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P H V SIC S OF THE IMPOSSIBLE
THE BOTTOM-UP
APPROACH
Because of the limitations of the top-down approach to artificial intelligence, attempts have been made to use a "bottom-up" approach instead, that is, to mimic evolution and the way a baby learns. Insects, for
example, do not navigate by scanning their environment and reducing
the image to trillions upon trillions of pixels that they process with supercomputers. Instead insect brains are composed of "neural networks," learning machines that slowly learn how to navigate in a
hostile world by bumping into it. At MIT, walking robots were notoriously difficult to create via the top-down approach. But simple buglike
mechanical creatures that bump into the environment and learn from
scratch can successfully scurry around the floor at MIT within a matter of minutes.
Rodney Brooks, director of MIT's famed Artificial Intelligence Laboratory, famous for its huge, lumbering "top-down" walking robots,
became a heretic when he explored the idea of tiny "insectoid" robots
that learned to walk the old-fashioned way, by stumbling and bumping into things. Instead of using elaborate computer programs to mathematically compute the precise position of their feet as they walked,
his insectoids used trial and error to coordinate their leg motions using little computer power. Today many of the descendants of Brooks's
insectoid robots are on Mars gathering data for NASA, scurrying across
the bleak Martian landscape with a mind of their own. Brooks believes
that his insectoids are ideally suited to explore the solar system.
One of Brooks's projects has been COG, an attempt to create a mechanical robot with the intelligence of a six-month-old child. On the
outside COG looks like a jumble of wires, circuits, and gears, except
that it has a head, eyes, and arms. No laws of intelligence have been
programmed into it. Instead it is designed to focus its eyes on a human
trainer, who tries to teach it simple skills. (One researcher who became pregnant made a bet as to which would learn faster, COG or her
child by the age of two. The child far surpassed COG.)
For all the successes in mimicking the behavior of insects, robots
P H V SIC S OF THE IMPOSSIBLE
THE BOTTOM-UP
APPROACH
Because of the limitations of the top-down approach to artificial intelligence, attempts have been made to use a "bottom-up" approach instead, that is, to mimic evolution and the way a baby learns. Insects, for
example, do not navigate by scanning their environment and reducing
the image to trillions upon trillions of pixels that they process with supercomputers. Instead insect brains are composed of "neural networks," learning machines that slowly learn how to navigate in a
hostile world by bumping into it. At MIT, walking robots were notoriously difficult to create via the top-down approach. But simple buglike
mechanical creatures that bump into the environment and learn from
scratch can successfully scurry around the floor at MIT within a matter of minutes.
Rodney Brooks, director of MIT's famed Artificial Intelligence Laboratory, famous for its huge, lumbering "top-down" walking robots,
became a heretic when he explored the idea of tiny "insectoid" robots
that learned to walk the old-fashioned way, by stumbling and bumping into things. Instead of using elaborate computer programs to mathematically compute the precise position of their feet as they walked,
his insectoids used trial and error to coordinate their leg motions using little computer power. Today many of the descendants of Brooks's
insectoid robots are on Mars gathering data for NASA, scurrying across
the bleak Martian landscape with a mind of their own. Brooks believes
that his insectoids are ideally suited to explore the solar system.
One of Brooks's projects has been COG, an attempt to create a mechanical robot with the intelligence of a six-month-old child. On the
outside COG looks like a jumble of wires, circuits, and gears, except
that it has a head, eyes, and arms. No laws of intelligence have been
programmed into it. Instead it is designed to focus its eyes on a human
trainer, who tries to teach it simple skills. (One researcher who became pregnant made a bet as to which would learn faster, COG or her
child by the age of two. The child far surpassed COG.)
For all the successes in mimicking the behavior of insects, robots