Teachable Moment: Great science experiments are indistinguishable from magic and this little video is a wonderful example using viscocity to demonstrate laminar flow.
As explained on the web site: http://panda.unm.edu/flash/viscosity.phtml
The Reynolds number R is the dimensionless combination:
in which ρ is the density, ν the speed of the fluid, R the size of the flow, and η the viscosity. When R ≤ 1, friction dominates inertia and the fluid flows in layers (laminar flow).Here we are using corn syrup which has a viscosity of 5 (Pa s); its viscosity is 5000 times that of water, and the Reynolds number R is less than unity.This experiment is being demonstrated by Kevin Cahill for his Biophysics II students.The couette cell used in this experiment was fabricated by John DeMoss in the Machine Shop of the Department of Physics and Astronomy at the University of New Mexico.