Tuesday, June 26, 2012

Implications of the laws of Thermodynamics

Philosophical and Theological
If there are any scientific laws that have universal acceptance, and universal applicability, they are the laws of thermodynamics. Thermodynamics literally means "energy in action." It is a word with roots that indicate that it has to do with both heat and motion. (See here for the Wikipedia article on the first law , and on the second law . There are actually more than two laws, but I won't consider any but the first and second in this document.)


The first law of thermodynamics may be stated thus: "energy can neither be created nor destroyed." This law does not rule out transformations of energy from one form to another, or even transformations of energy to matter, and the reverse, as according to Einstein's E=mc2 equation. If it is true, it means that neither energy, nor matter, can be created from nothing.
The second law of thermodynamics is more difficult to state in plain English. Here is an attempt: "In any transformation of energy from one form to another, 'useful' energy is lost."The first law is sometimes stated as "you can't get something for nothing." The second law tells us that not only can't we get something for nothing, but that we always lose in the process. We give up more than we get, energetically speaking.
A familiar consequence of that is the fact that much of the energy of automobile engines does not end up in motion, but in overcoming friction. Another is that it is not possible to have a refrigerator, freezer, or air conditioner that merely removes energy from one place to another. In the process of moving energy, each of these actually increases the total heat in the universe, as it uses electricity (or gas, etc.) to do its work, and some of that work is not merely to transfer heat, but to overcome friction. Another consequence is that when light energy is transformed into chemical energy in green plants by photosynthesis, and then to chemical energy in animals that eat green plants, most of the light energy is not actually transformed into chemical energy in animals, but does various "non-useful" things. As a result, meat of all kinds is more expensive than plant food, either in the grocery store, or if you grow your own. To put it another way, you can feed a family on a lot less space, using a garden, than the space required to feed the same family, if they eat only meat.

An ordered system. Entropy is low. There is a concentration of some substance in one area.
Another statement of the second law is that entropy, or randomness, is constantly increasing. We rely on the fact that the universe is not random. For instance, there are concentrations of water, oil, and iron that we can use. If water molecules were distributed evenly throughout the universe, life would be impossible, because there would be no concentration of water for us to drink. Another homely consequence of this is that, left to itself, any system, such as your house, or room, or desk, or hard disk, or car, gets more and more disordered.
You can not put such a system in order without expending energy. In the very process of applying energy, for instance to run the vacuum cleaner, the amount of useful energy in the universe declines, or the entropy increases.
Scientists say that the increase of entropy must take place in a closed system. Your house isn't a closed system. Energy is brought in from outside, so that it isn't "left to itself." But the universe is a closed system, unless there is an external power acting on it.
A disordered system. Entropy is high. There isn't a concentration of a substance.


There are important philosophic and religious implications of the laws of thermodynamics.
If the first law is true, and has always been true, then the universe has always existed. If the second law is true, and has always been true, then if the universe has always existed, by this "time" it would have achieved complete entropy. If you don't understand these statements, read the first section over again, carefully. Obviously these statements are not both true. If they were, the universe would be uninhabitable. How to explain this? The only explanation is that laws of thermodynamics haven't always been true. Why not? One possibility is that there was intervention by a supernatural God, creating something from nothing, in the initial creation of the universe. Another way to say this is that the universe had a definite beginning. There was a time when it did not exist, at least in its present form, then God brought it into being. It is impossible to prove or disprove this, scientifically. However, it is a solution to the dilemma posed in the italicized statements at the beginning of this paragraph.
Unfortunately, some people consider all explanations involving God to be non-scientific, regardless of their merits. Just as unfortunately, many people do not understand the dilemma at the beginning of the previous paragraph. Also unfortunate is the fact that some religious people, at least some Christians, have put limits on the length of time from the initial creation to the present. Scripture does not say when the universe began.

Another solution to the dilemma is to say that the "big bang" (That is, a giant explosion that changed the universe from some original state to the present one, at some specific time in the distant past) started the universe, or started it over. The two solutions, that God began the universe, or that there was a big bang, are not necessarily contradictory. Many Christian scientists believe that God used the big bang to start the universe as we know it. The big bang is not an explanation, by itself. It merely puts the question one step back. What caused the big bang? (Referring to God also leads to a question one step back, namely "Where did God come from?" The usual explanation is that God has always existed; He is eternal.) It seems to me that any explanation of the beginning of the universe depends on ideas that cannot be proved, that require faith , in other words.

