If It’s Interesting, It’s Complex Too

Science seeks, above all things, a pure, elegant simplicity.

Or so I’ve written in this column, more than once.

In fairness, I should confess that a chemist friend tells me I’ve been brainwashed by the theoretical physicists.

True, the fundamental laws may be simple, he says, but everything interesting is complicated: the frenzied nerve firings that allow you to make sense of these words, or pick up a pen to write a nasty letter to the editor; the patchwork of continental plates whose scraping and shifting creates the ground on which you sit; the brew of chemical elixirs that churn up emotions; the dozens of molecules it takes to make up the aroma of chocolate. Rain, music, rocks, puppy dogs, sand dunes, fire--all unspeakably complicated things.

Even atoms, if truth be told, are complicated. We like to think of them as neat little planetary systems, electrons orbiting a hard, sedentary center. Nothing could be further from the truth. At heart, they are a froth of restless uncertainty.

A single atom can’t be red, sweet, hard, sticky, soft, shiny, loud, rude or kind. It takes a village, or at least several million. And even then, it’s how you arrange the atoms that matters. From dull carbon alone you can get soot and diamonds, graphite and soccer-ball-shaped Buckminsterfullerenes --depending on how you shuffle the pieces.

As for purity, it doesn’t exist.

“If you were to look at the purest things in our environment,” writes chemist Roald Hoffmann in “The Same and Not the Same,” “you would find that at the parts-per-million level, you might not want to know what is in there. Everything is in fact quite dirty.”

The purest spring water, he tells us, “is a downright frightening mixture.”

Even pure mathematical forms exist only in our imaginations. There is no such thing in this universe as a perfect square or circle. To the extent purity does exist, we probably wouldn’t much care for it. Purity is boring. “Mountains are not pyramids and trees are not cones,” says the teenage mathematical prodigy Thomasina in Tom Stoppard’s play, “Arcadia.” “God must love gunnery and architecture if Euclid is his only geometer.”

It takes many thousands of different kinds of molecules to make a person, almost as many to make a pear. Life is complicated in part because it has been pieced together by evolution, borrowing whatever worked from whatever ingredients were handy (off-the-shelf, as it were) at the time.

More intelligent design would no doubt have produced much more streamlined beings; a lot more like robots; a lot less endearing. The most beautiful people, after all, tend to be mixtures. (Think of Brazil.)

From complexity comes the capacity for difference. A sphere is a sphere is a sphere but no two snowflakes are exactly alike. And snowflakes are constructed only of simple water, a molecule of merely three atoms--H2O.

Hemoglobin, by contrast, contains 2,954 atoms of carbon, 4,516 of hydrogen, 780 of nitrogen, 806 of oxygen, 12 of sulfur and four of iron.

With so many varieties of each atom possible, and so many combinations of atoms in large biological molecules, it’s probably safe to assume, writes Hoffmann, that “there are no two identical molecules in [a] Burmese cat.”

Never mind two cats. There is no such thing as a simple individual.

To be sure, we like the idea that science can make things simple. It’s part of the appeal. And so we get understandably angry when weather forecasters predict sun and then it rains; or scientists can’t tell us exactly what’s happening to the climate, or how to cure AIDS, or why people kill, or when a human life begins--or ends.

Even the physicists are pretty useless when it comes to keeping track of more than a few particles (or planets) at a time--at least not without high-powered computers to help them. Sedate as it seems, our nine-planet solar system will eventually descend into chaos simply because it has too many moving parts for long-term stability.

On the level of fundamental law, it’s true that Nature seems to prefer simplicity. You can reduce a Burmese cat to quarks and electrons. But then you have neither Burmese nor cat.

Besides, we don’t live at the level of fundamental law. On the human scale, things are messy; with so many different players and moving parts, it’s impossible to keep track of what’s going on, much less completely understand it.

So we shouldn’t expect simple answers from science in a complicated world, whether they have to do with climate change or disease control, car safety or crime prevention.

“If we insist that [complex things] must be reducible, all that we do is put ourselves into a box,” says Hoffmann.

And then, all we’ve reduced is ourselves.