What Is Relativity? is a well-written and uniquely readable book that beautifully serves as an introduction to special and general relativity. Jeffrey Bennett carefully avoids bombastic statements and 'spectacularization' of the subject, sticking with well-established facts and presenting them in a clear and compelling manner.--Alberto Nicolis, Columbia University
Since it first appeared more than a decade ago, I have used Cosmic Perspectives by Jeffrey Bennett and his colleagues in no small part because of the excellence of its chapters on relativity. It is wonderful to now have a stand-alone volume in which his lucid, explanatory text and figures are coupled with a thoughtful commentary on why relativity is important in constructing our scientific and personal views of space and time.--David J. Helfand, President, American Astronomical Society, and President and Vice Chancellor, Quest University Canada
I have read lots of introductions to relativity, but none is as clear and compelling as this one. For anyone who is keen to grasp the fundamentally simple yet non-intuitive ideas of both special and general relativity, Jeffrey Bennett's book is the way to go. Impressively understandable and interesting.--Seth Shostak, Senior Astronomer, SETI Institute
...Bennett's fun book shows readers what relativity means, and what it reveals about our universe.--Publishers Weekly
For in its relatively few pages, Bennett explains relativity to ordinary readers... An impressively accessible distillation of epoch-making science.--Booklist (starred review)
A sober, comprehensible account of what every intelligent layman should know about space and time.--Kirkus Reviews
... [P]erhaps the best homage that anyone can pay to [Einstein] for such a groundbreaking contribution to physics in particular and science in general.--BrainDrain
Bennett... has written an entertaining, brilliant introduction to Einstein's ideas... that is impressively understandable.--CHOICE