst upon the world in 1915 some of the most brilliant minds of our century have sought to decipher the mysteries bequeathed by that theory, a legacy so unthinkable in some respects that even Einstein himself rejected them. Which of these bizarre phenomena, if any, can really exist in our universe?

Black holes, down which anything can fall but from which nothing can return; wormholes, short spacewarps connecting regions of the cosmos; singularities, where space and time are so violently warped that time ceases to exist and space becomes a kind of foam; gravitational waves, which carry symphonic accounts of collisions of black holes billions of years ago; and time machines, for traveling backward and forward in time.

Kip Thorne, along with fellow theorists Stephen Hawking and Roger Penrose, a cadre of Russians, and earlier scientists such as Oppenheimer, Wheeler and Chandrasekhar, has been in the thick of the quest to secure answers.

n this masterfully written and brilliantly informed work of scientific history and explanation, Dr. Thorne, the Feynman Professor of Theoretical Physics at Caltech, leads his readers through an elegant, always human, tapestry of interlocking themes, coming finally to a uniquely informed answer to the great question: what principles control our universe and why do physicists think they know the things they think they know?

Where the science of black holes, gravitational waves, and time travel will likely lead us, as reported by spacetime's most important theoreticians and observers.

Our minds tell us that some things in the universe must be true. The New Physics tells us that they are not, and in the process, blurs the line between science and science fiction. Here are six accessible essays by those who walk that line, moving ever further out in discovering the patterns of nature, aimed at readers who share their fascination with the deepest mysteries of the universe.

• Richard Price: "An Introduction to Spacetime Physics"
• Stephen Hawking: "Chronology Protection"
• Igor Novikov: "Can We Change the Past?"
• Kip S. Thorne: "Speculations about the Future"
• Timothy Ferris: "On the Popularization of Science"
• Alan Lightman: "The Physicist as Novelist"

"This is story making that lifts the human spirit out of our sometimes petty terrestrial concerns and places us among the stars."—Scientific American

The Euclidean approach to Quantum Gravity was initiated almost 15 years ago in an attempt to understand the difficulties raised by the spacetime singularities of classical general relativity which arise in the gravitational collapse of stars to form black holes and the entire universe in the Big Bang. An important motivation was to develop an approach capable of dealing with the nonlinear, non-perturbative aspects of quantum gravity due to topologically non-trivial spacetimes. There are important links with a Riemannian geometry. Since its inception the theory has been applied to a number of important physical problems including the thermodynamic properties of black holes, quantum cosmology and the problem of the cosmological constant. It is currently at the centre of a great deal of interest.This is a collection of survey lectures and reprints of some important lectures on the Euclidean approach to quantum gravity in which one expresses the Feynman path integral as a sum over Riemannian metrics. As well as papers on the basic formalism there are sections on Black Holes, Quantum Cosmology, Wormholes and Gravitational Instantons.

Cambridge University's Lucasian Professorship of Mathematics is one of the most celebrated academic positions in the world. Since its foundation in 1663, the chair has been held by seventeen men who represent some of the best and most influential minds in science and technology. Principally a social history of mathematics and physics, the story of these great natural philosophers and mathematical physicists is told here by some of the finest historians of science. The journey begins with the search for a benefactor able to establish a 'mathematicus professor honorarius', and travels through the life and work of the professors, exploring aspects from the heroic to the absurd. Covering both the great similarities and the extreme differences in mathematical physics over the last four centuries, this informative work offers interesting perspectives on world-famous scientists including Isaac Newton, Charles Babbage, G. G. Stokes, Paul Dirac and Stephen Hawking.

The Euclidean approach to Quantum Gravity was initiated almost 15 years ago in an attempt to understand the difficulties raised by the spacetime singularities of classical general relativity which arise in the gravitational collapse of stars to form black holes and the entire universe in the Big Bang. An important motivation was to develop an approach capable of dealing with the nonlinear, non-perturbative aspects of quantum gravity due to topologically non-trivial spacetimes. There are important links with a Riemannian geometry. Since its inception the theory has been applied to a number of important physical problems including the thermodynamic properties of black holes, quantum cosmology and the problem of the cosmological constant. It is currently at the centre of a great deal of interest.This is a collection of survey lectures and reprints of some important lectures on the Euclidean approach to quantum gravity in which one expresses the Feynman path integral as a sum over Riemannian metrics. As well as papers on the basic formalism there are sections on Black Holes, Quantum Cosmology, Wormholes and Gravitational Instantons.

This social history of mathematics and physics tells the story of Cambridge University's mathematical physicists. The University's Lucasian Professorship of Mathematics is one of the world's most celebrated academic positions. Since its foundation in 1663, the chair has been held by seventeen men who represent some of the most influential minds in science and technology. This informative work offers new perspectives on such world-famous scientists as Isaac Newton, Charles Babbage, Paul Dirac, and Stephen Hawking.