Ever wonder if the five-second rule was really a rule? The Dr. Oz Show teamed up with NSF International to find out just that. NSF tested two food types, wet and dry (wet being an apple; dry, a wafer), on three different surfaces: tile, carpet, and concrete. After adding bacteria to each surface, food was dropped for two seconds, five seconds, and five minutes. After taking a culture of the food samples, the bacteria was counted to see if the rule was really valid. Watch this short video to find out the results.