Parallel universes, the Matrix, and superintelligence

June 26, 2003 by Michio Kaku

Physicists are converging on a “theory of everything,” probing the 11th dimension, developing computers for the next generation of robots, and speculating about civilizations millions of years ahead of ours, says Dr. Michio Kaku, author of the best-sellers Hyperspace and Visions and co-founder of String Field Theory, in this interview by Editor Amara D. Angelica.

Published on June 26, 2003.

What are the burning issues for you currently?

Well, several things. Professionally, I work on something called Superstring theory, or now called M-theory, and the goal is to find an equation, perhaps no more than one inch long, which will allow us to "read the mind of God," as Einstein used to say.

In other words, we want a single theory that gives us an elegant, beautiful representation of the forces that govern the Universe. Now, after two thousand years of investigation into the nature of matter, we physicists believe that there are four fundamental forces that govern the Universe.

Some physicists have speculated about the existence of a fifth force, which may be some kind of paranormal or psychic force, but so far we find no reproducible evidence of a fifth force.

Now, each time a force has been mastered, human history has undergone a significant change. In the 1600s, when Isaac Newton first unraveled the secret of gravity, he also created a mechanics. And from Newton’s Laws and his mechanics, the foundation was laid for the steam engine, and eventually the Industrial Revolution.

So, in other words, in some sense, a byproduct of the mastery of the first force, gravity, helped to spur the creation of the Industrial Revolution, which in turn is perhaps one of the greatest revolutions in human history.

The second great force is the electromagnetic force; that is, the force of light, electricity, magnetism, the Internet, computers, transistors, lasers, microwaves, x-rays, etc.

And then in the 1860s, it was James Clerk Maxwell, the Scottish physicist at Cambridge University, who finally wrote down Maxwell’s equations, which allow us to summarize the dynamics of light.

That helped to unleash the Electric Age, and the Information Age, which have changed all of human history. Now it’s hard to believe, but Newton’s equations and Einstein’s equations are no more than about half an inch long.

Maxwell’s equations are also about half an inch long. For example, Maxwell’s equations say that the “four-dimensional divergence of an antisymmetric, second-rank tensor equals zero.” That’s Maxwell’s equations, the equations for light. And in fact, at Berkeley, you can buy a T-shirt which says, "In the beginning, God said the four-dimensional divergence of an antisymmetric, second rank tensor equals zero, and there was Light, and it was good."

So, the mastery of the first two forces helped to unleash, respectively, the Industrial Revolution and the Information Revolution.

The last two forces are the weak nuclear force and the strong nuclear force, and they in turn have helped us to unlock the secret of the stars, via Einstein’s equations E=mc2, and many people think that far in the future, the human race may ultimately derive its energy not only from solar power, which is the power of fusion, but also fusion power on the Earth, in terms of fusion reactors, which operate on seawater, and create no copious quantities of radioactive waste.

So, in summary, the mastery of each force helped to unleash a new revolution in human history.

Today, we physicists are embarking upon the greatest quest of all, which is to unify all four of these forces into a single comprehensive theory. The first force, gravity, is now represented by Einstein’s General Theory of Relativity, which gives us the Big Bang, black holes, and expanding universe. It’s a theory of the very large; it’s a theory of smooth, space-time manifolds like bedsheets and trampoline nets.

The second theory, the quantum theory, is the exact opposite. The quantum theory allows us to unify the electromagnetic, weak and strong force. However, it is based on discrete, tiny packets of energy called quanta, rather than smooth bedsheets, and it is based on probabilities, rather than the certainty of Einstein’s equations. So these two theories summarize the sum total of all physical knowledge of the physical universe.

Any equation describing the physical universe ultimately is derived from one of these two theories. The problem is these two theories are diametrically opposed. They are based on different assumptions, different principles, and different mathematics. Our job as physicists is to unify the two into a single, comprehensive theory. Now, over the last decades, the giants of the twentieth century have tried to do this and have failed.

For example, Niels Bohr, the founder of atomic physics and the quantum theory, was very skeptical about many attempts over the decades to create a Unified Field Theory. One day, Wolfgang Pauli, Nobel laureate, was giving a talk about his version of the Unified Field Theory, and in a very famous story, Bohr stood up in the back of the room and said, "Mr. Pauli, we in the back are convinced that your theory is crazy. What divides us is whether your theory is crazy enough."

