The Example Applied to the Sun and Earth
Heat flows from the Sun to the Earth just as it flows from the hot stone to the cold water. The Sun’s or stone’s heat loss makes the Sun’s or stone’s entropy decrease slightly, and the Earth’s or water’s heat gain makes the Earth’s or water’s entropy increase greatly. To carry the analogy further we must take into account the source of energy that heated the stone in the first place. To heat the stone we have to burn fuel. The Sun burns fuel to stay hot. The heat the Sun generates by burning fuel is the heat the Sun loses by shining, because the flow has been going on long enough for the Sun to reach equilibrium. The amount of heat generated is exactly equal to the amount of the heat radiated. But when fuel burns, energy flows out of it, leaving degraded matter in the form of ashes. Heat entering the Earth’s atmosphere drives winds that wear down the mountains. Therefore both the Sun’s and the Earth’s entropy constantly increase. To summarize and rebut the Darwinist argument, solar influx makes the Earth’s entropy increase continuously.
The example of the hot stone and cold water is a simple, straightforward application of the second law of thermodynamics. Brush and the editors of AIP News should note that the version of the second law above is “the one taught in thermodynamics courses.”[i] Richard Phillips Feynman (American physicist, 1918–1988, 1965 Nobel prizewinner) taught an introductory course on physics to freshman and sophomore classes at the California Institute of Technology in the academic years 1960–1961 and 1961–1962. His colleagues recorded and published his lectures. The Feynman Lectures on Physics analyze the illustration of the hot stone and the cold water.[ii]
[i] Brush, Stephen G., op. cit.
[ii] Feynman, Richard P. et al., op. cit., p. 44‑12.
Now let’s apply the same reasoning in greater detail to the hot Sun and the cool Earth. Let’s consider any place on the Earth’s surface exposed to sunlight. There is a small decrease in the Sun’s entropy when we take into account only the tiny fraction of its sunlight that strikes the selected area. The area of the Earth’s surface exposed to sunlight corresponds to the cold water. The area’s entropy increases by a large amount. The Sun corresponds to the hot stone. The overall change of entropy of the Sun and Earth together is positive. There is an increase of entropy of the Sun-Earth system, so the change is irreversible. But let’s notice particularly that the Sun’s entropy decreases slightly, and the Earth’s entropy increases by a larger amount.
Now let’s return to the Darwinist answer to thermodynamics. Brush said, “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.”[iii] The calculation we have just made says the Sun’s entropy decreases and the Earth’s entropy increases. Brush says just the opposite.
[iii] Brush, Stephen G., op. cit.
Brush says, truly enough, that Darwinism can defeat thermodynamics if the Earth’s entropy decreases while the Sun’s entropy increases. But this never happens. If it did, heat would flow from the Earth to the Sun. Heat could flow from the Earth to the Sun only if the Sun, which appears to be hot and bright to unbiased observers, were really cold and dark. In fact, scientific measurements with instruments agree with the unbiased observers. Both types of observers agree that the Sun is hot and bright relative to the Earth. Brush’s argument against thermodynamics is wrong, contrary to facts.
Without doing any calculations at all, anyone can see that the Darwinist argument is completely backward. Sunlight makes ice and snow melt. Water thus passes from a low-entropy frozen phase to a high-entropy liquid phase. Plastic bags carelessly scattered on the landscape harden when exposed to sunlight and eventually break up. This process is irreversible and shows that entropy increases on the Earth because of sunlight.
Sunlight can, of course, produce useful work. Work is a low-entropy form of energy. Sunlight can drive winds that run windmills and produce useful work. Sunlight evaporates water, and evaporated water, rising to high altitudes, falls as rain that can run turbines and generate electricity. Sunlight energizing chlorophyll makes plants grow and store low-entropy food. All these applications of sunlight to produce low-entropy energy and food require some form of structure, either a machine or a complex molecule. There is no conversion of heat to work without structure. Structure does not arise without creative design.
