# A lot of fluid dynamics at Technopolis

Here Simon explains one more effect he has played with at home, the Magnus effect.

# Fluid Dynamics: Laughing and Crying

Simon was watching Daniel Shiffman’s live coding lesson on Wednesday, and when fluid dynamics and Navier-Stokes equations came up (describing the motion of fluid in substances and used to model currents and flow), Simon remarked in the live chat that the Navier–Stokes equations are actually one of the seven most important unsolved math problems and one can get a million dollar prize for solving them, awarded by the Clay Mathematics Institute.

(I looked this up on Wikipedia and saw that it has not yet been proven whether solutions always exist in 3D and, if they do exist, whether they are “smooth” or infinitely differentiable at all points in the domain).

We had read an in-depth history of the Navier–Stokes equations in Ian Stewart’s book several weeks ago, but I must confess I didn’t remember much of what we’d read anymore. “Is it that chapter where Stewart describes how Fourier’s paper got rejected by the French Academy of Sciences because his proof wasn’t rigid enough?” I asked Simon. – “No, Mom, don’t you remember? That was Chapter 9 about Fourier Transform! And the Navier-Stokes equations was Chapter 10!” – “Oh, and the Fourier Transform was also the one where there was a lot about the violin string, right?” – “No!”, – Simon really laughs at me by now, – “That was in Chapter 8, about the Wave Function! You keep being one chapter behind in everything you say!” Simon honestly finds it hilarious how I can’t seem to retain the information about all of these equations after reading it once. I love his laugh, even when he’s laughing at me.

Today though, he was weeping inconsolably and there was nothing I could do. Daniel Shiffman had to cancel the live session about CFD, computer fluid dynamics. Simon had been waiting impatiently for this stream. My guess, because it’s his favourite teacher talking about something interesting from a purely mathematical view, a cocktail of all things he enjoys most. And because he never seems to be able to postpone the joy of learning. He had explained to me once that if he has this drive inside of him to conduct a certain experiment or watch a certain tutorial now, he simply can’t wait, because later he doesn’t seem to get the same kick out of it anymore.

I’m baking Simon’s favourite apple pie to pep him up. Here are a couple more screen shots of him taking part in the Wednesday lesson:

# Physics Experiments: Hydrodynamic Levitation

A really fun phenomenon that Simon learned from the Veritasium channel, based upon the Coanda effect. Simon later went on to repeat this experiment several times, even in the cold fountain at the park – anything for science!