The horizon of a black hole is the boundary from which not even light can escape. But in 1974, Stephen Hawking showed that due to the laws of Quantum Field, this boundary glows faintly. The empty space near the horizon behaves like boiling water: pairs of particles are constantly being born and vanishing, and occasionally one particle flies away, carrying off a tiny fraction of the hole's mass. Thus the black hole slowly evaporates.

For a long time, physicists could only calculate the simplest cases — for instance, the emission of massless particles like light. But the real particles that make up matter have mass and are more complicated. Such massive particles are described by the Standard Model — our best guide to elementary particles. Using numerical simulation, scientists have for the first time computed the emission of massive particles by a rotating black hole. And here rotation comes into play. If the hole spins, its gravity twists the spacetime curvature around it, and the hole begins to act like a conductor setting the rhythm for three different waves. These waves are like three voices in a jazz trio.

The first voice is a deep double bass. It is strong while the hole is lazy and spins slowly. The second is a piercing violin. When the hole spins at nearly its maximum speed, this wave begins to extract rotational energy from it and grows stronger. This effect is called superradiance. The third voice is a quiet viola, barely audible and of little importance to the overall picture.

The most surprising result concerns particle mass. Usually the heavier the particle, the harder it is to be born near the horizon — much like a heavy stone is hard to splash out of boiling water. But rapid rotation changes the rules. It can throw out particles a hundred times heavier than expected from the hole's temperature. This is like a storm that lifts not dust but stones into the air. The first voice, on the contrary, almost falls silent as the mass increases. The three voices behave completely differently.

This knowledge is crucial for the search for primordial black hole — tiny objects possibly left over from the birth of the Universe. Their mass is about 10¹⁵ grams (like a small asteroid), and they should be evaporating right now, ejecting high-energy particles. Such bursts could be detected by gamma-ray telescopes like Fermi-LAT. Without precise understanding of all three voices, we risk missing the signal or confusing it with background noise.

Thus the edge of a black hole, where the quantum vacuum boils, becomes the stage for a three-voice concert. Every escaping particle is a note sung in three voices, and the fate of the hole depends on how each voice sounds. This evaporation process is closely linked to the concept of entropy of a black hole, first understood by Jacob Bekenstein. To decipher this music is to learn to hear the last breaths of vanishing black holes.