Surface tension: microscopic interpretation

This lecture covers the concept of surface tension, explaining its two interpretations: as surface energy that needs to be minimized and as associated to a force. It delves into the microscopic interpretation of surface tension, highlighting how cohesive forces in fluids affect molecules at the interface differently than in the bulk. The energetic cost of creating an interface between immiscible fluids is discussed, along with the work required to prevent motion in soap films. The lecture also explores the behavior of spherical drops or bubbles, analyzing the pressure and surface tension balance. Various laws and experiments related to surface tension are presented, including Laplace's law and Jurin's law.