Excellent when Kaku focuses on technology, physics or string theory. When he veers onto other topics such as history, education, or culture Kaku produces about one WTF? statement per page. Not only are his opinions on these subjects often totally unsupported by evidence, they occasionally contradict other assertions found a few pages away. Even when Kaku sticks with what he knows, his predictions for the future seem almost laughably optimistic and naive. Every problem has a technological solution that, like a glittery rainbow unicorn, will swoop down to make us happier and wealthier. Never mind that all technologies have dark sides--in one blackly humorous passage Kaku extols the virtues of antimatter as rocket fuel while briefly sweeping over its potential as a global suicide device. By the fiftieth time Kaku used the phrase "In the future," I was thinking: In the future, we'll all have access to drugs as good as the ones Kaku's taking right now.