Maxwell’s Demon — be the demon from the famous physics puzzle

How to play

1. Hold the door button, the field or the Space key to open the door. It closes again after one molecule passes.
2. Fast molecules glow orange, slow ones glow blue. Send the orange ones to the kettle side and the blue ones to the ice side.
3. Win by bringing the kettle side to 100 °C and the ice side to 0 °C and holding both for three seconds.
4. Earn up to three stars: for finishing, for speed and for sorting with few mistakes.
5. On levels with two doors, press 1 or 2 to choose the door.

A thought experiment you can play

Left alone, heat only flows from hot to cold, so a box of gas never splits itself into a hot half and a cold half. Maxwell asked what would happen if someone could pick and choose which molecules get through. Here you find out: with good timing you can boil one side and freeze the other at the same time.

The molecules move and collide on their own, so no two runs are the same and every opening of the door is a small decision.

Nine experiments

Each of the nine experiments changes one rule — a second door, a demon whose memory fills up, and more — so the puzzle keeps turning into something new. It is calm and tactile at first and surprisingly tense when the last molecules refuse to cooperate.