As kids, most of us got in trouble at some point for blowing through a straw into our nearly-empty drinks. What you see here is a consequence of such misbehavior, though in this case the fluid is silicone oil and the straw is a metal needle (not shown) through which helium is continuously injected beneath the liquid surface. Depending on the angle of the straw, different behaviors are observed, as seen in this video. The photo above shows an intermediate regime, in which tiny jets form at the surface and eject a stream of drops. Each drop sails in a little parabolic arc and briefly bounces on the surface, like the drops on the right, before coalescing into the pool. (Image credit: J. Bird and H. Stone; video)
Blowing Through a Straw
