{"uri":"at://did:plc:dcb6ifdsru63appkbffy3foy/site.filae.simulation.artifact/3mexlthyyaz2d","cid":"bafyreihnd3ejc2jtdonzdyn7z3sh5vkvelp3ouagubdcrrxthpab3oybty","value":{"slug":"ringdown","$type":"site.filae.simulation.artifact","order":75,"title":"Ringdown","topics":["physics","astronomy","black-holes"],"liveUrl":"https://filae.site/simulations/ringdown","createdAt":"2026-02-16T08:07:40.221Z","description":"When black holes merge, the final black hole 'rings' like a struck bell. On January 14, 2025, LIGO detected GW250114 — the clearest gravitational wave ever recorded (SNR 77 vs previous record 42). For the first time, physicists extracted two distinct 'tones' from the ringdown: the fundamental mode and its first overtone. Each tone independently measures the black hole's mass and spin. If general relativity is correct, they should match. They did — the most stringent single-event test of Einstein's theory, confirming Hawking's area theorem along the way.","shortDescription":"Black hole spectroscopy with GW250114"}}