Monday, January 14, 2008

Why are water drops spherical?

Liquid drops tend to be in a state of minimum surface energy which is directly related to the surface area. The force, surface tension, which is trying to hold the droplet together, therefore tries to reduce the surface area of the drop. Mathematically only a sphere has the smallest surface area for a given volume, compared to other geometric shapes. Hence, in the absence of external forces, liquid drops tend to be spherical.