Here at the University of Illinois, nameless researchers (assumed to be graduate employees) toil to answer questions that plague humanity. Case in point:
It's the so-called 5-second rule, although some call it the 3- or 10-second rule. It's folk wisdom that says if you drop food on the floor and pick it up quickly enough, you can still eat it.
The real answer is yes and no. A lab intern at the University of Illinois at Urbana-Champaign actually carried out a study to prove whether the 5-second rule is valid. She tested one-inch squares of floor in high-traffic areas throughout the university and failed to find a countable number of bacteria or spore-forming organisms.
But when she took floor tiles, infected them with E. coli and then dropped food on the tiles, the food picked up the germs by simply coming in contact with the tile, regardless of how many seconds it spent there. [link]