The more we examine the Darwinist solar-influx argument the less sense it makes. We wonder why the American Physical Society’s editors would print erroneous deductions from physical laws to bolster biological speculations. Are they really that desperate to defend themselves from clear evidence that points to creative design? If the Sun were dark and cold it would draw heat out of the Earth and reduce the Earth’s entropy. Would people who call themselves scientists rather say that the Earth warms the Sun than admit that life cries out for an explanation involving creative design?
The argument shows glaringly that Darwinism is not merely imprecise. Darwinists trying to do a physics calculation can’t even get the choice of plus sign or minus sign right. What should be positive is negative, and vice versa. The sign is the most significant part of a number, even more significant than the leading digit. Suppose you added up all the checks and fees in your checking account, subtracted all the deposits, and at the end concluded that you had $13 768.92 in the bank. If you show your calculations to the bank officers, they will agree with your calculations down to the penny, except that they will say that you always got the wrong sign and therefore that you owe the bank $13 768.92. How would you react? Does that show why, in any number or calculation, the plus sign or minus sign is the most significant part?
Let’s examine the solar-influx argument a bit further. Earlier we took into account the fact that the Earth radiates the Sun’s heat to the cold of outer space. If the Earth absorbed the Sun’s energy and radiated it without delay there would be no temperature change at all and therefore there would be no net change in entropy. However, the Earth rotates on its axis. As a specific portion of the Earth’s surface turns from night to dawn, the portion is relatively cool. As the Sun rises over the portion, the portion absorbs energy and its temperature rises. Long after sunset the same portion “gives back” the heat, radiating it into space. When a cool portion of the Earth’s surface heats up during the day, it starts at a low temperature. Its entropy increases greatly, because the entropy change is large when the temperature is low. When the same portion cools at night, heat goes out from it, starting at a high temperature. Its entropy decreases somewhat, but the magnitude of the change is small because the temperature is high. In one day-and-night cycle there is first a large increase in entropy during the day and then a small decrease at night. The net effect of sunlight and the Earth’s rotation is a continuous increase in the Earth’s entropy, year after year. Once again, this is completely contrary to the Darwinist scenario, in which sunlight shining on the Earth supposedly defeats the second law of thermodynamics and gives evolution a chance to produce more and more complex life forms.
If the cooling and heating cycle occurred under carefully controlled laboratory conditions, we could make the changes in air temperature and pressure very gradual, without allowing turbulence in the air. Without turbulence the initial decrease in entropy could be made large enough in magnitude to offset almost completely the later increase in entropy. If the net increase in entropy is very small the cooling and heating cycle is nearly reversible. However, there must be a cylinder and piston to contain the air as it heats and cools, so the work the air does as it expands may be recovered and used to compress the air when it cools.
There is nothing similar to a containing vessel for the air over the Earth’s surface. The daily heating and cooling of the air drives winds that dissipate their energy in turbulence. Free, uncontained, fresh air is necessary for life, but the freedom of the air also contributes to the continual destruction of order. The Sun’s energy arrives hot and intense, but it is dissipated as general warmth spread out through the atmosphere. The warmth makes the Earth an agreeable place to live, but it cannot be concentrated and made to serve any other useful purpose. Therefore, sunlight drives an irreversible increase of entropy on the Earth.
¿Qué hace que la luz del sol sea adecuada?
La luz del sol tiene una serie de propiedades que la hacen adecuada para sustentar la vida y proporcionar información. Comencemos con la propiedad más obvia, tan obvia que puede parecer trivial, y luego pasemos a propiedades que no se entienden tan bien pero son igual de importantes para la vida.
La luz del Sol llega a la superficie de la Tierra desde una sola dirección en un momento dado. Si la luz del sol llegara a la Tierra desde todas las direcciones, no habría alternancia entre el día y la noche, porque ninguna rotación de la Tierra podría proteger de la luz ninguna parte de su superficie. Una cierta cantidad de energía fluye constantemente desde el Sol a la superficie de la Tierra, y esa energía es necesaria para sustentar la vida.
