Simple

Hawking's Area Law: How Black Holes Test Quantum Gravity ⚡ экспресс

Original: "Hawking area law in quantum gravity"
· Gianluca Calcagni
arXiv:2604.18669 · 2026-04-20 · CC BY · ⏱ 1 min · General Relativity HEP Theory
Black hole collisions detected by LIGO are weeding out many quantum gravity theories.
Abstract

Gravitational wave detectors confirmed: a black hole's surface does not shrink, like an inflatable balloon never deflates by itself. This law ruthlessly cuts out many elegant but overly loose quantum gravity theories. So the Universe tidies up our theoretical library—what other simple principle will turn out to be the key to the mysteries?

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When two black holes merge, their event horizons – surfaces of 'no return' – combine like two pieces of sticky film. The total area never decreases. This is the law discovered by Stephen Hawking in the 1970s.

The LIGO and Virgo detectors, which pick up gravitational waves, confirmed the rule in practice. Then physicists went further: they took the law as absolute and demanded that quantum gravity theories obey it. It turned out to be a strict filter – only those constructs survive where extra mathematical add-ons vanish, and curved spacetime is free of hidden instabilities. An unexpected bonus: strictly following the law automatically leads to the formula first proposed by Jacob Bekenstein, S = A/4, linking entropy and area, and even hints that a black hole's horizon might not be a perfect sphere but could have microscopic wrinkles. Such simplifications weed out many complex theories and bring us closer to solving the quantum nature of gravity.

🎯 If the horizon area could shrink, you could endlessly extract energy from a black hole – but the universe's design forbids it.

S = \frac{A}{4}
S is the black hole's entropy, A is the area of its event horizon
Scientists
Stephen HawkingJacob BekensteinAlbert EinsteinFritz ZwickyVera RubinBernhard Riemann
Tags
black hole gravitational waves entropy spacetime curvature
Laws
second law of thermodynamicsHawking radiationgravitational lensingBekenstein-Hawking entropyEinstein field equationsBoltzmann distribution
Original: arXiv:2604.18669 · CC BY · bridge42worlds