杏吧原创

SOMETIMES Einstein isn鈥檛 enough. was 8 years old when Einstein died in 1955, and he remembers hearing adults talk in hushed tones about the physicist鈥檚 life, his death and his 鈥渋mpossible dream鈥� of unifying the laws of physics. Kaku was to make it his life鈥檚 goal to carry on the cause. But another figure was needed before Kaku was sold on science. That figure arrived in the form of Flash Gordon鈥檚 Dr Zarkov. 鈥淎s I grew older, I began to realise that, although Flash Gordon was the hero and always got the girl, it was the scientist who made the TV series work,鈥� Kaku writes in Physics of the Impossible. 鈥淲ithout Dr Zarkov there would be no rocket ship, no trips to Mongo, no saving the Earth.鈥� And so a young physicist was born.

Zarkov and Einstein inspired Kaku to great things. 鈥淵ears ago,鈥� Kaku writes, 鈥淚 successfully wrote the theory of strings in terms of the force fields of Faraday, thereby founding string field theory.鈥� That was for Einstein. His latest book is for Dr Zarkov.

We have had The Science of Star Trek, The Science of Harry Potter, The Science of Doctor Who, The Science of Discworld and The Science of the Hitchhiker鈥檚 Guide to the Galaxy, so it was inevitable that someone would roll them all into one book, covering topics such as teleportation, psychokinesis, force fields and perpetual motion machines. But Kaku has a unique selling point: a hierarchy of impossibility.

鈥淜aku鈥檚 unique selling point is a hierarchy of impossibility鈥�

Class I impossible technologies are impossible today but do not defy the laws of physics. Class II impossibilities sit at the very edge of our understanding of the physical world; if possible, they are at least thousands of years off. Class III impossibilities violate the known laws of physics. Interestingly, only two of the 15 technologies Kaku discusses fall into the category of the truly impossible.

The hierarchy hook adds interest, but the genre still has its problems in trying to hang the dead weight of science fact onto the free-flying imagination of science fiction. When J. K. Rowling equipped Harry Potter with an invisibility cloak, she could hardly have imagined a physicist working out that to make Potter invisible would require us 鈥渢o liquefy him, boil him into steam, crystallise him, heat him and then cool him鈥�. With Kaku working so hard to kill Potter, who needs Lord Voldemort?

Not all the facts are so deadening. There is a certain joy in discovering that to wield a hand-held ray gun, you have to power it with the explosion from a hydrogen bomb 鈥� setting your phaser to stun suddenly seems futile. Kaku even tells us how to build that bomb, as it鈥檚 the only way to create the firepower seen in Star Wars鈥� planet-frazzling Death Star.

There is also a more serious side to the book. Wernher von Braun once said, 鈥淚 have learned to use the word 鈥榠mpossible鈥� with the greatest caution.鈥� Kaku cites the 1920s dogma surrounding the 鈥渋mpossibility鈥� of rocket propulsion as an example of how we cry impossible at our peril. The Nazis didn鈥檛 baulk at such impossibilities and rained havoc on London with the V-2 rocket.

The study of the impossible has opened up entirely new vistas for science, Kaku rightly points out. It is here that the book鈥檚 strength lies: the impossible is a gateway for discussing what we still do not quite understand, those grey areas that are surely the most fascinating part of physics. Skipping over the sci-fi plot summaries (which Kaku could have severely cut in number and length with little regret) there is a surprising amount of heavyweight, cutting-edge science woven into the fabric of the book. String theory, dark energy, metamaterials and quantum theory are just a few topics 鈥� Physics of the Impossible is, in fact, an easy-to-read physics primer in disguise. Kaku has a huge reach as a writer and speaker. Hopefully his accessible, entertaining and inspiring book will set the next Einstein on his or her path to glory. Then we鈥檒l have someone else to inspire future generations.