The Mpemba Effect
A pot of boiling water and a pot of cold water go into the same freezer. Which freezes first?
1963 (observed), 1969 (published)8 min read
British physics and science education
Denis Osborne
1932
British physicist who, during a visit to a school in Tanzania in 1966, was asked by student Erasto Mpemba whether his observation that hot water can freeze faster than cold water was real. Osborne tested it back in Dar es Salaam and confirmed it. He co-authored the 1969 paper in Physics Education that introduced the effect to the wider scientific community, crediting Mpemba in the title. The experiment described in that paper remains the canonical documentation of what became known as the Mpemba effect.