What happens if an LLM hallucination quietly becomes “fact” for decades?

We usually talk about LLM hallucinations as short-term annoyances. Wrong citations, made-up facts, etc. But I’ve been thinking about a longer-term failure mode. Imagine this: An LLM generates a subtle but plausible “fact”: something technical, not obviously wrong. Maybe it’s about a material property, a medical interaction, or a systems design principle. It gets picked up in a blog, then a few papers, then tooling, docs, tutorials. Nobody verifies it properly because it looks consistent and keeps getting repeated. Over time, it becomes institutional knowledge.