So today, we realize that a true Unified Field Theory must be bizarre, must be fantastic, incredible, mind-boggling, crazy, because all the sane alternatives have been studied and discarded.

Today we have string theory, which is based on the idea that the subatomic particles we see in nature are nothing but notes we see on a tiny, vibrating string. If you kick the string, then an electron will turn into a neutrino. If you kick it again, the vibrating string will turn from a neutrino into a photon or a graviton. And if you kick it enough times, the vibrating string will then mutate into all the subatomic particles.

Therefore we no longer in some sense have to deal with thousands of subatomic particles coming from our atom smashers, we just have to realize that what makes them, what drives them, is a vibrating string. Now when these strings collide, they form atoms and nuclei, and so in some sense, the melodies that you can write on the string correspond to the laws of chemistry. Physics is then reduced to the laws of harmony that we can write on a string. The Universe is a symphony of strings. And what is the mind of God that Einstein used to write about? According to this picture, the mind of God is music resonating through ten- or eleven-dimensional hyperspace, which of course begs the question, "If the universe is a symphony, then is there a composer to the symphony?" But that’s another question.

Parallel worlds

What do you think of Sir Martin Rees’ concerns about the risk of creating black holes on Earth in his book, Our Final Hour?

I haven’t read his book, but perhaps Sir Martin Rees is referring to many press reports that claim that the Earth may be swallowed up by a black hole created by our machines. This started with a letter to the editor in Scientific American asking whether the RHIC accelerator in Brookhaven, Long Island, will create a black hole which will swallow up the earth. This was then picked up by the Sunday London Times who then splashed it on the international wire services, and all of a sudden, we physicists were deluged with hundreds of emails and telegrams asking whether or not we are going to destroy the world when we create a black hole in Long Island.

However, you can calculate that in outer space, cosmic rays have more energy than the particles produced in our most powerful atom smashers, and black holes do not form in outer space. Not to mention the fact that to create a black hole, you would have to have the mass of a giant star. In fact, an object ten to fifty times the mass of our star may in fact form a black hole. So the probability of a black hole forming in Long Island is zero.

However, Sir Martin Rees also has written a book, talking about the Multiverse. And that is also the subject of my next book, coming out late next year, called Parallel Worlds. We physicists no longer believe in a Universe. We physicists believe in a Multiverse that resembles the boiling of water. Water boils when tiny particles, or bubbles, form, which then begin to rapidly expand. If our Universe is a bubble in boiling water, then perhaps Big Bangs happen all the time.

Now, the Multiverse idea is consistent with Superstring theory, in the sense that Superstring theory has millions of solutions, each of which seems to correspond to a self-consistent Universe. So in some sense, Superstring theory is drowning in its own riches. Instead of predicting a unique Universe, it seems to allow the possibility of a Multiverse of Universes.

This may also help to answer the question raised by the Anthropic Principle. Our Universe seems to have known that we were coming. The conditions for life are extremely stringent. Life and consciousness can only exist in a very narrow band of physical parameters. For example, if the proton is not stable, then the Universe will collapse into a useless heap of electrons and neutrinos. If the proton were a little bit different in mass, it would decay, and all our DNA molecules would decay along with it.

In fact, there are hundreds, perhaps thousands, of coincidences, happy coincidences, that make life possible. Life, and especially consciousness, is quite fragile. It depends on stable matter, like protons, that exists for billions of years in a stable environment, sufficient to create autocatalytic molecules that can reproduce themselves, and thereby create Life. In physics, it is extremely hard to create this kind of Universe. You have to play with the parameters, you have to juggle the numbers, cook the books, in order to create a Universe which is consistent with Life.

However, the Multiverse idea explains this problem, because it simply means we coexist with dead Universes. In other Universes, the proton is not stable. In other Universes, the Big Bang took place, and then it collapsed rapidly into a Big Crunch, or these Universes had a Big Bang, and immediately went into a Big Freeze, where temperatures were so low, that Life could never get started.

