Anthropic’s Claude Fable 5.2 finishes a 23-year-old black hole calculation

The new model worked out that black holes form abruptly in very small universes, closing a physics problem left open since 2003 An AI model just finished homework that physicists started in 2003. Anthropic’s Claude Fable 5.2, formally announced on November 9, 2026, completed a black hole calculation that had gone unresolved for 23 years. The result: in very small universes, black holes don’t ease into existence. They appear suddenly. What the model actually worked out The breakthrough came during prerelease testing, before the model was publicly available. Fable 5.2 completed the calculation that began in 2003 and showed that black hole formation in tiny universes happens through a first-order phase transition. If that phrase sounds intimidating, picture a pot of water on the stove. Nothing visible happens for a while, then the water abruptly starts to boil. A first-order phase transition is that kind of sharp, all-at-once change, and the research describes this black hole behavior as akin to boiling. The physics framework behind the result is holographic duality. Under that approach, the dynamics of gravity in one description line up with a quantum theory that contains no gravity ...