There's an update to our story from Tuesday about those people who were busted on suspicion of using their cellphones to cheat at roulette. There had been some dispute over whether such a thing wes even possible but apparently it can be done, just not using cellphones with laser scanners, which is what the three people arrested at a casino in London are suspected of doing. According to Norman Packard, a physicist who tried to break the bank in Vegas in the Seventies, you have to use the cellphones as stopwatches:

Such a caper is "fairly easy to set up", he says. Just two equations - one for the ball and one for the wheel, which move in opposite directions - predict the likely area where the ball will stop. These equations comprise only a handful of parameters, including the mass and size of the ball, the shape and roughness of the track, and the tilt of the wheel. A scouting mission to the casino could give these values for a particular wheel and ball in advance, meaning the equations can be partially solved before attempting betting. The cell phones reportedly used in the alleged London scam could have been used to determine the ball's speed if buttons on the phones were pressed when the ball was released and then after one revolution, Packard says. In fact, some cell phones have their own built-in stopwatches.



Polishing your iPod