Consider matter on a larger scale. If you randomly select an Earth-sized region anywhere in space, the probability that a heavenly body (such as a star or a planet) were present in that region is also extremely low, less than one in a trillion. Yet we nonetheless have billions of trillions of such heavenly bodies in the Universe.
Consider the life cycle of mammals on Earth. The mission of an Earth male mammalian sperm is to fertilize an Earth female mammalian egg, but the likelihood of it fulfilling its mission is far less than one in a trillion. Yet we nonetheless have more than a hundred million such fertilizations each year, just considering human eggs and sperm. Again, rare and plentiful.
Now consider the evolution of life-forms on a planet, which we can define as self-replicating designs of matter and energy. It may be that life in the Universe is similarly both rare and plentiful, that conditions must be just so for life to evolve. If, for example, the probability of a star having a planet that has evolved life were one in a million, there would still be 100,000 planets in our own galaxy on which this threshold has been passed, among trillions on other galaxies.
We can identify the evolution of life-forms as a specific threshold that some number of planets have achieved. We know of at least one such case. We assume there are many others.
As we consider the next threshold, we might consider the evolution of intelligent life. In my view, however, intelligence is too vague a concept to designate as a distinct threshold. Considering what we know about life on this planet, there are many species that demonstrate some levels of clever behavior, but there does not appear to be any clearly definable threshold. This is more of a continuum rather than a threshold.
A better candidate for the next threshold is the evolution of a species of life-form that in turn creates “technology.” We discussed the nature of technology earlier. It represents more than the creation and use of tools. Ants, primates, and other animals on Earth use and even fashion tools, but these tools do not evolve. Technology requires a body of knowledge describing the creation of tools that can be transmitted from one generation of the species to the next. The technology then becomes itself an evolving set of designs. This is not a continuum but a clear threshold. A species either creates technology or it doesn’t. It may be difficult for a planet to support more than one species that creates technology. If there’s more than one, they may not get along with one another, as was apparently the case on Earth.
A salient question is: What is the likelihood that a planet that has evolved life will subsequently evolve a species that creates technology? Although the evolution of life-forms may be rare and plentiful, I argued in chapter 1 that once the evolution of life-forms sets in, the emergence of a species that creates technology is inevitable. The evolution of the technology is then a continuation by other means of the evolution that gave rise to the technology-creating species in the first place.
The next stage is computation. Once technology emerges, it also appears inevitable that computation (in the technology, not just in the species’ nervous systems) will subsequently emerge. Computation is clearly a useful way to control the environment as well as technology itself, and greatly facilitates the further creation of technology. Just as an organism is aided by the ability to maintain internal states and respond intelligently to its environment, the same holds true for a technology. Once computation emerges, we are in a late stage in the exponential evolution of technology on that planet.
Once computation emerges, the corollary of the Law of Accelerating Returns as applied to computation takes over, and we see the exponential increase in power of the computational technology over time. The Law of Accelerating Returns predicts that both the species and the computational technology will progress at an exponential rate, but the exponent of this growth is vastly higher for the technology than it is for the species. Thus the computational technology inevitably and rapidly overtakes the species that invented it. At the end of the twenty-first century, it will have been only a quarter of a millennium since computation emerged on Earth, which is a blink of an eye on an evolutionary scale—it’s not even very long on the scale of human history. Yet computers at that time will be vastly more powerful (and I believe far more intelligent) than the original humans who initiated their creation.
The next inevitable step is a merger of the technology-inventing species with the computational technology it initiated the creation of. At this stage in the evolution of intelligence on a planet, the computers are themselves based at least in part on the designs of the brains (that is, computational organs) of the species that originally created them and in turn the computers become embedded in and integrated into that species’ bodies and brains. Region by region, the brain and nervous system of that species are ported to the computational technology and ultimately replace those information-processing organs. All kinds of practical and ethical issues delay the process, but they cannot stop it. The Law of Accelerating Returns predicts a complete merger of the species with the technology it originally created.
Failure Modes
But wait, this step is not inevitable. The species together with its technology may destroy itself before achieving this step. Destruction of the entire evolutionary process is the only way to stop the exponential march of the Law of Accelerating Returns. Sufficiently powerful technologies are created along the way that have the potential to destroy the ecological niche that the species and its technology occupy Given the likely plentifulness of life- and intelligence-bearing planets, these failure modes must have occurred many times.
We are familiar with one such possibility: destruction through nuclear technology—not just an isolated tragic incident, but an event that destroys the entire niche. Such a catastrophe would not necessarily destroy all life-forms on a planet, but would be a distinct setback in terms of the process envisioned here. We are not yet out of the woods in terms of this specter here on Earth.
