A black hole is not eternal. Even in a perfect vacuum, it slowly loses energy — a process known as Hawking radiation. Quantum effects near the event horizon create pairs of particles, one of which escapes, carrying away some of the black hole's mass.

But what if spacetime itself is not smooth, but made of tiny "atoms"? This is the idea behind loop quantum gravity. In a new study, scientists calculated the evaporation of quantum black holes — objects that account for this granularity. They looked at how particles with different spins (their intrinsic angular momentum, like a spinning top) are emitted.

The result was surprising: a quantum black hole evaporates differently than a classical one. The rate of mass loss and the spectrum of Hawking radiation change depending on the spin of the emitted particles. Previously, for simplicity, only a massless scalar field (spin 0) was often considered, but that appears to be insufficient.

The difference in evaporation is not just a theoretical curiosity. If we ever manage to detect radiation from a real black hole, its characteristics could tell us what spacetime is "made of." Thus, a distant cosmic object could become a laboratory for testing quantum gravity.