Australasian Science: Australia's authority on science since 1938

Big Bang Theory

Michio Kaku

This month Kaku is bringing his stage talks to Australia in a series of “fireside chats” followed by questions and answers in Sydney, Melbourne and Brisbane.

By Stephen Luntz

String theory inventor Michio Kaku talks to Australasian Science about the recent discovery of gravitational waves, the search for parallel universes and a unified theory of everything.

Professor Michio Kaku’s specialisation as a physicist was in string theory, one of the areas of science that the general public finds hardest to fathom. So there is a certain irony in the fact that Kaku now helps millions of people understand every scientific field through radio, documentaries and books.

When Kaku was a child he learned that Einstein had died with a manuscript unfinished. Deciding that his life’s ambition was to finish that work, Kaku went to his local library to find out more about what Einstein had been working on. “There was nothing written for kids,” Kaku says. “Later on I decided I wanted to write books for myself as a child.”

Kaku’s latest book, The Future of the Mind, was number one on the New York Times non-fiction bestseller list when Australasian Science interviewed him. While a book on the mind seems a long way from Einstein’s attempt to unite the four forces of nature, Kaku reveals he was also fascinated by telepathy and telekinesis as a child and spent hours trying to move objects with his thoughts. “I decided it was impossible, but now as a physicist I realise we can read minds, move things with the mind,” he says.

Such control currently requires bulky EEG machines and awkward robotics – not quite the smooth control of remote objects we think of as telekinesis. Nevertheless it is a start – and a lifeline of hope for people hampered with disabilities.

Kaku’s vision of technologies of the mind remains controversial. Reviewing the book in The New York Times, Adam Frank wrote: “For Kaku, the brain is a computer made of meat, and understanding the mind is just a really, really hard engineering problem. The fundamental laws are already known, and Kaku tells us we’ll soon be manipulating the stuff of consciousness with the same acuity we push electrons around in our digital devices.”

Still, even those with different perspectives on the big questions of science hail Kaku’s capacity to both excite and explain. Despite Frank’s reservations, other reviewers have been overwhelmingly positive and dubbed Kaku “the next Carl Sagan”.

Taking a Stand

Kaku is far from a mere fanboy of technology. In 1997 he was the most prominent figure in a campaign opposing the launch of the Cassini spacecraft to Saturn. He argued that the payload of 33 kg of plutonium was too dangerous, and that an explosion during the launch phase or a disaster during the subsequent fly-by could have spread radioactive elements across a vast area of the planet.

After the enormous, and ongoing, success of the Cassini mission, Kaku says his view is “exactly the same as it was years ago. I think the people who opposed the mission were successful in getting NASA to scale back plans. People in NASA tell me that when they talk about shooting things into space they say they’ve ‘gotta minimise’ what is being sent. I think we were lucky.

“The chances were that it would be a success. Nevertheless, the odds were not good enough. If there had been an explosion it would have been the end of the space program. The backlash would have killed it. We had to modify the space program to save it or people would have seen NASA as reckless space jockeys.

“I would congratulate the people who worked on the mission. They did a great job and we learned a lot, but the bottom line is we should not be sending up so much dangerous material.”

Cassini was hardly the first time Kaku has ventured into controversial territory, nor is he a stranger to taking on scientific friends in the process. In the 1970s he campaigned against nuclear weapons, and he is an ongoing critic of nuclear power, calling it a “Faustian bargain”.

Kaku is far more in step with his colleagues in his vocal stance on the need for a safe climate. He has called it “the 800 pound gorilla that the media dances around, but in the scientific community it’s a settled question”. As the public is not adequately informed, Kaku worries that “people don’t plan for the future”.

Kaku’s research field may be unrelated, but his public profile has made him a spokesperson for scientists unwilling to be silenced. Some scientists feel as though their public contributions on this issue are lost in the welter of misinformation and half-truths, but Kaku says: “I think we are making a difference.”

An Early Quest for Anti-Matter

One of the foremost advocates of both atomic power and nuclear bombs was the physicist Edward Teller, who spotted Kaku’s talent and awarded him a scholarship to Harvard after he created a particle accelerator for a science fair project during high school. Later he decided to dream large and build a machine capable of smashing particles together so hard it would produce antimatter.

Kaku recalls asking his mother: “Mom, can I have permission to build a 2.3 million volt atom smasher betatronic accelerator in my garage?” And she kind of stared at me and said: ‘An atom smasher in the garage? I mean, sure. Why not? And don’t forget to take out the garbage.’”

