In a pot of boiling water, steam bubbles rise and pop. In the quantum world of a superfluid, bubbles behave differently: they can collide and give birth to vortices — tiny swirling flows, like whirlpools in a river.

Scientists modeled such a liquid using a holographic approach. This method links a quantum system to its description in a higher-dimensional space, much like a shadow on a wall reflects a three-dimensional object. They found that near the threshold of bubble nucleation, the time the bubble spends in the critical state grows logarithmically: the closer to the threshold, the longer the bubble “hesitates.” The speed of the bubble wall increases with charge density, but due to strong friction (dissipation) it remains small, as if the bubble were being pushed through thick honey.

This discovery shows that nonequilibrium processes play a key role in strongly interacting superfluids. Understanding vortex nucleation helps in the physics of condensates and the early Universe, where similar defects could have arisen during phase transitions.