Harvard physicist open-sources BootLoops science harness
Matthew Schwartz has released BootLoops, an open-source harness that steers LLMs toward exact-calculation problems suited to their strengths, and reports results ranging from Feynman integrals to population genetics.
Harvard physicist Matthew Schwartz has open-sourced BootLoops, a toolkit for exact calculations in quantitative science. He introduced it in a guest post on Anthropic's research blog.
Schwartz says there is an "impedance mismatch" between what scientists want from AI and what current models do well. In an earlier experiment he wrote about as "Vibe Physics," he found Claude Opus 4.5 worked like a strong graduate student at 20 times the speed. He also says he had to correct every sentence it wrote. His new approach is to look for "Claude-shaped" problems instead: problems in one field that a known technique from mathematics, physics, or computer science could solve outright.
BootLoops began as a set of mathematical-physics tools, built with Claude, for scattering amplitudes and the S-matrix bootstrap. Schwartz describes it as a harness, comparable to Claude Code or Codex, and says it works with any model. He began the work after Anthropic released Claude Fable 5 this summer, to see whether its coding abilities carried over to scientific computing.
Claude then found uses for the same methods in ecology, population genetics, geology, economics, linguistics and other fields. Schwartz says many of these connections were technically correct but unremarkable at first, so he worked with domain experts to aim the tool at questions those fields care about. According to the post, the reported results include:
- 15 elliptic Feynman integrals computed for the first time
- a solution to Etienne's neutral-biodiversity equation
- evidence of gene conversion across 5.7 billion mutation pairs
The results come from 36 manuscripts that have not yet been peer-reviewed. The source material does not say how they were checked.