Hot Water Freezes Faster Than Cold

It’s a puzzle that defies everyday intuition: under the right circumstances, a container of hot water will turn to ice before an identical container of cold water. This strange phenomenon is known as the Mpemba effect, named after the Tanzanian high school student who brought it to the scientific community's attention. In 1963, while making ice cream for a school project, Erasto B. Mpemba observed that his hot mixture froze much faster than the cooler batches prepared by his classmates. After his teacher dismissed the observation as impossible, Mpemba posed the question to a visiting university physicist, who was intrigued enough to conduct experiments and confirm the boy's findings.

Decades later, there is still no single, universally accepted explanation for the effect, though several compelling theories exist. One leading idea points to evaporation: hotter water loses more mass through steam, leaving less volume to freeze. Another possibility involves dissolved gases, which are less soluble in hot water; since these gases can slightly inhibit the formation of ice crystals, their absence could speed up the process. Other theories focus on convection