1.1 What is friction? Take this everyday example: when a coffee mug rests on a flat table, the kinetic frictional force is zero. There is no force trying to move the mug across the table, so there is ...

The familiar heat, wear and general grinding to a halt of friction are all caused by what's going on at the microscopic level when two things rub. And down there, even the smoothest surfaces usually ...

In today's episode, Shini tells us about Static and Kinetic friction. Why is it hard to move a heavy bookcase across a carpeted floor? And why is it easier to keep it moving than it was to get it ...

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 ...

Moiré pattern evolution. Courtesy: Andrea Silva and Xin Cao. If you’ve ever struggled to shift a heavy piece of furniture, you have probably noticed that rotating the furniture while pushing it makes ...

If you have ever been near a train when it starts to move, you see (and hear) something interesting. The engine car at the front starts to move and in doing so, you get this wave of compressing ...