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PAYSON ROUNDUP
FALL/WINTER 2013
The miracle of ice Standing in the snow on the banks of the frozen East Verde River, water gleams in all its forms about me — still flowing in the stream, gathered in vapor on my breath, crystallized into snow on every hand, frozen into ice underfoot. I kneel at the edge of the stream and study the ice, perhaps the most unlikely of water’s forms, appreciating the lovely moderation of ice in Rim Country. Here at 5,000 feet we have all four seasons — but they’re not fanatic about it. We get snow — storms that stick half a dozen times between November and February — but hardly enough to shovel. And still sections of the river will freeze at night — and thaw in the sunlight — just enough to make you appreciate the crystalline gleam. Here’s a nugget to suck on: Chill any other liquid and the jittery molecules will slow down — bouncing about less as the temperature drops. Eventually, the liquid will settle into a stable crystal lattice — which takes up less space than the liquid did. That’s why all other liquids most sensibly condense when they freeze. But not water, thank the Lord. Water’s made of one molecule of hydrogen linked to two molecules of oxygen. These amiable molecular companions actually share electrons to keep everyone happy. Moreover, a water molecule has a slight positive electrical charge at one end and a faint negative electrical charge at the other end. This accounts for the nearly miraculous chemistry of water — on which life on the planet utterly depends. For starters, as water cools below 32 degrees F the molecules slip into a strange and counter-intuitive crystalline lattice. Once they click into place, they actually take up about 9 percent more space than they did as a warm liquid. Now, that won’t work out so well for folks in Rim Country who left the water on in empty houses during the hard freezes, when expanding ice in the neglected pipes can split open even copper or steel. But water’s demented determination to expand when it ought to contract makes life on the planet possible. If water contracted as it froze, then sea ice would form at the surface every winter and sink to the bottom. Over time, the oceans would freeze solid — and we could not be here. We could go on and on about the fortunate strangeness of water. For instance, the positive and negative ends of water molecules account for surface tension — so useful to water skiers, stone-skippers and water bugs. But it also explains what’s called “capillary action,” which causes water to seep from wet areas to dry areas as when it soaks into a sponge or spreads out in a dry paper towel. More importantly,
Pete Aleshire/Roundup
During cold snaps the East Verde River freezes at the surface. If water didn’t expand when it freezes, such streams would freeze solid.
capillary action also allows water to creep up through the roots of plants in defiance of gravity — once more making life possible with a bit of chemical weirdness. But for the moment, I’m focused on water’s frozen state — the ice and snow that have transformed Rim Country. Kneeling in the snow, studying the translucent dreamscape of ice, I peer at a frond-like tracery of ice — a giant, white crystal shaped like a lacy fern, brilliant against the dark brooding of the clear ice on which it rests. Frozen water from the sky comes in a bewilderment of forms. Hailstones form when some speck of dust triggers the formation of an ice crystal, which then gets bounced around in a chilled storm cloud. The growing hailstone picks up fresh layers of ice as it rises to the top of the cloud and more yet when it hits an updraft and rises again. Eventually, it grows heavy enough to ignore the updraft and falls to earth — with record hailstones weighing as much as a pound. Tiny ice pellets — like the ones that dusted my driveway last night — form when snowflakes drifting down from high in a freezing cloud fall through a
BY PETE ALESHIRE ROUNDUP EDITOR
warmer layer at an elevation between 5,000 and 10,000 feet, which causes them to start to melt. But as their fall continues, they hit another layer of freezing air closer to the ground and refreeze — becoming ice pellets as round as a hailstone but nearly light as a snowflake. But most often, frozen water falls as snow —water molecules that crystallize around some nucleus — like a speck of dust. The water molecules crystallize as they freeze, with the structure depending on the temperature and the moisture content. Some assume exquisite six-sided shapes, some triangles, most with breathtaking symmetry. A single snowflake contains about 3 x 10 to the 13th water molecules — don’t ask me how much that is, except that it dwarfs a thousand trillion. That’s why no two snowflakes are ever exactly alike. The world’s largest measured snowflake was reportedly 15 inches across and fell in Montana in 1887. The intricate crystal on the stream ice at my feet suggests that it formed at between 0 and 10 degrees, which promotes the growth of these bizarre shapes. Cautiously, I rise from my cold, wet knees and step out onto the ice, which is dangerously slick. Scientists used to assert ice is slippery because stepping on the ice instantly melts a microscopic layer. Subsequent experiments demolished the theory, proving how little we know about even the simplest of things. Instead, the leading theory now suggests that the top layer of ice molecules doesn’t get locked securely into the ice lattice, since it has only fickle air to bond to on the top side. So a layer of molecules almost too thin to measure slides easily about, sending we clumsy monsters crashing to earth. I stand, unsteadily, on the ice, to admire the gleam and the sparkle. Underneath, the stream still trickles, making its stealthy way to the sea — which covers 70 percent of the planet, just as water comprises 70 percent of my substance. I can see the water moving beneath the blurred patterns of the ice, which did not sink and murder the stream because it expanded when it froze. The sky is highlighted with high white clouds the color of snow, which is the color of my breath. My heart pumps blood made mostly of water and the naked trees also made mostly of water lean in toward the stream, waiting patiently for the capillary action of spring. I do not know the proper prayers to thank whatever Providence arranged for water to expand when it freezes, creep upward in roots and make the world such a happy place for stone-skippers. But I give thanks, nonetheless — every moist breath a puff of steam.