The Second Law of Thermodynamics… says that the cosmos is winding down, entropy always increases, the universe and any closed system within it have an inexorable tendency toward disorder. To create order, one must expend energy. The energy must be borrowed from somewhere else. If a fern spreads its special kind of order, sprouting yellow branches across a forest floor or a crevice of lava, it has presumably drained its orderliness from the sunlight that penetrated the shadows. Thus the universe slowly winds down. Its balance sheet cannot be cheated. It heads toward a final, featureless heat bath of maximum entropy—this, anyway, is the fate implied by the Second Law.

As a rule of thermodynamics, the Second Law is undeniable. As a guide to organization and disorganization in nature, it seems to fail. Few scientific subjects so confound specialists with problems of definition. Order, Disorder, Entropy, Randomness—these words are notorious traps. Even the most random-seeming of the earth’s images—the cracks, large or small, that appear in drying mud beds, or the rocks that drift helter-skelter across a mountain’s slope—distribute themselves according to laws that subtly organize the relation of things large and small. Whether the subtly shaped and misshapen needles of an ice crystal are more or less orderly than a cube from the refrigerator ice tray is, at best, not obvious. Still, structure emerges.

–James Gleick