Earth-Sun Thermodynamics
Living organisms are the most complex of natural structures. Before tackling the thermodynamics of life, let’s start with simpler physical structures. We will apply the laws of thermodynamics to the Earth and Sun.
Entropy Produced in the Sun and Stars
The entropy produced in the Sun is the heat of combustion divided by the temperature. For every four hydrogen nuclei burned to a helium nucleus, the entropy produced is 4.282 micro-microwatt-seconds divided by 15 million kelvins. The Sun’s entropy increases constantly as it burns its fuel, and the same happens in every star.
Decreases and Compensating Increases
As we said before, Darwinists propose the spontaneous growth of unplanned complexity. Long ago scientists noticed that the Darwinist proposal goes against the natural tendency toward disorder. Later, thermodynamics and information theory elevated the observed tendency to universal physical law. But Darwinists often counter that thermodynamics does not apply to their process in isolation. Changes in living organisms take place on Earth, but the Sun helps sustain life. A correct thermodynamic analysis of Darwinism must therefore include the Sun as well as the Earth. Darwinists often summarize this argument by saying that “the Earth is not a closed system—it receives energy from the Sun.” The summary statement is true, but the argument is not.
This argument was part of an educational documentary in the 1950’s, made to teach young people not to rebel against the teaching of evolution. Few high school teenagers know enough physics to see through it. Ilya Prigogine (Russian-born Belgian chemist, 1917–2003) disproved the argument conclusively in a very simple, straightforward analysis in 1967. His work extended the methods of thermodynamics to non-equilibrium conditions, to nonlinear processes, and to situations in which some kind of order or organization arises.[i] For his work applying the second law to the thermodynamics of biological systems Prigogine won the 1977 Nobel Prize in Chemistry.
[i] Prigogine, Ilya, Introduction to Thermodynamics of Irreversible Processes (New York: John Wiley & Sons, 1967), pp. v–xii.
This argument was part of an educational documentary in the 1950’s, made to teach young people not to rebel against the teaching of evolution. Few high school teenagers know enough physics to see through it. Ilya Prigogine (Russian-born Belgian chemist, 1917–2003) disproved the argument conclusively in a very simple, straightforward analysis in 1967. His work extended the methods of thermodynamics to non-equilibrium conditions, to nonlinear processes, and to situations in which some kind of order or organization arises.[i] For his work applying the second law to the thermodynamics of biological systems Prigogine won the 1977 Nobel Prize in Chemistry.
[i] Prigogine, Ilya, Introduction to Thermodynamics of Irreversible Processes (New York: John Wiley & Sons, 1967), pp. v–xii.
Unfortunately, the solar-influx argument has persisted until this day. As recently as November, 2 000, Stephen G. Brush, a professor of the history of science at the University of Maryland, College Park, used the argument in an article called “Creationism Versus Physical Science.”
Physicists should also be concerned about the Creationist claim that Darwinist evolution violates the Second Law of Thermodynamics. It turns out that their version of the Second Law is different from the one taught in thermodynamics courses: it simply asserts that entropy can never decrease. The usual response is to insist that entropy can decrease in an “open system” such as the Earth, as long as it interacts with another open system, such as the Sun, in which there is a compensating increase.[i]
[i] Brush, Stephen G., in “Creationism Versus Physical Science” on what is called “The Back Page” of APS News: A Publication of the American Physical Society, 9 (Number 10, November 2000), page 8.
Brush merely repeats the old argument. His article has no trace of analysis. The history of science he teaches evidently is not sufficiently up to date to include Prigogine’s work. But the editors of the American Physical Society allowed Brush to continue propagating this error. Usually, the editors reject papers by authors who are not careful with their wording. Why were they lax with Brush?
Perhaps the argument persists because Prigogine disproved it in mathematical terms. A number of Darwinists, notably Stephen Jay Gould (American paleontologist, 1941–2002), have lamented their lack of mathematical skills.
Perhaps the argument persists because Prigogine disproved it in mathematical terms. A number of Darwinists, notably Stephen Jay Gould (American paleontologist, 1941–2002), have lamented their lack of mathematical skills.
