Xiaofeng Wu

A vortex in a superfluid gas is like a whirlpool in a sink: the fluid swirls around an empty core. If you spin such a vortex three times harder than usual, it won't hold: it breaks into three separate whirlpools, much like a thick stream of water splits into droplets.

A green flashlight beam dives into a pool and reaches the bottom with barely any loss. Water is transparent to green light, which is why it's used for underwater communication. But to send video or sensor data, the light needs to be switched on and off very quickly — billions of times per second. Ordinary lasers are too slow and unstable for this.