There are other destructive scenarios. As I discussed in chapter 7, a particularly likely one is a malfunction (or sabotage) of the mechanism that inhibits indefinite reproduction of self-replicating nanobots. Nanobots are inevitable, given the emergence of intelligent technology. So are self-replicating nanobots, as self-replication represents an efficient, and ultimately necessary, way to manufacture this type of technology Through demented intention or just an unfortunate software error, a failure to turn off self-replication at the right time would be most unfortunate. Such a cancer would infect organic and much inorganic matter alike, since the nanobot life-form is not of organic origin. Inevitably, there must be planets out there that are covered with a vast sea of self-replicating nanobots. I suppose evolution would pick up from this point.
Such a scenario is not limited to tiny robots. Any self-replicating robot will do. But even if the robots are larger than nanobots, it is likely that their means for self-replication makes use of nanoengineering. But any self-replicating group of robots that fails to follow Isaac Asimov’s three laws (which forbid robots to harm their creators) through either evil design or programming error presents a grave danger.
Another dangerous new life-form is the software virus. We’ve already met—in primitive form—this new occupant of the ecological niche made available by computation. Those that will emerge in the next century here on Earth will have the means for harnessing evolution to design evasive tactics in the same way that biological viruses (for example, HIV) do today As the technology-creating species increasingly uses its computational technology to replace its original life-form-based circuits, such viruses will represent another salient danger.
Prior to that time, viruses that operate at the level of the genetics of the original life-form also represent a hazard. As the means become available for the technology-creating species to manipulate the genetic code that gave rise to it (however that code is implemented), new viruses can emerge through accident and/or hostile intention with potentially mortal consequences. This could derail such a species before it has the opportun
ity to port the design of its intelligence to its technology.
How likely are these dangers? My own view is that a planet approaching its pivotal century of computational growth—as the Earth is today—has a better than even chance of making it through. But then I have always been accused of being an optimist.
Delegations from Faraway Places
Our popular contemporary vision of visits from other planets in the Universe contemplates creatures like ourselves with spaceships and other advanced technologies assisting them. In some conceptions the aliens have a remarkably humanlike appearance. In others, they look a little strange. Note that we have exotic-appearing intelligent creatures here on our own planet (for example, the giant squid and octopus). But humanlike or not, the popular conception of aliens visiting our planet envisions them as about our size and essentially unchanged from their original evolved (usually squishy) appearance. This conception seems unlikely.
Far more probable is that visits from intelligent entities from another planet represent a merger of an evolved intelligent species with its even more evolved intelligent computational technology. A civilization sufficiently evolved to make the trek to Earth has likely long since passed the “merger” threshold discussed above.
A corollary of this observation is that such visiting delegations from faraway planets are likely to be very small in size. A computational-based superintelligence of the late twenty-first century here on Earth will be microscopic in size. Thus an intelligent delegation from another planet is not likely to use a spaceship of the size that is common in today’s science fiction, as there would be no reason to transport such large organisms and equipment. Consider that the purpose of such a visit is not likely to be the mining of material resources since such an advanced civilization has almost certainly passed beyond the point where it has any significant unmet material needs. It will be able to manipulate its own environment through nanoengineering (as well as picoengineering and femtoengineering) to meet any conceivable physical requirements. The only likely purpose of such a visit is for observation and the gathering of information. The only resource of interest to such an advanced civilization will be knowledge (that is close to being true for the human-machine civilization here on Earth today). These purposes can be realized with relatively small observation, computation, and communication devices. Such spaceships are thus likely to be smaller than a grain of sand, possibly of microscopic size. Perhaps that is one reason we have not noticed them.
How Relevant Is Intelligence to the Universe?
If you are a conscious entity attempting to do a task normally considered to require a little intelligence—say, writing a book about machine intelligence on your planet—then it may have some relevance. But how relevant is intelligence to the rest of the Universe?
The common wisdom is, Not very. Stars are born and die; galaxies go through their cycles of creation and destruction. The Universe itself was born in a big bang and will end with a crunch or a whimper; we’re not yet sure which. But intelligence has little to do with it. Intelligence is just a bit of froth, an ebullition of little creatures darting in and out of inexorable universal forces. The mindless mechanism of the Universe is winding up or down to a distant future, and there’s nothing intelligence can do about it.
That’s the common wisdom. But I don’t agree with it. My conjecture is that intelligence will ultimately prove more powerful than these big impersonal forces.
Consider our little planet. An asteroid apparently slammed into the Earth 65 million years ago. Nothing personal, of course. It was just one of those powerful natural occurrences that regularly overpower mere life-forms. But the next such interplanetary visitor will not receive the same welcome. Our descendants and their technology (there’s actually no distinction to be made here, as I have pointed out) will notice the imminent arrival of an untoward interloper and blast it from the nighttime sky. Score one for intelligence. (For twenty-four hours in 1998, scientists thought such an unwelcome asteroid might arrive in the year 2028, until they rechecked their calculations.)
