Two new papers explore the physics behind bubbles and foams

The Japanese researchers from Tokyo Metropolitan University who authored the recent paper in Scientific Reports were particularly interested in studying a phenomenon known as “collective bubble collapse,” or CBC, in which breaking one bubble at the edge of a foam results in a cascading effect as the breakage spreads to other bubbles in the foam. When they analyzed the data, the scientists identified two distinct mechanisms for the resulting CBCs: a so-called “propagating mode,” in which a broken bubble is absorbed into the liquid film, and a “penetrating mode,” in which the breakage of a bubble causes droplets to shoot off and hit other bubbles, causing them to break in turn. Among other useful findings: higher levels of liquid in the foam meant that slower droplets were released in the penetrating mode, slowing the spread of the collapse, since the droplets often lacked sufficient energy to penetrate another bubble’s surrounding film.

Source: arstechnica.com