For a long time, scientists have tried to figure out one of science’s greatest mysteries: why hot water freezes faster than cold water. Now, scientists have resorted to asking the public and offering a cash reward for the answer.
The Royal Society of Chemistry has offered £1,000 for a member of the public to find a convincing explanation.
The question was first posed in 1968, when Tanzanian student Erasto Mpemba met with professors visiting his school. Mpemba, who had been studying the problem for five years, asked Professor Denis Osborne of Dar es Dalaam University:
If you take two similar containers with equal volumes of water, one at 35°C and the other at 100°C, and put them in a refrigerator, the one that started at 100°C freezes first. Why?
The professor, unable to answer, published a paper about the problem the following year, calling the phenomenon the “Mpemba Effect.”
Brian Emsley, media relations manager at the Royal Society of Chemistry, wrote that the winner would need to “make a convincing case and employ some creative thinking.”
Theories about evaporation, convection, and supercooling have all been submitted.
The public has until July 30 to submit their entries.