Does Hot Water Freeze Faster Than Cold Water?
Hot water can freeze faster than cold water.
This strange fact is called the “Mpemba Effect”—named after the Tanzanian scientist Erasto Mpemba.
Mpemba described the effect in 1963 when he was 13.
As a student, he made hot and cold ice cream mixes for a cooking class.
He then noted that the hot blends froze before the cold ones.
He told his physics teacher about this effect, but the teacher laughed and said it was not real science.
But later, in high school, Mpemba invited a visiting physicist to test his discovery.
As it turned out, Mpemba was right.
In 1969, the physicist and Mpemba wrote a report on their research, and the name “Mpemba Effect” was born.
In 2012, the Royal Society of Chemistry gave a £1,000 prize for the best explanation of the effect.
The winning theory said that hot water “flows” more when chilled, so it freezes faster.
