Wednesday, April 22, 2009

Brains beat machines

On the Internet, transhumanism may be belittled as much as it is praised. Its science fiction dreams predict artificial intelligence, immortality through computing, and the wholesale re-engineering of mankind. Rev. David B. Hart described it as “a sensibility formed more by comic books than by serious thought.”

But its proponents are generally technology lovers who believe that foul devil Progress is on their side.
Derision, alas, is not enough to silence their claims.

Over at the New York Times, Sandra Aamodt and Sam Wang evaluate the prospective match-up of Computers vs. Brains.

Of the brain, they say:
One cubic centimeter of human brain tissue, which would fill a thimble, contains 50 million neurons; several hundred miles of axons, the wires over which neurons send signals; and close to a trillion (that’s a million million) synapses, the connections between neurons... unlike a computer, connections between neurons can form and break too, a process that continues throughout life and can store even more information because of the potential for creating new paths for activity.

Their back-of-the-envelope estimate suggests the human brain has a capacity for about one petabytes, one million gigs, of information. (They say all information stored on the internet only reaches three petabytes.)

The writers throw cold water on futurist Ray Kurzweil's optimism that Moore's Law (the so-far constant doubling of computer capacity) will overcome the difficulties. Even if it runs into no insurmountable design barriers, “By 2025, the memory of an artificial brain would use nearly a gigawatt of power, the amount currently consumed by all of Washington, D.C.”

The human brain runs on only 12 watts. If nigh-limitless power devices remain uninvented, substantive technological mock-ups of the human brain may never be possible.

Aamodt and Wang close on a humanist note.

...although it eventually may be possible to design sophisticated computing devices that imitate what we do, the capability to make such a device is already here. All you need is a fertile man and woman with the resources to nurture their child to adulthood. With luck, by 2030 you’ll have a full-grown, college-educated, walking petabyte. A drawback is that it may be difficult to get this computing device to do what you ask.

No comments: