The span of life.

A few years ago, I wrote here about the second law of thermodynamics and the lifespan of things. I still can’t muster a rigorous argument for what I’ve said below. I’m not sure I want to.

Everything that lives must eventually die. Entropy must increase. Equivalently, energy must flow from points of higher temperature to points of lower temperature. In the course of these flows of energy, dissipative structures may appear, drawing off these flows as an engine does the explosion of gasoline.

The Sun is dying for us: for the sake of the second law, it surrenders its radiation to the cold of the cosmos. It is this energy we draw upon to sustain ourselves. How long might we live?

A sand castle is easily destroyed by the motion of one hand. The resulting pile is more robust. There are so many more ways for the sand to just be a pile; that state is more permanent.

A fly lives for only a few weeks. One of our species might live for a hundred years.Living things, drawing on the flows of energy, are driven far from the state of the equilibrium of their parts.

So it is that the growth of entropy creates both order and disorder, it giveth and it taketh, each to a proper time and space, and according to a probability. The states far flung in the distribution, the rare and the low in entropy, are ever so briefly lived. They return to the dust and the ash of stars.

Some tribes in the Amazon rain forest have lived sustainably for thousands of years, while the cities of Mesopotamia rose and fell, and while the empires of Medieval Europe crumbled and were replaced. How long might we live?

Sometimes I think we ought not take our problems into the solar system. The problems of poverty and war, the problems that have followed our civilizations since the beginning, are they really an inescapable consequence of these same non-equilibrium thermodynamics? Yet they cannot remain with us if we want to survive and we’re left to hope they are not inevitable.

The signs from changing climate and the exhaustion of the planet suggest we are approaching a terminus. What will come after I don’t know, but the challenges that are coming will be the most difficult any human generation has ever faced. If we want to see what lies on the other side, we must try to find a way to live.

This is a terrible burden to be placed on the young. They are to suffer the cost of every shortsighted decision made by generations previous, and to somehow find a better way.

If these children can survive what’s coming, they will be marked forever as the greatest of all generations. We have little hope other than they might be more clever, more wise, more kind and generous than any that came before and muster the strength to live through.

Advertisements