ChatGPT co-creator Liam Fedus: AI scientists must run real experiments
Liam Fedus, a ChatGPT co-creator and former OpenAI post-training lead, told the podcast The Frontier, in conversation with Mercor founder Brendan Foody, why his startup Periodic Labs is building its own physical laboratories: math has judges like Lean that a compiler can check line by line, but questions in materials science, chemistry and physics can only be settled by real experiments, while web data is noisy, papers omit key details and negative results are almost never published. He said Periodic combines language-model reasoning, computational physics simulation and high-throughput lab work, starting with materials discovery, and that the company's first model, the roughly 1-trillion-parameter Periodic Neon released in September, beats GPT-6 Astra on its own benchmark — a company-reported result. He also referenced OpenAI's release of 722 math manuscripts from an unreleased internal frontier model, and discussed ChatGPT's shift from a completion interface to a chat interface and RLHF reward models' insensitivity to correctness.
If progress in AI-for-science hinges on verifiable feedback, building labs to generate clean, well-contextualized experimental data could matter as much as more compute or web text.