Some have argued that our tendency to think of a single universe demonstrates, like the medieval idea of the Earth being at the centre of the universe, an over-inflated sense of our own importance. Others suggest that, given we really know nothing, Occam’s Razor should keep the single universe theory central until any better evidence comes along. In this fat book, Michio Kaku explores the possibilities that, in universe terms, we are not alone – and ventures into some of the wildest cosmological speculation that billions of years from now, faced with the death of “our” universe, intelligent life may travel to another one.
He starts very well with the WMAP satellite results of 2003, giving a remarkably accurate age for the universe, and with Alan Guth, the inventor of inflation theory, pointing out that if inflation is true, it’s very likely that the universe keeps blowing new bubbles, so different parts of the universe, well out of view, may be suddenly inflating into whole new universes in their own right. We then get the basics that have brought us to inflation, with a whistle-stop tour of Newton, Einstein and friends. Kaku gives us plenty on string theory and M-theory too (not entirely surprising, given his background in this field), and leads us joyfully through the essentials of black holes, wormholes, and all sorts of potential ways to time travel. It’s probably here that the book is at its best – towards the end, when he gets into pure speculation and makes rather pompous remarks about civilization, you realise why scientists rarely make good politicians.
It’s funny that Kaku comments early on how cosmology used to be mostly speculation with very little real science (he quotes “there’s speculation, and then there’s more speculation, and then there’s cosmology”), but new data from sources like WMAP have made it much more solid… when he then spends a lot of the book on exactly those areas of cosmology that are still in that wild and wonderful class. It’s inevitable, though, as data-driven science has only penetrated very small areas of the cosmological minefield.
That isn’t a problem – it’s the way cosmology is – but there are still a couple of concerns. Kaku is a physicist, not a science writer, and has a tendency to do best when he’s talking theories – when he delves into history his versions of what happened can seem like quotes from a children’s encyclopedia and are sometimes of dubious accuracy, like perpetuating the myth that the Earth was thought to be flat in medieval times, or saying that Einstein’s illegitimate first child was called “Lieseral”, where the German girl’s name is “Lieserl” and that’s what everyone else seems to think she was called.
It’s also the case that his explanations of the science, which are admirably simple, are sometimes so simple that they confuse instead of enlightening. Perhaps the best example is where he is describing how Einstein’s version of gravity differs from Newton’s. He rightly says that there was no need for the “magic”, action at a distance (though he never uses that term) attractive pull of gravity, when the effect is generated by the “push” given by the warping of space. But all his explanation does is leave the reader confusedly wondering why a pull is a force, but a push isn’t. Look at this: “To a relativist [..] it is obvious that there is no force at all. [..] Earth moves around the Sun not because of the pull of gravity but because the Sun warps the space around Earth, creating a push that forces Earth to move in a circle.” [My italics.] So relativity shows us there is no force, and that’s what forcing the Earth to move? Hmm.
Perhaps the worst example, combining rather poor writing and strange oversimplification is when Kaku makes the comment that without electromagnetism we would be in darkness, and cites the example of the “blackout of the North East in 2003.” In writing terms this is stunningly parochial – North East what? (Okay, I know what he means, but it’s still highly presumptuous.) And bearing in mind that the sudden disappearance of electromagnetism would not only mean no light, but a rapid fall of heat, no photosynthesis – not to mention that the whole basis of matter depends on electromagnetic exchange. So a blackout would be the least of our worries!
It’s important, thought that you don’t let the negatives get in the way of the fact that this is a very readable book that gives a lucid, simple explanation of strings, m-theory, blackholes and shuch, a great picture of the possibilities for parallel universes, and even some wild speculation on far future lifeboats to another universe. It’s not really a problem overlooking the fact that it’ sometimes let down a little by Kaku’s lack of science writing credentials and tendency to oversimplify. It’s still a fascinating story, largely well told.