The Future of the Mind (46 page)

Drexler then fired back, stating that nanobots are not science fiction—they actually exist. Think of the ribosomes in our own body. They are essential in creating and molding DNA molecules. They can cut and splice DNA molecules at specific points, which makes possible the creation of new DNA strands.

But Smalley wasn’t satisfied, stating that ribosomes are not all-purpose machines that can cut and paste anything you want; they work specifically on DNA molecules. Moreover, ribosomes are organic chemicals that need enzymes to speed up the reaction, which occurs only in a watery environment. Transistors are made of silicon, not water, so these enzymes would never work, he concluded. Drexel, in turn, mentioned that catalysts can work even without water. This heated exchange went back and forth through several rounds. In the end, like two evenly matched prizefighters, both sides seemed exhausted. Drexler had to admit that the analogy to workers with cutters and blowtorches was too simplistic, that quantum forces do get in the way sometimes. But Smalley had to concede that he was unable to score a knockout blow. Nature had at least one way of evading the “sticky, fat fingers” problem, with ribosomes, and perhaps there might be other subtle, unforeseen ways as well.

Regardless of the details of this debate, Ray Kurzweil is convinced that these nanobots, whether or not they have fat, sticky fingers, will one day shape not just molecules, but society itself. He summarized his vision when he said, “
I’m not planning to die.… I see it, ultimately, as an awakening of the whole universe. I think the whole universe right now is basically made up of dumb matter and energy and I think it will wake up. But if it becomes transformed into this sublimely intelligent matter and energy, I hope to be part of that.”

As fantastic as these speculations are, they are only a preface to the next leap in speculation. Perhaps one day the mind will not only be free of its material body, it will also be able to explore the universe as a being of pure energy. The idea that consciousness will one day be free to roam among the stars is the ultimate dream. As incredible as it may sound, this is well within the laws of physics.

13
THE MIND AS PURE ENERGY

The idea that one day consciousness may spread throughout the universe has been considered seriously by physicists. Sir Martin Rees, the Royal Astronomer of Great Britain, has written, “
Wormholes, extra dimensions, and quantum computers open up speculative scenarios that could transform our entire universe eventually into a ‘living cosmos’!”

But will the mind one day be freed of its material body to explore the entire universe? This was the theme explored in Isaac Asimov’s classic science-fiction tale “The Last Question.” (He would fondly recall that this was his favorite science-fiction short story of all the ones he had written.) In it, billions of years into the future, humans will have placed their physical bodies in pods on an obscure planet, freeing their minds to control pure energy throughout the galaxy. Instead of surrogates made of steel and silicon, these surrogates are pure energy beings that can effortlessly roam the distant reaches of space, past exploding stars, colliding galaxies, and other wonders of the universe. But no matter how powerful humanity has become, it is helpless as it witnesses the ultimate death of the universe itself in the Big Freeze. In desperation, humanity constructs a supercomputer to answer the
final question: Can the death of the universe be reversed? The computer is so large and complex that it has to be placed in hyperspace. But the computer simply responds that there is insufficient information to give an answer.

Eons later, as the stars begin to turn dark, all life in the universe is about to die. But then the supercomputer finally discovers a way to reverse the death of the universe. It collects dead stars from across the universe, combines them into one gigantic cosmic ball, and ignites it. As the ball explodes, the supercomputer announces, “Let there be light!”

And there was light.

So humanity, once freed of the physical body, is capable of playing God and creating a new universe.

At first, Asimov’s fantastic tale of beings made of pure energy roaming across the universe sounds impossible. We are accustomed to thinking of beings made of flesh and blood, which are at the mercy of the laws of physics and biology, living and breathing on Earth, and bound by the gravity of our planet. The concept of conscious entities of energy, soaring across the galaxy, unimpeded by the limitations of material bodies, is a strange one.

