Liam Fedus

Co-founder and CEO, Periodic Labs · 1 appearance on the record.

computed by AI from the episodes · how this works → · full disclaimer →

founderscientistexecutive@LiamFedus ↗LinkedIn ↗acsweb.ucsd.edu/~wfedus ↗Wikipedia ↗

Liam Fedus is the co-founder and CEO of Periodic Labs, focused on discovery in the physical and materials sciences. Previously, he was Vice President of Post-Training Research at OpenAI, where he co-created ChatGPT.

11statements → 2claims → 0claims resolved → 4.09/5average certainty → 2.09/5average debate potential →

1 not yet assessed 1 not checkable as stated how the 2 claims stand · each chip opens the sources

1 prediction · 1 assertion · 7 insights · 2 disclosures · every statement was checked. The prediction and assertion are the 2 claims: statements the public record can support or contradict. 0 are resolved, 1 is not yet assessed, and 1 names no date, number or outcome precise enough to check. Everything else (opinions, insights, what ifs, disclosures) can never be settled by the record, so it carries no assessment.

The record, in short

What the tape says about how Liam argues and how the claims held up. Everything they said, and everything said about them, is in the tabs below.

How they sound: speaking style how? →

236 words/min while actually speaking · 21.1 um and uh per 1k words

No argument clarity score for Liam Fedus: no usable question→answer exchanges on raw tape (a fair score needs 8+). We do not score a sample that small. Roundtable and news formats yield far fewer direct exchanges than interviews.

Measured by listening to the audio itself: 3,975 words across 1 episode of raw-level tape, transcribed verbatim with every um and uh kept, each one attributed only where the alignment onto our timed stream is unambiguous. These are measurements of speaking style. We do not rank them: across this corpus, fluency and argument quality are nearly uncorrelated (ρ≈0.2), and smooth talking does not signal clear thinking. How it's measured →

What they said11 Episodes1

Everything Liam Fedus said on the a16z Podcast that made the record, most notable first. Filter by type, assessment or year in the ledger →

Insight

Fedus: Pre-training on domain data outperforms retrieval-augmented generation

“However, as we've seen with things like ChatGPT and other things, when you pre-train on the data, when you actually encode the knowledge into the weights, it's not just a retrieval system, you have a richer, deeper understanding of the material.”

Liam Fedus Sep 30, 2025 ▶ 39:20 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Assertion Not checkable as stated

Fedus: Physics and chemistry demonstrate scaling laws similar to AI

“On the material science side, we're seeing scaling laws within physics, within chemistry both with respect to simulations, with respect to experiment, and it's like the same kind of principles at play and ML.”

Liam Fedus Sep 30, 2025 ▶ 3:02 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: Physics provides ideal verifiable reward functions for AI

“Physics is very verifiable. It's a great reward function, fairly fast iteration loop. You have simulators for large classes of physical systems.”

Liam Fedus Sep 30, 2025 ▶ 3:35 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Disclosure

Fedus: Periodic Labs uses physical experiments as RL reward functions

“And what we're doing, and by having the lab, is we create a physically grounded reward function. That becomes the basis on which we're optimizing against. And so, If a simulator has some deficiencies or some issues, we always error correct, because for us, the…”

Liam Fedus Sep 30, 2025 ▶ 5:01 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Disclosure

Fedus: Early ChatGPT was mathematically weak due to friendliness rewards

“The reward functions that we were using originally couldn't determine whether you were mathematically correct or not. So early versions of Chachapiti were mathematically not particularly strong, and it sort of results from the reward function. What did you opt…”

Liam Fedus Sep 30, 2025 ▶ 7:02 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: AI physics requires generating new experimental data, not web scrapes

“The technology that we think is necessary to do it has really just emerged in the last couple of years, and this data Isn't like on a Reddit forum or something like you need to actually go produce experimental data, simulation data.”

Liam Fedus Sep 30, 2025 ▶ 16:08 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: AI science requires real-world experimental feedback loops

“Ultimately science is driven against experiment in the real world. And so that's what we're doing with periodic labs. We're taking these precursor technologies and we're saying, okay, if you care about advancing science, we need to have experiment in the loop.”

Liam Fedus Sep 30, 2025 ▶ 7:46 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: Unpublished negative scientific results are uniquely valuable for AI

“Then another point is, it's very uncommon to publish negative results. All of the results are basically positive, and a valid negative result is very valuable.”

Liam Fedus Sep 30, 2025 ▶ 12:03 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Prediction Open · timeframe Sep 2028

Fedus: Periodic Labs will build AI co-pilots for space and defense

“Basically co-pilots for engineers, researchers in advanced industries. So maybe perhaps just being in Silicon Valley, we, you know, we really think about like computer oriented work. Everything is digital. Everything is bits, but there's so many industries. Li…”

Liam Fedus Sep 30, 2025 ▶ 27:32 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: High-compute reinforcement learning is essential for AI tool use

“High compute reinforcement learning is really effective. This is how you should think about the strategies it's using. This is how you create effective tool using towards those problems, and this is how you optimize it effectively.”

Liam Fedus Sep 30, 2025 ▶ 40:35 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Insight

Fedus: Mixing data distributions does not guarantee AI model generalization

“If you just sort of mix together distribution A, B, and C, there's no guarantee of generalization. What you want to hope to see from these systems is the inclusion of this other data set is improving performance on the other data sets.”

Liam Fedus Sep 30, 2025 ▶ 43:02 Building an AI Physicist: ChatGPT Co-Creator’s Next Venture

Appearances (1)

Episode	Date	Speaking time
Building an AI Physicist: ChatGPT Co-Creator’s Next Venture	Sep 30, 2025	20m

Liam Fedus

The record, in short

How they sound: speaking style how? →

Appearances (1)

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