Wednesday, February 3, 2010

Ten to the 120th power

The other day Samuel was here with Don and they got to playing a game of chess. Their game was pretty sophisticated, although Samuel needs to develop more pieces and avoid bringing his queen out too early. As it turned out Don got to chasing Samuel's queen around with his pair of knights and that put him on the path to the win.

During the game Don got talking about playing chess on the internet and to practicing by playing against chess programs. That led to me mentioning this article I had seen by Garry Kasparov in which he discusses why even computers can't play chess by brute force calculation because the possible move combinations in a chess game is about 10 to the 120th power, or 10 followed by 120 zeros. That's an all but ungraspable number. I'm too lazy to look it up, but I think the number of elementary particles in the universe is something like 10 to the 86th power.

Even the first eight moves in a chess game allow for more move combinations than there are stars in the Milky Way Galaxy. Computers currently solve the first eight moves and many more; but they don't even come close to solving a full game. It's possible to imagine a computer that will "solve" chess the way a computer recently solved checkers; but there is no current technology that would allow a computer to be fast enough to fully compute a chess game. Current chess playing computers use shortcuts to rule out whole classes of move patterns that are unlikely to be successful as a way to cut down the possibilities.

If you're interested at all in chess or in how the human mind works here's that article by Kasparov in which he talks about how he beat the computers until IBM finally built Deep Blue. Deep Blue was finally fast enough to compute moves out beyond what Kasparov could do by intuition; but to beat him it still it needed the advice of a couple of human chess grandmasters who helped it by making suggestions for how to avoid traps.

Interestingly, Kasparov, a very smart and well rounded man who writes on many topics besides chess reveals in the article that he's more or less in awe of Bobby Fisher who was by no means a well rounded sort of fellow.

In other news Sam had to get a tetanus shot because of his little incident with the Cutco knife the other day. He's confident that his sewn up finger will be up to golf when he heads down to The Villages later this month.

Finally, Darwin got to describing his discovery of petrified trees high up in the foothills of the Andes, which reminded me of when Jas and I walked around Petrified Forest National Monument when we drove the southwest a few years ago. While we were walking the paved path Jas wondered if the park had gathered up all the petrified logs and put them near the visitor center. So we left the path at a point where we were out of sight of the ranger station and walked the dry washes for a couple of miles to see how much petrified wood there was out beyond where the tourists regularly go. There were other clumps of logs, although none as impressively dense as those near the visitor center.

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