Yet this dream of exploring the universe as beings of pure energy is well within the laws of physics. Think of the most familiar form of pure energy, a laser beam, which is capable of containing vast amounts of information. Today trillions of signals in the form of phone calls, data packages, videos, and e-mail messages are transmitted routinely by fiber-optic cables carrying laser beams. One day, perhaps sometime in the next century, we will be able to transmit the consciousness of our brains throughout the solar system by placing our entire connectomes onto powerful laser beams. A century beyond that, we may be able to send our connectome to the stars, riding on a light beam.

(This is possible because the wavelength of a laser beam is microscopic, i.e., measured in millionths of a meter. That means you can compress vast amounts of information on its wave pattern. Think of Morse code. The dots and dashes of Morse code can easily be superimposed on the wave pattern of a laser beam. Even more information can be transferred onto a beam of X-rays, which has a wavelength even smaller than an atom.)

One way to explore the galaxy, unbound by the messy restrictions of ordinary matter, is to place our connectomes onto laser beams directed at the moon, the planets, and even the stars. Given the crash program to find
the pathways of the brain, the complete connectome of the human brain will be available late in this century, and a form of the connectome capable of being placed on a laser beam might be available in the next century.

The laser beam would contain all the information necessary to reassemble a conscious being. Although it may take years or even centuries for the laser beam to reach its destination, from the point of view of the person riding on the laser beam, the trip would be instantaneous. Our consciousness is essentially frozen on the laser beam as it soars through empty space, so the trip to the other side of the galaxy appears to take place in the blink of an eye.

In this way, we avoid all the unpleasant features of interplanetary and interstellar travel. First, there is no need to build colossal booster rockets. Instead, you simply press the “on” button of a laser. Second, there are no powerful g forces crushing your body as you accelerate into space. Instead, you are boosted instantly to the speed of light, since you are immaterial. Third, you don’t have to suffer the hazards of outer space, such as meteor impacts and deadly cosmic rays, since asteroids and radiation pass right through you harmlessly. Fourth, you don’t have to freeze your body or endure years of boredom as you lumber tediously inside a conventional rocket. Instead, you zip across space at the fastest velocity in the universe, frozen in time.

Once we reach our destination, there would have to be a receiving station to transfer the data of the laser beam onto a mainframe computer, which then brings the conscious being back to life. The code that was imprinted onto the laser beam now takes control of the computer and redirects its programming. The connectome directs the mainframe computer to begin simulating the future to attain its goals (i.e., it becomes conscious).

This conscious being inside the mainframe then sends signals wirelessly to a robotic surrogate body, which has been waiting for us at the destination. In this way, we suddenly “wake up” on a distant planet or star, as if the trip took place in the blink of an eye, inside the robotic body of our surrogate. All the complex computations take place in a large mainframe computer, which directs the movements of a surrogate to carry on with our business on a distant star. We are oblivious to the hazards of space travel, as if nothing had happened.

Now imagine a vast network of these stations spread out over the solar system and even the galaxy. From our point of view, hopping from star to star would be almost effortless, traveling at the speed of light in journeys
that are instantaneous. At each station, there is a robotic surrogate waiting for us to enter its body, just like an empty hotel room waiting for us to check in. We arrive at our destination refreshed and equipped with a superhuman body.

The type of surrogate robotic body that awaits us at the end of this journey would depend on the mission. If the job is to explore a new world, then the surrogate body would have to work in harsh conditions. It would have to adjust to a different gravitational field, a poisonous atmosphere, freezing-cold or blistering-hot temperatures, different day-night cycles, and a constant rain of deadly radiation. To survive under these harsh conditions, the surrogate body would have to have super strength and super senses.

If the surrogate body is purely for relaxation, then it would be designed for leisurely activities. It would maximize the pleasure of soaring through space on skis, surfboards, kites, gliders, or planes, or of sending a ball through space propelled by the swing of a bat, club, or racket.

Or if the job is to mingle with and study the local natives, then the surrogate would approximate the bodily characteristics of the indigenous population (as in the movie
Avatar
).

