There was orderly behavior, there was chaotic behavior; and on their border, in their interplay, so to speak, lay a very large and convoluted zone, the realm of the complex. This was the zone in which viriditas made its appearance, the place where life could exist. Keeping life in the middle of the zone of complexity was, in the most general philosophical sense, what the longevity treatments had been about— keeping various incursions of chaos (like arrhythmia) or of order (like malignant cell growth) from fatally disrupting the organism.
But now something was causing the gerontologically treated individual to go from negligible senescence to extremely rapid senescence— or, even more disturbingly, straight from health to death, without senescence at all. Some heretofore unseen irruption of chaos or order, into the border zone of the complex. This was how it seemed to him, in any case, at the end of one very long session of reading the most general descriptions of the phenomenon he could find. And it suggested certain avenues of investigation as well, in the mathematical descriptions of the complexity-chaotic border, likewise the order-complexity border. But he lost this holistic vision of the problem in one of his blankouts, the train of thought concerning the substance of the math gone forever. And it had probably (he tried to console himself afterward) been too philosophical a vision to do him any good anyway. The explanation after all was not going to be obvious, or else the massive concerted effort of medical science would have searched it out by now. On the contrary; it was likely to be something very subtle in the biochemistry of the brain, an arena that had resisted five hundred years of effort to investigate it scientifically, resisted like the hydra, every new discovery only suggesting another headful of mysteries. . . .
Nevertheless he persevered. And over the course of a few weeks’ absorbed reading, he certainly gave himself a better orientation in the field than he had ever had before. Previously his impression had been that the longevity treatment consisted of a fairly straightforward injection of the subject’s own DNA, the artificially produced strands reinforcing the ones already in the cells, so that the breaks and errors that crept in over time were repaired, and the strands generally strengthened. This much was true; but the longevity treatment was more than this, just as senescence itself was more than cell-division error. It was, as one might have predicted, much more complicated than just breaking chromosomes; it was an entire complex of processes. And while some were well understood, others were not. Senescencial action (aging) took place on every level: molecule, cell, organ, organism. Some senescence resulted from hormonal effects that were positive for the young organism in its reproductive phase, and only later negative for the post-reproductive animal, when in evolutionary terms it no longer mattered. Some cell lines were virtually immortal; bone-marrow cells and the mucus in the gut went on replicating for as long as their surroundings were alive, with no sign at all of time-related changes. Other cells, such as the nonreplaced proteins in the lens of the eye, underwent change that was driven by exposure to heat or light, regular enough to function as a kind of biological chronometer. Each kind of cell line aged at a different speed, or did not age at all; thus it was not just “a matter of time” in the sense of a kind of Newtonian absolute time, working entropically on an organism; there was no such time. Rather it was a great many trains of specific physical and chemical events, moving at different speeds, and with varying effects. There was a fantastically large number of cell-repair mechanisms inherent in any large organism, and an immune system of great and various power; the longevity treatments often supplemented these processes, or worked on them directly, or replaced them. The treatment now included supplements of the enzyme photolyase, to correct DNA damage, and supplements of the pineal hormone melatonin, and dehydroepiandrosterone, a steroid hormone produced by the adrenal glands. . . . There were about two hundred components like these in the longevity treatment now.
So vast, so complex— sometimes Sax finished his day’s reading and walked down to Odessa’s seafront, to sit on the corniche with Maya, and he would pause in eating a burrito and stare at it— contemplate everything that went into its digestion, everything that kept them alive— feel his breath which he had never noted at all, before— and suddenly he would feel breathless— lose his appetite— lose his belief that any such complex system could exist for more than a moment before collapsing into primordial chaos and the simplicities of astrophysics. Like a house of cards a hundred stories tall, in a wind. Tap it anywhere. . . . It was lucky Maya did not require much in the way of active companionship, because often he was rendered speechless for many minutes at a time, rapt in the contemplation of his own evident impossibility.