دانلود کتاب ماشین، پلت فرم، جمعیت

Learning to play Go well has always been difficult for humans, but programming computers to play it well has seemed nearly impossible. Go is a pure strategy game—no luck involved*—developed at least 2,500 years ago in China. One player uses white stones; the other, black. They take turns placing stones on the intersections of a 19×19 grid. If a stone or group of stones has all of its freedoms removed—if it’s completely surrounded by opposing stones, essentially—it’s “captured” and taken off the board. At the end of the game† the player with more captured territory wins. People who love strategy love Go. Confucius advised that “gentlemen should not waste their time on trivial games—they should study Go.” In many quarters, it’s held in higher regard even than chess, another difficult two-person, luck-free strategy game. As the chess grand master Edward Lasker says, “While the Baroque rules of chess could only have been created by humans, the rules of Go are so elegant, organic, and rigorously logical that if intelligent life forms exist elsewhere in the universe, they almost certainly play Go.” The game’s apparent simplicity belies a complexity that’s difficult to even conceptualize. Because of the large board and the great freedom that players have in placing their stones, it is estimated that there are about 2 × 10^170 (that is, 2 followed by 170 zeros) possible positions on a standard Go board. How big is this number? It’s larger than the number of atoms in the observable universe. In fact, that’s a completely inadequate benchmark. The observable universe contains about 1082 atoms. So, if every atom in the universe were itself an entire universe full of atoms, there would still be more possible Go games than atoms.