The Marangoni Effect: When Surface Tension Makes Liquids Move The Marangoni effect is a fascinating phenomenon in physics and fluid dynamics where a liquid begins to flow without being pushed, simply because of differences in surface tension along its surface. Surface tension isn’t constant—it changes with temperature and chemical composition. When one area of a liquid has lower surface tension (due to heat, soap, alcohol, or oil) and another has higher surface tension, the liquid naturally flow