Intelligence does not exactly cause the repeal of the laws of physics, but it is sufficiently clever and resourceful to manipulate the forces in its midst to bend to its will. In order for this to happen, however, intelligence needs to reach a certain level of advancement.
Consider that the density of intelligence here on Earth is rather low. One quantitative measure we can make is measured in calculations per second per cubic micrometer (cpspcmm). This is, of course, only a measure of hardware capacity, not the cleverness of the organization of these resources (that is, of the software), so let’s call this the density of computation. We’ll deal with the advancement of the software in a moment. Right now on Earth, human brains are the objects with the highest density of computation (that will change within a couple of decades). The human brain’s density of computation is about 2 cpspcmm. That is not very high—nanotube circuitry, which has already been demonstrated, is potentially more than a trillion times higher.
Also consider how little of the matter on Earth is devoted to any form of computation. Human brains comprise only 10 billion kilograms of matter, which is about one part per hundred trillion of the stuff on Earth. So the average density of computation of the Earth is less than one trillionth of one cpspcmm. We already know how to make matter (that is, nanotubes) with a computational density at least a trillion trillion times greater.
Furthermore, the Earth is only a tiny fraction of the stuff in the Solar System. The computational density of the rest of the Solar System appears to be about zero. So here on a solar system that boasts at least one intelligent species, the computational density is nonetheless extremely low.
At the other extreme, the computational capacity of nanotubes does not represent an upper limit for the computational density of matter: It is possible to go much higher. Another conjecture of mine is that there is no effective limit to this density, but that’s another book.
The point of all these big (and small) numbers is that extremely little of the stuff on Earth is devoted to useful computation. This is even more true when we consider all of the dumb matter in the Earth’s midst. Now consider another implication of the Law of Accelerating Returns. Another of its corollaries is that overall computational density grows exponentially And as the cost-performance of computation increases exponentially, greater resources are devoted to it. We can see that already here on Earth. Not only are computers today vastly more powerful than they were decades ago, but the number of computers has increased from a few dozen in the 1950s to hundreds of millions today. Computational density here on Earth will increase by trillions of trillions during the twenty-first century.
Computational density is a measure of the hardware of intelligence. But the software also grows in sophistication. While it lags behind the capability of the hardware available to it, software also grows exponentially in its capability over time. While harder to quantify,1 the density of intelligence is closely related to the density of computation. The implication of the Law of Accelerating Returns is that intelligence on Earth and in our Solar System will vastly expand over time.
The same can be said across the galaxy and throughout the Universe. It is likely that our planet is not the only place where intelligence has been seeded and is growing. Ultimately, intelligence will be a force to reckon with, even for these big celestial forces (so watch out!). The laws of physics are not repealed by intelligence, but they effectively evaporate in its presence.
So will the Universe end in a big crunch, or in an infinite expansion of dead stars, or in some other manner? In my view, the primary issue is not the mass of the Universe, or the possible existence of antigravity, or of Einstein’s so-called cosmological constant. Rather, the fate of the Universe is a decision yet to be made, one which we will intelligently consider when the time is right.
TIME LINE 12
HOW TO BUILD AN INTELLIGENT MACHINE IN THREE EASY PARADIGMS
As Deep Blue goes d
eeper and deeper, it displays elements of strategic understanding. Somewhere out there, mere tactics are translating into strategy. This is the closest thing I’ve seen to computer intelligence. It’s a weird form of intelligence, the beginning of intelligence. But you can feel it. You can smell it.
—Frederick Friedel, assistant to Gary Kasparov, commenting on the computer that beat his boss
The whole point of this sentence is to make clear what the whole point of this sentence is.
—Dougtas Hofstadter
“Would you tell me please which way I ought to go from here?” asked Alice. “That depends a good deal on where you want to get to,” said the Cat. “I don’t much care where ... ,” said Alice. “Then it doesn’t much matter which way you go,” said the Cat. “... so long as I get somewhere,” Alice added as an explanation. “Oh, you’re sure to do that,” said the Cat, “if you only walk long enough.”
—Lewis Carroll
A professor has just finished lecturing at some august university about the origin and structure of the universe, and an old woman in tennis shoes walks up to the lectern. “Excuse me, sir, but you’ve got it all wrong,” she says. “The truth is that the universe is sitting on the back of a huge turtle.” The professor decides to humor her. “Oh really?” he asks. “Well, tell me, what is the turtle standing on?” The lady has a ready reply: “Oh, it’s standing on another turtle.” The professor asks, “And what is that turtle standing on?” Without hesitation, she says, “Another turtle.” The professor, still game, repeats his question. A look of impatience comes across the woman’s face. She holds up her hand, stopping him in mid-sentence. “Save your breath, sonny, she says. ”It’s turtles all the way down.“