Structure, Design, Intelligence, and Creativity
Science writers seldom emphasize the connection between entropy, structure, and design. The steam engine is a cleverly designed structure James Watt (Scottish inventor and mechanical engineer, 1736–1819) invented. Heat is a highly disorganized form of energy. If we are out in the woods far from home some cold night we may build a fire to get warm. The fire will not help us to get home unless we have available a fairly complex, intelligently designed structure to convert some of the heat into useful work. For instance, we may be able to get home if we have an automobile. The engine has several cylinders where the mechanism injects fuel and starts fires repeatedly at just the right times to drive the pistons and transmit energy through the crankshaft, transmission, drive shaft, differential, and axles to the wheels. Magic or the random jumbling together of a lot of junkyard parts obviously did not make the car and its engine appear. The automobile’s very existence implies that there are creative designers, inventers, engineers, and machinists who worked together to create it. One designer can recognize the work of another.
There is a strong connection between information, entropy, and structure. Structure is needed to control physical processes to make them efficient and reversible. Anyone who reads through a text on thermodynamics will find frequent references to cylinders and pistons, semi-permeable membranes, valves, tubes, and constant-temperature baths. All such structures are artifacts with human inventors. All were created under the control of minds that processed information intelligently.
One may well wonder if there are natural structures for getting useful work out of heat. We don’t have to look far. Human bodies are heat engines that consume low-entropy forms of material called food, do useful work, use some of the remaining energy to keep warm, and expel heat along with three degraded, high-entropy forms of matter. Breathing ejects carbon dioxide, which is waste material for animals and people but useful to green plants. Certain insects and bacteria use our solid and liquid waste materials. All animals are also heat engines. People and animals rely on plants to manufacture their food.
Plants are a kind of heat engine run in reverse, to make fuel from energy. They take the energy of sunlight and use it to make carbohydrates, food for themselves and for animals. Some of the ingredients of carbohydrates come from soil. In the process of making carbohydrates plants also take in water and carbon dioxide, strip the hydrogen from the water molecules, and discharge the water’s oxygen into the atmosphere. To do this, plants use a complex molecular machine called chlorophyll.
Atmospheric oxygen enables animals to extract energy from food by reconstituting the water and carbon dioxide, molecules that animals then discharge into the atmosphere. A complex molecule called hemoglobin, similar to chlorophyll, carries oxygen in our blood to our cells as they burn food and work. The same hemoglobin removes the carbon dioxide. Many other complex molecules, called enzymes, control the manufacture of proteins. Proteins make up the working structure of our bodies. Long chains of deoxyribonucleic acid (DNA) encode the information for making the molecular machines we find in living organisms. Where is the intelligence that designed these complex structures? Did they just come to be through random processes and the automatic design capabilities of natural selection? Or did some greater intelligence work to create life on Earth?
There is a strong connection between information, entropy, and structure. Structure is needed to control physical processes to make them efficient and reversible. Anyone who reads through a text on thermodynamics will find frequent references to cylinders and pistons, semi-permeable membranes, valves, tubes, and constant-temperature baths. All such structures are artifacts with human inventors. All were created under the control of minds that processed information intelligently.
One may well wonder if there are natural structures for getting useful work out of heat. We don’t have to look far. Human bodies are heat engines that consume low-entropy forms of material called food, do useful work, use some of the remaining energy to keep warm, and expel heat along with three degraded, high-entropy forms of matter. Breathing ejects carbon dioxide, which is waste material for animals and people but useful to green plants. Certain insects and bacteria use our solid and liquid waste materials. All animals are also heat engines. People and animals rely on plants to manufacture their food.
Plants are a kind of heat engine run in reverse, to make fuel from energy. They take the energy of sunlight and use it to make carbohydrates, food for themselves and for animals. Some of the ingredients of carbohydrates come from soil. In the process of making carbohydrates plants also take in water and carbon dioxide, strip the hydrogen from the water molecules, and discharge the water’s oxygen into the atmosphere. To do this, plants use a complex molecular machine called chlorophyll.
Atmospheric oxygen enables animals to extract energy from food by reconstituting the water and carbon dioxide, molecules that animals then discharge into the atmosphere. A complex molecule called hemoglobin, similar to chlorophyll, carries oxygen in our blood to our cells as they burn food and work. The same hemoglobin removes the carbon dioxide. Many other complex molecules, called enzymes, control the manufacture of proteins. Proteins make up the working structure of our bodies. Long chains of deoxyribonucleic acid (DNA) encode the information for making the molecular machines we find in living organisms. Where is the intelligence that designed these complex structures? Did they just come to be through random processes and the automatic design capabilities of natural selection? Or did some greater intelligence work to create life on Earth?