The betatron accelerates electrons within a vacuum tube. It works on the same principles as transformers, using two sets of wires wound around the same magnetic core. Transformers step voltage up or down, but have the electrons circulating within the wires. In a betatron the high voltage particles travel in a vacuum and can focus electrons onto a metal plate where their collisions will produce high energy X-rays or gamma rays.

Having taken out the garbage, Kaku bought 200 kg of steel and 35 km of copper wire. He wound the wire around the goalposts of the school’s football oval and plugged the system into his home’s electric powerpoints. Unsurprisingly, the experiment blew every circuit in the house.

This experience could have made Kaku change paths had his science fair project not prompted Teller to award him the Hertz Engineering Scholarship at Harvard. After graduating and then completing a PhD at the Berkeley Radiation Laboratory, Kaku spent 2 years in the US Army. “I realised I was too narrow – there is a larger world out there. Unless you say something, others will make decisions for you, so I decided I should make public statements, including on how science is driving the wealth around us.”

Once again Kaku takes Einstein as his role model. “The Nazis put a price on his head, put out a picture of him reading “not yet hanged”, but it didn’t silence him. It made him speak out more for what he believed in.”

The end of the Vietnam War saved Kaku from seeing active service, and he took up a position at Princeton and subsequently New York University and City College New York. He published more than 70 peer-reviewed papers on supergravity, supersymetery and particle physics.

String Theory and Gravity Waves

By far Kaku’s greatest influence as a scientist, rather than communicator, has been on string theory. In 1974 he co-wrote the first papers on string field theory, in which the language of quantum field theory is used to describe the way relativistic strings move.

String theory – the idea that subatomic particles behave not like points but like one-dimensional objects – was once dismissed for being impossible to test experimentally, and therefore not meeting the definition of true science. However, the same was said of gravitational waves – after raising the concept as part of the General Theory of Relativity, Einstein doubted we would ever have the technology to detect them. However, in March this year the Harvard-Smithsonian Centre for Astrophysics (HSA) stunned the world with the announcement that the cosmic background radiation left over from the universe’s formation is polarised in a manner reflecting the influence of gravitational waves.

A gravitational wave that could cause such substantial polarisation would be consistent with the upper end of “inflationary” theories, where the universe’s rate of expansion dramatically accelerated fractions of a second after it formed. The HSA team hailed the discovery as proof of inflation, but other researchers have since suggested that gravitational waves from different sources could be responsible.

String theory remains one possibility to provide the “theory of everything” explaining how the four fundamental forces of the universe combine. This was Einstein’s unfinished project that intrigued Kaku as a child.

While string theory is generally considered the best possibility for a theory of everything, it is far from confirmed. Kaku is understandably cheering it on, however, and sees the HSA announcement as a big win for his team.

“Inflation theory tells us what happened, but it does not tell us what was the match, the spark, that set off inflation – just that it happened,” Kaku says. “We need a higher theory for why. The leading candidate for that is string theory. It naturally gives you an inflationary big bang and naturally gives you a multiverse.”

As the name suggests, multiverse theory holds that the universe we can see is just one of many, with other universes possibly having different laws of physics and values for constants such as the speed of light.

“We now believe there are other bubbles out there representing other parallel universes,” Kaku says. “These bubbles can collide or peel off others. We think the Big Bang is either the collision of two bubbles or the splitting off of a new one. We hope to eventually prove this using gravitational waves. We hope that LISA [the proposed Laser Interferometer Space Antenna] will give us the baby pictures of the universe, and this might give evidence connecting our baby universe to a parent.

“It took us 98 years to find what Einstein predicted. Optical telescopes opened up the universe through light to us, then radio. The third great instrument is gravity telescopes that should allow us to peer into the heart of black holes and the Big Bang.”

For Kaku, there is no danger of running out of things to learn.

A Fireside Chat

This month Kaku is bringing his stage talks to Australia in a series of “fireside chats” followed by questions and answers in Sydney, Melbourne and Brisbane. How will he condense his many interests into one evening?

“Put simply,” he says, “I will talk about the future. I have the privilege of being able to access the world’s top scientists. These are the people who are inventing the future – robots, biotechnology, space travel. I want to convey the excitement, the authenticity of what they are doing.

“Science is the engine of prosperity. Our wealth today comes from quantum mechanics, which made the transistor and the laser possible. I’ll talk about how science will generate wealth.”

Kaku’s vision of wealth is far broader than simple economic statements. It includes the wealth of knowledge about our universe, and the richness that comes with this understanding.

Professor Michio Kaku is appearing in Brisbane, Melbourne and Sydney from 5–7 June. To book tickets see