The Mpemba effect is a mystery where hot Water sometimes freezes faster than warm water. Usually this is attributed to how вода loses heat and entropy (a measure of disorder). But in a glass of water, chaos prevents a precise model.

Physicists built a quantum model: a particle in a well with two depressions separated by a barrier. Like a ball on a hill with two dips: to roll from one to the other requires energy. In classical physics, a hot ball jumps more often. In the quantum world at ultra-low temperatures, the particle spreads into a wave and seeps through the barrier – without heating.

Surprise: the quantum Mpemba effect manifests not at room temperature, but only near absolute zero, where liquid helium is used. Hot cools down faster, but only when thermal motion halts. Moreover, reverse paradoxes arise: cold overtakes hot, and sometimes a double reversal is observed – phenomena impossible in everyday life.