Sin embargo, algún otro arreglo podría proporcionar la entrada de energía equivalente. Supongamos, por ejemplo, que pudiéramos colocar la Tierra dentro de una cavidad cúbica hueca en algún tipo de cuerpo masivo a 280 kelvin o 7 °C, aproximadamente 45 °F. Las paredes de la cavidad tendrían que ser muy fuertes para evitar que se derrumbe. Esta idea es bastante hipotética porque no se conoce ninguna materia lo suficientemente fuerte como para hacer una cavidad rígida lo suficientemente grande como para albergar un planeta. Incluso si la hubiera, las paredes no proporcionarían luz. Las materias a temperatura ambiente o inferior no están lo suficientemente calientes para emitir luz. Cualquiera que dude de esto puede ingresar a una habitación cerrada, apagar las luces y notar que las paredes no se ven brillantes. La Tierra dentro de una cálida cavidad estaría en perpetua noche. El calor no tendría direccionalidad. Incidiría por igual en la Tierra desde todas las direcciones. No podría proporcionar la información de cronometraje que tenemos del Sol, incluso si la Tierra en la cavidad continuara girando al mismo ritmo. Sin embargo, lo más importante es que no habría alimento para bacterias, plantas o animales.
La energía solar entrante mantiene toda la vida en la Tierra al alimentar los motores de calor molecular que fotosintetizan los carbohidratos y liberan oxígeno. La clorofila es el componente más importante de estos motores. Refleja la luz verde y absorbe la luz roja, azul y violeta. La clorofila es lo que hace que las plantas verdes sean verdes. La superficie superior de una hoja es transparente, lo que permite que la luz del sol llegue a los cloroplastos, pequeños cuerpos en las hojas que contienen clorofila. Los colores absorbidos corresponden a rayos de longitudes de onda y energías fotónicas específicas. Las energías son las necesarias para mover los electrones en la molécula de clorofila desde el estado de menor energía (el estado fundamental) a ciertos estados excitados. Los importantes estados excitados de la clorofila son metaestables. Es decir, no son completamente estables, pero persisten por tiempos relativamente largos. Su meta-estabilidad les permite retener la energía de excitación el tiempo suficiente para catalizar las reacciones químicas que convierten el agua y el dióxido de carbono en un tipo de azúcar llamado glucosa. Otros motores moleculares convierten el azúcar en almidón. El almidón y los azúcares son carbohidratos, alimentos para la planta.
Cuando las sustancias químicas absorben luz, absorben un fotón por molécula. Por supuesto, dos fotones, cada uno de baja energía, pueden combinar su energía para formar el equivalente a un fotón rojo, azul o violeta. Esto es posible, pero las sustancias químicas rara vez absorben dos o más fotones a la vez. La luz se mueve muy rápido. Es muy poco probable que dos fotones lleguen a una molécula dada lo suficientemente cerca al mismo tiempo para que su energía pueda combinarse.
El Sol proporciona fotones rojos, azules y violetas. Su máxima emisión son fotones amarillos. Proporciona algunos fotones ultravioletas, pero no demasiados. Los fotones de demasiada energía son destructivos. Arrancan electrones de los átomos y hacen que las moléculas se rompan. Por otro lado, los fotones infrarrojos no tienen suficiente energía para poner la clorofila en estados excitados que pueden producir azúcar a partir de dióxido de carbono y agua. A una temperatura de 280 kelvins, 7º C o 45º F, las paredes oscuras de una cavidad emiten fotones infrarrojos con una longitud de onda de 10 micrómetros. Su energía es solo alrededor del 4% de la energía necesaria para producir luz violeta. Veinticinco de ellos tendrían que unirse a la clorofila para tener el mismo efecto que un fotón violeta. Los fotones de calor de las paredes de una cavidad cálida nunca se agrupan de esa manera. No habría fotosíntesis de carbohidratos si la luz del sol no proporcionara la luz del día en la Tierra. Muchos escolares han realizado el experimento científico de privar de luz a una planta verde. El resultado es siempre el mismo. La planta muere por falta de luz roja, azul y violeta.
Los animales dependen de las plantas verdes para obtener alimento y oxígeno. Hay algunas plantas que no tienen clorofila y no utilizan la luz solar para elaborar su alimento. La mayoría de estas plantas obtienen carbohidratos de otros organismos. Si los organismos están vivos, las plantas que se alimentan de ellos son parásitos. Las plantas que se alimentan de materia orgánica muerta son saprofitas. Tanto los parásitos como los saprofitos dependen claramente de las plantas verdes y la clorofila.
