Video and Photo Credits to J. P. Kubitschek & P. D. Weidman
(the University of Colorado at Boulder)
This is an interesting but a beautiful way of showing a transition from laminar to turbulent flow. As can be seen in the video, the rotating shape of the liquid was simple at the low rotational rate but becomes more complicated at a higher rotational speed. As the viscous liquid rotates at high rotational velocities the flow starts out laminar but becomes unstable and as depicted in the picture by the authors, the rim starts widening until it reaches its first instability and worsens as it falls more.
