IN THE past year, we discovered an entirely new kind of ice. Frozen water is usually found with its atoms arranged in a regular tetrahedral lattice. But if you chill it to −200°C and bombard it with small steel balls, the ice becomes disordered and amorphous.
In fact, there are two other amorphous types of ice (high and low density – this new one has a medium density, almost the same as that of water), and we also know of at least 18 crystalline “phases” other than regular ice, strange configurations that exist fugitively under high pressure in lab…