A year ago (WS Jan. 2019) I reported on “the coffee cup acoustics” demonstration explained by Professor Tokieda amongst others. Since then, several folks have directed me to a number of videos by Tokieda analyzing other interesting “simple” phenomena, including his “Toy Models” talk. Besides the coffee cup demo, he examines the end cycloids of a fast-spinning tube, phase transition-like behaviors of wooden balls sloshed in a bowl, vibrationally walking a nut along a bolt, rolling polygons, making regular n-gons from knotted, tightened, and flattened paper strips, rolling cylinders partially filled with granules moving viscously and inviscidly, and the infamous self-filling unsealed paper balloon. A nice hands-on activity with a paper strip, paper clips, and rubber bands ends the Princeton video, and is then explored at greater length in the second Mathbytes video. His third (2014) video from the Princeton Institute for Advanced Study looks at spinning...