Tuesday, December 02, 2008

Advent 2008: Week One Tuesday

I hurried through that bit yesterday, and we weren't done by a long shot. So let us resume our study of this strange cruciform substance called "water".

You may have a tough time visualizing what this thing is, because it is hard to get a good three-d picture on a two-d screen. You might think of one of those kid's toy "jacks" - those little metal star-shaped things - water is like that, but it has ONLY four legs. If you know anything about medieval military gear, you may know the word "caltrop". It is kind of an anti-horse (or anti-anything-with-feet) device, with four pointed legs, so that when three are on the ground, the fourth is straight up. Like this:

Now, you have to imagine the single blue oxygen in the center, and the two red hydrogens in two of the four legs. Then, there will be four "partial poles" - a fractional charge of electrostatic force: two blue arcs representing the two partial negative poles, caused by the strong pull of the oxygen tending to keep those two electrons it is "sharing" from the hydrogens, and two red arcs representing the two partial positive poles, caused by now partially uncovered nucleus of the two hydrogens. Each partial pole is 0.41 of the charge of a single electron (the negative) or proton (the positive). Like this:

Remember, this is THREE dimensional. You might make one with modelling clay or something else if you are really anxious to see what it looks like. Then, try tilting it, and you will see the cross.

Yes, each and every water molecule has that shape. And it is not a very quiet and peaceful shape: "Think ye, that I am come to give peace on earth? I tell you, no; but separation." [Luke 12:51] Another translation uses "division" here. Oh my, yes - it is war. (No wonder that the Church blesses water and uses it against our Foe - and it is used in bringing a person into the Church!)

I said it is not peaceful - why? Because these little blue-and-red four-legged "jacks" (or caltrops) are like magnets, with "poles" - not very strong, of course, but strong enough to stick together, or to repel. This is the very important "hydrogen bond" - it is not enough of a bond to be a true "chemical" bond, like the ionic bond in salt, or the covalent bonds in sugar - but it is strong enough to make a difference. As I said, one might write a chapter or a book about it. When water is cooled, the motion of the molecules slow down, and gradually, the red legs push the other reds away, and try to stay close to the blues - ah! but when this happens the "jacks" start lining up in a hexagonal pattern. Why is that odd? Because in that regular pattern, they take up more room than they do when they are in some "random" (and moving) arrangement. That means the same amount of water takes up more space once it starts getting stuck together - and hence ice floats.

Now, there is another thing about this "cross" shape. Everyone knows that there is this ASCII character called the "plus" - it looks like this "+" and you can see it on your keyboard above the equals-sign. Every time I hear that gospel from St. Luke (or I do the Fourth Joyful Mystery) where Simeon tells Mary that Jesus is "the sign of contradiction" or (in another translation) "the sign that will be opposed" [Lk 2:34] I think of the plus-sign. No, not the negative sign! The negative IS opposition, but it is nothing more than a negation of something positive - just as evil is nothing more than a negation of something good. So water carries that sign - no - it IS that sign, in its own very nature. It is paradoxical, because it is something neutral which is simultaneously very active - as Chesterton says, "Christianity got over the difficulty of combining furious opposites, by keeping them both, and keeping them both furious." [Orthodoxy CW1:299] Water is a neutral substance which is also a dipole.

And therefore though water might be considered a great and ancient symbol of unceasing change - think of the rivers that run to the restless sea - it is paradoxically the substance that makes for unvarying form! Its partial poles exert a force against other substances - in particular two very important stubstances called "proteins" and "lipids" ("fats" to those who cook or eat), and we shall hear more about them soon.

But for now, just consider the great paradox of water: even in a drop there are vast numbers of tiny crosses, beyond all vision, each with its partial poles, clinging to, or dodging past, its neighbours, clustering to such a great extent that (I am told) even just at the boiling point, three of these hydrogen bonds are in existence for any given molecule! And this is why it takes so long to make water boil! If you have two identical pans, and put (say) a cup of water in one, and a cup of oil in the other, and heat them with the same heat - in a little while the oil will be ready to fry your potatoes (or your fingers) - but the water will just be tepid! You can stick your hand into it, and probably it's not warm enough for coffee yet. Isn't that strange? Scientists say it has a high "specific heat".

Why? Because of those hydrogen bonds! You have to break them before you can get the water molecules to move around... Takes energy.

Remember that strange list of virtues St. Francis gave to his Sister Water? "useful, lowly (humble) precious, pure". Here is another - we could say water is "steadfast" or "reliable", because its own nature helps to maintain its temperature - which is advantageous for us organisms who live on this spinning planet that gets colder and hotter as the days and months go by.

Yes, water is "elemental" to life. It gives shape to life's major components, and it helps preserve a suitable environment for the "work" of life to be carried out. We shall hear more about that "work" in a future post.

For now, ponder the intense mystery of how, at the beginning of things, the Spirit of God "hovered" over the face of the waters, and how God divided the waters - how intensely poetic an image, for water is a divider, not only in rivers and oceans, but in the micro-ocean of the living cell - because it has partial poles, in the three-dimensional form of a cross.

PS. Two references I am using for this effort are Rawn's Biochemistry and McGee's On Food and Cooking. If these postings are reduced to a cleaner and printed form, I shall give a more rigorous exposition, and give proper footnotes.


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