Can Hot Water Freeze Faster than Cold Water?
” Thorough background research, a precise formulation of the hypothesis, and careful experimental design are especially important for the success of this experiment. Introduction It may seem counterintuitive, but folk wisdom and a body of published evidence agree that, under some conditions, warmer water can freeze faster than colder water (for an excellent review on the subject, see Jeng, 2005). This phenomenon has been known for a long time, but was rediscovered by a Tanzanian high school student, Erasto Mpemba, in the 1960s. He and his classmates were making ice cream, using a recipe that included boiled milk. The students were supposed to wait for the mixture to cool before putting it in the freezer. The remaining space in the freezer was running out, and Mpemba noticed one of his classmates put his mixture in without boiling the milk. To save time and make sure that he got a spot in the freezer, Mpemba put his mixture in while it was still hot. He was surprised to find later that
