> In fact, due to time reversal symmetry we know that the formation of the concentrated drop is explicitly allowed. To take this further: you can physically do

> In fact, due to time reversal symmetry we know that the formation of the concentrated drop is explicitly allowed. To take this further: you can physically do this with a similar system (replace diffusion with stirring) for very low Reynolds number flows, which are time-reversible. It's called the Taylor-Couette experiment, you can see it in action here: https://youtu.be/k7ZZtxdtmeQ https://youtu.be/k7ZZtxdtmeQ