Without surfactants to stabilize them, bubbles don’t last long at room temperature. But adding a little heat changes the picture. When heated, the bubbles get stabilized by a thermal gradient that lifts fluid toward the bubble’s peak, where it cools and gathers. Eventually, the cold fluid grows heavy enough to sink down the side of the bubble (in either a constant stream or occasional drips); with warm fluid getting pulled up to replace it (via the Marangoni effect), the process repeats and the bubble lives on. (Video credit: S. Nath et al.; see also)