If you toss a book into a black hole, the pages don't vanish without a trace: their content remains encoded in the radiation the hole emits. But how exactly does that happen? In some models, 'islands' appear — regions inside the hole that seem to push information back out. The problem is that in the simplest, most natural versions, these islands don't hold up: they collapse like a soap bubble, and the information stays trapped.
The authors of the new study found a way to shore up the island without breaking the whole framework. They imagined that at the junction of two universes in the mathematical model sits an extra clump of quantum fields, like a drop of glue. This drop adds its own share of entropy (a measure of disorder) to the overall balance. When the island tries to collapse, the drop stretches and its entropy grows. This creates a counterforce, like a spring that won't let the island compress. As a result, the island remains stable and can do its job: transmitting information from the black hole's depths to the outside.
Previously, stabilizing islands in such models required introducing ghost particles — objects with negative energy that violate the laws of physics. The new mechanism does away with them: everything rests on ordinary, healthy fields. It's like using elastic glue instead of fragile glass props — the glue finds the right tension on its own. Now the island isn't just hovering above the horizon; it's firmly anchored. It can exist even when the graviton (the carrier of gravity) has no mass.
The entropy of a black hole with the mass of the Sun is about a billion times greater than that of the Sun itself, even though the hole's size is only a few kilometers.
In William Sleator's novel 'Singularity', information swallowed by a black hole returns via quantum fluctuations at its boundary — similar to the idea of entanglement islands.