Sometimes the simplest question can lead down a deep rabbit hole to new worlds. How fast germs contaminate food that falls on the floor is a good example of such a question. When you start to think about it, you realize that you don’t quite now what it means for two objects to touch, and when you start analyzing the microscopic and then the quantum mechanical details, you cross multiple scientific disciplines.
This is the intellectual journey that Michael Stevens goes on in his video that debunks the “five second rule,” a popularly held belief that food that falls on a dirty floor is safe to eat if it is picked up quickly enough. One of the main benefits of this type of video is its ability to connect seemingly unrelated issues and motivate viewers to conduct their own thought experiments. You may think it’s a silly question, but you’re sure to be surprised by at least some aspects of the answer.