5. Create Negative Energy
If Kerr rings prove to be lethal or too unstable for use as cosmic portals, an advanced civilization might instead contemplate opening up a new wormhole by using negative matter or negative energy. (In principle, negative matter or energy should weigh less than nothing and fall up rather than down. This is different stuff from antimatter, which contains positive energy and falls down.) In 1988 Kip Thorne and his colleagues at Caltech showed that with sufficient negative matter or negative energy, one could create a wormhole through which a traveler could freely pass back and forth between, say, his laboratory and a distant point in space or time.
Although no one has yet seen negative matter or negative energy in the wild, it has been detected in the laboratory, in the form of something called the Casimir effect. Consider two uncharged, parallel plates. Theoretically, the force between them should be zero. But if they are placed only a few atoms apart, then the space between them is not enough for some quantum fluctuations to occur. As a result, the number of quantum fluctuations in the region around the plates is greater than in the space between. This differential creates a net force that pushes the two plates together. Hendrik Casimir predicted the effect in 1948; it has since been confirmed experimentally.
The amount of energy involved is minuscule. To employ the Casimir effect to practical ends, one would have to use advanced technology to place the parallel plates at a fantastically small distance apart—10–33 centimeter, the Planck length (the smallest measurement of length with any meaning). Now suppose that these two parallel plates could be shaped into a single sphere, with the plates forming a sort of double lining, and pressed together to within this fractional distance. The resulting Casimir effect might generate enough negative energy to open a wormhole within the sphere.
6. Make a Baby Universe
If both Kerr rings and negative-energy wormholes prove unreliable, Guth’s inflation theory points the way to another, more difficult escape strategy: creating a baby universe.
As Guth points out, to create something resembling our universe would require “1089 photons, 1089 electrons, 1089 positrons, 1089 neutrinos, 1089 antineutrinos, 1079 protons, and 1079 neutrons.” However, Guth notes, the positive energy of this matter is almost but not entirely balanced out by the negative energy of gravity. (If our universe were closed, which it isn’t, the two values would cancel each other out exactly.) In other words, the net total matter required to create a baby universe might equal only a few ounces.
But what ounces! In principle, baby universes are born when a certain region of space-time becomes unstable and enters a state called the false vacuum. The false vacuum needed to create our universe is extraordinarily small, on the order of 10–26 centimeter wide. If one created this false vacuum from one ounce of matter, its density would be a phenomenal 1080 grams per cubic centimeter. Acquiring a few ounces of matter is easy; compressing it into the small volume necessary is not possible today.
The solution requires that a fantastic amount of energy, roughly equal to the Planck energy, be concentrated on a tiny region. Here are two approaches an advanced civilization might try.
6(a). Build a Laser Implosion Machine
The power of laser beams is essentially unlimited, constrained mainly by the stability of lasing material and the energy of the power source. Lasers that can produce a brief terawatt, or trillion-watt, burst are commonplace, and petawatt lasers capable of generating a quadrillion watts are possible. By contrast, a large nuclear power plant produces only a billion watts of continuous power. It is theoretically possible for an X-ray laser to focus the output of a nuclear bomb to create a pulse of unimaginable power.
At the Lawrence Livermore National Laboratory, scientists have used a laser to fire a series of high-energy pulses radially onto a single pellet made of deuterium and tritium, the basic ingredients of a hydrogen bomb, thus creating the conditions for thermonuclear fusion. An advanced civilization could create a similar device on a much larger scale. By placing huge laser stations on asteroids and then firing millions of laser pulses onto a single point, future scientists could generate temperatures and pressures that swamp today’s technology. Each laser could be powered by a nuclear bomb; however, such a device would be usable only once.
The aim of firing this massive bank of laser beams would be to either heat a chamber sufficiently high—about 1029 degrees Kelvin—to create a false vacuum inside or compress a pair of spherical plates to within the Planck distance of each other, creating negative energy via the Casimir effect. One way or the other, a wormhole connecting our universe to another one should open within the chamber, allowing us to exit.
6(b). Build a Cosmic Atom Smasher
One of the most powerful energy-generating devices currently available to scientists is the Large Hadron Collider, which, when it becomes operational in 2007, will be able to generate 14 trillion electron volts. Even that is one-quadrillionth the energy necessary to create a false vacuum.
But a particle accelerator with the diameter of our solar system might do the trick. Gigantic coil magnets could be placed at strategic intervals on asteroids to bend and focus a particle beam in a circular path around the sun. (Since the vacuum of empty space is better than any vacuum attainable on Earth, the beam of subatomic particles would not need light-years of tubing to contain it; it could be fired into empty space.) Fair warning: The magnetic field required by each coil to bend the beam would be so huge that the surge of power through it might melt the coil, making it usable only once. After the beam has passed, the melted coils would have to be discarded and replaced in time for the next pass.
Alternatively, it is worth noting that the Large Hadron Collider may be the last generation of giant particle accelerators to use radio-frequency energies to boost subatomic particles around a giant ring. Physicists are already attempting to build tabletop-size laser-driven accelerators that, in principle, could attain billions of electron volts. So far, scientists have used powerful laser beams to attain an acceleration of 200 billion electron volts per meter, a new record. Progress is rapid, with the energy growing by a factor of 10 every five years. Although technical problems hamper the development of a true tabletop accelerator, an advanced civilization has billions of years to perfect these and other devices.
In the interim, to reach the Planck energy with something like current laser technology would require an atom smasher 10 light-years long, reaching beyond the nearest star. Power stations would need to be placed along the path in order to pump laser energy into the beam and to focus it—a minor task for a Type III civilization.
7. Send in the Nanobots
Assume now that the wormholes created in the previous steps prove unworkable. Perhaps they are unstable, or too small to pass through, or their radiation effects are too intense. What if future scientists find that only atom-size particles can safely pass through a wormhole? If that is the case, intelligent life may have but one remaining option: Send a nanobot through the wormhole to regenerate human civilization on the other side.
This process occurs all the time in nature. An oak tree produces and scatters seeds that are compact, resilient, packed with all the genetic information necessary to re-create a tree, and loaded with sufficient nourishment to make colonization possible. Using nanotechnology, an advanced civilization might well be able to encode vast quantities of information into a tiny, self-replicating machine and send this machine through a dimensional gateway. Atom-size, it would be able to travel near the speed of light and land on a distant moon that is stable and full of valuable minerals. Once situated, it would use the raw materials at hand to create a chemical factory capable of making millions of copies of itself. These new robots would then rocket off to other distant moons, establish new factories, and create still more copies. Soon, a sphere of trillions of robot probes would be expanding near the speed of light and colonizing the entire galaxy.
Next, the robot probes would create huge biotechnology laboratories. They would inject their precious cargo of information—the preloaded DNA sequences of the civilization’s original inhabitants—into incubators and thereby clone the entire species. If future scientists manage to encode the personalities and memories of its inhabitants into these nanobots, the civilization could be reincarnated.
Mathematically, this is the most efficient way for a Type III civilization to colonize a galaxy, not to mention a new cosmos. If we ever encounter another intelligent life-form, chances are it won’t be in a flying saucer like the starship Enterprise. More likely, we’ll make contact with a robot probe they’ve left on a moon somewhere. This was the basis of Arthur C. Clarke’s 2001: A Space Odyssey, which may be the most scientifically accurate depiction of an encounter with an extraterrestrial intelligence. In the film version, this logic was originally articulated by scientists in the film’s opening minutes, but director Stanley Kubrick cut the interviews from the final edit.