Thu, Sep 30, 2004 - Page 9 News List

Scientists explain the meaning of life (and we don't matter much)

A new theory states that it is entropy which drives evolution to higher levels of complexity -- for the sole purpose of disseminating energy gradients

By Arne Jernelov

Most religions embrace and promote certain notions about the meaning of life, offering the faithful reasons why we and all other organisms exist. Indeed, perhaps the fundamental definition of religious faith is the belief that life serves a (divine) purpose. Science, however, has always given a resounding "no" to the question "Does life have a higher meaning?"

At least until now.

In a series of lectures and in a forthcoming book, science writers Eric Schneider and Dorion Sagan argue that even from a scientific perspective, life does serve a purpose, and thus does have a meaning that transcends the self. They arrived at this conclusion when trying to reconcile a contradiction that has long puzzled those who study both biology and physics.

Living organisms obviously embody arrangements of matter into complex structures. They transform chemicals and, in an orderly fashion, transport and store them in purposeful ways. Above the level of individual organisms, they form societies and ecosystems. All of us are familiar with these fundamental biological notions, and we are all part of these processes. Order seems to be the name of the biological game, and evolution leads to more complex organisms and more organized structures.

This is, of course, at odds with one of the fundamental principles of physics: the second law of thermodynamics, which holds that entropy -- the degradation of all matter and energy in the universe to an ultimate state of inert uniformity -- increases as a result of each and every process. The more the world develops the more disorder there will be. Physics even accepts the idea that entropy defines the direction of time. In the end everything will be broken down and randomly distributed.

How do Schneider and Sagan reconcile the contradiction between what appears true of life -- that it organizes matter into increasingly complex creatures and structures -- and the notion that disorder should increase and order should be lost? Equally important, how can science see any meaning of life in the reconciliation of that apparent contradiction?

The bottom line is that the second law of thermodynamics rules and that the existence of life helps increase entropy. In other words, life promotes disorder. Some might think that this could be true only if the logical end of evolution and intelligent life were to be a nuclear explosion that pulverized Earth. But that is not what Schneider and Sagan mean. Instead, they make a distinction between matter and energy and say that matter organized in structures disseminates energy gradients faster than randomly distributed matter.

As one example, they consider a phenomenon of which beer drinkers have long been aware. If you want to empty a bottle of water (or beer) and turn it upside down, the water will come out in uneven glugs. If you spin the bottle and create an eddy inside it, the water will flow out much faster and more smoothly. The eddy in the bottle is a structure in the water. Water running down is matter losing its potential energy. The structure speeds up the dissemination of the energy gradient.

Similarly, on a hot day, the air in a forest is cooler than over adjacent bare lands, thanks to evaporation and transpiration in the trees. The energy gradient, in this case that of heat, is disseminated more effectively by the structure of the forest and the life within it.

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