ENTROPY AND THE SNOWFLAKE

ENTROPY AND THE SNOWFLAKE

One of the arguments Creationists use against evolution is to claim that the spontaneous organization of life is a decrease in “entropy” and therefore a violation of the “Second Law of Thermodynamics.” They keep harping on how evolution is not possible because it is “contrary” to entropy. Somewhere I came across an article about how to identify life elsewhere in the Universe. Part of the problem was how to define “living.” The article argued that the ability to reverse entropy was a key characteristic. The Creationists, of course, argue that life is a “miracle” because of this. Actually it nullifies their argument. Entropy can be reversed, locally, with the input of energy which is what living organism do. They gather energy from the environment and use it to organize and run themselves.

Creationists claim that the appearance of life on this earth is contrary to the physical laws of the Universe and so has to the result of a “miracle,” divine will. Because life violates the Second Law of Thermodynamics it has to have been created by God. Following this line of argument every time a snowflake forms it is by an act of divine creations, billions of trillions of acts of creation by God during each snow storm. God may be infinite but a winter’s worth of storms and blizzards must keep him somewhat occupied. Allow me to explain.

First of all, just what is the “Second Law of Thermodynamics?” The first law is the “conservation of energy.” Energy can be neither created nor destroyed, it can be converted from one form to another form (e.g. heat, light, motion. magnetic, mass, etc.). The second law is that in any conversion, any flow of energy (“work”), there is some loss of energy. This “loss” of energy is not the destruction of energy but a wastage. Some of the energy is lost to friction, that is, no energy conversion is 100% efficient. This loss is called “entropy,” and in any closed system it will increase until there is no usable energy left and the system ceases to function. This is why perpetual motion machines are impossible. Entropy is also defined as “the disorder that increases in any organized system until it is completely random.” An example of this is the “heat death” of the Universe. The Universe, with its galaxies, stars, solar systems,etc., is an organized system. Energy is flowing in vast amounts and vast amounts of this energy is lost. Entropy increases and eventually the Universe will cease to exist as we know it, all this organization will be gone and presumably, it will be just some heat and matter spread evenly and thinly throughout space. Fortunately for us this is billions of years in the future and  we will never have to worry about it.

On a more local scale, a pot of hot water will cool to the surrounding air temperature. The organized system of some higher energy atoms (the hot water) collected in a close group (the pot) separate from some lower energy atoms (the surrounding air) will become increasingly cooler (less ordered) until there is no difference in the energy levels between the water and the air. Given even more time, the water evaporates, mixing with the less humid air until the water molecules are randomly distributed among the air molecules. Over even longer periods of time the pot will do the same (corrosion) and it will cease to exist as a separate, organized entity.

Creationists interpret the Second Law of Thermodynamics to mean that complex, organized molecules such as the amino acids used by living organisms cannot occur “naturally” because there formation would require a reduction of entropy. The appearance of the molecules needed to form living organisms would violate the Second Law of Thermodynamics. According to their interpretation of it and so God had to intervene and by divine miracle (miracles are by definition a violation of natural law) create life. This particular interpretation predicts that the organized structure of a snowflake, formed when water vapor crystallizes into an orderly arrangement, cannot occur by natural processes and is thus an act of divine creation. It also can be stretched, but only slightly, to predict that a hot bath or, as Issac Asimov  pointed out (Asimov on Physics, 1976:228-ff), refrigerators are then, if not caused by God, at least possessing God-like attributes.

Having gone from the sublime to the ridiculous, it would seem that there is something wrong with the Second Law of Thermodynamics or at least how it is interpreted. There is. Let’s go back to the definition, particularly that part about “closed system” that I skimmed right past and the idea that the Second Law of Thermodynamics was more about the loss of energy in any energy conversion than about “increasing disorder.”

I passed over the “closed system” without comment deliberately. The Creationists do this too, but unlike them, I will come back and comment on it. A closed system is one that no energy either enters it or leaves it, it is a system that is completely isolated from the rest of the Universe. I do mean The Universe (with a capital U), not just some part of it, but all of it in any way, shape, or form. Such a system exists more in theory than in actuality. We can construct systems that are almost completely isolated, systems closed enough for our purposes. (The “cold fusion” flap was because the experimenters failed to take into account the heat of the room and mistook it for energy generated by the experiment.) However there is only one true closed system, the Universe.

If energy enters a system from outside it, the system can become more organized. This increased order (decreased entropy) is only local to that system. Entropy increases elsewhere, even within the system. The energy that entered it was used to increase order and part of that energy was also lost as entropy (friction). The energy level of the system increased as more energy entered,some work was performed to increase organization and the entropy of the system increased as some of the energy was lost because of friction.

Any truly closed system will run down as friction reduces the amount of usable energy. Any system that has more energy entering it than is lost by friction (entropy) can continue to run and even. locally, reverse entropy and become more organized. Energy does not have to enter the system for work to be done, it does have to come from somewhere though.

Defining entropy as the “measure of disorder in a system . . . ” (Webster’s II New Riverside University Dictionary, 1984:436) is not the sole definition. In fact it is not the first and primary definition in my dictionary, it is the second. “Disorder” is hard to define, the original definition of entropy as “the energy that is unavoidably lost as non-useful heat,” (Issac Asimov, The Intelligent Man’s Guide to Science, 1960:365) is a more accurate and useful definition. When water vapor in the atmosphere condenses to form water droplets or crystallizes to form ice, the molecules are at a lower energy state and have to release energy. This energy is released as heat, the “heat of condensation.” For snowflakes, this heat is absorbed by the atmosphere. by the molecules of the atmospheric gases. I remember being outside one cloudy winter day and feeling the air warm up just as it started to snow. On this occasion I was actually able to detect the release of that “heat of condensation” as the water vapor turned to snow. The change was only a few degrees, those few degrees represented the increase in entropy caused by the increase in the organization of the water molecules.

When I wrote the draft of this it was snowing outside, this is a normal, natural phenomena. The spontaneous organization of water molecules into the intricate, patterned structure of a snowflake is not considered a violation of the Second Law of Thermodynamics that requires the intervention of God. Physicists can demonstrate how the formation of snowflakes is in accord with the Second Law of Thermodynamics. The millions, billions, or trillions of snowflakes now forming and falling outside of my window are evidence that complex structures can and do form by natural processes without violating the Second Law of Thermodynamics. Life, its origin and evolution, is a natural phenomena. It does not violate the Second Law of Thermodynamics. In point of fact, the processes of life demonstrate the working of the Second Law of Thermodynamics.