I am not innumerate, but how I wish for the mathematical creativity, a pure blank for me, that drives so many scientists to fine accomplishment. I am not illogical, but how I yearn for the awesome ability I note in many colleagues to identify, develop, and test the linear implications of an argument.[i]
[i] Gould, Stephen Jay, Dinosaur in a Haystack (New York: Harmony Books, 1995), p. xi.
The scandalously few physicists who understand thermodynamics know that the Sun’s energy can never reduce the Earth’s entropy. We will present Prigogine’s analysis in words so everyone can understand it. Then we will illustrate it by analyzing entropy changes in a simple experiment, when a hot stone falls into cold water. We will follow a standard textbook that teachers often use “in thermodynamics courses.”
The proof consists in calculating the entropy changes correctly. A few quotations from Prigogine’s book should have settled forever the fallacy that the Sun’s energy can decrease the Earth’s entropy.
In the first chapter of his book Prigogine establishes a boundary around a system to be analyzed, and the exterior, whatever is not included in the system. The system may be the Earth, a living organism, or the entire universe.
The proof consists in calculating the entropy changes correctly. A few quotations from Prigogine’s book should have settled forever the fallacy that the Sun’s energy can decrease the Earth’s entropy.
In the first chapter of his book Prigogine establishes a boundary around a system to be analyzed, and the exterior, whatever is not included in the system. The system may be the Earth, a living organism, or the entire universe.
It is useful to classify thermodynamic systems according to the exchanges of energy (heat and work) and matter through their boundaries. We shall distinguish between isolated systems that can exchange neither energy nor matter, closed systems that exchange energy but no matter and open systems that exchange both energy and matter with the exterior.
Classical thermodynamics has been concerned mainly with the study of closed systems. One striking achievement of recent developments has been to withdraw this limitation so as to generalize the methods of thermodynamics to open systems, which are of great importance for biological thermodynamics as well as for many other fields such as meteorology and geology.[i]
[i] Prigogine, Ilya, op. cit., p. 3.
The universe as a whole is an isolated system because there is nothing physical exterior to it. A living organism is an open system because the organism receives and expels both matter and energy.
Notice that in Prigogine’s vocabulary open systems exchange both energy and matter with their environment. Closed systems exchange energy with their environment but not matter. The Earth receives ultraviolet radiation, light, and heat from the Sun and radiates heat at a lower temperature into space. These are all inflows and outflows of energy.
The Earth is, strictly speaking, an open system, because small amounts of matter reach it from outer space. Meteors burn up as they enter the Earth’s atmosphere, and the ashes eventually fall to the surface. Some meteors are big enough to have a remnant that survives the fall through the atmosphere and strikes the Earth’s surface as a solid object known as a meteorite. The Earth also receives occasional asteroid impacts. These bring matter from space into the Earth, but they do nothing to increase the organization of life forms on the Earth. Some people think that an asteroid impact destroyed the dinosaurs.
The Earth sends even less matter into space. In the past half-century or so rocket-propelled vehicles have gone beyond the Earth’s atmosphere. A few of our space probes have gone so far that they will never return. But for every space probe launched, rocket motors burned huge amounts of fuel and released great quantities of heat into the Earth’s atmosphere. Space launches have never decreased the Earth’s entropy.
Meteors and space probes make the Earth an open system. But the amount of mass exchanged with the Earth’s environment is so small relative to the mass of the Earth that, to a very good approximation, we may consider the Earth to be what Prigogine calls a closed system, and Brush and many Darwinists erroneously call an open system.
Now let’s follow Prigogine’s method for accounting for entropy production, omitting his notation and expressing his formulas in words.
Notice that in Prigogine’s vocabulary open systems exchange both energy and matter with their environment. Closed systems exchange energy with their environment but not matter. The Earth receives ultraviolet radiation, light, and heat from the Sun and radiates heat at a lower temperature into space. These are all inflows and outflows of energy.
