Summary
Aristotle, Rene Descartes and Sir Francis Bacon have all observed that hot water may actually cool more quickly. The modern term for hot water freezing faster than cold water is the Mpemba effect.
Erasto Mpemba made the discovery in 1969 in a paper published in the journal Physics Education. Mpmba was a teenager in Tanzania when he and his classmates were making ice cream. His mixture had frozen into ice cream, whereas those of his more patient classmates remained a thick liquid slurry.
Over the decades, scientists have offered a wide variety of theoretical explanations to explain the Mpemba effect. Some have suggested that heating water might destroy the loose network of weak polar hydrogen bonds between water molecules.
Aristotle wrote in the fourth century BCE that “many people, when they want to cool water quickly, begin by putting it in the sun,” the benefits of which were presumably noticeable. School-age Mpemba was similarly able to observe the unsubtle difference between his frozen ice cream and his classmates’ slurry.
The Mp3 is a device that allows the user to see the full extent of a person’s body. The Mp2 is used to monitor the body’S temperature.
The Mpemba effect could appear in a significant fraction of disordered materials, such as glass. A Spanish group began simulating what are known as granular fluids.
The scientists submerged a landscape in water and used optical tweezers to position the glass bead within it 1,000 times. The deeper of the two valleys in this landscape is a stable resting place. The shallower valley is a “metastable” state.
“The results are clear,” said Raúl Rica Alarcón of the University of Granada in Spain. But not everyone is entirely persuaded that the Mpemba effect has been demonstrated in any system.
After igniting a decades-long controversy with his teenage interrogations, Mpemba himself went on to study wildlife management. He became a principal game officer in Tanzania’s Ministry of Natural Resources and Tourism before retiring.
