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.
So the problem is not the sheer amount of data sent on laser beams. In principle, laser beams can carry an unlimited amount of data. The real bottlenecks are the receiving stations at either end, which must have switches that rapidly manipulate this amount of data at blinding speed. Silicon transistors may not be fast enough to handle this volume of data. Instead, we might have to use quantum computers, which compute not on silicon transistors but on individual atoms. At present, quantum computers are at a primitive level, but by the next century they might be powerful enough to handle zettabytes of information.
FLOATING BEINGS OF ENERGY
Another advantage of using quantum computers to process this mountain of data is the chance to create beings of energy that can hover and float in the air, which appear frequently in science fiction and fantasy. These beings would represent consciousness in its purest form. At first, however, they may seem to violate the laws of physics, since light always travels at the speed of light.
But in the last decade, headlines were made by physicists at Harvard University who announced that they were able to stop a beam of light dead in its tracks. These physicists apparently accomplished the impossible, slowing down a light beam to a leisurely pace until it could be placed in a bottle. Capturing a light beam in a bottle is not so fantastic if you look carefully at a glass of water. As a light beam enters the water, it slows down, bending as it enters the water at an angle. Similarly, light bends as it enters glass, making telescopes and microscopes possible. The reason for all this comes from the quantum theory.
Think of the old Pony Express, which delivered the mail in the nineteenth century in the American West. Each pony could sprint between relay stations at great speed. But the bottleneck was the delay factor at each relay station, where the mail, rider, and pony had to be exchanged. This slowed down the average velocity of the mail considerably. In the same way, in t
he vacuum between atoms, light still travels at c, the speed of light, which is roughly 186,282 miles per second. However, when it hits atoms, light is delayed; it is briefly absorbed and then reemitted by atoms, sending it on its way a fraction of a second later. This slight delay is responsible for light beams, on average, apparently slowing down in glass or water.
The Harvard scientists exploited this phenomenon, taking a container of gas and carefully cooling it down to near absolute zero. At these freezing temperatures, the gas atoms absorbed a light beam for longer and longer time periods before reemitting it. Thus, by increasing this delay factor, they could slow down the light beam until it came to rest. The light beam still traveled at the speed of light between the gas atoms, but it spent an increasing amount of time being absorbed by them.
This raises the possibility that a conscious being, instead of assuming control of a surrogate, may prefer to remain in the form of pure energy and roam, almost ghostlike, as pure energy.
So in the future, as laser beams are sent to the stars containing our connectomes, the beam may be transferred into a cloud of gas molecules and then contained in a bottle. This “bottle of light” is very similar to a quantum computer. Both of them have a collection of atoms vibrating in unison, in which the atoms are in phase with one another. And both of them can do complex computations that are far beyond an ordinary computer’s capability. So if the problems of quantum computers can be solved, it may also give us the ability to manipulate these “bottles of light.”
FASTER THAN LIGHT?
We see, then, that all these problems are ones of engineering. There is no law of physics preventing traveling on an energy beam in the next century or beyond. So this is perhaps the most convenient way of visiting the planets and stars. Instead of riding on a light beam, as the poets dreamed, we become the light beam.
To truly realize the vision expressed in Asimov’s science-fiction tale, we need to ask if faster-than-light intergalactic travel is truly possible. In his short story, beings of immense power move freely between galaxies separated by millions of light-years.
Is this possible? To answer this question, we have to push the very boundaries of modern quantum physics. Ultimately, things called “wormholes” may provide a shortcut through the vastness of space and time. And beings made of pure energy rather than matter would have a decisive advantage in passing through them.
Einstein, in some sense, is like the cop on the block, stating that you cannot go faster than light, the ultimate velocity in the universe. Traveling across the Milky Way galaxy, for example, would take one hundred thousand years, even sailing on a laser beam. Although only an instant of time has passed for the traveler, the time on the home planet has progressed one hundred thousand years. And passing between galaxies involves millions to billions of light-years.
But Einstein himself left a loophole in his work. In his general theory of relativity of 1915, he showed that gravity arose from the warping of space-time. Gravity is not the “pull” of a mysterious invisible force, as Newton once thought, but actually a “push” caused by space itself bending around an object. Not only did this brilliantly explain the bending of starlight passing near stars and the expansion of the universe, it left open the possibility of the fabric of space-time stretching until it ripped.
In 1935, Einstein and his student Nathan Rosen introduced the possibility that two black-hole solutions could be joined back to back, like Siamese twins, so if you fell into one black hole, you could, in principle, pass out of the other one. (Imagine joining two funnels at their ends. Water that drains through one funnel emerges from the other.) This “wormhole,” also called the Einstein-Rosen Bridge, introduced the possibility of portals or gateways between universes. Einstein himself dismissed the possibility that you could pass through a black hole, since you would be crushed in the process, but several subsequent developments have raised the possibility of faster-than-light travel through a wormhole.
