Is artificial intelligence ready to rule the world?

THIS week humankind was delivered a body blow by an artificial intelligence (AI) called AlphaGo that beat Go's world champion, Lee Sedol, so is it now time for humans to let the machines rule the world? Not just yet--while this adds to a growing list of machines that have beaten the best humans at chess, checkers and backgammon, Lee Sedol won a game back against AlphaGo, so there is still hope for us. The ancient Chinese strategy game Go has substantially more moves to consider each turn than chess. With the two players having to look several moves ahead with more possible outcomes than there are atoms in the universe before deciding what move to make. For each move in a game such as Go, the AI uses a tree search that plays out scenarios, notes which lead to the most victories, and then works back to find out the next move that will lead to the best scenario.