It sounds completely counterintuitive, but whether hot water freezes faster than cold water has been debated for centuries.

The Mpemba Effect

The Mpemba effect is the term used for hot water freezing faster than cold water after a Tanzanian student named Erasto Mpemba found that his mixture of hot milk and sugar froze faster than his classmate’s mixtures that had been left to cool before freezing.

You can test to see if the Mpemba Effect occurs by placing two equal amounts of water in a freezer to investigate which freezes first. One sample should be at room temperature, and the second should be hot or boiling water.

If you’re interested in the quite complex science behind the Mpemba effect, How Stuff Works has a great article explaining it.

Last Updated on August 23, 2024 by Emma Vanstone