Heat flows from the Sun to the Earth just as it flows from the hot stone to the cold water. The Sun’s or stone’s heat loss makes the Sun’s or stone’s entropy decrease slightly, and the Earth’s or water’s heat gain makes the Earth’s or water’s entropy increase greatly. To carry the analogy further we must take into account the source of energy that heated the stone in the first place. To heat the stone we have to burn fuel. The Sun burns fuel to stay hot. The heat the Sun generates by burning fuel is the heat the Sun loses by shining, because the flow has been going on long enough for the Sun to reach equilibrium. The amount of heat generated is exactly equal to the amount of the heat radiated. But when fuel burns, energy flows out of it, leaving degraded matter in the form of ashes. Heat entering the Earth’s atmosphere drives winds that wear down the mountains. Therefore both the Sun’s and the Earth’s entropy constantly increase. To summarize and rebut the Darwinist argument, solar influx makes the Earth’s entropy increase continuously.
The example of the hot stone and cold water is a simple, straightforward application of the second law of thermodynamics. Brush and the editors of AIP News should note that the version of the second law above is “the one taught in thermodynamics courses.”[i] Richard Phillips Feynman (American physicist, 1918–1988, 1965 Nobel prizewinner) taught an introductory course on physics to freshman and sophomore classes at the California Institute of Technology in the academic years 1960–1961 and 1961–1962. His colleagues recorded and published his lectures. The Feynman Lectures on Physics analyze the illustration of the hot stone and the cold water.[ii]
[i] Brush, Stephen G., op. cit.
[ii] Feynman, Richard P. et al., op. cit., p. 44‑12.
Now let’s apply the same reasoning in greater detail to the hot Sun and the cool Earth. Let’s consider any place on the Earth’s surface exposed to sunlight. There is a small decrease in the Sun’s entropy when we take into account only the tiny fraction of its sunlight that strikes the selected area. The area of the Earth’s surface exposed to sunlight corresponds to the cold water. The area’s entropy increases by a large amount. The Sun corresponds to the hot stone. The overall change of entropy of the Sun and Earth together is positive. There is an increase of entropy of the Sun-Earth system, so the change is irreversible. But let’s notice particularly that the Sun’s entropy decreases slightly, and the Earth’s entropy increases by a larger amount.
Now let’s return to the Darwinist answer to thermodynamics. Brush said, “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.”[iii] The calculation we have just made says the Sun’s entropy decreases and the Earth’s entropy increases. Brush says just the opposite.
[iii] Brush, Stephen G., op. cit.
Brush says, truly enough, that Darwinism can defeat thermodynamics if the Earth’s entropy decreases while the Sun’s entropy increases. But this never happens. If it did, heat would flow from the Earth to the Sun. Heat could flow from the Earth to the Sun only if the Sun, which appears to be hot and bright to unbiased observers, were really cold and dark. In fact, scientific measurements with instruments agree with the unbiased observers. Both types of observers agree that the Sun is hot and bright relative to the Earth. Brush’s argument against thermodynamics is wrong, contrary to facts.
Without doing any calculations at all, anyone can see that the Darwinist argument is completely backward. Sunlight makes ice and snow melt. Water thus passes from a low-entropy frozen phase to a high-entropy liquid phase. Plastic bags carelessly scattered on the landscape harden when exposed to sunlight and eventually break up. This process is irreversible and shows that entropy increases on the Earth because of sunlight.
Sunlight can, of course, produce useful work. Work is a low-entropy form of energy. Sunlight can drive winds that run windmills and produce useful work. Sunlight evaporates water, and evaporated water, rising to high altitudes, falls as rain that can run turbines and generate electricity. Sunlight energizing chlorophyll makes plants grow and store low-entropy food. All these applications of sunlight to produce low-entropy energy and food require some form of structure, either a machine or a complex molecule. There is no conversion of heat to work without structure. Structure does not arise without creative design.
