How Do Heat Pumps Work?

Wired with another great piece on heat pumps.

And here’s a crucial fact: According to the second law of thermodynamics, thermal energy only transfers from hot things to cold things; it doesn’t go the other way. So despite what you might think, the ice cubes in your drink aren’t “cooling” the liquid; the liquid is heating the ice cubes—which means it’s losing energy and getting colder, while the ice gains energy and melts.

If you really want to bend people’s brains, just share this law of physics and you will start to see the wheels turn as they try to figure that out.

Send this article whenever someone you know is curious about heat pumps and how they work.