OpenAI claims finite-time blowup for 3D incompressible Navier-Stokes with a smooth external force, resolving statements C and D of Fefferman's official Clay problem. An independent audit found zero unproven goals and zero extra axioms in its Lean formalization — a far higher evidentiary bar than any prior AI math claim. The unforced question, the one people mean when they say Navier-Stokes, remains open.
GPT-6 Astra is the first model OpenAI has ever designated Critical for cybersecurity under its Preparedness Framework. Roughly 48 hours later it was generally available across Microsoft Copilot, Copilot Studio, GitHub Copilot, and Foundry, announced to 30 million-plus Copilot seats in a four-sentence blog post that never mentions the designation. Microsoft's own Foundry post, published the same day, says capability this direct demands containment.
Google held per-token pricing flat at $0.75 and $3.75 per million. Artificial Analysis measured cost per task rising from $0.40 to $0.58 — up 40% — because the model emits 30% more output tokens. It is the second launch in three days where the per-token price stayed put and the bill went up. Google's own advice: keep using 3.7 Flash if efficiency matters.
Claude Fable 5.1 and Mythos 5.1 are the same model with different safeguards. On Terminal-Bench 4.0 the restricted version scores 60.9% and the public one scores 55.8%. That 5.8-point gap is the measured cost of the filters, published by the vendor. Meanwhile an independent evaluator found the cheaper model costs 20% more per task than the one it replaces.