THE ASCENDANCE OF SCIENCE AND TECHNOLOGY
545
Moore's Law is a paradigm that people have heard of: it reflects the
exponential growth of computers. You only have to open up your morn–
ing paper to see that this week's computers are far more powerful, less
expensive, and smaller than last week's. There's been some concern that
we're going to run out of space. Exponential trends eventually run out of
steam. That's true. Within approximately twelve years, the key features of
a transistor will only be a few atoms in width, and we won't be able to
shrink them any more. So is that going to be the end of Moore's Law?
Well, the answer is yes, that will be the end of Moore's Law for that par–
ticular paradigm, but it's not going to be the end of the exponential growth
of computing. To get some insight into that I put forty-nine famous com–
puters on an exponential chart-again, not a linear chart-so as you go
up the chart it represents multiplying computer power by a factor of, in
this case, a hundred. So at the lower left there's the electro-mechanical cal–
culators used in the
1890
American census, using punch cards. (Those
machines were subsequently shipped to the Florida election commission.)
Then in
1942
came relay-based computers, built out of old telephone
relays that Alan Turing and his colleagues used to crack the Nazi enigma
code.
In
1952,
vacuum tubes came in, and CBS predicted the election of
Eisenhower. They were shrinking vacuum tubes to be able to fit more of
them into a computer and make computers more cost-effective. They
finally couldn't shrink them anymore and keep the vacuum, and people
thought that was going to be the end of the exponential growth of com–
puting. Well, a whole different paradigm came along: transistors. It's a dif–
ferent approach, which kept the exponential growth going.
So integrated circuits is the fifth paradigm, not the first one, to provide
exponential growth to computing. When that runs out of steam we'll go to
the sixth paradigm, which is to go into the third dimension. Chips are very
dense, but they're flat, they're two dimensional. We live in a three–
dimensional world;
OUf
brain is three-dimensional. Even though our brain
uses a very cumbersome, slow form of information processing-our
interneural connections compute at about two hundred calculations per
second; that's ten million times slower than our electronic circuits today.
The brain gets its tremendous power because it is organized massively par–
allel, in three dimensions. There have been at least twenty different projects
that are making very significant progress developing three-dimensional cir–
cuits. Some use fallouts from biological technology, such as DNA comput–
ers. My favorite is carbon nanotubes, which are organized a bit differently
than the carbon of life. These are hexagonal arrays of carbon atoms that
can compute in three dimensions. A one-inch cube of nanotube circuitry
would be a million times more powerful than the capacity of the human
