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Out of Control

But Chris Langton doesn't find the prospect of artificial life creating its own civilization so goofy. Langton has gotten a lot of press for being the maverick who launched the fashionable field of artificial life. He has a good story, worth retelling very briefly because his own journey recapitulates the awakening of human-made, open-ended evolution.

Several years ago Langton and I attended a week-long science conference in Tucson, and to clear our heads, we played hooky for an afternoon. I had an invitation to visit the unfinished Biosphere 2 project an hour away, and so as we cruised the black ribbon of asphalt that winds through the basins of southern Arizona, Langton told me his life story.

At the time, Langton worked at the Los Alamos National Laboratory as a computer scientist. The entire town and lab of Los Alamos were originally built to invent the ultimate weapon. So I was surprised to hear Langton begin his story by saying he was a conscientious objector during the Vietnam War.

As a CO, Langton scored a chance to do alternative service as a hospital orderly at Boston's Massachusetts General Hospital. He was assigned the undesirable chore of transporting corpses from the hospital basement to the morgue basement. On the first week of the job, Langton and his partner loaded a corpse onto a gurney and pushed it through the dank, underground corridor connecting the two buildings. They needed to push it over a small concrete bridge under the only light in the tunnel, and as the gurney hit the bump, the corpse belched, sat upright, and started to slide off its perch! Chris spun around to grab his partner, but he saw only the distant doors flapping behind his coworker. Dead things could behave as if they were alive! Life was behavior; that was the first lesson.

Langton told his boss he couldn't go back to that job. Could he do something else? "Can you program computers?" he was asked. "Sure."

He got a job programming early-model computers. Sometimes he would let a silly game run on the unused computers at night. The game was called Life, devised by John Conway, and written for the mainframe by an early hacker named Bill Gosper. The game was a very simple code that would generate an infinite variety of forms, in patterns reminiscent of biological cells growing, replicating, and propagating on an agar plate. Langton remembered working alone late one night and suddenly feeling the presence of someone, something alive in the room, staring at him. He looked up and on the screen of Life he saw an amazing pattern of self-replicating cells. A few minutes later he felt the presence again. He looked up again and saw that the pattern had died. He suddenly felt that the pattern had been alive -- alive and as real as mold on an agar plate -- but on a computer screen instead. The bombastic idea that perhaps a computer program could capture life sprouted in Langton's mind.

He started fooling around with the game, probing it, wondering if it was possible to design a game like Life that would be open ended -- so that things would start to evolve on their own. He honed his programmer skills. On the job Langton was given the task of transferring a program from an out-of-date mainframe computer to a very different newer one. In order to do this, the trick was to abstract the operation of the hardware of the old computer and put it into the software of the newer one -- to extract the essential behavior of the hardware and cast it in intangible symbols. This way, old programs running on the new machine would be running in a virtual old computer emulated in software in the new computer. Langton said, "This was a first-hand experience of moving a process from one medium to another. The hardware didn't matter. You could run it on any hardware. What mattered was capturing the essential processes." It made him wonder if life could be taken from carbon and put into silicon.

After his service stint Langton spent his summers hang-gliding. He and a friend got a job hang-gliding over Grandfather Mountain in North Carolina for $25 per day as an airborne tourist attraction. They stayed aloft for hours at a time in 40-mile-per-hour winds. Swiped by a freak gust one day, Langton crashed from the sky. He hit the ground in a fetus position and broke 35 bones, including all the bones in his head except his skull. Although he smashed his knees through his face, he was alive. He spent the next six months on his back, half-conscious.

As he recovered from his massive concussions, Langton felt he was watching his brain "reboot," just as computers that are turned off have to rebuild their operating system when turned back on. One by one certain deep functions of his mind reappeared. In an epiphany of sorts, Langton remembers the moment when his sense of proprioception -- the sense of being centered in a body -- returned. He was suddenly struck with a "deep emotional gut feeling" of his own self becoming integrated, as if his machine had completed its reboot and was now waiting for an application. "I had a personal experience of what growing a mind feels like," he told me. Just as he had seen life in a computer, he now had a visceral appreciation of his own life being in a machine. Surely, life must be independent of its matrix? Couldn't life in both his body and his computer be the same?

Wouldn't it be great, he thought, if he could get something alive with evolution going in a computer! He thought he would start with human culture. That seemed an easier simulation to start with than simulated cells and DNA. As a senior at the University of Arizona, Langton wrote a paper on "The Evolution of Culture." He wanted his anthropology, physics, and computer science professors to let him design a degree around building a computer to run artificial evolution, but they discouraged him. On his own he bought an Apple II and wrote his first artificial world. He couldn't get self-reproduction or natural selection, but he did discover the literature of cellular automata -- of which the Game of Life, it turned out, was only one example.

And he came across John von Neumann's proofs of artificial self-replication from the 1940s. Von Neumann had come up with a landmark formula that would self-replicate. But the program was unwieldy, inelegantly large and clumsy. Langton spent months of long nights coding his Apple II (a handy advantage that von Neumann didn't have; he did his with pencil on paper). Eventually guided only by his dream to create life in silicon, Langton came up with the smallest self-replicating machine then known to anyone. On the computer screen the self-replicator looked like a small blue Q. Langton was able to pack into its loop of only 94 symbols a complete representation of the loop, instructions on how to reproduce, and the trick of throwing off another just like itself. He was delirious. If he could engineer such a simple replicator, how many of life's other essential processes could he also mimic? Indeed, what were life's other essential processes?

A thorough search of the existing literature showed that very little science had been written on such a simple question, and what little there was, was scattered here and there in hundreds of tiny corners. Emboldened by his new research position at the Los Alamos Labs, in 1987 Langton staked his career on gathering an "Interdisciplinary Workshop on the Synthesis and Simulation of Living Systems," -- the first conference on what Langton was now calling Artificial Life. In his search for any and all systems that exhibit the behavior of living systems, Langton opened the workshop to chemists, biologists, computer scientists, mathematicians, material scientists, philosophers, roboticists, and computer animators. I was one of the few journalists attending.