By Adam Becker
By Fritz Rohrlich (Syracuse University, New York)
By John Gribbin, Mary Gribbin
By M. Remoissenet
By Michel Remoissenet
By Christophe Galfard
By Bruce A. Schumm (Professor of Physics, University of California, Santa Cruz)
By David Deutsch
By Gleick, James
By Stephen J. Gustafson, Israel Michael Sigal
By Carlo Rovelli
By Max Tegmark
By John Gribbin
By Sean Carroll
By Carlo Rovelli, Erica Segre, Simon Carnell
By Stephen Hawking (University of Cambridge)
By James J. Callahan, Jr.
By Hendrik F. Hameka ( University of Pennsylvania, Berwyn, Pa, USA)
By ARTHUR BEISER
By David Lindley
By George Ellis, Ruth M. Williams
By P. C. W. Davies, D.S. Betts
By Alastair I. M. Rae (University of Birmingham, UK)
By Edward George Steward (Emeritus Professor, City Univ, London, UK)
By Gary Bowman (Department of Physics and Astronomy, Northern Arizona University)
By Andrew Rex, Stephen T. Thornton
By Daniel F. Styer (Oberlin College, Ohio)
By Stephen Thornton, Jerry Marion
By Patricia M. Schwarz, John H. Schwarz (California Institute of Technology)
By French, A. P., Taylor, Edwin F.