Sunday, October 28, 2007

Grunting

Breaking news, scientists discover grunting.

Well, something like that anyway. For many years (at least as far back as Jimmy Connors) there has been debate in the tennis world about players who grunt and those who are distracted by it and want to forbid it.

It was shown recently that grunting does in fact have a positive effect on performance. link

To summarize, various study participants had a 1% - 5% performance boost if they grunted during weighlifting. And some rather colorful speculation as to why this works (or doesn't):
1. "Grunting quiets inhibitory nerves cells in the spinal cord. Those cells would normally impede the ability of muscles to contract and generate force."
2. "It's a psychological thing. But psychology is very important in sports in general -- if you think you can, it raises the possibility that you can."
3. "Some people grunt to give others the impression that [the grunters] are doing a lot of work. It's just like flexing and strutting, trying to attract attention."
4. "They're not breathing properly. In order to grunt, they have to hold their breath and exhale forcefully."

I have a confession. I used to not be a grunter, but I found one day that I had become one. I play soccer with college students half my age, and when I
need a burst of acceleration, I grunt loudly and instinctively. Once I realized I was doing that, the reason became clear, at least to me. I needed to force blood/oxygen into my leg muscles. The grunt does this by increasing blood pressure.

Now if only I can figure out why I yawn...

Monday, September 3, 2007

The end of Moore's law

Briefly, Moore's law is the observation, valid for the last four decades or so, that the number of transistors you can pack on a chip has been doubling every two years. This translates to computing power mostly because you can flip a smaller switch faster.

Eventually this must come to an end when the circuits reach the atomic level, around 2020. Some futurists (Vernor Vinge, Ray Kurzweil) think some other unspecified technology will allow the law to continue beyond this. It's fun to speculate about a technological singularity, where an AI becomes smarter than humans, and can advance the field so fast that humans can no longer participate meaningfully. Vinge predicts the end of the human era before 2030.

But lets be a little more sober for a sec. First of all, Moore's law is very nearly at a standstill already. The problem is, clock speeds reach a hard limit around 4GHz. After that they run too hot. Combine that with the fact that they can process a number of instructions on the order of 1, and you have a problem. That's why in recent years they have been making multi-core processors, and developing architectures that can execute two or even three instructions per clock tick. That will help for a while, but what happens when you have as many cores as processes? (note: someone recently put 1000 cores on one wafer)

Second, there is much more to AI than computing power. A computer can win at chess, by brute force computation. But the best go programs in the world cannot compete with even casual club players. And it's not for lack of trying. It's just that computers are not good at judgement. Correct me if I'm wrong, but no robot can run on two legs, because they can't balance well enough. Surely they already have the necessary computing power for that task. And visual perception is primitive. And is it really all that hard to figure out what letters are scribbled in those little boxes to foil spammers? Even the tiny brain of a mosquito exceeds our best AI efforts.

So, sorry Vernor. I don't know what's in store for 2100, but your singularity just ain't happening before 2030.