For over a century, the Navier-Stokes existence and smoothness problem stood as one of mathematics' most enduring open questions — a symbol of the gap between what we can use and what we can prove. This week, OpenAI claimed to have closed that gap, not through the solitary labor of a human mind, but through an AI system whose reasoning its own creators cannot fully trace. The announcement arrives less as a triumph than as a threshold, forcing mathematics, academia, and society to ask not only whether the proof is correct, but who owns a discovery when no single human made it.