Vortices Play Leapfrog in Liquid Light ⚡ экспресс
Physicists have witnessed light vortices playing leapfrog in a two-dimensional fluid of light for the first time. The dance of the vortices, captured frame by frame with phase-sensitive imaging, matched the point-vortex model with a radial background flow perfectly. But the leapfrog stumbled at certain starting distances: either due to phase slips at high speeds, or because a shock wave from multi-charged vortices served as a constant source of phase hiccups. This explains how vortices lose energy in superfluids.
Superfluid helium flows without friction, and vortices are born within it—microscopic funnels, much like whirlpools in water. Two such vortices can play leapfrog: one jumps over the other, and they hop in a circle. This game was predicted by Richard Feynman back in the 1950s. Only now has it been directly observed.
Now physicists have staged leapfrog in "liquid light"—a medium where light behaves like a superfluid. They created vortices with a laser and tracked their motion with an ultrafast camera. When the vortices were sped up too much, a sharp jolt occurred—a shock wave. The game broke down: the vortices collided and vanished, releasing heat. That’s the only way such a perfect fluid can lose energy. Capturing the moment was possible thanks to ultra-high-speed filming.
This discovery helps understand how motion decays in superfluid media and could lead to ultra-precise rotation sensors.
🎯 Feynman predicted vortex leapfrog while pondering the mysteries of turbulence, and it's only now been physically seen—in laser light.
🎬 Liquid light is almost like a lightsaber from science fiction, where energy becomes tangible.