A drop or two of cold cream in hot coffee can go a long way toward improving one’s morning. But what if the two liquids didn’t mix?
MIT scientists have now explained why under certain conditions a droplet of liquid should not coalesce with the liquid surface below – using silicone oil sitting on a warm bath. If the droplet is very cold, and the bath sufficiently hot, then the droplet should “levitate” on the bath’s surface, as a result of the flows induced by the temperature difference.
The team’s results, published in the Journal of Fluid Mechanics, offer a detailed, mathematical understanding of drop coalescence, which can be observed in everday phenomena, from milk poured in coffee to raindrops skittering across puddles, and sprays created in surf zones.
Originally published by Cosmos as A floating droplet
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