So, in the Multiverse of Universes, many of these Universes are in fact dead, and our Universe in this sense is special, in that Life is possible in this Universe. Now, in religion, we have the Judeo-Christian idea of an instant of time, a genesis, when God said, "Let there be light." But in Buddhism, we have a contradictory philosophy, which says that the Universe is timeless. It had no beginning, and it had no end, it just is. It’s eternal, and it has no beginning or end.

The Multiverse idea allows us to combine these two pictures into a coherent, pleasing picture. It says that in the beginning, there was nothing, nothing but hyperspace, perhaps ten- or eleven-dimensional hyperspace. But hyperspace was unstable, because of the quantum principle. And because of the quantum principle, there were fluctuations, fluctuations in nothing. This means that bubbles began to form in nothing, and these bubbles began to expand rapidly, giving us the Universe. So, in other words, the Judeo-Christian genesis takes place within the Buddhist nirvana, all the time, and our Multiverse percolates universes.

Now this also raises the possibility of Universes that look just like ours, except there’s one quantum difference. Let’s say for example, that a cosmic ray went through Churchill’s mother, and Churchill was never born, as a consequence. In that Universe, which is only one quantum event away from our Universe, England never had a dynamic leader to lead its forces against Hitler, and Hitler was able to overcome England, and in fact conquer the world.

So, we are one quantum event away from Universes that look quite different from ours, and it’s still not clear how we physicists resolve this question. This paradox revolves around the Schrödinger’s Cat problem, which is still largely unsolved. In any quantum theory, we have the possibility that atoms can exist in two places at the same time, in two states at the same time. And then Erwin Schrödinger, the founder of quantum mechanics, asked the question: let’s say we put a cat in a box, and the cat is connected to a jar of poison gas, which is connected to a hammer, which is connected to a Geiger counter, which is connected to uranium. Everyone believes that uranium has to be described by the quantum theory. That’s why we have atomic bombs, in fact. No one disputes this.

But if the uranium decays, triggering the Geiger counter, setting off the hammer, destroying the jar of poison gas, then I might kill the cat. And so, is the cat dead or alive? Believe it or not, we physicists have to superimpose, or add together, the wave function of a dead cat with the wave function of a live cat. So the cat is neither dead nor alive.

This is perhaps one of the deepest questions in all the quantum theory, with Nobel laureates arguing with other Nobel laureates about the meaning of reality itself.

Now, in philosophy, solipsists like Bishop Berkeley used to believe that if a tree fell in the forest and there was no one there to listen to the tree fall, then perhaps the tree did not fall at all. However, Newtonians believe that if a tree falls in the forest, that you don’t have to have a human there to witness the event.

The quantum theory puts a whole new spin on this. The quantum theory says that before you look at the tree, the tree could be in any possible state. It could be burnt, a sapling, it could be firewood, it could be burnt to the ground. It could be in any of an infinite number of possible states. Now, when you look at it, it suddenly springs into existence and becomes a tree.

Einstein never liked this. When people used to come to his house, he used to ask them, "Look at the moon. Does the moon exist because a mouse looks at the moon?" Well, in some sense, yes. According to the Copenhagen school of Neils Bohr, observation determines existence.

Now, there are at least two ways to resolve this. The first is the Wigner school. Eugene Wigner was one of the creators of the atomic bomb and a Nobel laureate. And he believed that observation creates the Universe. An infinite sequence of observations is necessary to create the Universe, and in fact, maybe there’s a cosmic observer, a God of some sort, that makes the Universe spring into existence.

There’s another theory, however, called decoherence, or many worlds, which believes that the Universe simply splits each time, so that we live in a world where the cat is alive, but there’s an equal world where the cat is dead. In that world, they have people, they react normally, they think that their world is the only world, but in that world, the cat is dead. And, in fact, we exist simultaneously with that world.

This means that there’s probably a Universe where you were never born, but everything else is the same. Or perhaps your mother had extra brothers and sisters for you, in which case your family is much larger. Now, this can be compared to sitting in a room, listening to radio. When you listen to radio, you hear many frequencies. They exist simultaneously all around you in the room. However, your radio is only tuned to one frequency. In the same way, in your living room, there is the wave function of dinosaurs. There is the wave function of aliens from outer space. There is the wave function of the Roman Empire, because it never fell, 1500 years ago.

