Refrigerators cool food by moving heat outward rather than by creating coldness from nothing.

The longer version

Cooling machines work by shifting heat from one place to another rather than destroying it. A fluid inside the system evaporates in the cold compartment, soaking up energy as it changes state, then travels outside where it is compressed back into a liquid and gives that energy up.

Work is needed to run the compressor, and that energy ends up as warmth released at the back. The insulated box simply slows the leak of heat back in. Because the process moves energy against its natural direction, it always consumes power, and the room housing such a unit grows slightly warmer overall.

Where this entry sits

Everyday physics and chemistry hide small wonders in plain sight, from kitchen reactions to the light in the sky. These short facts explain matter, energy, electricity, magnets, sound, and the simple units we use to measure the world. The full list sits on the Science and Physics page, where every entry is listed in order.