Between its three states, water has six doors, each with its scientific name:
- solid liquid: melting; liquid solid: solidification (freezing);
- liquid gas: vaporization — roaring fast at the boil, quiet and cool as evaporation; gas liquid: condensation;
- solid gas directly: sublimation, and gas solid directly — rarer doors, but real: frost feathers on a freezing window grow straight from invisible vapor, skipping the liquid entirely.
Examples
Example 39.2 (Doors all around you)
Morning frost melting off the grass; laundry evaporating on the line; a cold mirror condensing your shower’s vapor; the freezer solidifying tomorrow’s ice cubes; frost feathers grown overnight on the pane. One substance, six doors, all within a day of ordinary life — name them and you own them.
Example 39.9 (The great round trip, with vocabulary)
The childhood story of sea, cloud and rain now reads like a ledger. The Sun’s warmth drives vaporization from the seas — tonnes upon tonnes rise invisibly. High and cold, the vapor condenses into cloud droplets; colder still, droplets freeze into snow. Snow piles into glaciers; glaciers melt into rivers; rivers return every gram to the sea. Around the whole circuit, Proposition 39.4 holds: the planet neither gains nor loses a drop — the water in your glass has sailed this loop since before the dinosaurs.