CHAPTER 20
In the early 1990s, Carl Sagan met with me to pitch a cause he held dear. The federal government had been funding the SETI (Search for Extra-Terrestrial Intelligence) Institute through NASA, in what was supposed to be a ten-year plan to observe neighboring stars. But Congress balked, with one senator from Nevada calling the initiative “a great Martian chase,” and the appropriation was canceled. The search for a signal from outside our solar system was about to be shut down.
“SETI’s taking on one of the great scientific questions,” Sagan said. “We need someone to step in and save it.” He was delightfully sharp-witted and persuasive, and it didn’t hurt that I’d watched every episode of Cosmos, his classic PBS documentary series on the universe and man’s quest to understand it. Along with Gordon Moore, Bill Hewlett, and David Packard, I agreed to give $1 million to keep the SETI Institute running. It was just enough for the operation to pay for a bit of observation time on giant radio telescopes in Australia, West Virginia, and Puerto Rico. SETI was then looking at a mere 750 stars, a paltry number against the 200 billion in the Milky Way alone. To have even a ghost of a chance to succeed, it seemed clear that a dedicated telescope was needed.
Several years later, researchers figured out how to process data from “ganged” small-dish radio antennas, a big breakthrough for radio astronomy. The idea of creating the world’s best SETI telescope—at a fraction of the cost of a single large dish—was enticing. I underwrote the creation of an installation at Hat Creek Observatory in the Lassen National Forest in northeastern California. Nathan Myhrvold, the former chief technology officer at Microsoft, chipped in for an electronics laboratory at the site. In 2007, after years of research and development, the Allen Telescope Array opened its “ears”: a set of forty-two six-meter dishes combing the sky in a thorough, methodical hunt for a signal that might change everything.
The telescope array works on the principle that objects in space emit radio wave “signatures” that describe their size, shape, and chemistry. Much longer than optical waves, radio waves are less scattered by space dust and can get to us intact from the edges of our galaxy and beyond. When SETI uses the array to search for a signal, it can scan ten times more of the radio spectrum than any previous installation. Its detection beams can focus on six stars at once, or on three stars with two simultaneous beams apiece.
The array’s other big advantage is its wide-angle, high-resolution view, which captures a field of sky as large as seven full moons across. (The thousand-foot-diameter Arecibo Telescope in Puerto Rico is far more sensitive, but it looks at a small area of space through the equivalent of a soda straw.) SETI has compiled a list of a quarter-million sunlike stars, the ones most likely to have livable planets within six hundred light-years of earth. In five years or so, after the galactic census satellite Gaia begins sending back its survey data, that catalog will swell to several million stars, a decent foundation for this type of search.
What’s more, the array is a Moore’s-law telescope; its digital signal processing will keep improving exponentially. It’s already 100 trillion times more capable than the one that SETI founder Frank Drake used when he started signal hunting in 1960. The Institute’s goal is to expand to 350 dishes, which would make the array one of the more powerful radio telescopes in the world.
Though there are no guarantees that SETI will turn up an alien communication, the history of astronomy suggests that its new-generation technology may lead to unexpected discoveries. With a portion of the array’s observing time, the University of California–Berkeley’s Radio Astronomy Lab is conducting investigations in more conventional astronomy: gamma ray bursts, black holes, stellar explosions. By mapping our galaxy’s distribution of hydrogen gas, an essential ingredient in star formation, the Berkeley data should give us a clearer picture of the nature of dark matter, the galactic life cycle, and the structure of the cosmos itself.
WHENEVER THE ARRAY finds a SETI “candidate signal” that stands out from the background of garden-variety electromagnetic noise, a gauntlet of tests winnows out false positives. Computers quickly determine whether the candidate came from the scanned star or an orbiting satellite—or a stray cell-phone crackle. Once a signal successfully passes those tests, other radio telescopes will be contacted for independent confirmation. And if and when SETI actually verifies an engineered communication, a tweet across the cosmos, I’m told that I’ll be the first person that director Jill Tarter calls outside her professional community.
My phone hasn’t rung yet, and there’s no way of knowing if it ever will. Frank Drake devised an equation that can theoretically calculate the number of communicating civilizations in the Milky Way. But because we can’t determine the Drake equation’s parameters (such as the life spans of civilizations that develop broadcast-capable technologies), it’s hard to know what the real probabilities are. If those civilizations last only a few thousand years, the SETI Institute may be out of luck. If they last a few million years, our odds are far better.
When it comes to the existence of extraterrestrial life, there are strong arguments on both sides. In Rare Earth: Why Complex Life Is Uncommon in the Universe, Peter Ward and Donald Brownlee suggest that the specific conditions that produced animal life on earth—our distance from the sun, the amount of water in our atmosphere—add up to an unlikely accident. Yet recent research has shown that cellular organisms can exist at more extreme temperatures than we ever thought. Nearly five hundred exoplanets, those belonging to other stars, have already been discovered, and the Gaia probe should find tens of thousands more. In theory, any one of them could be the winning lottery ticket.
SETI is the longest of long shots, but I find its question gripping. Do we have company in the universe, even in our own galaxy? A yes would have implications we can only guess at. Any society with the ability to signal its existence would almost surely be older and wiser than we are, with technology that might offer huge benefits. But even if we never made contact (or followed Stephen Hawking’s recent warning and declined to return the call), a confirmed signal by itself would permanently alter our perception of the universe.
