Rotate the disk and watch the flow of the liquid within!

The disk is filled with rheoscopic fluid, which shows the currents in the fluid. To create such a fluid, one needs to find some particles that will align in the direction of shear in the fluid, and are also light enough to be suspended for some period of time. For this demonstration, mica was mixed with water and a bit of blue dye. Updated on Jan 17, 2017