I recently had the pleasure of meeting Robert Deegan from the University of Michigan. He has been involved in research that focuses on the dynamics of non-equilibrium systems for many years. Recently, he has become ‘famous’ among physicists for the discovery of the so-called “cornstarch fingers”. They can be observed when accelerating a non-newtonian liquid rapidly up and down by eg. placing it on a loudspeaker.
Deegan’s setup involves some pretty expensive hardware but this weekend, I decided to give it a try myself with a couple of friends: tjansson and haalle. Below is a photo of our setup, which consisted of a signal generator, an amplifier and a 8″ loudspeaker.
The first movie we recorded shows the effect of accelerating water rapidly up and down. You clearly see patterns, known as Faraday waves, forming on the fluid surface.