The answer is science! (But it's actually called the Mpemba effect)
| Channel | Publish Date | Thumbnail & View Count | Actions |
|---|---|---|---|
 SciShow | 2015-10-20 21:00:56 |  715,417 Views |
Does warm water freeze faster than cold water?
You’ve probably heard before that hot water freezes faster than cold water that’s the Mpemba effect. I remember my older sister telling me that when we were kids. I didn’t believe her then and didn’t believe her for years. It’s the kind of thing that sounds like a fairy tale.
When researchers at the School of Electrical and Electronic Engineering at Nanyang Technological University in Singapore proposed the most plausible explanation yet for the Mpemba effect [PDF] it was more evidence that a strange phenomenon persists.
But let's get one thing straight: there's really no debate that the Mpemba effect exists. It has been observed in countless controlled experiments.* Aristotle first noted its existence when he wrote about how ice fishermen would heat water to make it freeze faster more than two thousand years ago. The effect is named after Tanzanian Erasto Mpemba who as a high school student in 1963 noticed that warm ice cream mixes freeze faster than cold ice cream mixes. His question to visiting professor Dr. Denis G. Osborne "If you take two equal containers containing equal volumes of water one at 35 °C (95 °F) and the other at 100 °C (212 °F) and put them in a freezer the one that started at 100 °C (212 °F) freezes first. Why?" was initially ridiculed but Osborne later reproduced Mpemba's results and co-authored a paper with him explaining the observations in 1969.
