Last night, Terminator 3 was on television. I'd never seen the movie, so this gave me a chance to make fun of all the computer stuff in it.
The computer that controlled our national defense was a 60 Teraflops machine, meaning that it was capable of doing sixty trillion floating point operations per second. (A floating point operation is just any basic arithmetic operation involving a decimal point: 1.1+1.1, for example.) I looked at the Top 500 list from 2003, the year the movie came out, and the fastest supercomputer was the Earth Simulator, at 36 Teraflops, which had come out the year before, so I suppose that machine would have been considered super-powerful.
It's just that, to me, a 60 Teraflops machine is quaint. I work with a machine that is 1.6 Petaflops (that's 1.6 quadrillion floating point operations per second). Let me say something about these machines, though.
First, they are very delicate. In the movie, John Connor talks about having enough C4 to take out ten supercomputers, which made me laugh again. You don't need C4 to take out a supercomputer. The easiest way is to destroy its air conditioning system. Without air conditioning, it will be a pile of silicon goo in no time. If it is so smart that it has a backup system (more on the intelligence of these machines in a minute, by the way), then seriously, it would be pretty easy to just go in and pull out a few boards and cables and do a lot of damage. A machine that is fault-tolerant enough to handle something like that is but a dream at this point in time. And furthermore, you could probably just wait a couple of days and the machine would go down on its own. Without human intervention, these machines are helpless.
Second, supercomputers are stupid. They are tremendously skilled at performing floating point operations, but that is a far cry from intelligence. Our brains operate a whole lot differently than a computer's processors. Artificial intelligence is really the holy grail of computer science. All the petaflops in the world aren't going to help anything. I mean, humans are pretty flops-deficient, yet we've accomplished a lot more with our intelligence than computers have.
Here's just how flops-deficient we are compared to computers: if we took everyone in the world (babies, old people, and everyone in between) and we all did floating point operations at a rate of one flop per second (which is a pretty fast pace), it would take us more than three days to do what it takes my friendly neighborhood supercomputer to do. But floating point operations aren't the way that our intelligence operates, whereas they are the only way that a computer's intelligence operates. And there's not a very good way to use floating point operations to mimic our type of intelligence, which is why even a petaflops machine would not be able to take over the world.