Surface tension effects of surface tension can be seen with ordinary water: Surface tension is visible in other common phenomena, especially when surfactants are used to decrease it: Surface tension, represented by the symbol "γ" (alternatively "σ" or "T"), is measured in force per unit length. Its SI unit is newton per meter but the cgs unit of dyne per centimeter is also used. For example, Surface tension can be defined in terms of force or energy. In terms of force: surface tension of a liquid is the force per unit length. In the illustration on the right, the rectangular frame, composed
Rayleigh–Bénard convection = 1,100.65. In case of a free liquid surface in contact with air, buoyancy and surface tension effects will also play a role in how the convection patterns develop. Liquids flow from places of lower surface tension to places of higher surface tension. This is called the Marangoni effect. When applying heat from below, the temperature at the top layer will show temperature fluctuations. With increasing temperature, surface tension decreases. Thus a lateral flow of liquid at the surface will take place, from warmer areas to cooler areas. In order to preserve a horizontal (or nearly horizontal) liquid surface, cooler