Eli5: If heat is energy, how does cold wind exist? How can air move (have cold gusts of wind) if it’s not hot? Where does the energy for movement of cold air come from?

Question

I asked this in school and the teacher thought I was trolling and didn’t answer me. It’s been like 20 years and I still think about it, it drives me crazy lol.

In: Planetary Science

Answer 1

I think the main misunderstanding is that you’re thinking of “hot” and “cold” only in human terms. To an imaginary alien living on a planet with 1000 degree weather, even the warmest summer breeze on Earth would feel freezing cold.

“Cold” wind has plenty of heat energy in it. It’s just that our bodies happen to be hotter.

The other misunderstanding is that there are different types of energy. Heat is the vibration of atoms, roughly speaking. But it’s entirely possible for a cold thing to be moving very fast. Satellites in orbit are moving incredibly fast, but they don’t really heat up just because of that motion. And why should they?

To prevent confusion: fast moving things on Earth *do* tend to heat up, but only because they rub against the air or ground, and that rubbing creates heat. Also cars get heated up by the engine and bullets get heated up by the gunpowder explosion that shoots them.

If there were no air or ground (like in space) and no hot thing creating the motion (like an engine or explosion) then a very cold thing can move very fast indeed in space. Like a comet, which travels very fast but is made of ice.