Hot water sometimes freezes faster than cold — that's the classic Mpemba effect. In the quantum world, its counterpart is even more astonishing: tiny particles can reach equilibrium many times faster than expected, and what helps them is not forgetfulness, but memory.
Physicists discovered that if a system 'remembers' its history, special points appear in its dynamics — kind of temporal crossroads. There, the flow of internal time glitches, and relaxation goes into free fall. It's like a swing that stops almost instantly if you push out of sync.
They tested the idea on a model of a decaying quantum harmonic oscillator — a tiny spring losing energy. Calculations confirmed: the mechanism works, and it can be recreated with lasers and cooled atoms. This quantum Mpemba effect could speed up energy transfer in quantum computers. A twist: the classical Mpemba effect is still controversial and may not even exist, while its quantum counterpart is rigorously proven.
The classical Mpemba effect was described by Aristotle, and named after a schoolboy from Tanganyika who, in 1963, froze hot ice cream faster than cold.
In the novel 'The End of Eternity,' Asimov described machines controlling the pace of reality — the quantum Mpemba effect could be a first step toward something similar.