All you see is a smudge (a white smudge if that makes sense) but the whole crowd knows what it means. The player is out “leg before wicket,” the match is lost, and it’s time to pack up and go home. This is Hot Spot, a new high-tech way of gathering more and better information for sporting decisions in the game of cricket. Cameras sense and measure the heat that comes from the thumps and bangs of play, and the spot is white because the computerized infrared image left by the ball is negative, white on a black or gray ground.

Time was when cricket umpiring relied on the human eye. Umpires standing at each end of a cricket pitch, twenty-two yards long, had to guess whether the ball had actually struck the bat, or the stumps, or the batsman’s leg, before giving a decision “out” or “not out.” Some seemed to have worse eyes and ears than others and mistakes were made. This didn’t matter when the game was synonymous with the decorum of leisurely afternoon play on an English village green. But that was long ago. At international cricket matches today, one hundred thousand fans produce constant uproar, and calls are a matter of life and death—though some say it’s more important than that.

Adjudication has assumed diplomatic importance: the very latest science is employed, a billion vicarious spectators on the Indian subcontinent hang breathlessly upon news about the score, and it’s hardly surprising that