WATER

 

From The River Why, by David James Duncan:

"Life and water are inseparable: 70 to 95 percent of all fresh fruits and vegetables are composed of water, 70 percent of all human beings, and the chemical reactions that sustain the lives of every organism take place in aqueous solution, most involving water as a reactant - photosynthesis constituting but a single example. Eighty percent of the Earth's surface is covered with water in solid, liquid, and gaseous forms, its total amount being estimated as 1.33 x 10²⁴ kg - or 5 percent of the planet's total mass.

"Water is a thing so familiar to us all that we fail to appreciate its remarkable properties. To a massive extent it is the eccentricities of water that make the Earth inhabitable. On the Moon, temperatures vary from 120 degrees Centigrade at noon to negative 150 degrees at midnight, but on Earth, water's high specific heat prevents such drastic deviations of surface temperature, because oceans and lakes absorb solar heat throughout the day and release it into the atmosphere at night. Water's boiling point is some 260 degrees higher than that of methane, though both compounds sport comparable molecular weights; and water's vaporization point is, on a cal/g basis, greater than that of any other liquid: as a result, one-third of the solar energy that strikes the globe is dissipated by vaporizing water from oceans, lakes, and ice fields, thereby keeping the earth's temperature relatively constant. The same mechanism keeps the temperature of the bodies of humans, plants, and animals within astoundingly narrow limits - because much of the heat generated by metabolism is consumed by the vaporization of water through the pores of skin or leaf, or by panting. If water had the same vaporization point as n-heptane (another molecularly analogous liquid), we would have to consume seven times as much of it to keep from stewing in our own juices on a summer's day.

"Another mystery: water is one of the few substances whose solid form, ice, is less dense than its liquid. If it were otherwise, ice would form on the bottoms of lakes in winter, wold melt incompletely in summer, and our planet would soon enter a permanent - and fatal - ice age. Nor would a bourbon on the rocks tinkle so pleasingly.

"For many years analytically bent souls believed that liquid water consisted of H₂O molecules with a geometry identical to that of a small portion of ice crystal. But in time more astute scientists pointed out that if water consisted of "microcrystals" of ice and vapor, how was it possible that pure water could be cooled to minus 40 degrees Centigrade without freezing? Stubborn proponents of the ice-crystal theory took to calling water's structure merely 'ice-crystallish' or 'icelike,' but among those scientists unsatisfied with this semantic sophistry a second school of thought arose:

"This second, most recent and most widely accepted account of water's 'structure' involves what is called a 'flickering cluster.' Poetically dubbed doodads, 'flickering clusters' are said to be 'open clusters of H₂O molecules' united by hydrogen bonds and 'swimming in a sea of relatively 'free' water molecules,' like fish. These clusters come in an infinity of shapes and sizes, and and each cluster is constantly disintegrating, metamorphosing, forming new alliances, falling to pieces - hence 'flickering.' Indeed, they 'flicker' so fast that the analysts say their average life span is ten to the minus tenth of a second!

"This is hardly enlightening. If the next-door neighbor should solemnly announce to us that once an hour on the hour he is, for one one-billionth of a second, transformed into a kumquat, we shall - with our eyeballs and wristwatches - be unable to refute him. Nevertheless it would be reasonable, if not scientific, to tell him that what goes on during ten to the minus tenth of a second is of little moment. We must say the same to our structural analysts - whose flickering clusters are in fact an expensive, necromantic way of saying what man has always known: water has no structure. Tens of thousands of years ago, our wise forefathers shared myths wherein water was said to be the primal, chaotic substance from which all forms proceed. It is clear that our forefathers have not been refuted, clarified, or improved upon."