Bubble in a Bottle
If you invert a bottle of fluid and open the cap, an air bubble rises through the neck of the bottle. As the bottle empties, more and more air-filled bubbles rise up the neck of the bottle, causing mixing, and beautiful Worthington jets. To capture the striking chaos of these physics, I filled a bottle with water and mineral oil (2:1 ratio of water to mineral oil), inverted the bottle, and removed the cap.
This video was captured on an Olympus OMD E-M10 Mark II mirrorless camera with the kit lens (an M. Zuiko Digital 14 – 42mm 1:3.5-5.6) at 120 frames per second and a focal length of 42mm.