To give a cash prize to someone who can explain a very interesting phenomenon, made a promise to British scientists. Anyone can get $1000 for answering a strange question: why hot water freezes faster than cold.
One student once asked his teacher a question: "Why, if you put in the freezer two vessels with water at room temperature and boiling water, first freeze hot water?" This question is put in the awkward position of Professor Denis Osborne. Not finding the answer, Osborne wrote a scientific article, calling this phenomenon the Mpemba effect.
To explain this scientific fact tried in the days of Aristotle, but still no one was able to prove why hot water freezes sooner than cold. So Brian Emsley, head of media relations the Royal society of chemistry, guaranteed prize of 1,000 pounds to anyone who will explain this phenomenon.