Water at Rest

Liquid water is uncompressible and takes on the shape of whatever it is in. Archimedes discovered the fundamentals of buoyancy more than two millennia ago. His theory clarifies how water interacts with both submerged and floating objects, although stability of equilibrium needs to be carefully considered. On a global scale, buoyancy also explains why the Earth’s rigid crust floats on its more fluid mantle. The discovery of pressure’s concept and role was made possible through the combination of theory and experimentation, revealing knowledge about a wide range of natural phenomena and opening up a variety of applications. Gravity determines how water behaves at rest, but the role of capillarity cannot be neglected.