Physics of the Impossible, By Michio Kaku

Michio Kaku doesn't know the meaning of the word "impossible". Or rather, to be slightly more accurate, he has redefined the term to enable him realistically to examine and predict the future of science and technologies, from teleportation and time travel to robots and starships.

If this sounds like wild speculation, well, that's half right – it's certainly speculative, but it's far from wild. Kaku is well placed to try to imagine what developments might possibly occur in the fields of science and technology over the coming years, centuries, millennia and aeons.

He is an esteemed theoretical physicist and one of the world's leading authorities on string theory (essentially an attempt to discover a "theory of everything" combining all of the known physical forces), and he also specialises in future science, having presented several television programmes on the topic, most recently the BBC4 documentary Visions of the Future.

Handily, for those of us not au fait with the process of speculating on the future of physics, he's split his impossibilities into three categories. Class I impossibilities are technologies which are impossible today, but don't violate the known laws of physics. Kaku reckons that these impossibilities – including things such as teleportation and psychokinesis – might be possible in some reduced form sometime within the next couple of hundred years.

Class II impossibilities such as time machines and hyperspace travel are at the very edge of our scientific understanding, and may take millions of years to become possible. And the trickiest of all, Class III impossibilities, are technologies which break the laws of physics as we know them. Surprisingly, there are very few of these, and Kaku only examines two, perpetual motion machines and precognition (seeing into the future).

If this all sounds like pie in the sky, think again. After all, how would physicists 200 years ago have reacted if you'd told them about the internet, the atomic bomb or the moon landings? What would they have made of Einstein's theory of relativity?

What this book amounts to, in effect, is a serious look at the science behind all the crazy futuristic ideas that have been cropping up in science fiction over the years. Indeed, there are so many references to Star Trek and Star Wars scattered throughout this entertaining journey, that you sometimes wonder if physicists just spend all their time watching old sci-fi re-runs and trying to work out how to recreate the technologies included in them.

That's not to say that Physics of the Impossible is far-fetched. Kaku is very careful to present his cases in terms of recent scientific and technological developments where possible, and for the most part he is a clear and engaging writer, able to tackle some mind-boggling physics concepts in terms which are fairly easy to grasp.

In this respect, he fares better in the earlier chapters, when dealing with his Class I impossibilities. As the book progresses into more and more speculative territory, he is forced to rely less on extrapolating current research and development, and more on purely theoretical physics.

He indulges himself a little when talking about possible time travel and parallel universes, including perhaps a little too much high-end theory for the average reader, but that is a minor fault in what is otherwise a truly fascinating read.

So, what are the chances of force fields, telepathy, sentient robots and teleportation occurring in our lifetimes? Pretty good, but not in the way that Captain Kirk or Han Solo experienced them, that's for sure. Teleportation, for example, is already possible at a quantum level, scientists having successfully transported the information about an atom across a lab instantaneously. It's hugely complex, fraught with problems, and we're still a very, very long way from "Beam me up, Scotty". But the physics does back it up.

Similarly, researchers working on helping paralysed people have had some success in using brain waves to actually manipulate physical objects. Using microchips inserted in the brain, special software and hardware and a process called a biofeedback loop, patients can train their brains to signal for tasks to be performed. Again, this is a million miles from Carrie burning down the school dance in the Stephen King horror film, but it's remarkable nevertheless.

And what about starships? Kaku examines no less than 10 different methods of travelling to the stars, from plasma engines to solar sails, space elevators to nanoships. For many of these ideas, the physics is well known, but there are still colossal problems to overcome in terms of creating suitable technology at a cost which wouldn't cripple the world's economy.

In one sense, this is an intriguing vision of our possible development over the forthcoming millennia, but at the same time it's also frustrating. After reading Kaku's boundless enthusiasm for the future, what you wouldn't give for a real-life time machine to travel forwards and see just how accurate his predictions are.

Doug Johnston's new novel is 'The Ossians' (Viking £12.99)