The Mpemba Effect
Photo credit: Live Science
The Mpemba effect has blown educated minds throughout history, including Aristotle and Francis Bacon. They observed what seemed like a freak of nature—that hot water freezes faster.
This phenomenon was named after Erasto Mpemba, a Tanzanian high school student, whose studies confirmed the ancient thinkers’ observations in 1963. He showed that the effect happens when hot and cold bowls were left in identical subzero temperatures and the warm water turned to ice first.
There are several theories to explain this madness. In the 1980s, Polish physicists attempted (and failed) to prove that warmer water might have less heat-retaining gas. A more likely reason could be that when hot water steams, evaporation reduces the mass that needs to be cooled.
Another factor might be warm water’s coolest point. In a container, cold liquid sinks to the bottom and pushes the hottest layer to the surface. This creates a current that speeds up freezing. However, the precise process that enables hot water to chill quicker than its colder cousin remains a mystery.
I find this interesting and have no idea of the science behind it. I figure that it's just one more way Mother Nature has to confuse us.
Coffee in the kitchen this morning. Lemon creme cookies anyone?