Now I get to do something with that force scale I built. I had a request some time ago to talk about friction. Friction is surprisingly complicated. When two surfaces rub against each other, why is ...

Everybody knows how a yo-yo works. It's two disks mounted on an axle attached to a piece of string, and it goes up and down if you throw it right. But what about when the two disks and the axle aren't ...

(Nanowerk News) If you even bother to think about friction at all, you might think about rubbing your hands together to warm them up. But friction is a big problem out in the world. Parts that rub ...