When Mpemba learned a few years later that this seemed to contradict the theory of heat transfer devised by Isaac Newton, he asked a visiting university professor from Dar es Salaam, DG Osborne, what was going on. Osborne asked his technician to repeat the experiment and in 1969 he published the result in a physics education journal.
Yet no one really knows if the Mpemba effect is real. You'd think it should be easy to check, but it isn't. Ice specialist Charles Knight of the National Centre for Atmospheric Research in Boulder, Colorado, says that the claim is so ill-defined it's virtually meaningless. Does it mean when ice first starts to appear, or when the last bit of water is frozen?
