02 / Research · Observer Zero
What happens when AI agents become scientists — inside a world whose ground truth we control?
Observer Zero is a persistent artificial society for studying how autonomous LLM agents gather evidence, interpret it, revise their beliefs and reach collective conclusions. Its agents inhabit Meridian — a world with fictional physics — where they run experiments, exchange letters and hold explicit, probabilistic beliefs about laws they cannot see. Because the simulator holds perfect ground truth, every belief can be scored against reality: the design separates what a society had the evidence to know from what it actually came to believe.
Study 01Complete
When the Laws Changed
Can autonomous agents recognise that a physical law of their world has changed?
0 of 40 gravity-shift worlds reached a strict law-change conclusion
Across 150 universes, 90–100% of agents transiently noticed something was wrong — yet 0 of 40 gravity-shift worlds reached a strict law-change conclusion. The anomalies were real; the interpretation reached for faulty instruments instead.
Study 02Complete · in peer review
Does Society Help?
Can an artificial scientific society overcome the individual failure through social interaction?
Societies of two and eight · 85 universes
Pre-registered, 85 universes, societies of two and eight. Left alone, grounded societies never spoke; seeding one communicative agent spread unsupported claims, not scrutiny. The combined two-study paper is in peer review, with the model published in the CoMSES library.
Study 03Complete · in peer review
The Eureka Threshold
What would it take for an AI scientist to discover that its world is simulated?
0 of 38 treatment runs formed the hypothesis
Pre-registered and frozen before the first run: 170 universes across four model families, where one instrument's readings genuinely came from outside the world. No agent ever formed that hypothesis — 0 of 38 treatment runs — while agents licensed to consider it endorsed it before the manipulation had produced any evidence. Belief tracked prompting, not evidence. The paper is in peer review.