In his The Unconscious Quantum (Amherst, New York: Prometheus Books, 1995) Victor J. Stenger says that "In fact, our best current estimate of the total energy of the universe, including the rest energy of matter, is essentially consistent with zero. Within observational accuracies, the rest and kinetic energies of the material bodies of the universe are almost exactly balanced by the negative potential energy of their gravitational interactions." (p. 219) He goes on to say that this includes so-called dark matter, and to explicitly indicate that, if the total energy in the universe is now zero, no violation of the first law of thermodynamics would have been necessary at the beginning of the universe. Dark matter is beyond the scope of the courses I teach, which is a good thing, because I don't understand it. (I'm not sure anyone does.) However, even if Stenger is correct, (which would make an argument for a creator from the laws of thermodynamics weaker, or nullify it entirely) three points can be raised. 1) Why and how did the universe arise from nothing? 2) What he says does not rule out God's activity, at the beginning, and now. 3) There has still been a very long time for the second law to operate, if the beginning of the universe took place as far back as standard scientific theory says it did. For more on this subject, see the Energy of the Cosmos section of the Wikipedia article on Physical Cosmology. I include this paragraph because I want to acknowledge views which differ with mine. I am not sure how well Stenger represents the part of the scientific community with expertise in this area. A review of this book , by an atheist with physics qualifications, indicates that he is obsessively against anything that hints of the spiritual.
Although the second law of thermodynamics does mean that energy transformations are inefficient in practical terms, and implies that all energy transformations result in lost useful energy, this does not apply to every energy transformation. For example, if an electron absorbs energy, it can be said to have been raised to a new electron level, or to a higher shell. This situation is an unstable state, and eventually the electron will move back to its original position, and the energy be given off. (In fact, this is what is happening when a fluorescent object, such as a watch that glows in the dark, gives off light--some of its electrons were boosted to a higher energy level during exposure to light, and fall back to the original level over a period of time.) When energy is given off by an electron falling, the energy given off is exactly the same amount as the original energy absorbed.

The Resurrection

. . . and his incomparably great power for us who believe. That power is like the working of his mighty strength, which he exerted when he raised him from the dead and seated him at his right hand in the heavenly realms . . . (Ephesians 1:19-20, NIV)

The definitions of life and death are complex, and philosophical as well as biological. Generally, living things are in a constant battle with the second law of thermodynamics. However, so long as they can obtain enough energy, they win this battle. They can build themselves as non-random, ordered objects. We do this, however, only at the expense of order in the universe at large. We can expend energy to build. However, when we do so, we are taking energy from somewhere else, which means that there are processes involved that change energy from one form to another.

One of the things that happens as a result of death is that the ability of a living thing to stave off the inexorable increase of entropy is gone. Death leads to decay. As Polkinghorne puts it:

In our present world, change and decay are built into the fabric of the universe. The processes by which genetic mutations produce new forms of life are the processes by which cells become cancerous. Death is the necessary cost of life. In fact, a theological defense of the existence of physical evil is that it is not gratuitous but the inescapable price of an evolutionary world, free to make itself within the independence its Creator has granted to it. John C. Polkinghorne, Serious Talk: Science and Religion in Dialogue. Harrisburg, PA: Trinity Press International, 1995, p. 107.

Not only does death lead to decay, but this decay is, in the practical sense, irreversible. If I had the money, and offered some famous research institution a trillion dollars if they could bring one dead oak leaf back to life, I wouldn't lose my money. It is not humanly possible to reverse the decay in a dead organism, or part of an organism, and bring it back to life.
The resurrection, of course, is miraculous, any way you want to look at it. It wasn’t, or isn’t, humanly possible. We cannot reverse the effects of the second law on a dead leaf, much less a dead human. No wonder Paul called resurrection power "immeasurable" in Ephesians 1:19-20 . God’s promise is that Christians have this power working in us.

(Note also the fourth paragraph in this document, which deals with plant vs. animal food.) Body processes often transform energy from one form to another. When this happens, according to the second law, useful energy is lost. As a result, even adults must have a source of energy to live on. The only significant source of energy for humans is the food they eat. By the laws of thermodynamics, there are three possibilities. If you take in less useful energy than you lose, you will lose energy (calories). Since calories are stored in material, chemical, form, that means that you will lose weight. If you take in more energy than you lose, you will gain calories and weight. If you take in the same amount, on the average, you will maintain your current calorie amount and weight.