Admittedly, in order to create this network of laser stations in the first place, it might be necessary first to travel to the planets and stars in the old-fashioned way, in more conventional rocket ships. Then one could build the first set of these laser stations. (Perhaps the fastest, cheapest, and most efficient way of creating this interstellar network would be to send self-replicating robotic probes throughout the galaxy. Because they can make copies of themselves, starting with one such probe, after many generations there would be billions of such probes streaming out in all directions, each one creating a laser station wherever it lands. We will discuss this further in the next chapter.)

But once the network is fully established, one can conceive of a continual stream of conscious beings roaming the galaxy, so that at any time crowds of people are leaving and arriving from distant parts of the galaxy. Any laser station in the network might look like Grand Central Station.

As futuristic as this may sound, the basic physics for this concept are already well established. This includes placing vast amounts of data onto laser beams, sending this information across thousands of miles, and then decoding the information at the other end. The major problems facing this
idea are therefore not in the physics, but in the engineering. Because of this, it may take us until the next century to send our entire connectome on laser beams powerful enough to reach the planets. It might take us still another century to beam our minds to the stars.

To see if this is feasible, it is instructive to do a few simple, back-of-the-envelope calculations. The first problem is that the photons inside a pencil-thin laser beam, although they appear to be in perfectly parallel formation, actually diverge slightly in space. (When I was a child, I used to shine a flashlight at the moon and wonder if the light ever reached it. The answer is yes. The atmosphere absorbs over 90 percent of the original beam, leaving some remaining to reach the moon. But the real problem is that the image the flashlight finally casts on the moon is miles across. This is because of the uncertainty principle; even laser beams must diverge slowly. Since you cannot know the precise location of the laser beam, it must, by the laws of quantum physics, slowly spread out over time.)

But beaming our connectomes to the moon does not give us much advantage, since it’s easier simply to remain on Earth and control the lunar surrogate directly by radio. The delay is only about a second when issuing commands to the surrogate. The real advantage comes when controlling surrogates on the planets, since a radio message may take hours to reach a surrogate there. The process of issuing a series of radio commands to a surrogate, waiting for a response, and issuing another command would be painfully slow, taking days on end.

If you want to send a laser beam to the planets, you first have to establish a battery of lasers on the moon, well above the atmosphere, so there is no air to absorb the signal. Shot from the moon, a laser beam to the planets could arrive in a matter of minutes to a few hours. Once the laser beam has sent the connectome to the planets, then it’s possible to directly control the surrogate without any delay factors at all.

So establishing a network of these laser stations throughout the solar system could be accomplished by the next century. But the problems are magnified when we try sending the beam to the stars. This means that we must have relay stations placed on asteroids and space stations along the way, in order to amplify the signal, reduce errors, and send the message to the next relay station. This could potentially be done by using the comets that lie between our sun and the nearby stars. For example, extending about a light-year
from the sun (or one-quarter of the distance to the nearest star) is the Oort cloud of comets. It is a spherical shell of billions of comets, many of which lie motionless in empty space. There is probably a similar Oort cloud of comets surrounding the Centauri star system, which is our nearest stellar neighbor. Assuming that this Oort cloud also extends a light-year from those stars, then fully half the distance from our solar system to the next contains stationary comets on which we can build laser relay stations.

Another problem is the sheer amount of data that must be sent by laser beam. The total information contained in one’s connectome, according to Dr. Sebastian Seung, is roughly one zettabyte (that is, a 1 with twenty-one zeros after it). This is roughly equivalent to the total information contained in the World Wide Web today. Now consider shooting a battery of laser beams into space carrying this vast mountain of information. Optical fibers can carry terabytes of data per second (a 1 with twelve zeros after it). Within the next century, advances in information storage, data compression, and bundling of laser beams may increase this efficiency by a factor of a million. This means that it would take a few hours or so to send the beam into space carrying all the information contained within the brain.