The Earth is, strictly speaking, an open system, because small amounts of matter reach it from outer space. Meteors burn up as they enter the Earth’s atmosphere, and the ashes eventually fall to the surface. Some meteors are big enough to have a remnant that survives the fall through the atmosphere and strikes the Earth’s surface as a solid object known as a meteorite. The Earth also receives occasional asteroid impacts. These bring matter from space into the Earth, but they do nothing to increase the organization of life forms on the Earth. Some people think that an asteroid impact destroyed the dinosaurs.
The Earth sends even less matter into space. In the past half-century or so rocket-propelled vehicles have gone beyond the Earth’s atmosphere. A few of our space probes have gone so far that they will never return. But for every space probe launched, rocket motors burned huge amounts of fuel and released great quantities of heat into the Earth’s atmosphere. Space launches have never decreased the Earth’s entropy.
Meteors and space probes make the Earth an open system. But the amount of mass exchanged with the Earth’s environment is so small relative to the mass of the Earth that, to a very good approximation, we may consider the Earth to be what Prigogine calls a closed system, and Brush and many Darwinists erroneously call an open system.
Now let’s follow Prigogine’s method for accounting for entropy production, omitting his notation and expressing his formulas in words.
The second principle of thermodynamics postulates the existence of a function of state, called entropy (from the Greek en trope meaning “evolution”) which possesses the following properties: a) the entropy of the system is an extensive property. If a system consists of several parts, therefore the total entropy is equal to the sum of the entropies of each part. b) The change of entropy … can be split into two parts. [One is the] entropy due to interactions with the exterior, and [the other is] the contribution due to changes inside the system…. The entropy increase … due to changes inside the system is never negative. It is zero when the system undergoes reversible changes only, but it is positive if the system is subject to irreversible processes as well.
In this website we shall calculate explicit expressions for the entropy production of some important irreversible processes and also the entropy flow related to exchanges of matter and energy with the external environment.[i]
[i] Ibid. pp. 15–18.
Now we will pause to explain Prigogine’s concepts more fully. Entropy is a measure of a certain kind of disorder. The total disorder in a house is equal to the sum of the disorder in each room of the house. Entropy is a state variable. That is, it is a property of the state of things, a description of conditions as one finds them in a certain place.
To understand a state variable, consider a residence for elderly people on a day when young people are visiting. The presence of the young people does not change the state or condition of the elderly people. At best some of the elders may feel younger, but they cannot become young by associating with young people. Young people approach the state of their elders by moving toward the future at the standard rate of sixty minutes per hour. One group cannot pass its state or condition to another.
Since entropy is a state variable, it doesn’t flow from one place to another. Entropy is a property of matter or energy just as materials have properties like mass, density, temperature, and pressure. High-density stones can sink in low-density water, heat energy radiates, pressure can cause movement, and we carry disorganized materials from one place to another every time we take out the garbage. Flow of energy or movement of materials can change the entropy in different places, but the entropy does not flow or move all by itself.
Suppose that a messy desk is right beside a clean desk. The disorder of the first does not flow over to the second. The piles of books and papers stacked up precariously on the messy desk may topple, spill over onto the clean desk, and make it untidy. It would be imprecise to say that the disorder of the messy desk spilled over onto the clean desk. The things that spilled were books and papers. Once the material moved it disorganized its landing place.
A hot stove can change a frozen block of ice cream into a melted mess. The heat of the stove is disorganized energy. Does the disorder flow from the stove into the ice cream? No, entropy cannot flow. Heat can flow from one place to another and change the state of things in its destination. This illustration is different from the one above about the desks. In this illustration, energy, in the form of heat, moved from the hot stove and melted the ice cream. In the desk illustration, matter or material objects moved across the boundary and caused disorder. In neither case did entropy or disorder or messiness flow by itself. Entropy increased on the clean desk or in the ice cream because matter moved or energy flowed across a boundary.
