Surface Tension

A liquid at rest shows a distinctive and interesting property called surface tension. It is responsible for a whole range of everyday observations: a water spider is able to walk across the surface of still water without sinking; a greased sewing needle, though denser than water, can be made to float on a steady water surface; and raindrops and soap bubbles both consistently take up a spherical shape, however they are formed. All of these seemingly unrelated phenomena arise from the very same underlying property of a liquid's free surface — surface tension — which the following subsecti …