The more we examine the Darwinist solar-influx argument the less sense it makes. We wonder why the American Physical Society’s editors would print erroneous deductions from physical laws to bolster biological speculations. Are they really that desperate to defend themselves from clear evidence that points to creative design? If the Sun were dark and cold it would draw heat out of the Earth and reduce the Earth’s entropy. Would people who call themselves scientists rather say that the Earth warms the Sun than admit that life cries out for an explanation involving creative design?
The argument shows glaringly that Darwinism is not merely imprecise. Darwinists trying to do a physics calculation can’t even get the choice of plus sign or minus sign right. What should be positive is negative, and vice versa. The sign is the most significant part of a number, even more significant than the leading digit. Suppose you added up all the checks and fees in your checking account, subtracted all the deposits, and at the end concluded that you had $13 768.92 in the bank. If you show your calculations to the bank officers, they will agree with your calculations down to the penny, except that they will say that you always got the wrong sign and therefore that you owe the bank $13 768.92. How would you react? Does that show why, in any number or calculation, the plus sign or minus sign is the most significant part?
Let’s examine the solar-influx argument a bit further. Earlier we took into account the fact that the Earth radiates the Sun’s heat to the cold of outer space. If the Earth absorbed the Sun’s energy and radiated it without delay there would be no temperature change at all and therefore there would be no net change in entropy. However, the Earth rotates on its axis. As a specific portion of the Earth’s surface turns from night to dawn, the portion is relatively cool. As the Sun rises over the portion, the portion absorbs energy and its temperature rises. Long after sunset the same portion “gives back” the heat, radiating it into space. When a cool portion of the Earth’s surface heats up during the day, it starts at a low temperature. Its entropy increases greatly, because the entropy change is large when the temperature is low. When the same portion cools at night, heat goes out from it, starting at a high temperature. Its entropy decreases somewhat, but the magnitude of the change is small because the temperature is high. In one day-and-night cycle there is first a large increase in entropy during the day and then a small decrease at night. The net effect of sunlight and the Earth’s rotation is a continuous increase in the Earth’s entropy, year after year. Once again, this is completely contrary to the Darwinist scenario, in which sunlight shining on the Earth supposedly defeats the second law of thermodynamics and gives evolution a chance to produce more and more complex life forms.
If the cooling and heating cycle occurred under carefully controlled laboratory conditions, we could make the changes in air temperature and pressure very gradual, without allowing turbulence in the air. Without turbulence the initial decrease in entropy could be made large enough in magnitude to offset almost completely the later increase in entropy. If the net increase in entropy is very small the cooling and heating cycle is nearly reversible. However, there must be a cylinder and piston to contain the air as it heats and cools, so the work the air does as it expands may be recovered and used to compress the air when it cools.
There is nothing similar to a containing vessel for the air over the Earth’s surface. The daily heating and cooling of the air drives winds that dissipate their energy in turbulence. Free, uncontained, fresh air is necessary for life, but the freedom of the air also contributes to the continual destruction of order. The Sun’s energy arrives hot and intense, but it is dissipated as general warmth spread out through the atmosphere. The warmth makes the Earth an agreeable place to live, but it cannot be concentrated and made to serve any other useful purpose. Therefore, sunlight drives an irreversible increase of entropy on the Earth.
¿Qué hace que la luz del sol sea adecuada?
La luz del sol tiene una serie de propiedades que la hacen adecuada para sustentar la vida y proporcionar información. Comencemos con la propiedad más obvia, tan obvia que puede parecer trivial, y luego pasemos a propiedades que no se entienden tan bien pero son igual de importantes para la vida.
La luz del Sol llega a la superficie de la Tierra desde una sola dirección en un momento dado. Si la luz del sol llegara a la Tierra desde todas las direcciones, no habría alternancia entre el día y la noche, porque ninguna rotación de la Tierra podría proteger de la luz ninguna parte de su superficie. Una cierta cantidad de energía fluye constantemente desde el Sol a la superficie de la Tierra, y esa energía es necesaria para sustentar la vida.