The analysis and measurement of the dynamics of properties like state variables is the domain of physics, the most precise of the natural sciences. When we call a science precise, we mean that its theoretical predictions agree precisely with experimental measurements. The second law of thermodynamics says that in all processes without exception the total amount of entropy or disorder never decreases. We can calculate amounts of entropy theoretically and compare the amounts accurately with measurements in controlled physical and chemical experiments.
First, Prigogine comments on isolated systems, denying that there is any such thing as “flow of entropy.”
To understand a state variable, consider a residence for elderly people on a day when young people are visiting. The presence of the young people does not change the state or condition of the elderly people. At best some of the elders may feel younger, but they cannot become young by associating with young people. Young people approach the state of their elders by moving toward the future at the standard rate of sixty minutes per hour. One group cannot pass its state or condition to another.
Since entropy is a state variable, it doesn’t flow from one place to another. Entropy is a property of matter or energy just as materials have properties like mass, density, temperature, and pressure. High-density stones can sink in low-density water, heat energy radiates, pressure can cause movement, and we carry disorganized materials from one place to another every time we take out the garbage. Flow of energy or movement of materials can change the entropy in different places, but the entropy does not flow or move all by itself.
Suppose that a messy desk is right beside a clean desk. The disorder of the first does not flow over to the second. The piles of books and papers stacked up precariously on the messy desk may topple, spill over onto the clean desk, and make it untidy. It would be imprecise to say that the disorder of the messy desk spilled over onto the clean desk. The things that spilled were books and papers. Once the material moved it disorganized its landing place.
A hot stove can change a frozen block of ice cream into a melted mess. The heat of the stove is disorganized energy. Does the disorder flow from the stove into the ice cream? No, entropy cannot flow. Heat can flow from one place to another and change the state of things in its destination. This illustration is different from the one above about the desks. In this illustration, energy, in the form of heat, moved from the hot stove and melted the ice cream. In the desk illustration, matter or material objects moved across the boundary and caused disorder. In neither case did entropy or disorder or messiness flow by itself. Entropy increased on the clean desk or in the ice cream because matter moved or energy flowed across a boundary.
The analysis and measurement of the dynamics of properties like state variables is the domain of physics, the most precise of the natural sciences. When we call a science precise, we mean that its theoretical predictions agree precisely with experimental measurements. The second law of thermodynamics says that in all processes without exception the total amount of entropy or disorder never decreases. We can calculate amounts of entropy theoretically and compare the amounts accurately with measurements in controlled physical and chemical experiments.
First, Prigogine comments on isolated systems, denying that there is any such thing as “flow of entropy.”
For isolated systems, there is no flow of entropy so [the total entropy change is just the part due to internal processes, and it increases.] For isolated systems, this relation is equivalent to the classical statement that entropy can never decrease, so that in this case the behavior of the entropy function provides a criterion that enables us to detect the presence of irreversible processes…. The only general criterion of irreversibility is given by the entropy production ….[i]
[i] Ibid. pp. 15–18.
Prigogine then sets up equations for two systems, one inside the other. The boundary between the two is not a barrier. It is like the equator, an imaginary line that separates the Earth’s northern hemisphere from the southern hemisphere. There are no barriers or fortifications on the equator because the equator does not coincide with the boundary between any pair of unfriendly countries. The boundary Prigogine draws may be all around the Earth, separating it from the Sun and outer space, or it may be just outside the skin of a living organism, separating it from the exterior world. In either of these two cases, what Prigogine calls “the global system containing both” is the rest of the universe, and earlier he said that the universe as a whole is isolated.
Suppose we enclose a system … inside a larger system …, so that the global system containing both … is isolated. In both parts … some irreversible processes may take place. The classical statement of the second law of thermodynamics would be [that the total change in entropy is equal to the sum of the changes of entropy in each part, and the total entropy increases]. Applying now [the idea of splitting entropy changes into external influences of one part in the other and internal processes wholly contained within one of the parts] to each part separately, we shall postulate here that [in both parts the entropy due to internal processes increases]. A physical situation such that [the internal entropy in the inside increases, the internal entropy in the outside decreases, and the total entropy inside and outside increases] is excluded. We can therefore say that “absorption” of entropy in one part, compensated by a sufficient “production” in another part of the system is prohibited.[i]
[i] Ibid. pp. 15–18.
