填空题

Artificial Intelligence
I’m sure that Hans Moravec is at least as sane as I am, but he certainly brought to mind the classic mad scientist as we sat in his fifth-floor office at Carnegie-Mellon University on a dark and stormy night. It was nearly midnight, and he mixed for each of us a bowl of chocolate milk and Cheerios, with slices of banana piled on top.
Then, with banana-slicing knife in hand, Moravec, the senior research scientist at Carnegie Mellon’s Mobile Robot Laboratory, outlined for me how he could create a robotic immortality for Everyman, a deathless universe in which life would go on forever. By creating computer copies of our minds and transferring, or downloading, this program into robotic bodies, Moravec explained, humans could survive for centuries.
"You are in an operating room. A robot brain surgeon is in attendance ... Your skull but not your brain is anesthetized (麻醉). You are fully conscious. The surgeon opens your braincase and peers inside." This is how Moravec described the process in a paper he wrote called "Robots That Rove". The robotic surgeon’s attention is directed at a small clump of about one hundred neurons somewhere near the surface. Using high-resolution 3-D nuclear-magnetic-resonance holography, phased-array radio encephalography, and ultrasonic radar, the surgeon determines the three-dimensional structure and chemical makeup of that neural clump. It writes a program that models the behavior of the clump and starts it running on a small portion of the computer sitting next to you.
That computer sitting next to you in the operating room would in effect be your new brain. As each area of your brain was analyzed and simulated, the accuracy of the simulation would be tested as you pressed a button to shift between the area of the brain just copied and the simulation. When you couldn’t tell the difference between the original and the copy, the surgeon would transfer the simulation of your brain into the new, computerized one and repeat the process on the next area of your biological brain.
"Though you have not lost consciousness or even your train of thought, your mind--some would say soul--has been removed from the brain and transferred to a machine," Moravec said, "In a final step your old body is disconnected. The computer is installed in a shiny new one, in the style, color, and material of your choice."
As we sat around Moravec’s office I asked what would become of the original human body after the downloading. "You just don’t bother waking it up again if the copying went successfully." he said. "It’s so messy. Humans have got so many problems that you might just want to leave it retired. You don’t take your Junker car out if you’ve got a new one."
Moravec’s idea is the ultimate in life insurance. Once one copy of the brain’s contents has been made, it will be easy to make multiple backup copies, and these could be stashed in hiding places around the world, allowing you to embark on any sort of adventure without having to worry about aging or death. As decades pass into centuries you could travel the globe and then the solar system and beyond--always keeping an eye out for the latest in robotic bodies into which you could transfer your computer mind.
If living forever weren’t enough, you could live forever several times over by activating some of your backup copies and sending different versions of yourself out to see the world. "You could have parallel experiences and merge the memories later," Moravec explained.
In the weeks and months that followed my stay at Carnegie-Mellon, I was intrigued by how many researchers seemed to believe downloading would come to pass. The only point of disagreement was when--certainly a big consideration to those of us still knocking around in mortal bodies. Although some of the researchers I spoke with at Carnegie-Mellon, MIT, and Stanford and in Japan thought that downloading was still generations away, there were others who believed achieving robotic immortality was imminent and seemed driven by private passions never to die.
The significance of the door Moravec is trying to open is not lost on others. Olin Shivers, a Carnegie-Mellon graduate student who works closely with Moravec as well as with Allen Newell, one of the founding fathers of artificial intelligence, told me, "Moravec wants to design a creature, and my professor Newell wants to design a creature. We are all, in a sense, trying to play God."
At MIT I was surprised to find Moravec’s concept of downloading given consideration by Marvin Minsky, Donner Professor of Science and another father of artificial intelligence. Minsky is trying to learn how the billions of brain cells work together to allow a person to think and remember. If he succeeds, it will be a big step toward figuring out how to join perhaps billions of computer circuits together to allow a computer to receive the entire contents of the human mind.
"If a person is like a machine, once you get a wiring diagram of how he works, you can make copies," Minsky told me.
Although Minsky doesn’t think he’ll live long enough to download (he’s fifty-seven now), he would consider it. "I think it would be a great thing to do." he said, "I’ve spent a long time learning things, and I’d hate to see it all go away."
Minsky also said he would have no qualms about waving good-bye to his human body and taking up residence within a robot. "Why not avoid getting sick and things like that" he asked. "It’s hard to see anything against it. I think people will get fed up with bodies after a while. Then you’ll have another population problem: You’ll have all the people of the past, as well as the new ones."
Another believer is Danny Hillis, one of Minsky’s Ph. D students and the founding Scientist of Thinking Machines, a Cambridge-based company that is trying to create the kind of computer that might someday receive the contents of a brain. During my research, several computer scientists would point to Hillis’s connection machine as an example of a new order of computer architecture, one that’s comparable to the human brain. (Hillis’s connection machine doesn’t have one large central processing unit as other computers do but a network of 64,000 small units--roughly analogous in concept, if not in size, to the brain’s network of 40 billion neuronal processing units. )
"I’ve added up the things 1 want to do in my life, and it’s about fifteen hundred years’ worth of stuff," Hillis, now twenty-eight, told me one day as we stood out on the sixth-floor sundeck of the Thinking Machines building. "I enjoy having a body as much as anyone else does, but if it’s a choice between downloading into a computer--even one that’s stuck in a room someplace-- and still being able to think versus just dying, I would certainly take that opportunity to think."
Gerald J. Sussman, a thirty-six-year-old MIT professor and a computer hacker of historic proportions, expressed similar sentiments. "Everyone would like to be immortal. I don’t think the time is quite right, but it’s close. I’m afraid, unfortunately, that I’m in the last generation to die."
"Do you really think that we’re that close" I asked.
"Yes," he answered, which reminded me of something Moravec had written not too long ago: "We are on a threshold of a change in the universe comparable to the transition from nonlife to life.\
Moravec’s idea of robotic immortality is approved by the author.