The Large, the Small and the Human Mind

Born in England, the son of a geneticist, Roger Penrose received a Ph.D. in 1957 from Cambridge University. Penrose then became a professor of applied mathematics at Birkbeck College in 1966 and a Rouse Ball Professor of Mathematics at Oxford University in 1973. Penrose, a mathematician and theoretical physicist, has done much to elucidate the fundamental properties of black holes. With Stephen Hawking, Penrose proved a theorem of Albert Einstein's general relativity, asserting that at the center of a black hole there must evolve a "space-time singularity" of zero volume and infinite density, in which the current laws of physics do not apply. He also proposed the hypothesis of "cosmic censorship," which claims that such singularities must possess an event horizon. In 1969 Penrose described a process for the extraction of energy from a black hole, as well as how rotational energy of the black hole is transferred to a particle outside the hole. In addition, Penrose has done much to develop the mathematics needed to unite general relativity, which deals with the gravitational interactions of matter, and quantum mechanics, which describes all other interactions.

Shimony is professor emeritus of physics and philosophy at Boston University.

Malcolm Longair is Emeritus Jacksonian Professor of Natural Philosophy and Director of Development at the Cavendish Laboratory, University of Cambridge. He has held many highly distinguished positions within physics and astronomy and has served on and chaired many international committees, boards and panels, working with both NASA and the European Space Agency. He has received much recognition for his work, including the Pilkington Prize of the University of Cambridge for Excellence in Teaching and a CBE in the millennium honours list for his services to astronomy and cosmology. His previous well-received books for Cambridge University Press include Theoretical Concepts in Physics (2003), The Cosmic Century: A History of Astrophysics and Cosmology (2005) and High Energy Astrophysics (2011).

Nancy Cartwright is Professor of Philosophy at the London School of Economics and Political Science and at the University of California, San Diego. Her many publications include The Dappled World (1999).

Stephen William Hawking was born on January 8, 1942 in Oxford, England. As a student at Oxford University, Hawking studied Physics, and after three years was awarded a first class honors degree in Natural Science. After gaining a Ph.D. from Cambridge, Hawking became a Research Fellow, and later on a Professional Fellow at Gonville and Caius College. Widely regarded as one of the greatest theoretical physicists since Einstein, Hawking has held the post as Lucasian Professor of Mathematics at the University of Cambridge since 1979. Most famous for his research on black holes, he has written the books A Brief History of Time and Black Holes and Baby Universes, a collection of essays published in 1993. He also authored the books On the Shoulders of Giants, A Briefer History of Time, The Universe in a Nutshell, and The Grand Design. Hawking is also the author of numerous articles for scientific papers, has 12 honorary degrees and is a Fellow of The Royal Society and a Member of the U.S. National Academy of Sciences. Hawking was diagnosed with Lou Gehrig's disease in his early 20s and is now confined to a wheelchair. He uses a computer device to help him speak. Hawking holds a professorship at the University of Oxford.