A few years later, the head of Mpemba's school invited British physicist Denis Osborne (1932-2014) from the University of Dar es Salaam to give a guest lecture on his work. At the end of the presentation, Mpemba asked the question that had been bothering him for so long: “If you take two beakers with equal volumes of water, one at 35°C and the other at 100°C, and put them into a refrigerator, the one that started at 100°C freezes first. Why?” Teachers and classmates present thought the claim absurd and mocked Mpemba for the question.
A few years later, the head of Mpemba's school invited British physicist Denis Osborne (born in 1932 and died in 2014) from the University of Dar es Salaam to give a guest lecture on his work. At the end of the presentation, Mpemba asked the question that had been troubling him for so long: "If you take two beakers with equal volumes of water, one at 35°C and the other at 100°C, and put them into a refrigerator, the one that started at 100°C freezes first. Why?" Teachers and classmates present found the claim ridiculous and ridiculed Mpemba for the question.