If a drop of creamer falls from a spoon into a swirling cup of coffee, the whirlpool drags the drop into rotation. But what would happen if the coffee had no friction—no way to pull the drop into a synchronized spin?
![](https://scx1.b-cdn.net/csz/news/tmb/2020/theoreticalb.jpg)
Source:
https://phys.org/news/2020-06-theoretical-breakthrough-quantum-fluids-rotate.html