Thursday, July 24, 2003

A Memorable Fancy or Phylum and Forget ‘Em

I used to have a recurrent dream that recast the Oedipus legend in modern dress, rather in the style of the Brazilian movie about Orpheus. The only scene I remember with some clarity involved the encounter with the Sphinx, who in this version is a very cool but somewhat sinister jazz pianist, a demonic Ray Charles. The sphinx/hipster registers my approach somehow and, flashing the exaggerated grin of a blind man, lays the riddle on me, “Say, babe, at what temperature does meat keep best?” I answer instantly, “98.6°!” and win, though only for the time being.

Meat can keep for quite a while, several billion years in my case, though temperature isn’t necessarily the most critical parameter, some of my ancestors having been pretty cold fish long before they were really cool cats. The fundamental thing is the unbroken maintenance of a definable chemical tension between what is inside and what is outside. Thus life persists only so long as cells contain a lot more adenosine triphosphate than adenosine diphosphate—8 to 10 times more, I’m told. Since ATP spontaneously breaks down into ADP, only the perpetual uphill synthesis of ATP keeps everybody going. The treadmill must never be allowed to stop. It’s like the children’s pastime of seeing how long you can bounce a ball on a paddle. “A zillion and one. A zillion and two. A zillion and three. Oops!” Life also depends on a continuity of genetic information, of course; but the thermodynamic imperative is even more despotic since it rules every moment of every life.

Physicists describe the motion of things as world lines in space-time. The careers of living things form world tubes, cylinders enclosing small regions rich in energetic molecules. If we could view the Earth and its history from a fifth dimension, we would see trillions and trillions of these mostly microscopic tubes emerging from what was, presumably, a single primal mass. Many of the tubes ramify; but the overwhelming majority dead end almost immediately; and, in all probability, all the tubes end eventually. If you look very closely, you can just make out exceedingly thin tubes branching out from the rare thicker sections. A tiny fraction of these very tiny tubes connect with other tiny tubes and themselves grow into thick tubes. Despite these rare instances of joining, the overall shape of life is, as Darwin recognized, a rather bushy shrub. Topologically, the whole assembly appears to be a single volume in space-time but, because of sex, is actually multiply connected when you look at it closely.

No comments: