Your kid pushes a carrot off the table, what do you do? Duh — you invoke the 5-Second Rule and give it back to the kid. The next time someone (COUGH! Your wife) points out that the 5-Second Rule is not a real thing, show them this video, in which a NASA engineer explains that, yeah huh, it is too.
The video’s awesome, but this isn’t rocket science. For bacteria to hitch a ride on Junior’s carrot, it needs a perfect storm of moisture, exposed surface area, and time. As the engineer explains with his not-nearly-as-catchy 30 Second Moisture And Surface Rule: bacteria need moisture to thrive, so spaghetti on a tile floor equals big win for bacteria. Cookie on a shag carpet? Very few fibers actually touch the cookie, so you’re probably good to go. Spaghetti on a carpet? Not as bad as tile, but you probably already have bigger problems at that point.
So, dry food on a dry floor? Invoke the 5-Second Rule. If the food is covered in slobber and lands on a sticky subway car floor? Invoke the Common Sense Rule and let it lie. See? You’re as smart as a rocket scientist.
[H/T] The Daily Dot