Put Stephen Hawking, Kip Thorne, Igor Novikov, Timothy Ferris and Alan Lightman in a room together, and I would imagine that the intellectual sparks would fly lively and thick. The five essays collected in this book are adapted from those sparks, talks given at the California Institute of Technology in June 2000 to honor the 60th birthday of physicist Kip Thorne.
If there is a unifying theme to the essays, it is the possibility of time travel, one of Thorne's obsessions as a theoretician of general relativity and, of course, a topic of perennial popular interest. None of the authors was paid for his contribution, and royalties will go to a Caltech scholarship fund in Thorne's name.
This article was originally published with the title Riffs on General Relativity.