It worked!

The fluid dynamics class went very well. We used big aluminum turkey tins, lined with black construction paper on the bottom. I sprinkled oatmeal-based baby powder over the the water, and the kids were able to see the vortices (swirls) that the water made when they dragged objects through the water.

One kid asked, "Is this the baby powder you used on (your son)?" In fact, it was. You never know what kind of questions you'll get.

Fluid Dynamics in Elementary School

My younger son is taking an elective in Aerodynamics, and I volunteered to do a fluid mechanics demo next week. The subject is air resistance, and I am going to try to make a visualization of the whorls and eddies behind a moving object by floating talcum powder on top of water. I vaguely remember seeing this in college but I haven't tried it yet. I tend to leave things to the last minute, but I had better try this out later today to see if it really works...