An incredibly readable account of the history of theoretical physics and mathematics and the somewhat-recent developments and ideas in the field. Kaku is very lucid and conversational in his approach to writing, which makes the work much more interesting than a rambling exposition which many scientific books become. The book was published in the mid 90s, so some of the ideas are outdated (like the "Big Crunch" theory - ain't gonna happen; and Stephen Hawking's "terminal" case of ALS - apparently it isn't terminal). Anyway Kaku makes the development of multidimensional and quantum theories much more interesting reading than, say, more serious theoretical physicists. Who knows, maybe Michio could kick Richard Feynman's ass in a dual of quantum neutrino blasters (as long as he used charmed quark particles instead of a conventional mix of gluon-meson Gaussians). Well the bottom line is, this is a real page-turner as far as physics books go - the book is not only easy to understand, but fascinating for the average reader, as long as you're willing to engage in a little overly optimistic speculation. So if you're up for science reading with substance, but not as heavy as a teaspoon of a neutron star, this is a great starting point.