Water

A glass of water is a paradoxical image: to be precise, one liquid encloses another for glass is nothing other than a frozen, super-cooled liquid which is, however, solid at the ambient temperatures we regard as normal.

If one waited a few thousand years the beautifully shaped wine goblet would flow downwards at an infinitesimally slow rate to form an unattractive lump.

Water also powers several of our cooling systems. Thanks to modern environmental technology we are able to use flowing water from the surrounding countryside and to return it, almost completely untainted, back into the natural water cycle.