In 1997, when IBM’s “Deep Blue” beat chess master Garry Kasparov, it seemed like the computers were on the verge of taking over. Now, the computers have taken one step closer to total domination. A machine designed by Google just to beat a master at Go, an ancient board game that’s even more complicated than chess. It’s a major milestone for the humans designing the artificial intelligence that will power the next generation of computers. But how big a step?