Most people are familiar with bubbles. Bubbles are a thin film of a liquid containing a volume of gas. But have you heard of anti-bubbles? Anti-bubbles are the opposite: a thin film of gas containing a volume of liquid. Dianna Cowern (Physics Girl), creates some anti-bubbles and explains what they are in the video below.
At the beginning of her video while performing the classic milk and food coloring experiment, Dianna created some liquid drops that did not coalesce (merge) with the liquid on top of which they moving. This is a different physical phenomenon from anti-bubbles which Destin from SmarterEveryDay calls “walking water”. Destin investigates walking water in the video below with the help of Don Pettit, a chemical engineer and NASA astronaut.
Although I think his video was awesome, the explanation that the droplets don’t merge because they are resting on a layer of air has been challenged by a competing hypothesis.