Seniors at Connecticut College tested the old adage and found out that it takes about half a minute for food to get germy on a cafeteria floor. Score! They tested apple slices and skittles and here is what happened (link to article is above):
"No bacteria were found on any food left on the floor for up to half a minute. Apple slices and Skittles both got germy after a minute (although one Skittle took five minutes)."
The real question is though, would you still want to eat an apple slice that was on a Cafeteria floor? It may not have bacteria on it, but whose hair is that?
This is excellent news for clumsy people everywhere! Why, just yesterday, while dining at a friend's, I dropped half a very delicious new potato on the floor. I have to confess that I did NOT eat it, despite being well within the limits of the five-second (thirty-second?) rule -- I was more worried about cat hair than bacteria, though.