First, in 1963, mathematician Roy Kerr discovered that a spinning black hole does not collapse into a single dot, as previously thought, but into a rotating ring, spinning so fast that centrifugal forces prevent it from collapsing. If you fell through the ring, then you could pass into another universe. The gravitational forces would be large, but not infinite. This would be like Alice’s Looking Glass, where you could pass your hand through the mirror and enter a parallel universe. The rim of the Looking Glass would be the ring forming the black hole itself. Since Kerr’s discovery, scores of other solutions of Einstein’s equations have shown that you can, in principle, pass between universes without being immediately crushed. Since every black hole seen so far in space is spinning rapidly (some of them clocked at one million miles per hour), this means that these cosmic gateways could be commonplace.
In 1988, physicist Dr. Kip Thorne of Cal Tech and his colleagues showed that, with enough “negative energy,” it might be possible to stabilize a black hole so that a wormhole becomes “transversable” (i.e., you can freely pass through it both ways without being crushed). Negative energy is perhaps the most exotic substance in the universe, but it actually exists and can be created (in microscopic quantities) in the laboratory.
So here is the new paradigm. First, an advanced civilization would concentrate enough positive energy at a single point, comparable to a black hole, to open up a hole through space connecting two distant points. Second, it would amass enough negative energy to keep the gateway open, so that it is stable and does not close the instant you enter it.
We can now put this idea into proper perspective. Mapping the entire human connectome should be possible late in this century. An interplanetary laser network could be established early in the next century, so that consciousness can be beamed across the solar system. No new law of physics would be required. A laser network that can go between the stars may have to wait until the century after that. But a civilization that can play with wormholes will have to be thousands of years ahead of us in technology, stretching the boundaries of known physics.
All this, then, has direct implications for whether consciousness can pass between universes. If matter comes close to a black hole, the gravity becomes so intense that your body becomes “spaghettified.” The gravity pulling on your leg is greater than the gravity pulling on your head, so your body is stretched by tidal forces. In fact, as you approach the black hole, even the atoms of your body are stretched until the electrons are ripped from the nuclei, causing your atoms to disintegrate.
(To see the power of tidal forces, just look at the tides of Earth and the rings of Saturn. The gravity of the moon and sun exert a pull on Earth, causing the oceans to rise several feet during high tide. And if a moon comes too close to a giant planet like Saturn, the tidal forces will stretch the moon and eventually tear it apart. The distance at which moons get ripped apart by tidal forces is called the Roche limit. The rings of Saturn lie exactly at the Roche limit, so they might have been caused by a moon that wandered too close to the mother planet.)
Even if we enter a spinning black hole and use negative energy to stabilize it, then, the gravity fields still might be so powerful that we’d be spaghettified.
But here is where laser beams have an important advantage over matter when passing through a wormhole. Laser light is immaterial, so it cannot be stretched by tidal forces as it passes near a black hole. Instead, light becomes “blue-shifted” (i.e., it gains energy and its frequency increases). Even though the laser beam is distorted, the information stored on it is untouched. For example, a message in Morse code carried by a laser beam becomes compressed, but the information content remains unchanged. Digital information is untouched by tidal forces. So gravitational forces, which can be fatal to beings made of matter, may be harmless to beings traveling on light beams.
In this way, consciousness carried by a laser beam, because it is immaterial, has a decisive advantage over matter in passing through a wormhole.
Laser beams have another advantage over mat
ter when passing through a wormhole. Some physicists have calculated that a microscopic wormhole, perhaps the size of an atom, might be easier to create. Matter would not be able to pass through such a tiny wormhole. But X-ray lasers, with a wavelength smaller than an atom, might possibly be able to pass through without difficulty.
Although Asimov’s brilliant short story was clearly a work of fantasy, ironically a vast interstellar network of laser stations might already exist within the galaxy, yet we are so primitive that we are totally unaware of it. To a civilization thousands of years ahead of us, the technology to digitalize their connectomes and send them to the stars would be child’s play. In that case, it is conceivable that intelligent beings are already zapping their consciousness across a vast network of laser beams in the galaxy. Nothing we observe with our most advanced telescopes and satellites prepares us to detect such an intergalactic network.
Carl Sagan once lamented the possibility that we might live in a world surrounded by alien civilizations and not have the technology to realize it.
Then the next question is: What lurks in the alien mind?
If we were to encounter such an advanced civilization, what kind of consciousness might it have? One day, the destiny of the human race may rest on answering this question.
Sometimes I think that the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.
—BILL WATTERSON
Either intelligent life exists in outer space or it doesn’t. Either thought is frightening.
—ARTHUR C. CLARKE
14 THE ALIEN MIND
In War of the Worlds by H. G. Wells, aliens from Mars attack Earth because their home planet is dying. Armed with death rays and giant walking machines, they quickly incinerate many cities and are on the verge of seizing control of Earth’s major capitals. Just as the Martians are crushing all signs of resistance and our civilization is about to be reduced to rubble, they are mysteriously stopped cold in their tracks. With all their advanced science and weaponry, they failed to factor in an onslaught from the lowliest of creatures: our germs.