IF SETI REPRESENTS our outward search for intelligence, a Vulcan initiative called Project Halo is helping to lead the inward search: to design software that can simulate certain aspects of human thinking. What we now refer to as artificial intelligence, or “AI,” dates back at least to 1921, when a Czech science fiction play called R.U.R. coined the term “robot.” When I was young, HAL-9000 (in Kubrick’s 2001) and Colossus (from the novel and movie of the same name) embodied nightmare scenarios in which super-intelligent computers turned on their human masters. Machines that behaved like people, even people gone mad, were all the rage back then.
But for me, even more compelling was the sci-fi theme of a dying or threatened civilization that saves itself by finding a trove of knowledge. Tagging along with my father to his library job, I spent hours amid acres of shelves that held what seemed like an infinite mass of information. The idea of gathering all the world’s knowledge in one accessible repository—like the Final Encyclopedia in Gordon R. Dickson’s classic of that title—seemed both grandiose and seductive, with untold benefits for humankind.
With the development of the World Wide Web in the nineties, there were glimmers of hope that this repository might be under construction online. In reality, though, the “knowledge explosion” left us with mounds of sources but no direct way to get a quick and concise answer. It became too easy to get lost in a tangle of text and hyperlinks. And while modern search engines have proven to be invaluable in presenting lists of pages with specified keywords, they still fall far short of the ultimate goal of software that understands.
Aristotle, the Greek scientist and philosopher, was literally a know-it-all. He mastered the knowledge of his day on every topic that mattered, from history and political science to medicine and physics. Even more impressively, he could explain what he knew to his students. But in today’s world, where scientific knowledge may be doubling by the year, it’s impossible for any one person to absorb more than a small fraction of it.
Over the last decade, I began to think about a “Digital Aristotle,” an easy-to-use, all-encompassing knowledge storehouse. I wasn’t aiming to solve the mystery of human consciousness. I simply wanted to advance the field of artificial intelligence so that computers could do what they do best (organize and analyze information) to help people do what they do best, those inspired leaps of intuition that fuel original ideas and breakthroughs.
That’s why we began Project Halo, a research program that is trying to create a Digital Aristotle. One near-term goal is Halobook, an electronic textbook that can answer typed-in questions with expert-level accuracy. Running on a laptop or tablet, Halobook could serve as a research aide for working scientists or as a tutor for college and high school students, like a personal digital teaching assistant.
In the inaugural Halobook, targeted for release in 2015, we’ll have encoded most of the Advanced Placement biology syllabus, something no one else has yet attempted. After that, we may reach into biochemistry or move to a whole new area, like civil engineering. We might even take on economics or U.S. government. The humanities—philosophy, religion, history, classics—would be much, much tougher. As subject matter shifts from how things work to the values and language that define the human condition (fairness, morality, love), software systems quickly move out of their depth. I recognized this roadblock as early as 1977, in my interview with Microcomputer Interface:
In order to be truly intelligent, computers must understand—that is probably the critical word. It is one thing to feed The Tale of Two Cities into a computer. It’s another to have the computer understand what’s being said. You can’t ask it a question about the theme of a book or why a character does something and get a coherent answer. We haven’t yet reached that level with intelligent computers.
And we still haven’t today, but we’re getting closer. (For a further explanation of Project Halo, see the appendix.)
Ultimately, a Digital Aristotle should make us more inventive and creative. With its steady progress in attacking classic problems like learning, language, and reasoning, I can foresee a time when artificial intelligence could greatly speed our ability to ferret out cures for diseases or help us preserve the environment. As Douglas Engelbart wrote in 1962 in Augmenting Human Intellect: A Conceptual Framework:
Man’s population and gross product are increasing at a considerable rate, but the complexity of his problems grows still faster, and the urgency with which solutions must be found becomes steadily greater. … By “augmenting human intellect” we mean increasing the capability of a man to approach a complex problem situation, to gain comprehension to suit his particular needs, and to derive solutions to problems. …
One of the tools that shows the greatest immediate promise is the computer, when it can be harnessed for direct online assistance, integrated with new concepts and methods.
As computing grows increasingly cheaper and more powerful, it is now conceivable that virtually all the world’s data will soon be found online. Organizing it coherently and logically will take a Herculean effort. Given the ever-accelerating expansion of human knowledge, not to mention its breadth and complexity, a final encyclopedia is an elusive goal. But it just might be closer than you think.
IN HIS ESSAY “The Law of Accelerating Returns,” the futurist Ray Kurzweil predicted that the increase in computer processing power will soon lead to a “singularity” of technological change “so rapid and profound it represents a rupture in the fabric of human history.” Kurzweil foresees the imminent arrival of “strong AI,” machines as smart as human beings, the first step in an accelerating progression of smarter and smarter machines—to the point that we’ll be able to download our personalities and self-awareness into computers and gain a sort of digital immortality.
Though I won’t say that a singularity is impossible, I believe that it is centuries away at best. Although Kurzweil credits Moore’s law as an inspiration, Gordon Moore agrees with me, noting that human development “involves a lot more than just the intellectual capability,” and doubting that machines “could overcome that overall gap. …” The sheer complexity of human brain function is daunting in the extreme. It took forty years to develop a computer chess program that could consistently beat the best human players, even though grandmaster-level chess can be achieved with simple sequential logic and brute-force processing. To get a computer to read and understand human language is incomparably harder. We can’t replicate the brain because we’ve barely begun to understand how it works.
There are two basic approaches to artificial intelligence, both of them journeys of thousands of small steps. You can take the Halo approach, in which we’re inventing software to emulate some of the things the brain can do. Or you can try to reverse-engineer the physical brain itself to see how it really functions, which is the story of an institute I founded in Seattle.