A pressing matter

It began some 400 years ago with a simple question: can water be compressed? At that time it was clear that gases were compressible, but liquids presented a greater experimental challenge. Francis Bacon and the Accademia del Cimento in Florence were the first to attempt an answer, by filling a metal sphere with water and sealing it with solder. Although able to indent the sphere by striking it with a hammer, the Florentines concluded that the volume lost was equal to that of the beads of water that forced their way through the insufficiently strong seal. Thus, they deduced that water is incompressible. A century later, however, John Canton overturned this finding with a more precise experiment, and the experimental science of high-pressure physics was set in motion.