Mr Parallel Universe: Michio Kaku

There is a contradiction in Professor Michio Kaku's appearance, as if he had been drawn by a composite artist, based on the memories of an unreliable witness. It is to do with the smoothness of his skin being at odds with the silver hair that flows down to his shoulders. The latter reflects his age, 61; the former suggests he is a teenager.

Perhaps he has the face he deserves. There is kindness in his eyes and a smile tugs gently at the corners of his mouth as he talks. His optimism about the future of the human race knows no bounds. He is a deep, deep thinker. His ambition is to crack the elusive ‘theory of everything', one that defeated even Einstein, his mentor of sorts.

Although Kaku is known as a populariser of science — he has authored books such as Hyperspace and Parallel Worlds, and presents programmes such as Time and Visions of the Future for BBC4 — he is very much a practising theoretical physicist. He co-founded field string theory, after all.

We will come to that in a minute. For now it is enough to say that Stephen Hawking believes string theory may hold the key to the theory of everything: that is, to the single equation that unifies the theories of general relativity and gravity with quantum mechanics. This is what the Cern experiment in Switzerland is all about, where physicists are recreating the conditions of the Big Bang in a Super Collider that is 27km in circumference.

Although Kaku is awaiting the results with eagerness, he does wish the experiment had taken place in America. “In 1994, we were going to build one [Super Collider] near Dallas that would have been several times bigger than the one in Switzerland. But we needed to win Congress over to get $20 billion worth of funding for it. On the last day of the hearings, a Congressman asked one of the physicists if we would find God with our machine. The physicist answered that we would discover the Higgs Boson. Our machine was duly cancelled.''

Picture perfect

How would Kaku have answered the question? “I would have said: ‘This machine will take us as close as is humanly possible to the creation of the universe .... And yes, it may even let us read the mind of God.' I think they would have opened their chequebooks.''

Kaku has a gift for communicating complex scientific ideas in a way that lay people can understand. He argues that good physics should be simple, so simple that it can be understood as an image.

“A good physicist is driven by a childlike fascination and imagination. If we find ourselves getting jaded or bored we have to try to recapture that childishness. Einstein used to do that. He also believed that if a theory couldn't be broadly explained to a child, it wasn't working. He believed that there should be a picture behind the theory. So his special relativity, for example, can be understood as a 16-year-old boy out-racing a light beam.''

So what is the picture guiding Kaku's string theory? Just that. String. Sub-atomic particles composed of tiny vibrating strings. “It is a strange theory that goes way beyond what Einstein was doing. It is so fantastic that some physicists can't get their heads around it and prefer not to work on it. I think Einstein would have got there eventually.''

The importance Kaku places on childishness in theoretical physics extends to science fiction, and this, in part, is the subject of his new book, Physics of the Impossible. It argues that because there is no law of physics preventing the existence of concepts such as time travel, teleportation and invisibility, physics has to take their possibility seriously.

“A lot of this stuff sounds like science fiction,'' he says, “and that is no coincidence because a lot of physicists became interested in their subject through a love of science fiction.''

Does he ever worry that he is devoting too much of his energy to his television work and books and neglecting his serious theoretical calling? “Einstein played the violin. Most physicists I know like mountain climbing. But two of my acquaintances have died mountain climbing, so I prefer to popularise science.''

So it is his hobby? “I also like to figure-skate.''

Kaku was born near San Francisco but his parents were originally from Japan. His father was a trucker and gardener. His mother was a maid. “My parents were poor and hadn't had the benefit of a university education. I realised early on in life that I would have to make it on my own.''

It was the death of Einstein that prompted his interest in physics. “In the news reports they flashed up a picture of Einstein's desk and on it was a manuscript, which was described as his ‘unfinished work'. That was the moment I became hooked. I wanted to finish that work.''

By the time he was 16, Kaku had bought 400 pounds (181.4 kg) of steel and 22 miles of copper wire and built his own atom smasher in the family garage. It was powerful enough to pull fillings out of teeth, but the only thing it smashed was the house. “It broke every fuse and ruined every circuit-breaker,'' he says.

His experiment attracted the attention of the physicist Edward Teller, “the father of the hydrogen bomb''. He took Kaku under his wing and secured a place for him to read physics at Harvard.

Kaku graduated summa cum laude in 1968, pursued a doctorate at Berkeley and then took up a lectureship at Princeton. He later discovered that all Teller's scholarship students were earmarked for the “Star Wars'' programme at Los Alamos.

Kaku was offered a chance to work there, but turned it down. “I've always thought science was about creation, not destruction,'' he says.

He gives examples in his new book of scientists who were so ahead of their time that no one would listen to them; they would become depressed and even suicidal. Is that how he feels sometimes?

“I have felt frustrated sometimes but never depressed. People laughed at us when we discovered in the early Seventies that our strings could only vibrate coherently in [as was thought then] ten-dimensional hyperspace.''

With the taunts of fellow physicists ringing in his ears, Kaku started work on another theory, only to realise he was looking at the same phenomenon, except at a higher vibration on the string. This amounted to proof. The academic world soon stopped laughing.

To achieve in a lifetime

Kaku may well one day achieve immortality through his work, as Einstein did, but he would rather achieve it in the way Woody Allen recommended: by not dying.

Nevertheless, losing his mental faculties is, he says, his greatest fear. “We scientists play in the world of equations. They dance in our heads constantly. If you can't do that, if you no longer have the ability to manipulate equations, you are like a painter who is blind or a musician who is deaf.''

And take this line he has on the future of the planet: It has no future.... It is the law of physics that one day we must leave the Earth or die.

“Yet it need not be a death warrant for all human life. We could escape through a wormhole. Perhaps civilisations billions of years ahead of ours will harness enough energy to punch a hole in space and escape, in a hyper-dimensional space ark, to a new universe.''

I ask if that isn't just as outlandish an idea as life after death. “The difference is we have no mathematics to calculate life after death. No mathematics of God. But we do have a testable mathematics, in principle, about wormholes, though it is all speculation billions of years into the future ... ''

As I listen, I recall where I have read ideas as fanciful as his before: in The Hitchhiker's Guide to the Galaxy. He is a fan, it turns out. Met the author once.

Douglas Adams, of course, imagined a computer that was able to calculate the answer to the question of life, the universe and everything. The answer was 42.

It turned out that the answer on its own was meaningless. What was needed was a proper question .... I think we create our own meaning, and if we do it well, that brings us happiness.

“It is too easy to have a guru on a mountaintop saying the answer is this and this. The meaning of life is to struggle and find your own meaning of life.''