Last week I learned about an incredible fluid flow project from Jessica Rosenkrantz. I don’t want to give away the delightful surprise, so I’m not going to share the original tweets, but here is RosenKrantz’s pinned tweet – check her timeline for tweets on June 24, 2018 to see the inspiration for this project (and to see the idea we explore in today’s project executed to perfection):
Also, here are two other projects we’ve done with her work at Nervous System:
The puzzles and everything else from Nervous System will blow your mind!
Using the Infinite Galaxy Puzzle from Nervous System to talk topology with kids
For today’s project you need a little bit of paint (or s similar liquid), and two sheets of glass. Be careful doing this project with young kids – my kids are 12 and 14 and I thought they’d be able to handle the sharp glass themselves with gloves.
You spread out a bit of paint on one pane of glass, put the second pane on top, and then pull the two panes apart. What shapes do you expect to see in the paint after the panes are separated?
My younger son tried it out first:
My older son went second:
I think this is an amazing project to try with kids. Hearing what they think will happen and then hearing how they react to and describe what happens is really fun!
Mike's Math Page 
Speaking of “incredible fluid flow,” in a bit of serendipity just this morning someone posted a link (sorry, I’ve already lost who?) to fascinating video of vortex rings colliding:
(I’ve posted it to my blog for tomorrow, but neat if you’ve not already seen it.)