Chapter 28 Chapter 6 Life on the Edge of Chaos

On a sunny morning on September 22, 1987, Brown Arthur had just been invited to participate in a new economics research project at the Santa Fe Institute, so he got into a car sleepily, and John Holland Go to Los Alamos together for an artificial life workshop.The five-day seminar had started the day before. Arthur was still a little confused about the exact meaning of "artificial life".In fact, last week's economics seminar had exhausted him.He's a little bit out of his mind about a lot of things now.Holland explained to him that artificial life is similar to artificial intelligence.The only difference is that artificial life uses computers to simulate the basic biological mechanisms of evolution and life itself, instead of using computers to simulate thought processes like artificial intelligence.Holland said that the research on artificial life is very similar to his research on genetic algorithms and classifier systems, except that the research on artificial life is more extensive and has a greater appetite.

The entire artificial life research is the labor of Los Alamos postdoc Chris Langton.Langton was a student of Holland and Box at the University of Michigan.Langton was like a late bud, Holland said.At thirty-nine, he is ten years older than most postdocs, and he has not yet begun his last-ditch effort to complete his dissertation.But he was a very outstanding student. "He has a very rich imagination and is very good at summing up various experiences." Langton put a lot of energy into this artificial life seminar.The artificial life was his baby, he had named it, and spent nearly a decade trying to articulate the concept.He planned the workshop as an attempt to turn artificial life into a real scientific discipline.But he didn't know how many people would come to the meeting.He ignited the Los Alamos Nonlinear Research Center's confidence in artificial life research, which made it sponsor $15,000 for the seminar, persuaded the Santa Fe Institute to invest $5,000 for the conference, and Agreed to publish a collection of conference proceedings as part of a series of books on complexity theory.Judging from the situation at the beginning of yesterday's meeting, Holland thinks Langton has done a very good job.Arthur would have to come and see for himself to know.

Indeed, Arthur came to see it himself.When he and Holland entered the auditorium, he quickly got two impressions.The first impression was that he had greatly underestimated his roommate. "It was as if I walked into the synagogue with Gandhi," he said. "I thought I was in the room with a small, pleasant computer whiz, and here people thought he was a great figure in the field. In the corridors of the conference hall, people flocked to him, chanting : 'John Holland!' kept asking him, what's your take on this question? What's your take on that question? Did you get the paper I sent you?"

Arthur's roommate tried to answer these questions as he walked, but still lost sight of the other.Holland was already famous, which embarrassed him.In the past 25 years, he has trained one or two doctoral students every year, so he has many followers of his theories, and they spread his ideas everywhere.Meanwhile, the world is closing in on him.Neural networks are trendy again.Coincidentally, the problem of learning has also become the hottest topic in the mainstream of artificial intelligence. The first international academic conference on genetic algorithms was held in 1985, and such conferences will be held soon. "Everybody's standard opening line seems to be, John Holland said such and such, and here's my take on his theory."

Arthur's second impression was that the artificial life was strange.He never saw Langton's face.It was a rather lanky fellow with long, thick brown hair and a wrinkled face that made him look a lot like the young and affable Walter Marshall, the famous American character actor.Langton is always busy, copying materials, installing something, worrying about something, frantically trying to make everything work as expected. So Arthur simply passed the time looking at the computer demonstrations arranged in the corridors surrounding the conference hall.It was the most wonderful computer demonstration he had ever seen: animated flocks of birds flying suddenly on the electronic screen, lifelike plants growing and developing right on the screen in front of your eyes, and those weird and strange things that fluctuated and sparkled. Fragmentary organisms and models.All of this is dizzying, but what does it mean?

And those speeches!All Arthur heard was a mixture of bold thinking and solid experience.No one seemed to know what the speaker was going to say until he stood up to speak.Many of them wore ponytails and jeans (one woman stood up barefoot to speak). The word "emerge" keeps popping up in speeches.And more importantly, there is an uncanny exuberance and camaraderie and loyalty here, an atmosphere that breaks down barriers and unleashes new ideas, an atmosphere of freedom that is spontaneous, unpredictable, and open-minded. .The artificial life symposium smacks of rebellion in a strangely intellectual way, like the post-Vietnam counterculture movement.Epiphany at Massachusetts General Hospital

Although Chris Langton can't remember the exact date of the birth of artificial life, he still remembers that moment clearly.That was late 1971, or early 1972, in winter anyway.Like a standard computer freak, he was alone on the sixth floor of Massachusetts General Hospital in Boston, sitting in front of the console of a PDP-9 computer as huge as a desk in the Department of Psychology, at three in the morning. Point is still fixing computer coding errors. He likes this way of working."It's not because we have to be here at a certain time to work," Langton explained. "The man in charge of the place, Frank Ervin, is a very creative, very good guy. He hires A group of bright young people came to program and gave them full freedom. So, serious people come here during the day to do some extremely boring programming, but we are used to coming here at four or five o'clock in the afternoon and staying here all the time. Until three or four o'clock in the morning. During this time we can play on the computer as much as we want."

Indeed, as far as Langton was concerned, programming was the most fun game.Programming wasn't his deliberate career choice.After being dropped out of a college two years ago, he came to Massachusetts General Hospital to perform alternative service duties as a conscientious opponent of the Vietnam War, but soon he couldn't help but become involved with Alvin's group.In fact, aside from what little he learned in middle school summer classes, he was almost entirely self-taught in his programming skills.But as soon as he got involved in the computer, he was intoxicated with it, and he stayed at Massachusetts General Hospital until he fulfilled his obligations.

