Most people have heard of the "five second rule"—that if food spends just a few seconds on the floor, dirt and germs won't have enough time to contaminate it. Parents sometimes apply the rule to pacifiers (after their first child of course). The history of the five-second rule is difficult to trace. One legend attributes the rule to Genghis Khan, who declared that food could be on the ground for five hours and still be safe to eat.

But a 2016 experiment should permanently debunk the five second rule. Professor Donald W. Schaffner, a food microbiologist at Rutgers University, reported that a two-year study concluded that no matter how fast you pick up food that falls on the floor, you will pick up bacteria with it. You can check it out for yourself in his journal article "Is the Five-Second Rule Real?" found in the always exciting journal for Applied and Environmental Microbiology.

Professor Schaffner tested four surfaces—stainless steel, ceramic tile, wood, and carpet—and four different foods: cut watermelon, bread, buttered bread, and strawberry gummy candy. They were dropped from a height of five inches onto surfaces treated with a bacteria. The researchers tested four contact times—less than one second and five, 30 and 300 seconds. A total of 128 possible combinations of surface, food, and seconds were replicated 20 times each, yielding 2,560 measurements. So after those 2,560 drops they found that no fallen food escaped contamination, leading Professor Schaffner to conclude, "Bacteria can contaminate instantaneously." In other words, they debunked the legendary five second rule.

Possible Preaching Angles: False Teachings; False Doctrine; Doctrine—We suggest a tongue-in-cheek retelling of this study (after all, the five-second rule is kind of a joke anyway) and then asking, What other biblical, theological, cultural, or lifestyle legends we've adopted without critical study.