There are few things as refreshing as feeling the wind blow against your hair. There are few things as scary as violent winds smashing and crumbling a town. So what is wind? And where does it even come from?

PBS It's Okay to be Smart series answers that saying its air molecules bumping and bashing to create a force that makes pressure. But air pressure changes because of different temperature! And everything changes because the Earth rotates. It's a good brain exercise trying to wrap your brain around it. [PBS]