Sin embargo, algún otro arreglo podría proporcionar la entrada de energía equivalente. Supongamos, por ejemplo, que pudiéramos colocar la Tierra dentro de una cavidad cúbica hueca en algún tipo de cuerpo masivo a 280 kelvin o 7 °C, aproximadamente 45 °F. Las paredes de la cavidad tendrían que ser muy fuertes para evitar que se derrumbe. Esta idea es bastante hipotética porque no se conoce ninguna materia lo suficientemente fuerte como para hacer una cavidad rígida lo suficientemente grande como para albergar un planeta. Incluso si la hubiera, las paredes no proporcionarían luz. Las materias a temperatura ambiente o inferior no están lo suficientemente calientes para emitir luz. Cualquiera que dude de esto puede ingresar a una habitación cerrada, apagar las luces y notar que las paredes no se ven brillantes. La Tierra dentro de una cálida cavidad estaría en perpetua noche. El calor no tendría direccionalidad. Incidiría por igual en la Tierra desde todas las direcciones. No podría proporcionar la información de cronometraje que tenemos del Sol, incluso si la Tierra en la cavidad continuara girando al mismo ritmo. Sin embargo, lo más importante es que no habría alimento para bacterias, plantas o animales.
La energía solar entrante mantiene toda la vida en la Tierra al alimentar los motores de calor molecular que fotosintetizan los carbohidratos y liberan oxígeno. La clorofila es el componente más importante de estos motores. Refleja la luz verde y absorbe la luz roja, azul y violeta. La clorofila es lo que hace que las plantas verdes sean verdes. La superficie superior de una hoja es transparente, lo que permite que la luz del sol llegue a los cloroplastos, pequeños cuerpos en las hojas que contienen clorofila. Los colores absorbidos corresponden a rayos de longitudes de onda y energías fotónicas específicas. Las energías son las necesarias para mover los electrones en la molécula de clorofila desde el estado de menor energía (el estado fundamental) a ciertos estados excitados. Los importantes estados excitados de la clorofila son metaestables. Es decir, no son completamente estables, pero persisten por tiempos relativamente largos. Su meta-estabilidad les permite retener la energía de excitación el tiempo suficiente para catalizar las reacciones químicas que convierten el agua y el dióxido de carbono en un tipo de azúcar llamado glucosa. Otros motores moleculares convierten el azúcar en almidón. El almidón y los azúcares son carbohidratos, alimentos para la planta.
Cuando las sustancias químicas absorben luz, absorben un fotón por molécula. Por supuesto, dos fotones, cada uno de baja energía, pueden combinar su energía para formar el equivalente a un fotón rojo, azul o violeta. Esto es posible, pero las sustancias químicas rara vez absorben dos o más fotones a la vez. La luz se mueve muy rápido. Es muy poco probable que dos fotones lleguen a una molécula dada lo suficientemente cerca al mismo tiempo para que su energía pueda combinarse.
El Sol proporciona fotones rojos, azules y violetas. Su máxima emisión son fotones amarillos. Proporciona algunos fotones ultravioletas, pero no demasiados. Los fotones de demasiada energía son destructivos. Arrancan electrones de los átomos y hacen que las moléculas se rompan. Por otro lado, los fotones infrarrojos no tienen suficiente energía para poner la clorofila en estados excitados que pueden producir azúcar a partir de dióxido de carbono y agua. A una temperatura de 280 kelvins, 7º C o 45º F, las paredes oscuras de una cavidad emiten fotones infrarrojos con una longitud de onda de 10 micrómetros. Su energía es solo alrededor del 4% de la energía necesaria para producir luz violeta. Veinticinco de ellos tendrían que unirse a la clorofila para tener el mismo efecto que un fotón violeta. Los fotones de calor de las paredes de una cavidad cálida nunca se agrupan de esa manera. No habría fotosíntesis de carbohidratos si la luz del sol no proporcionara la luz del día en la Tierra. Muchos escolares han realizado el experimento científico de privar de luz a una planta verde. El resultado es siempre el mismo. La planta muere por falta de luz roja, azul y violeta.
Los animales dependen de las plantas verdes para obtener alimento y oxígeno. Hay algunas plantas que no tienen clorofila y no utilizan la luz solar para elaborar su alimento. La mayoría de estas plantas obtienen carbohidratos de otros organismos. Si los organismos están vivos, las plantas que se alimentan de ellos son parásitos. Las plantas que se alimentan de materia orgánica muerta son saprofitas. Tanto los parásitos como los saprofitos dependen claramente de las plantas verdes y la clorofila.
