Quantum Mpemba effect: hot cools faster, but only near absolute zero ⚡ экспресс
The Mpemba effect — when hot freezes faster than warm. Scientists studied its quantum version in a model with two wells (bistable potential). Quantization shifted the effect to ultralow temperatures, orders of magnitude colder than the classical case, and caused inverse and double inverse effects — as if not only the hot outpaced the warm, but the freezing order flipped. This shows that quantum effects can radically change even canonical non-equilibrium phenomena.
The Mpemba effect is a mystery where hot вода sometimes freezes faster than warm water. Usually this is attributed to how вода loses heat and энтропию (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 гелий 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.
🎯 The effect is named after Tanzanian schoolboy Erasto Mpemba, who in 1963 noticed that hot ice cream mix freezes in the freezer faster than cold, and convinced physicists of this.