Structure and Breakdown, Death and Decay
It is universal human experience that tools wear out, machines break down, and all living organisms die and decay. Many people confuse this tendency with the physical concept of entropy. Analogy is the only relation between the two. The second law of thermodynamics says nothing about the breakdown of structure.
Physicists can write no laws predicting when machines will break down, because some machines are made better than others. We must refer the question to engineers. They can test machines, analyze the reliability of the different parts, and predict the “mean time between failures,” how often breakdowns will occur. Their predictions do not set an absolute limit to the performance of individual machines.
Heat engines break down when their parts wear out or their tubes become clogged with scale and rust. The engines do not stop because their entropy becomes too large. The waste heat they exhaust into the environment carries away entropy. This allows the machines to maintain constant average internal entropy. They can continue working as long as they have fuel, sufficient working fluids, and adequate maintenance.
Entropy does not doom a star to destruction or extinction. The second law of thermodynamics says that entropy will increase in any reaction that emits heat. However, no law of physics limits how much fuel there may be. Some stars renew themselves for a time by drawing in hydrogen from clouds they encounter moving through space. In the 19th century people thought that the stars could only burn a few million years. This is because they only knew of chemical reactions. Such reactions can produce at most a few light photons for each atom that enters the reaction. But nuclear reactions can produce millions of light photons for every atom in the reaction. This 20th-century discovery, nuclear energy, has greatly increased the life expectancy of the stars. They have for a long time been burning a fuel we have only recently discovered.
Stars stop shining when they exhaust their fuel, not because their entropy becomes too great. Light and heat from stars carry much of their entropy away to the rest of the universe. The rest remains in the ashes. These sink down into the center of the star. Nuclear combustion continues in a spherical shell around the inert center as long as there is fuel.
The second law of thermodynamics does not doom living organisms to die, either. We can apply to our own bodies the above discussion about machines and stars. All living organisms maintain themselves in a state of low entropy by consuming food and expelling degraded matter. Telomeres, the terminators at the ends of DNA strands that keep the double helix from unraveling, get shorter and shorter as cells replicate. This presently sets the upper limit of human longevity. Actuaries can calculate average life expectancy sufficiently well to make the insurance business profitable, but not well enough so any individual may be certain of the date and time of his or her death. Mortality tables do not limit anyone’s longevity. The universality and irreversibility of death are not a consequence of the second law of thermodynamics.
The formulas engineers and actuaries use are not laws of physics. Such predictions are only statistical, not deterministic. Let’s note the contrast between statistical predictions and entropy. Entropy is calculable and measurable in controlled circumstances. Therefore, entropy is not the same as wear and tear, breakdown, disease, death, and decay.
We can calculate entropy when there is some sort of structure, a gas in a box, a heat engine, or a string of coded symbols. The second law of thermodynamics is about how efficient the structure is in handling energy. The second law says nothing about the possible breakdown modes of the structure, or even if breakdown is inevitable. When physicists say that entropy is disorder, they mean a very specific measure of disorder, not general disorganization.
Physicists can write no laws predicting when machines will break down, because some machines are made better than others. We must refer the question to engineers. They can test machines, analyze the reliability of the different parts, and predict the “mean time between failures,” how often breakdowns will occur. Their predictions do not set an absolute limit to the performance of individual machines.
Heat engines break down when their parts wear out or their tubes become clogged with scale and rust. The engines do not stop because their entropy becomes too large. The waste heat they exhaust into the environment carries away entropy. This allows the machines to maintain constant average internal entropy. They can continue working as long as they have fuel, sufficient working fluids, and adequate maintenance.
Entropy does not doom a star to destruction or extinction. The second law of thermodynamics says that entropy will increase in any reaction that emits heat. However, no law of physics limits how much fuel there may be. Some stars renew themselves for a time by drawing in hydrogen from clouds they encounter moving through space. In the 19th century people thought that the stars could only burn a few million years. This is because they only knew of chemical reactions. Such reactions can produce at most a few light photons for each atom that enters the reaction. But nuclear reactions can produce millions of light photons for every atom in the reaction. This 20th-century discovery, nuclear energy, has greatly increased the life expectancy of the stars. They have for a long time been burning a fuel we have only recently discovered.
