Big troubles over tiny bubbles
Conventional wisdom suggests that nanosized bubbles should barely exist at all, so their stability for hours or days has surprised many. Philip Ball takes a close look at these minute miracles
You might call it a fuss over nothing. Nanobubbles are smaller than a bacterium, and empty except for the tiniest puff of gas. But what a furore they’ve caused.
The reason for the controversy is simple: they should not exist. These tiny blebs pocking the surface of a solid immersed in water, too small to be seen in an ordinary optical microscope, seem to defy the usual laws of liquids. They should vanish in an instant, yet they persist defiantly for weeks. Even now, over a decade since they were first sighted, no one really knows why.