All of this coexists inside your living room. However, just like you can only tune into one radio channel, you can only tune into one reality channel, and that is the channel that you exist in. So, in some sense it is true that we coexist with all possible universes. The catch is, we cannot communicate with them, we cannot enter these universes.

However, I personally believe that at some point in the future, that may be our only salvation. The latest cosmological data indicates that the Universe is accelerating, not slowing down, which means the Universe will eventually hit a Big Freeze, trillions of years from now, when temperatures are so low that it will be impossible to have any intelligent being survive.

When the Universe dies, there’s one and only one way to survive in a freezing Universe, and that is to leave the Universe. In evolution, there is a law of biology that says if the environment becomes hostile, either you adapt, you leave, or you die.

When the Universe freezes and temperatures reach near absolute zero, you cannot adapt. The laws of thermodynamics are quite rigid on this question. Either you will die, or you will leave. This means, of course, that we have to create machines that will allow us to enter eleven-dimensional hyperspace. This is still quite speculative, but String theory, in some sense, may be our only salvation. For advanced civilizations in outer space, either we leave or we die.

That brings up a question. Matrix Reloaded seems to be based on parallel universes. What do you think of the film in terms of its metaphors?

Well, the technology found in the Matrix would correspond to that of an advanced Type I or Type II civilization. We physicists, when we scan outer space, do not look for little green men in flying saucers. We look for the total energy outputs of a civilization in outer space, with a characteristic frequency. Even if intelligent beings tried to hide their existence, by the second law of thermodynamics, they create entropy, which should be visible with our detectors.

So we classify civilizations on the basis of energy outputs. A Type I civilization is planetary. They control all planetary forms of energy. They would control, for example, the weather, volcanoes, earthquakes; they would mine the oceans, any planetary form of energy they would control. Type II would be stellar. They play with solar flares. They can move stars, ignite stars, play with white dwarfs. Type III is galactic, in the sense that they have now conquered whole star systems, and are able to use black holes and star clusters for their energy supplies.

Each civilization is separated by the previous civilization by a factor of ten billion. Therefore, you can calculate numerically at what point civilizations may begin to harness certain kinds of technologies. In order to access wormholes and parallel universes, you have to be probably a Type III civilization, because by definition, a Type III civilization has enough energy to play with the Planck energy.

The Planck energy, or 1019 billion electron volts, is the energy at which space-time becomes unstable. If you were to heat up, in your microwave oven, a piece of space-time to that energy, then bubbles would form inside your microwave oven, and each bubble in turn would correspond to a baby Universe.

Now, in the Matrix, several metaphors are raised. One metaphor is whether computing machines can create artificial realities. That would require a civilization centuries or millennia ahead of ours, which would place it squarely as a Type I or Type II civilization.

However, we also have to ask a practical question: is it possible to create implants that could access our memory banks to create this artificial reality, and are machines dangerous? My answer is the following. First of all, cyborgs with neural implants: the technology does not exist, and probably won’t exist for at least a century, for us to access the central nervous system. At present, we can only do primitive experiments on the brain.

For example, at Emory University in Atlanta, Georgia, it’s possible to put a glass implant into the brain of a stroke victim, and the paralyzed stroke victim is able to, by looking at the cursor of a laptop, eventually control the motion of the cursor. It’s very slow and tedious; it’s like learning to ride a bicycle for the first time. But the brain grows into the glass bead, which is placed into the brain. The glass bead is connected to a laptop computer, and over many hours, the person is able to, by pure thought, manipulate the cursor on the screen.

So, the central nervous system is basically a black box. Except for some primitive hookups to the visual system of the brain, we scientists have not been able to access most bodily functions, because we simply don’t know the code for the spinal cord and for the brain. So, neural implant technology, I believe is one hundred, maybe centuries away from ours.

Will robots take over?

On the other hand, we have to ask yet another metaphor raised by the Matrix, and that is, are machines dangerous? And the answer is, potentially, yes. However, at present, our robots have the intelligence of a cockroach, in the sense that pattern recognition and common sense are the two most difficult, unsolved problems in artificial intelligence theory. Pattern recognition means the ability to see, hear, and to understand what you are seeing and understand what you are hearing. Common sense means your ability to make sense out of the world, which even children can perform.

