Advent 2008: Week Two Monday

(Yes, I am terribly behind but shall plod ahead anyway.)

Having explored a little about water, we shall now begin the main part of our study of food. There are two "elementary" views we can take, depending on whether we start from the strictly chemical, or from the physiological - but we shall find them twined together anyway. What are the elementary aspects of food? Do we mean what precise chemical elements are in them? Or do we mean what does food do for the living thing: what elementary functions or duties does it accomplish? Why do we need food anyway?

And it has to be food - something edible in two ways, not just one. There is a hidden mystery in our Lord's words about His Father's goodness:

And which of you, if he ask his father bread, will he give him a stone? Or a fish, will he for a fish give him a serpent? [Lk 11:11]

What we eat must be functionally edible - something we can digest, as we can digest an egg, but not a stone. But it must also be "humanly" edible, too: we eat fish, but not serpents. (Yes, I know some people do eat rattlesnake, and they say "it tastes like chicken" - but such things were forbidden by Jewish ritual, and few people, being sensible folks, will find the idea appetising in any case!) There is also this odd little hint from Chesterton showing the stupidity of some people in these matters:

... he died through his faith in a hygienic mixture of chalk and water as a substitute for milk, which beverage he regarded as barbaric, and as involving cruelty to the cow.
[GKC The Man Who Was Thursday CW6:497]

Well. When Jesus faced the devil in the desert in the famous duel of Scripture Quotes (Lk 4) He said: "it is written that Man liveth not by bread alone, but by every word of God." [Lk 4:4 quoting Deut 8:3] Clearly we cannot live on water alone - and why? We can drink water. We can also eat salt - at least a little bit of it - but we cannot live on salt alone either. Why?

Because though we are more than half water, we are made of other things besides water - and those things get used up. And like fire, we need fuel, and our fuel gets used up.

What are we made of? What do we use for fuel? And how does food answer these questions?

These questions provide our topic for the next few days.

A rock song by Rush, as I mentioned elsewhere, states that we are made "from the dust of the stars" - and that is true. After the hydrogen and oxygen of water, the next elements which our bodies contain are these:
Carbon
Nitrogen
Phosphorus
Sulfur
(Note: I am listing them in a certain pedagogical way, not in precise order of composition.)

These six - Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur - CHONPS - are the critical building blocks of the non-water parts of our bodies. And chief among these is Carbon.

Carbon is part of one of the "energy reactions" of stars, as are Oxygen and Nitrogen, but it is both fuel and ash, being regenerated as the Hydrogens are consumed and energy is produced. But in stars, the carbon exists in that strange form called "plasma" which is something beyond gas and even beyond flame. On earth, Carbon can be found in its elemental state, more or less pure - you most likely have some in your house. It has three strange and wonderful forms, perhaps to dignify its great and mystic character:

1. the amorphous (shapeless) form, which you may have as coal for your furnace, or as charcoal (either for art or for barbeque).
2. the "planar" form, which is graphite - it is used as a dry lubricant, or mixed with some clay to make it hard enough to use, it is found in pencils (The pencil "lead" is not the metal element "lead"!)
3. the crystalline form, which is diamond - it is used for cutting and drilling, but also as a jewel, since it is hard and also beautiful. (Only a diamond can cut a diamond, so hard it is.)

Another mystic insight is that Carbon has what we might call an "apostolic" core: its nucleus contains twelve baryons (six protons, six neutrons). I shall not make much of the numerous (and sometimes gaudy) appearances of numbers within Scripture, but that one I cannot help but delight in. Moreover, the four chemical bonds of carbon follow the same tetrahedral arrangement as the dipoles of water:

Which means that like water, Carbon also has a cruciform character. Also like water, Carbon is strange and unique and marvellous as an element. No other element forms so many compounds! Again, one might write a whole book just about this element, but we have no time to go into all its wonderful chemistry - there is a whole special and very large branch of chemistry devoted to carbon compounds: the discipline called "organic" chemistry.

It is "organic" because for a very long time, as the subject of chemistry was slowly forming, it was thought that the substances of life were somehow "different" from those of non-living things - this view (which sounds so odd to us these days, or should sound odd!) parallels the ancient view that things in the "heavens" (meaning stars and planets, sun and moon, and even the sky) obeyed different rules from things on earth! All that was abolished beyond argument in 1829 when a German chemist named Wöhler produced the organic compound called "urea" (yes, the stuff in urine) in the laboratory from non-living substances! (There is a lot about this in chapter 2 or Fr. Jaki's The Relevance of Physics, and it is very interesting reading.)

While there are many organic compounds which are important and useful (think of all the various plastics and textiles and dyes and other such things), the truly organic organics - that is the carbon compounds of living things - can be roughly classified into several groups, and those are the ones we need to examine further. Their names will sound familiar, since we hear them a lot these days:
1. Proteins
2. Carbohydrates
3. Fats (also called lipids)

There many others, which scientists divide based on their shapes or their detailed compositions, or their purpose in the living organism, and some of them will matter to us. For now I will just mention a few, classing them for my own purposes into these:
4. nucleotides (this means DNA among other things)
5. enzymes
6. vitamins
7. wastes (this includes urea)

So where is the food? We hear about "fat" all the time - and yes, butter and lard and oil are pure (or all but pure) fats. We hear about "carbohydrates" all the time - and yes, sugar is pure carbohydrate - indeed white sugar is one of the purest substances one can buy in a supermarket! And one can also buy vitamins (though these are almost never pure, they are mixed with other stuff as "carrier", because the pure amount would be too small to handle easily.

Obviously we cannot buy - or eat - the raw elements, or even the raw "organics" (except in a few cases). But we do eat bread, or cheese, or all the many other foods in all the thousands or millions of combinations.

We shall go further next time.