"Computer programming is amazing," he said. "I'm a machinist at heart, and I like to build things, and I like to see these things actually work." Of the hardware structure on the PDP-9 computer, he said: "You have to understand the operation mechanism of the hardware in a chain. ...you have to take into account the actual capabilities of the computer hardware when you program it. Say, 'store this particular name in memory, and get it back,' is a logical instruction, but it's also very mechanical." At the same time he liked the eccentric abstract games in which he got involved.A good example of this is his first project to allow experimental psychologists to run programs on PDP-9 computers.They have been recording data on the old, extremely slow PDO-SS type machine for many years, and they have reached the point where they can't bear it.But the problem is that they have developed various software with special functions on the PDO-SS machine, and these software cannot run on the PDP-9 machine, and they don't want to rewrite the program for changing the computer.So Langton was tasked with writing a program that would trick legacy software into thinking it was still running on the old machine.In other words, he had to write a virtual PDP-SS program inside the PDP-9.

"I didn't take a formal computer theory course; so my first introduction to the concept of a virtual computer was purely instinctive, by creating a virtual computer environment," Langton said. "I liked it immediately. Concept. The abstraction of the workings of a real computer into a program means that the program has captured all the important features of the computer, and you can leave the hardware behind." He said, anyway, on that special night, I was fixing coding errors, knowing that he couldn't run anything on the machine for a while, so he pulled it out of the box in front of the computer's big cathode ray tube Take a roll of paper tape, insert it into a tape reader, and start playing the Game of Life on your computer.

This is one of his favorite computer games."We got this software program from Bill Gosper's group, who were playing the 'Game of Life' at MIT. We're playing it too," Langton says. The game has an irresistible allure force.This program, developed a few years ago by British mathematician John Conway, isn't really a game you can play.It's more like a miniature universe that can evolve to your will.At the beginning, only one image of the universe appears on the computer screen: a flat coordinate grid filled with "living" black squares and "dead" white squares, the initial pattern can be manipulated by you.But once you get the game going, the cubes come to life or die according to a few simple rules.Each block of each generation must first look around its neighbors. If there are too many living blocks in the neighbors, the next generation of this block will die due to the excess amount.If there are too few survivors among its neighbors, the block will die of loneliness.But if there are two or three "living" blocks among its neighbors in the right ratio, the next generation of this block will survive.That is to say, either this next generation is already alive and can continue to survive, and if not, a new generation will be produced. It's that simple.These rules are just a caricature of biology.However, the wonderful thing about the "Game of Life" is that when you turn these simple rules into a computer program, it seems that you can really make the computer screen come to life.Compared with the computer screens you can see today, the game's motion is very slow and sluggish, as if it was replayed in slow motion on a video recorder.But if you pay attention, you can see the computer screen seething with activity, like looking at microbes in a drop of pond water under a microscope.You can start with a few living blocks at will, and watch how they quickly self-organize into various coherent structures.Some of the structures are tumbling endlessly, and some of the structures are oscillating like the breath of a wild animal.You'll also find "gliders," small clusters of living cells that glide across the screen at constant speed.You'll also see the "glider gun" that steadily fires out new gliders, as well as other structures that are there to devour gliders calmly.If you're lucky, you might even see a "Chesha cat" like the one in the movie, slowly disappearing, leaving behind only smiles and footprints.The patterns that appear on the screen will vary with each replay, and no one can exhaust the possibilities."The first patterns I saw were big, stable jewel-like structures," Langton said. "But when you add a glider from the outside, you disrupt this flawless crystalline beauty. The structure slowly dies." To disappear without a trace, as if the glider were some foreign contagion. It's as if it were Andromeda's lineage." So that night, the computer was beeping, little graphics animating on the computer screen, and Langton was fixing coding errors. "Once I glanced up at the computer screen where the Game of Life was zigzagging away. Then I glanced again at the computer code I was modifying. The hairs on the back of my neck stood on end. I felt There are others in this room." Langton looked back, thinking that one of his colleagues was secretly standing behind him.It was a crowded room, with a huge blue cabinet containing a PDP-9, many shelves for various electronic equipment, and an old EEG recorder and oscilloscope tubes.There were boxes huddled in corners, long lines of wires and pipes trailing all over the floor, and many things that were never used.It's a true computer geek's paradise.But no one stood behind him, no one hid there, he was completely alone here. Langdon looked back at the computer screen. "I realized that the 'Game of Life' must be at work. Something was alive on the computer screen. I can't express how I felt at that moment, I couldn't tell what was the hardware from what was the process. It’s a deep realization that what’s happening on the computer isn’t really that different from what’s happening in my body. What’s happening on the computer screen is really the same process of those two things.” "I remember looking out the window late at night, and the computer was still running loudly. It was a clear cold night, the stars were twinkling in the sky, and I could see the Science Museum and the surrounding area across the Charles River in Cambridge from the window. I think about the pattern of movement and everything that happens in it. The city just lies there, it's alive, it's like the same thing as the 'Game of Life'. Of course it's much more complicated, but It doesn't make a difference."