Claude just computed a nine-loop scattering amplitude in planar N=4 super-Yang-Mills, past the eight-loop record. What that means. Scattering amplitudes predict how particles behave & physicists compute them in layers of correction called loops. Each loop makes the answer more precise & costs exponentially, sometimes factorially, it’s more work. Most real amplitudes have only been taken to two or three loops. The most precise prediction in particle physics, the electron's anomalous magnetic moment, used five. The challenge came from physicist Matt von Hippel, who publicly asked whether an AI could push past eight loops using only compute an academic could afford. Given one prompt & periodic instructions to continue, Claude ran largely unsupervised for days & did it, using bootstrap methods that Lance Dixon & collaborators developed. Total cost: a few thousand dollars. Dixon, who held the prior record, checked the result independently. Three caveats that matter more than the headline: 1. N=4 super-Yang-Mills is a toy model which is a testing ground for techniques, not a theory describing our universe. No new real-world particle prediction came out of this. 2. Claude applied existing human methods rather than inventing new ones. 3. A human-led group at the Chinese Academy of Sciences, using GPT-6 for parts of it, had concurrently obtained most of the same result & published a dataset on September 17. So the honest version isn't that a machine beats humans. It's that a hard calculation at the edge of a field now costs only a few thousand dollars & takes several days, by more than one route at once.