A relatively small number of bacteria are as autotrophic as green plants, that is, they also make their own carbohydrates. These bacteria need carbon dioxide and energy from sunlight, but they use hydrogen sulfide (H2S) instead of water (H2O). Although they do not use chlorophyll, they do require low-entropy sunlight for photosynthesis.
In the middle of Earth's ocean floors are deep-sea hydrothermal vents where heat from Earth's magma warms the water. Sunlight never penetrates to the depths of the ocean. There, another type of autotrophic bacteria oxidize sulfides and use the energy to synthesize organic compounds. Bacteria depend on dissolved oxygen in seawater. This comes from photosynthesis near the surface.
Taking green plants, chlorophyll, and autotrophic bacteria into account, we conclude that all life on Earth depends on photosynthesis and sunlight.
Olber's paradox
In 1826, Heinrich Wilhelm Matthäus Olbers (German physician and astronomer, 1758–1840) realized that if the universe is limitless, every line of sight from Earth should terminate at the surface of a star. No matter how many stars the line missed, there would eventually be a star in the way. The entire day-and-night sky should always be as bright and hot as the surface of an average star. The effect would be like having the sky filled with many copies of our Sun. The fact that the stars are much further away than our Sun makes no difference, because the Earth has had time to reach equilibrium temperature with them. The temperature of the Earth should be like that of the Sun, 10,000º F or 6,000º C. At such high temperatures, life on Earth would be impossible. Atom-based life requires very complex compounds of atoms, but even the simplest compounds of two or three atoms break down at such high temperatures. We should burn much worse than a French fry.
But we are not roasted, and the night sky is dark. This contradiction is called Olbers' paradox. Olbers did not know of the expansion in the heavens that cools light. Hubble discovered that in 1929. Olbers also didn't know that the universe was created a finite time ago. The age of the universe was not known until recently. These two factors, the expansion and the limited age of the universe, keep the sky cold.
The finite age of the universe prevents us from seeing beyond a certain limit. We run out of prior time before we ran out of space. The limit that we can see is not the edge of the universe, but the beginning. Some sight lines stop when they reach the surface of stars, but most sight lines go back to times long before the stars.
The darkness of space is now cold. It is much less energetic than the darkness of the first night. The beginning and expansion caused the present darkness of space. Let's try to understand this from a simple example.
Taking green plants, chlorophyll, and autotrophic bacteria into account, we conclude that all life on Earth depends on photosynthesis and sunlight.
Olber's paradox
In 1826, Heinrich Wilhelm Matthäus Olbers (German physician and astronomer, 1758–1840) realized that if the universe is limitless, every line of sight from Earth should terminate at the surface of a star. No matter how many stars the line missed, there would eventually be a star in the way. The entire day-and-night sky should always be as bright and hot as the surface of an average star. The effect would be like having the sky filled with many copies of our Sun. The fact that the stars are much further away than our Sun makes no difference, because the Earth has had time to reach equilibrium temperature with them. The temperature of the Earth should be like that of the Sun, 10,000º F or 6,000º C. At such high temperatures, life on Earth would be impossible. Atom-based life requires very complex compounds of atoms, but even the simplest compounds of two or three atoms break down at such high temperatures. We should burn much worse than a French fry.
But we are not roasted, and the night sky is dark. This contradiction is called Olbers' paradox. Olbers did not know of the expansion in the heavens that cools light. Hubble discovered that in 1929. Olbers also didn't know that the universe was created a finite time ago. The age of the universe was not known until recently. These two factors, the expansion and the limited age of the universe, keep the sky cold.
The finite age of the universe prevents us from seeing beyond a certain limit. We run out of prior time before we ran out of space. The limit that we can see is not the edge of the universe, but the beginning. Some sight lines stop when they reach the surface of stars, but most sight lines go back to times long before the stars.
The darkness of space is now cold. It is much less energetic than the darkness of the first night. The beginning and expansion caused the present darkness of space. Let's try to understand this from a simple example.