Why Navier-Stokes Pushes Math and Physics to the Edge

My students are going to remember '88 hours' from this clip. I'd rather they remembered 'under some conditions', from the very last sentence. Lean checking every step is real, but Lean only checks the statement it's handed, and this one needs a smoothed-out external force pushing on the fluid. Fair answer to the Clay question. Much thinner answer to whether the equations blow up for water left to itself.