I learned to respect friction, as a phenomenon with many nuances, when I was a graduate student. One day, while teaching a problem session in elementary mechanics, I unwisely invented a new problem to ...

Explore how forces and friction work to hold a block against a vertical wall. This video explains normal force, frictional force, and equilibrium conditions, showing how these forces balance to ...

Really, this is the experiment I wanted to start on. How does friction work in Bad Piggies? Let me start with a quick summary of my experiments so far. Scale. For the size of stuff in Bad Piggies, I ...

Is friction real? Once, with the quiet certainty of someone who just stayed up all night in the company of equations describing concrete, my college roommate told me that friction was made up. Now, ...