As anyone who drinks their coffee with milk knows, it’s much easier to mix liquids together than to separate them. In fact, the second law of thermodynamics would seem to dictate that a mixture would never be able to separate again if there are no attractive forces between similar particles. However, investigators from the Institute of Industrial Science at the University of Tokyo showed the mechanism by which a mixture of actively spinning particles, such as bacteria, in a fluid can sort themselves in a process called phase separation even without attractions between particles.
Click here for original story, Demixing behavior of disks rotating in opposite directions can be explained by turbulent effects
Source: Phys.org