Water: A Work of Art
28 Mar 2005

And we amateur astronomers here in southern California have had to deal with plenty of the meddlesome wet stuff this year. Just a week ago our astronomy club had to cancel another star night for a local elementary school. A perfect cosmic setting - above all those clouds – passed over.
But how about for a moment we take off our astronomer’s cap, rimmed with a fringe of bad attitude, and just sit back and admire the tiny water molecule and see how utterly unique it is.
Composed of just one oxygen atom bonded to two hydrogens, water molecules are tiny to be sure. And molecules as small as water are almost always gases. Nitrogen, oxygen, and carbon dioxide - all bigger than water - are all gases in our atmosphere. There is no chance under present conditions that we will get an oxygen downpour or a nitrogen snow storm.
They don’t liquefy naturally on our planet because they just are not very “sticky” at all, and at these temperatures the little guys are moving just too fast to have any chance of holding on to each other. Then what gives smaller, faster water molecules the right to stick together so well that they not only form a liquid on our planet but a solid, as well?
It all has to do with the shape of those wee beasties. Because of the laws of physics, water is shaped like a little Mickey Mouse balloon. Imagine Mickey’s head as the oxygen atom and his two ears as the bonded hydrogens. So what? Well, this shape effectively gives water a slight charge.
The bonds that hold it all together are made of electrons and the oxygen has this greedy tendency to pull those bonding electrons more toward itself, away from hydrogen.
This means the oxygen has what’s called a “partial negative” charge on it. The hydrogens get stuck wearing a “partial positive” badge. So what we have here is a molecule with a negative side (Mickey’s head) and a positive side (his ears).
You can actually see this charge with a tiny experiment. Comb your hair to a fare-thee-well on a relatively dry day (remember those?). Bring the comb up to a thin, smooth stream of water from the faucet. The watery stream, attracted to the static-electrically charged comb, will bend towards it.
What’s this all got to do with the miracle of water? This charged character of water means that the little guys are attracted to each other – and rather strongly at that. This attraction allows them to stick to each other like socks to pants fresh out of a dryer.
This stickiness means they don’t mind congregating in the b-zillions to form tiny invisible droplets suspended in the air. If cool enough, these tiny droplets don’t mind at all clinging to each other, becoming big enough to be seen, as in fog or clouds. If conditions are right, these megadroplets don’t mind then gathering into conglomerates so big that they can fall as raindrops.
And the beauty of it all is that they aren’t too sticky. With a little energy thrown their way, the stickiness can be overcome and they are off by themselves again.
Just think of how important that is. Water molecules in oceans are sticking together. But at the surface where the water molecules are exposed to the pounding energy of the sun, they can leave en masse. They evaporate purely, leaving their salty ion friends behind.
Carried aloft they can travel literally thousands of miles. Cooling, they stick and fall as rain, injecting new life into an area, with the excess flowing back toward the ocean to start again.
Bottom line: That little molecule called water has been engineered so brilliantly – perfect size, shape, charge, etc. - that it can be transported deep into dry continents assuring life virtually everywhere on this great rock of ours.
Should I also get into the stunning ability of water to dissolve all kinds of stuff, allowing everything from erosion to the biochemistry in every cell of every living creature?
Should I elaborate on one unique property of water, unlike just about every other compound in existence, to actually become less dense when it is frozen, thus allowing ice to float rather than sink? Ice that sinks would turn our world into a giant iceball.
And on and on and on…
Yes, clouds and rain can wash out an otherwise perfect night of observation. But that little molecule, with its two H’s and single O, is a great work of art, worthy of observation in and of itself.
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