Normally, things expand when heated and contract when cooled. Water is an exception
to this rule. Even though water does expand when heated and contract when cooled at
most temperatures, water expands when cooled and contracts when heated between 4
degrees Celsius and 0 degrees Celsius.
'To myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.'