Why Does Hot Water Sometimes Freeze Faster than Cold Water?
The Royal Society of Chemistry is offering a £1,000 prize to anyone who can crack this age-old ice puzzle.
The problem of why hot water sometimes freezes faster than cold, known as the Mpemba effect, defeated Aristotle. We know that Aristotle said: "All paid jobs absorb and degrade the mind." We can be pretty sure he said: "One swallow does not make a summer." But we can hazard a guess that at some stage he would also have declared angrily: "This bloody ice thing is doing my head in."
The great Athenian polymath couldn't solve the mystery of why hot water sometimes
freezes faster than cold water. He must have been annoyed to be defeated by what
appears to be such a simple question.
But here we are, more than two thousand years later and we still don't know the answer to what has become known as the Mpemba effect. The moon has been walked upon, Mars has been explored, hearts transplanted – but that old chestnut of ice and hot water still baffles humankind.
The Royal Society of Chemistry has decided enough is enough. In an attempt to nail the matter once and for all, we're asking the public to come up with a convincing
explanation of a phenomenon that defeated Aristotle, Francis Bacon and René
Descartes. To win the £1,000 prize, you will need to make a convincing case and employ some creative thinking.
The deadline for public entries is 30 July, because hard on the public's heels will be a
bunch of the world's acutest postgraduate scientists who, sponsored by the Royal
Society of Chemistry, will be attacking the same problem while locked in a posh hotel in Windsor Great Park during the first week of the Olympic Games.
The 60 brains are part of Hermes 2012, a project to harvest some of the brightest talent from around the globe: a cerebral Olympian gathering, one might say. They will be in Windsor to compete against each other in the project, run with major input from Imperial College.
If those flying in next month are anything like Aeneas Wiener, Jassel Majevadia and the other students at Imperial who are running the show, the rooms at the Cumberland Lodge Hotel will need to be spacious to accommodate their brains. It was these Imperial postgraduates who proposed the Mpemba effect as a perfect example of science in action, and the outcome was the RSC's £1K reward.
We are asking anyone who thinks they can crack this age-old ice puzzle to go to the
Hermes website, where they can submit their theory.
Brian Emsley is media relations manager at the Royal Society of Chemistry.
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See story at http://www.guardian.co.uk/science/blog/2012/jun/26/hot-water-freeze-faster-cold-water