It’s a sunny day, and the two of us are taking a stroll in the park. Children are playing with bubble wands. We see the bubbles shimmering brightly as they float up into a clear blue sky. Because we are physicists, we couldn’t help wondering whether the physics of blowing soap bubbles had been described in the literature. Our intuition was that, like most classical capillary phenomena, the common experience of bubble blowing would have been explained centuries ago. To our surprise, we found that the formation of those ephemeral and fascinating fluid structures had not been fully investigated. That gap in the literature whetted our appetite for an understanding of soap-bubble formation and led to months of experimental investigations and modeling work that we carried out with two PhD students, Louis Salkin and Alexandre Schmit.
Every bubble blown with a commercial wand, as in figure 1, forms under...
