Physicists Help Show Math Behind Growth of ‘Coffee Rings’
Have you ever left a cup of coffee sitting for a few hours and prior to dumping it out you notice a ring remains at the top-level of the fluid? That is the ‘coffee ring effect’, and recently physicists have helped to demonstrate the effect both theoretically and on the microscopic level. The studies looked at particle aggregation based on Poisson and Kardar-Parisi-Zhang (KPZ) processes. KPZ is harder to study because any impurities in the experiment will impact the behavior of the system. The combined theoretical and practical study looked at a variety of particle types and shapes as drops…