Temperature and Heat

Temperature is a measure of the velocity of the average molecule. In other words, when the temperature is 100 any molecules that can move easily are moving considerably faster than they would be at 50. At absolute zero, all molecular motion would cease. (Actually, absolute zero has never been detected. It is possible to come close to it in laboratory situations, and some remarkable things happen when you do. Absolute zero is about -473o Fahrenheit.) 
Heat is a measure of the total heat energy in a body. Among other things, heat depends on the size of the object. Two liters of water of water at 100o would have twice as much heat as one liter of water at the same temperature. The average molecular motion, or temperature, would be the same in both portions of water.
The reason mercury or alcohol thermometers (the kind with fluid in a tube) work is that as the temperature rises, the molecules move faster, and thus tend to move farther apart. In other words, the fluid expands. The actual motion of a molecule depends on a number of factors, one of them being the size. All other things being equal, a large molecule moves more slowly than a smaller molecule or atom. Hydrogen atoms can move very rapidly. Hydrogen and Helium molecules are very small. They do not remain in the atmosphere very long. They move fast enough to escape from earth’s gravity. There is little free Hydrogen or Helium in our atmosphere.

Nuclear Fusion

Please remember that when a system gives off energy, it becomes more stable. This is true of atomic nuclei, too. The mass of a neutron is 1.008665 atomic mass units. (amu) The mass of a proton is 1.007276 amu. The mass of a Helium4 nucleus is 4.002603 amu. The total mass of the 2 neutrons and 2 protons which make up a Helium4 nucleus is 4.031882 amu. What happened to the remaining 0.029279 amu? It was converted to energy according to Einstein’s E=mc2 equation. This is the binding energy. Since there are 4 nucleons in He4, the binding energy per nucleon is equivalent to 0.00731975 amu = 0.029279amu/4. This energy was given up in the formation of the Helium4 nucleus.

Consider a pile of kindling wood and enough matches to light it, versus the pile of ashes that would be formed if it were burned. Which is most stable? The ashes. Which would be more stable, partially burned or totally burned wood? Totally burned wood. Which would have given off more energy? Totally burned wood. Binding energy and burning can be compared. The more binding energy that is given off, the more stable a nucleus will be.
The sun is an enormous object. Its mass is about six trillion metric tons, or about 333,000 greater than the mass of the earth. This means that the gravitational attraction of the sun is much greater than that of the earth. This, in turn, means that it is difficult for Hydrogen nuclei to escape the gravitational pull of the sun. Almost 75% of the sun is made of Hydrogen, and most of the remainder is made of Helium.

I indicated above that Helium4 has a binding energy, and that mass is lost in the formation of He4 from protons and neutrons. Helium4 can be made from Hydrogen1. Most of the energy of the sun comes from just that reaction. The temperature of the interior of the sun is estimated to be in the millions. One consequence of that is that high temperature is that electrons almost always leave their nuclei entirely—they are just sort of running madly around, not attached to anything. Another result of the high temperature is that the remaining Hydrogen nuclei, or protons, are moving so rapidly that they can overcome the repulsion between two positive objects, and combine into a single entity. In the process, one of them becomes a neutron. This new nucleus, H2, has given off binding energy. Actually, the process continues with further proton capture, and eventually a He4 nucleus is formed. This is even more stable than H2. Some of the energy given off by this process escapes the sun, and it is a good thing, because that energy is the energy which living things on earth depend on.

The sun is not burning in the usual sense. The energy of the sun comes from nuclear fusion.

Note - my source of data is Modern Physics, by Kenneth Krane. (New York: Wiley, 1983)
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This work is licensed under a Creative Commons License . The purpose of this is NOT to prevent use by others, but to prevent other users from restricting free use. I claim no ownership of materials in the above material which are quotations from other sources.
Version of April 22, 2008. I thank Southern Wesleyan University, which is not responsible for the contents of this document. I would appreciate any comments. Thank you, and thank God!  (this is a correct e-mail address, but, to prevent spam, it is a graphic. Type the symbols into your e-mail application. Sorry.)

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