The young John Keats remembered an organised game at his school in Enfield, in which all the boys whirled round the playground in a huge choreographed dance, trying to imitate the entire solar system, including all the known moons (to which Herschel had by then added considerably). Unlike Newton’s perfect brassy clockwork mechanism, this schoolboy universe-complete with straying comets — was a gloriously chaotic ‘human orrery’. Keats did not recall the exact details, but one may imagine seven senior boy-planets running round the central sun, while themselves being circled by smaller sprinting moons (perhaps girls), and the whole frequently disrupted by rebel comets and meteors flying across their orbits.

One, two, three ragged files of Canada geese skim the treetops, preceded and followed by their honking chorus. I freeze in my tracks to watch them pass, heading south, feathers ruffled by the last warm breezes of the season. When their honks have faded into silence, I notice a chill in the air. The spinning planet has leaned into its winter curve, away from the Sun. And then, just when I think the racket has passed, I hear another barely audible chorus of honks, high in the air. I look up to see a long, asymmetrical vee of perhaps a hundred geese, moving south at high altitude, catching the direct rays of a Sun that has not yet broken the horizon, like gold doubloons spilled across the sky.

Why the vee? Why that Euclidean arrow aimed at warmer climes? It is a fundamental tenet of science that things don't happen by happenstance, or merely to strew a vee of gold across a morning sky for the benefit of a human watcher. We find vee formations beautiful, but our taste for geometry has no value as explanation. Adaptation is the key to understanding the vee. Formation flying may increase aerodynamic efficiency by giving each successive goose in line a bit of extra uplift with something aeronautical engineers call wingtip vortex. Or geese may fly in vees merely to keep each other in view. Whatever the reason, creatures inevitably evolve the competitive edge that helps their genes flow into the future. It was Darwin's genius to recognize that natural selection leads to complexity—even, in the case of the Canada geese, to a spectacular morning geometry. The law of entropy asserts that as time passes the universe moves—on balance—toward disarray. Life builds patterns of order by drawing upon a correspondingly greater disordering process at the center of the Sun where solar energy is produced. The geese that etch their vees against the morning sky are creatures of our yellow star, which now—-just now—lifts its fiery rim above the horizon, bathing the path in golden light.

In one of his most popular essays, "The Colloid and the Crystal," the nature writer Joseph Wood Krutch wrote about these opposing forces in nature. "Order and obedience are the primary characteristics of that which is not alive," he wrote. "Life is rebellious and anarchical." He was wrong to identify obedience and rebellion with nonlife and life. respectively. We now know that the inanimate snowflake crystal, so apparently lawful and static, grows its six-pointed form under the controlling influence of exquisite molecular vibrations—every water molecule in the crystal is permanently aquiver, each in resonance with all the others—and it is delicate instabilities in these vibrations that allow snowflakes their lovely variations on the six-pointed theme. And life, we now understand, would not be possible unless nature had contrived elaborate molecular machinery to detect and repair any rebellious deviation of an organism's genetic code. The inanimate and the animate are equally products of law and chaos. Still, Krutch was right when he said that "the ultimate All is not one thing but two."