This is a wonderful, nonmathematical introduction to special and general relativity. Gardner is a talented popularizer, and the two-color illustrations help make this an enjoyable book to read. My only misgiving is that the book is getting out of date on many topics. Ch. 1-6 are fine, but ch. 7, Tests of Relativity, is sorely in need of updating, and ch. 10-12, on cosmology, predate the recent revolution that has made cosmology a high-precision science and revealed that the universe is even stranger than we thought. I would like to see Gardner hand off this book to another writer who can produce a new, up to date edition.