Those two problems are at the present time largely unsolved. Now, I think, however, that within a few decades, we should be able to create robots as smart as mice, maybe dogs and cats. However, when machines start to become as dangerous as monkeys, I think we should put a chip in their brain, to shut them off when they start to have murderous thoughts.

By the time you have monkey intelligence, you begin to have self-awareness, and with self-awareness, you begin to have an agenda created by a monkey for its own purposes. And at that point, a mechanical monkey may decide that its agenda is different from our agenda, and at that point they may become dangerous to humans. I think we have several decades before that happens, and Moore’s Law will probably collapse in 20 years anyway, so I think there’s plenty of time before we come to the point where we have to deal with murderous robots, like in the movie 2001.

So you differ with Ray Kurzweil’s concept of using nanobots to reverse-engineer and upload the brain, possibly within the coming decades?

Not necessarily. I’m just laying out a linear course, the trajectory where artificial intelligence theory is going today. And that is, trying to build machines which can navigate and roam in our world, and two, robots which can make sense out of the world. However, there’s another divergent path one might take, and that’s to harness the power of nanotechnology. However, nanotechnology is still very primitive. At the present time, we can barely build arrays of atoms. We cannot yet build the first atomic gear, for example. No one has created an atomic wheel with ball bearings. So simple machines, which even children can play with in their toy sets, don’t yet exist at the atomic level. However, on a scale of decades, we may be able to create atomic devices that begin to mimic our own devices.

Molecular transistors can already be made. Nanotubes allow us to create strands of material that are super-strong. However, nanotechnology is still in its infancy and therefore, it’s still premature to say where nanotechnology will go. However, one place where technology may go is inside our body. Already, it’s possible to create a pill the size of an aspirin pill that has a television camera that can photograph our insides as it goes down our gullet, which means that one day surgery may become relatively obsolete.

In the future, it’s conceivable we may have atomic machines that enter the blood. And these atomic machines will be the size of blood cells and perhaps they would be able to perform useful functions like regulating and sensing our health, and perhaps zapping cancer cells and viruses in the process. However, this is still science fiction, because at the present time, we can’t even build simple atomic machines yet.

Are we living in a simulation?

Is there any possibility, similar to the premise of The Matrix, that we are living in a simulation?

Well, philosophically speaking, it’s always possible that the universe is a dream, and it’s always possible that our conversation with our friends is a by-product of the pickle that we had last night that upset our stomach. However, science is based upon reproducible evidence. When we go to sleep and we wake up the next day, we usually wind up in the same universe. It is reproducible. No matter how we try to avoid certain unpleasant situations, they come back to us. That is reproducible. So reality, as we commonly believe it to exist, is a reproducible experiment, it’s a reproducible sensation. Therefore in principle, you could never rule out the fact that the world could be a dream, but the fact of the matter is, the universe as it exists is a reproducible universe.

Now, in the Matrix, a computer simulation was run so that virtual reality became reproducible. Every time you woke up, you woke up in that same virtual reality. That technology, of course, does not violate the laws of physics. There’s nothing in relativity or the quantum theory that says that the Matrix is not possible. However, the amount of computer power necessary to drive the universe and the technology necessary for a neural implant is centuries to millennia beyond anything that we can conceive of, and therefore this is something for an advanced Type I or II civilization.

Why is a Type I required to run this kind of simulation? Is number crunching the problem?

Yes, it’s simply a matter of number crunching. At the present time, we scientists simply do not know how to interface with the brain. You see, one of the problems is, the brain, strictly speaking, is not a digital computer at all. The brain is not a Turing machine. A Turing machine is a black box with an input tape and an output tape and a central processing unit. That is the essential element of a Turing machine: information processing is localized in one point. However, our brain is actually a learning machine; it’s a neural network.

Many people find this hard to believe, but there’s no software, there is no operating system, there is no Windows programming for the brain. The brain is a vast collection, perhaps a hundred billion neurons, each neuron with 10,000 connections, which slowly and painfully interacts with the environment. Some neural pathways are genetically programmed to give us instinct. However, for the most part, our cerebral cortex has to be reprogrammed every time we bump into reality.

