Stone to Silicon

Math & science · September 2025

Black hole area theorem confirmed

The clearest gravitational wave yet confirms a Hawking prediction.

LIGO's GW250114, detected on January 14, 2025 with a signal-to-noise ratio near 80, showed that the merged black hole's horizon area exceeded the two it came from. It confirmed Stephen Hawking's 1971 area theorem with high confidence.

See it in the living treeWikipediaSource

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1