Aristotle: "Preheated water helps it freeze faster."

At the same time, mpemba effect: According to the same mass and the same cooling environment, the molecules in direct contact with the cooling environment with a slightly higher temperature will drop faster than those with a slightly lower temperature. If the cooling environment can always maintain a consistent cooling capacity (constant temperature), the high-temperature liquid will first drop to the cooling environment temperature, and if the temperature is lower than the freezing point of the liquid, the high-temperature liquid will first freeze.

Extended data:

1963 One day, Tanzanian junior high school student Mpamba and his friends made ice cream with milk. While he was still cooking milk, friends around him had begun to cool the milk and stuffed it into the refrigerator. Seeing that there was no place, Mpamba got impatient and put the boiled milk directly in the refrigerator.

An hour and a half later, he was surprised to find that his ice cream had frozen to pieces, while other friends' ice creams were still sticky.

The stubborn Mpamba has been looking for the answer until he seized the opportunity of Dr. Osborn, the head of the Department of Physics at Dar es Salaam University, to visit their school and put forward his own questions.

The doctor didn't scoff at Mpamba's question, but returned to the laboratory. According to Mpamba, he conducted experiments on cold and hot milk and cold and hot water. As a result, he observed the strange phenomenon mentioned by Mpamba, so the doctor invited Mpamba to study this phenomenon with him, and wrote a paper on this phenomenon in 1969 * *, which aroused widespread concern in academic circles.

Therefore, people named the phenomenon that the liquid with slightly higher temperature freezes before the liquid with slightly lower temperature (impure water) in the same volume and cooling environment as "Mpumba effect".

Baidu encyclopedia -mpemba effect