From: gehrab@gmail.com   
      
   On Sunday, November 8, 2020 at 10:18:06 AM UTC-6, Jos Bergervoet wrote:   
   > The Navier-Stokes equations can be simplified in two ways:   
   > by putting to zero the compressibility and/or the viscosity,   
   > which then leaves us with 4 cases..   
   >   
   > Does the "millennium problem" of proving or disproving the   
   > smoothness of the solution require the full case, or would   
   > solving it for a simplified case already be enough? (I'm   
   > asking because we don't want to do the work and then still   
   > not get one million dollar, of course!)   
   >   
   > I would expect that the doubly simplified case is too   
   > trivial.. but is the solution in that case actually known   
   > already? That would be the question:   
   > "Are there solutions for a non-compressible, non-viscous   
   > fluid that start with smooth initial conditions and then   
   > develop a singularity?"   
   >   
   > Since non-viscosity means the equations are time reversal   
   > invariant, the question could also be: can you start with   
   > a singular solution and have the time-evolution smooth it   
   > out? (To me the answer seems likely to be yes, but as said,   
   > I don't know whether it has been proven. It might be both   
   > simple and difficult, like the Goldbach conjecture..)   
   >   
   > --   
   > Jos   
   Assume all of the simple ways have been tried, look them up, and   
   make sure you get the same results. If you don't, then figure out   
   where you made your mistake. Assume your results are wrong until   
   you prove that they are correct. Only then proceed to make a claim.   
   Good luck.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)