Notice that there is no such thing as “‘absorption’ of entropy in one part, compensated by a sufficient ‘production’ in another part of the system.” Prigogine specifically states that a sufficiently large increase in entropy in the Sun and the rest of the universe cannot compensate for an entropy reduction on Earth. The entropy produced on the Earth cannot flow back to the Sun.
This formulation implies that in every macroscopic region of the system the entropy production due to the irreversible processes is positive. The term macroscopic region refers to any region containing a number of molecules sufficiently large for microscopic fluctuations to be negligible. Interference of irreversible processes is only possible when they occur in the same region of the system. Such a formulation may be called a “local” formulation of the second law in contrast to the “global” formulation of classical thermodynamics. Its value lies in the fact that it permits a much closer analysis of irreversible processes and, as such, it will constitute the central postulate on which this book is based….
It is interesting to note that the splitting of the entropy change into two terms … permits an easy discussion of the difference between closed and open systems as will be shown below. Clearly, this difference has to appear in the [external entropy change] term that, for open systems, must contain terms due to the exchange of matter.[i]
[i] Ibid. pp. 15–18.
Biological systems are open systems. They all operate by taking in matter with low entropy like food and oxygen, and expelling degraded matter with high entropy (we all do it, but we don’t usually talk about it in polite society). Biological systems can do this because they have structure. Likewise heat engines consume fuel, expel waste heat and ashes or smoke, and have structure. Biological systems and heat engines can therefore keep their own entropy low at the expense of an increase in entropy in the environment. Mechanical heat engines accomplish this using a structure specifically designed for that purpose. Biological systems accomplish the same end using their structure. Was the structure of biological systems specifically designed for that purpose? It is possible that future creative designers will make new biological structures that, like all living organisms, keep their own entropy low. Did a natural, automatic design mechanism or some other intelligence design the existing biological structures?
The second law of thermodynamics has a great deal to say about the structure of biological systems. Entropy is the negative of information, and the information in the genetic code specifies biological structure. This is where the second law applies to creative design. We will use it later to evaluate the speculations of Darwinists.
To answer Brush and the American Physical Society briefly, sunlight increases the Earth’s entropy, year after year after year. If one counts only the cooling of the Sun as it radiates heat away to the Earth, then the Sun’s entropy decreases a small amount at the same time that the Earth’s entropy increases by a much larger amount. All of this is just the opposite of the Darwinist claim that the Earth’s entropy can decrease if there is a more-than-compensating increase of entropy in the Sun.
To be more rigorous, we must remember that the burning of the Sun’s fuel increases its entropy irreversibly. The Sun’s temperature does not change because the heat that flows out every second is equal to the heat generated by burning fuel. The entropy from burning fuel is the energy produced divided by the temperature. The entropy of the Sun and the entropy of the Earth are both constantly increasing. Looking in detail at each part of the picture, there is no decrease of entropy anywhere.
The second law of thermodynamics has a great deal to say about the structure of biological systems. Entropy is the negative of information, and the information in the genetic code specifies biological structure. This is where the second law applies to creative design. We will use it later to evaluate the speculations of Darwinists.
To answer Brush and the American Physical Society briefly, sunlight increases the Earth’s entropy, year after year after year. If one counts only the cooling of the Sun as it radiates heat away to the Earth, then the Sun’s entropy decreases a small amount at the same time that the Earth’s entropy increases by a much larger amount. All of this is just the opposite of the Darwinist claim that the Earth’s entropy can decrease if there is a more-than-compensating increase of entropy in the Sun.
To be more rigorous, we must remember that the burning of the Sun’s fuel increases its entropy irreversibly. The Sun’s temperature does not change because the heat that flows out every second is equal to the heat generated by burning fuel. The entropy from burning fuel is the energy produced divided by the temperature. The entropy of the Sun and the entropy of the Earth are both constantly increasing. Looking in detail at each part of the picture, there is no decrease of entropy anywhere.