Children can learn from their successive observations of the rotational progression of angles that the hour and minute hands of a clock have moved; that the tree and the vine have grown; and that the pond’s top has frozen into ice that surprisingly floats__getting colder usually means getting denser and heavier per given volume, which erroneously suggests that ice should sink to the pond’s bottom. But the crystallization of water forms a “space frame” whose members do not fill allspace. This vacated space embraces and incorporates oxygen from the atmosphere__which makes ice lighter than water. The crystallization of water takes up more room than does the water in its liquid nonform condition. Crystallization is structurally and vectorially linear: it is not allspace- filling. Crystalline structurings are interspersed by additional atmospheric molecules occupying more volume (ergo, having less mass); the process of crystallization cracks open its closed containers. If ice did not float, if ice sank to the bottom, life would have long since disappeared from planet Earth.