As a consequence, we cannot simply put a chip in our brain that augments our memory and enhances our intelligence. Memory and thinking, we now realize, is distributed throughout the entire brain. For example, it’s possible to have people with only half a brain. There was a documented case recently where a young girl had half her brain removed and she’s still fully functional.

So, the brain can operate with half of its mass removed. However, you remove one transistor in your Pentium computer and the whole computer dies. So, there’s a fundamental difference between digital computers–which are easily programmed, which are modular, and you can insert different kinds of subroutines in them–and neural networks, where learning is distributed throughout the entire device, making it extremely difficult to reprogram. That is the reason why, even if we could create an advanced PlayStation that would run simulations on a PC screen, that software cannot simply be injected into the human brain, because the brain has no operating system.

Ray Kurzweil’s next book, The Singularity is Near, predicts that possibly within the coming decades, there will be super-intelligence emerging on the planet that will surpass that of humans. What do you think of that idea?

Yes, that sounds interesting. But Moore’s Law will have collapsed by then, so we’ll have a little breather. In 20 years time, the quantum theory takes over, so Moore’s Law collapses and we’ll probably stagnate for a few decades after that. Moore’s Law, which states that computer power doubles every 18 months, will not last forever. The quantum theory giveth, the quantum theory taketh away. The quantum theory makes possible transistors, which can be etched by ultraviolet rays onto smaller and smaller chips of silicon. This process will end in about 15 to 20 years. The senior engineers at Intel now admit for the first time that, yes, they are facing the end.

The thinnest layer on a Pentium chip consists of about 20 atoms. When we start to hit five atoms in the thinnest layer of a Pentium chip, the quantum theory takes over, electrons can now tunnel outside the layer, and the Pentium chip short-circuits. Therefore, within a 15 to 20 year time frame, Moore’s Law could collapse, and Silicon Valley could become a Rust Belt.

This means that we physicists are desperately trying to create the architecture for the post-silicon era. This means using quantum computers, quantum dot computers, optical computers, DNA computers, atomic computers, molecular computers, in order to bridge the gap when Moore’s Law collapses in 15 to 20 years. The wealth of nations depends upon the technology that will replace the power of silicon.

This also means that you cannot project artificial intelligence exponentially into the future. Some people think that Moore’s Law will extend forever; in which case humans will be reduced to zoo animals and our robot creations will throw peanuts at us and make us dance behind bars. Now, that may eventually happen. It is certainly consistent within the laws of physics.

However, the laws of the quantum theory say that we’re going to face a massive problem 15 to 20 years from now. Now, some remedial methods have been proposed; for example, building cubical chips, chips that are stacked on chips to create a 3-dimensional array. However, the problem there is heat production. Tremendous quantities of heat are produced by cubical chips, such that you can fry an egg on top of a cubical chip. Therefore, I firmly believe that we may be able to squeeze a few more years out of Moore’s Law, perhaps designing clever cubical chips that are super-cooled, perhaps using x-rays to etch our chips instead of ultraviolet rays. However, that only delays the inevitable. Sooner or later, the quantum theory kills you. Sooner or later, when we hit five atoms, we don’t know where the electron is anymore, and we have to go to the next generation, which relies on the quantum theory and atoms and molecules.

Therefore, I say that all bets are off in terms of projecting machine intelligence beyond a 20-year time frame. There’s nothing in the laws of physics that says that computers cannot exceed human intelligence. All I raise is that we physicists are desperately trying to patch up Moore’s Law, and at the present time we have to admit that we have no successor to silicon, which means that Moore’s Law will collapse in 15 to 20 years.

So are you saying that quantum computing and nanocomputing are not likely to be available by then?

No, no, I’m just saying it’s very difficult. At the present time we physicists have been able to compute on seven atoms. That is the world’s record for a quantum computer. And that quantum computer was able to calculate 3 x 5 = 15. Now, being able to calculate 3 x 5 = 15 does not equal the convenience of a laptop computer that can crunch potentially millions of calculations per second. The problem with quantum computers is that any contamination, any atomic disturbance, disturbs the alignment of the atoms and the atoms then collapse into randomness. This is extremely difficult, because any cosmic ray, any air molecule, any disturbance can conceivably destroy the coherence of our atomic computer to make them useless.

Unless you have redundant parallel computing?

