Exclusive Interview

Michio Kaku:

Imagining the impossible

By Kulvinder Singh Chadha
Posted: May 14, 2008

Michio Kaku is professor of theoretical physics at City College New York. He is a best-selling author and TV presenter. Two of his most recent programs were shown on BBC Four and his latest book Physics of the Impossible (Allan Lane, ISBN 9780713999921) is on sale now. Astronomy Now's Kulvinder Singh Chadha talks to the man who dreams about the impossible. Image: Andrea Brizzi.

What is the appeal of physics, and theoretical physics in particular?
Physics, and particularly theoretical physics allows you to answer some of the deepest questions about space and time. Is time travel possible? Are there gateways to other universes? What happened before the instant of the big bang? How was the Universe created and how will it die? These are cosmic questions and the only way to answer them is with theoretical physics, using the work of Einstein, and quantum theory. These are the two main foundations of physical reality. This is fun business; we get to answer all these questions.

In layman’s terms, what is string field theory and how does it relate to the Universe?
String theory says that all matter, everything we see around us is nothing but vibrations in tiny strings. When I entered the field around 1970, it was a huge collection of formulas that seemed to have no rhyme or reason. There was no unifying equation for the whole theory. That’s string field theory; that’s my creation. String field theory allows you to summarise all of string theory into an equation around an inch long. And that was one of the goals of Einstein, to create the simplest possible equations that will describe the Universe. Now we think there are membranes that exist along with strings, so we have to find yet another higher theory. But string theory can be summarised by my equation.

In your books you say you built machines in your youth. What were they and did they work?
Basically I wanted to play about with antimatter. So, I took photographs of antimatter and I wanted to build a machine that could make a beam of it. So I had to build what’s called a betatron, which is a type of particle accelerator. I went to the national science fair with my creation and I immediately attracted the attention of physicist Edward Teller (known as the father of the hydrogen bomb). He immediately knew what I was doing, and he offered me a scholarship to go to Harvard. And that began my career as a physicist.

You are known for being a futurist, but is there any current technology or discovery that amazes you?
Years ago when I first started to study theoretical physics, the whole concept of a time machine was considered rather ridiculous. But now we physicists have changed our minds and now it’s fair game. There are scores of papers with blueprints, detailing how a time machine might be built. However I caution that the energy required to bend time into the desired shape is equivalent to that of a black hole. So, do not expect anyone to announce anytime soon that they’ve built a porthole that can take you to the past, or even another galaxy. They may or may not be possible, but they are certainly fantastic. But again it could be just an engineering problem. Astonishing as it may sound there appears to be no law of physics that would prevent time travel. Stephen Hawking once thought that time machines could not exist because, where are the tourists from the future? And to that I would say, maybe they’re invisible! It seems that we are going to have invisibility fairly soon, so that may the case with them. Or they could be so advanced that we would be like ants to them, so maybe they wouldn’t be interested in us.

Following on from that, if you had a once-in-a-lifetime opportunity to travel in time (past or future), where would you go and why?
Well two places; I often wondered about creation at the point of the big bang, but I’ve often also wondered about the future of civilisation. We are at the cusp of becoming what is known as a type I civilisation [on the Kardashev scale, a civilisation advanced enough to harness all the available energy on a single planet] — a planetary civilisation. And I would love to go maybe a hundred years into the future to see whether or not we safely made the transition to type I. English would be the language of this future civilisation, the Internet would be its telephone system and we already see huge trade blocks developing (such as the European Union). That’s the beginning of a type I economy, but we already have the beginnings of a type I culture. We even have a backlash against this emerging culture, in the form of terrorism. Terrorists instinctively know that we’re heading towards a scientific, progressive, planetary civilisation and they would rather not be part of a multicultural, tolerant society. They would rather be in a type minus I civilisation.

Is there any major advance you’re personally looking forward to in your lifetime?
I think if you were to look at some of the things coming along in the next ten, twenty, thirty years, one of them would be longevity. That is, being able to zero in on the mechanics of the aging process. And our descendants may have the option of becoming part cyborg [cybernetic organism — an organism that utilises biological and artificial parts] and part genetically modified. And at some point they may even become immortal. Now this is not for us, of course, but it is conceivable that our descendants will have a choice. One would be to die normally and the other one would be to live forever, being enhanced genetically, or with artificial parts. That may sound repulsive to some, but if the choice existed between dying and being immortal I imagine some people would choose immortality.

So if you yourself had to have bionic implants, would you enhance one of your senses or add new ones? Would you change any of your physical characteristics?
Well we’re doing that right now with stroke victims who are totally paralysed. We can put a chip in their brain, hook it up to a laptop, train them to move the cursor on the screen [by just thinking about it], and these people who are unable to communicate due to their paralysis can answer and write e-mails, play video games and surf the web. So this is a medical breakthrough. We can now actually access the minds of people who are paralysed. And think of what we can do with this. Perhaps one day someone like Stephen Hawking (who can only move his eyes) could be directly connected to a computer. And this is the beginning of a new way of interacting with our machines. One day even non-paralysed people may have a microscopic implant that could, say, allow them to surf the web by thinking.

You clearly relish communicating science to the public at large, but what advice would you give to the next generation of scientists — physicists, cosmologists and engineers?
Well you know, we’re all born scientists. We’re all born wondering about the stars and the Universe, but then it’s crushed out of us by the time we’re sixteen, seventeen, and eighteen. And this is very dangerous. The world is getting more technological, not less, and yet fewer and fewer young people are choosing the hard sciences [i.e. physics, chemistry, maths, engineering, etc]. I think it’s dangerous for a modern, industrial society that relies so much on technology to have a public that is not scientifically literate. The United States, for example, has one of the worst educational systems with regards to science. Its students are regularly placed below that of third world countries. That’s why I say it’s up to scientists to engage the public (even though we’re perfectly content just to do research in the laboratory). But sooner or later it’s going to bite back because eventually the taxpayer won’t know what we do any more and they may refuse to fund us. So I think it’s very important that we as scientists engage the public. We can’t be aloof and not think it’s part of our duty.

What are you currently working on at the moment? Is there another book or TV programme in the pipeline?
Not right now. Actually what I’m doing now scientifically is trying to complete string theory; the theory’s not in its final form and I want to help complete it. We don’t yet have that equation that could summarise all of membranes and all of strings. And I think that’s where the most interesting area of research is currently.