Stars stop shining when they exhaust their fuel, not because their entropy becomes too great. Light and heat from stars carry much of their entropy away to the rest of the universe. The rest remains in the ashes. These sink down into the center of the star. Nuclear combustion continues in a spherical shell around the inert center as long as there is fuel.
The second law of thermodynamics does not doom living organisms to die, either. We can apply to our own bodies the above discussion about machines and stars. All living organisms maintain themselves in a state of low entropy by consuming food and expelling degraded matter. Telomeres, the terminators at the ends of DNA strands that keep the double helix from unraveling, get shorter and shorter as cells replicate. This presently sets the upper limit of human longevity. Actuaries can calculate average life expectancy sufficiently well to make the insurance business profitable, but not well enough so any individual may be certain of the date and time of his or her death. Mortality tables do not limit anyone’s longevity. The universality and irreversibility of death are not a consequence of the second law of thermodynamics.
The formulas engineers and actuaries use are not laws of physics. Such predictions are only statistical, not deterministic. Let’s note the contrast between statistical predictions and entropy. Entropy is calculable and measurable in controlled circumstances. Therefore, entropy is not the same as wear and tear, breakdown, disease, death, and decay.
We can calculate entropy when there is some sort of structure, a gas in a box, a heat engine, or a string of coded symbols. The second law of thermodynamics is about how efficient the structure is in handling energy. The second law says nothing about the possible breakdown modes of the structure, or even if breakdown is inevitable. When physicists say that entropy is disorder, they mean a very specific measure of disorder, not general disorganization.
Perfection and Beauty
Is it possible to make a perfect machine that goes on working forever and never breaks down? This brings us to a fundamental difference between the large and the small. At the level of subnuclear particles everything is perfect. No particle is ever overweight or defective. All electrons have exactly the same electrical charge, and that charge is exactly right to cancel the charge on any proton. Subnuclear particles of the same species are identical and indistinguishable. When such particles are so close to each other that their wave amplitudes overlap, quantum mechanics must take into account the fact that they are indistinguishable. Identical, indistinguishable particles may switch places with each other without anyone being sure of what happened. When bound into atoms, electrons dance endlessly about the nucleus, with no friction, no wear, no dissipation of energy. Atoms are perpetual motion machines. We have noted before that the laws of thermodynamics do not deny the existence of perpetual motion machines. The laws only say that no machine can work usefully forever without fuel.
All subnuclear particles of the same kind are equal, but not all atoms. The nucleus of a neutral atom may have more or less than the usual number of neutrons. The presence of an extra neutron or two in one of the two oxygen atoms in a carbon dioxide molecule makes the molecule unsymmetrical. It spins out of balance and absorbs twice as many lines of far infrared radiation.
The first departure from the beauty of perfection thus has to do with excess or lack, or departure from ideal form. Some might claim this as a vindication of one of the ideas of Plato (Greek philosopher, about 428 BCE–about 347 BCE). However, unstable elements also play a role in making the universe suitable for life. Are the extra-heavy hydrogen atoms and the lightweight helium atoms ugly freaks? No, they play a key role in keeping the Sun and stars shining. As another example, some uranium nuclei have only 143 neutrons instead of the more usual 146. That makes the lighter uranium nuclei unstable. But uranium decay causes uneven heating of the interior of the Earth, helping to form the continents. Without unstable forms of uranium, a single ocean might completely cover the Earth.
Entropy is necessary for life. Without irreversible chemical changes we could not digest our food. Therefore, entropy and death are not the same.
All subnuclear particles of the same kind are equal, but not all atoms. The nucleus of a neutral atom may have more or less than the usual number of neutrons. The presence of an extra neutron or two in one of the two oxygen atoms in a carbon dioxide molecule makes the molecule unsymmetrical. It spins out of balance and absorbs twice as many lines of far infrared radiation.
The first departure from the beauty of perfection thus has to do with excess or lack, or departure from ideal form. Some might claim this as a vindication of one of the ideas of Plato (Greek philosopher, about 428 BCE–about 347 BCE). However, unstable elements also play a role in making the universe suitable for life. Are the extra-heavy hydrogen atoms and the lightweight helium atoms ugly freaks? No, they play a key role in keeping the Sun and stars shining. As another example, some uranium nuclei have only 143 neutrons instead of the more usual 146. That makes the lighter uranium nuclei unstable. But uranium decay causes uneven heating of the interior of the Earth, helping to form the continents. Without unstable forms of uranium, a single ocean might completely cover the Earth.
Entropy is necessary for life. Without irreversible chemical changes we could not digest our food. Therefore, entropy and death are not the same.