Artificial intelligence: Game over
AlphaGo, a computer program, has defeated Lee Sedol, a human Go grandmaster, in a five-game match, 4-1. The complex game had hitherto been a redoubt of human mental superiority. Tech companies are throwing money at the technology behind AlphaGo. Games make a good testing ground for artificial intelligence, but firms hope eventually to apply the technology in medicine and scientific research.