Even if you have parallel computing you still have to have each parallel computer component free of any disturbance. So, no matter how you cut it, the practical problems of building quantum computers, although within the laws of physics, are extremely difficult, because it requires that we remove all in contact with the environment at the atomic level. In practice, we’ve only been able to do this with a handful of atoms, meaning that quantum computers are still a gleam in the eye of most physicists.

Now, if a quantum computer can be successfully built, it would, of course, scare the CIA and all the governments of the world, because it would be able to crack any code created by a Turing machine. A quantum computer would be able to perform calculations that are inconceivable by a Turing machine. Calculations that require an infinite amount of time on a Turing machine can be calculated in a few seconds by a quantum computer. For example, if you shine laser beams on a collection of coherent atoms, the laser beam scatters, and in some sense performs a quantum calculation, which exceeds the memory capability of any Turing machine.

However, as I mentioned, the problem is that these atoms have to be in perfect coherence, and the problems of doing this are staggering in the sense that even a random collision with a subatomic particle could in fact destroy the coherence and make the quantum computer impractical.

So, I’m not saying that it’s impossible to build a quantum computer; I’m just saying that it’s awfully difficult.

SETI: looking in the wrong direction

When do you think we might expect SETI [Search for Extraterrestrial Intelligence] to be successful?

I personally think that SETI is looking in the wrong direction. If, for example, we’re walking down a country road and we see an anthill, do we go down to the ant and say, "I bring you trinkets, I bring you beads, I bring you knowledge, I bring you medicine, I bring you nuclear technology, take me to your leader"? Or, do we simply step on them? Any civilization capable of reaching the planet Earth would be perhaps a Type III civilization. And the difference between you and the ant is comparable to the distance between you and a Type III civilization. Therefore, for the most part, a Type III civilization would operate with a completely different agenda and message than our civilization.

Let’s say that a ten-lane superhighway is being built next to the anthill. The question is: would the ants even know what a ten-lane superhighway is, or what it’s used for, or how to communicate with the workers who are just feet away? And the answer is no. One question that we sometimes ask is if there is a Type III civilization in our backyard, in the Milky Way galaxy, would we even know its presence? And if you think about it, you realize that there’s a good chance that we, like ants in an anthill, would not understand or be able to make sense of a ten-lane superhighway next door.

So this means there that could very well be a Type III civilization in our galaxy, it just means that we’re not smart enough to find one. Now, a Type III civilization is not going to make contact by sending Captain Kirk on the Enterprise to meet our leader. A Type III civilization would send self-replicating Von Neumann probes to colonize the galaxy with robots. For example, consider a virus. A virus only consists of thousands of atoms. It’s a molecule in some sense. But in about one week, it can colonize an entire human being made of trillions of cells. How is that possible?

Well, a Von Neumann probe would be a self-replicating robot that lands on a moon; a moon, because they are stable, with no erosion, and they’re stable for billions of years. The probe would then make carbon copies of itself by the millions. It would create a factory to build copies of itself. And then these probes would then rocket to other nearby star systems, land on moons, to create a million more copies by building a factory on that moon. Eventually, there would be sphere surrounding the mother planet, expanding at near-light velocity, containing trillions of these Von Neumann probes, and that is perhaps the most efficient way to colonize the galaxy. This means that perhaps, on our moon there is a Von Neumann probe, left over from a visitation that took place million of years ago, and the probe is simply waiting for us to make the transition from Type 0 to Type I.

The Sentinel.

Yes. This, of course, is the basis of the movie 2001, because at the beginning of the movie, Kubrick interviewed many prominent scientists, and asked them the question, "What is the most likely way that an advanced civilization would probe the universe?" And that is, of course, through self-replicating Von Neumann probes, which create moon bases. That is the basis of the movie 2001, where the probe simply waits for us to become interesting. If we’re Type 0, we’re not very interesting. We have all the savagery and all the suicidal tendencies of fundamentalism, nationalism, sectarianism, that are sufficient to rip apart our world.

By the time we’ve become Type I, we’ve become interesting, we’ve become planetary, we begin to resolve our differences. We have centuries in which to exist on a single planet to create a paradise on Earth, a paradise of knowledge and prosperity.

© 2003