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==Second Law compared with other physical laws==

==Second Law compared with other physical laws==

Thermodynamics occupies an unusual place in the world of science, particularly at the high school and undergraduate levels.  The Second Law is the one that is especially peculiar.  (In fact, the other laws are comparatively mundane.  The first law is just a statement that heat is a form of energy, and that energy, whether in the form of heat or not, is conserved.  This was a very nontrivial result at first, but, with the understanding of heat and temperature that later developed, it's quite unremarkable.  The third law is a statement that absolute zero can't be reached by any finite number of Carnot cycles<ref>[https://en.wikiversity.org/wiki/Carnot_engine Carnot Engine]</ref>. While true, its significance pales in comparison to that of the Second Law.)

Thermodynamics occupies an unusual place in the world of science, particularly at the high school and undergraduate levels.  The Second Law is the one that is especially peculiar.  (In fact, the other laws are comparatively mundane.  The first law is just a statement that heat is a form of energy, and that energy, whether in the form of heat or not, is conserved.  This was a very nontrivial result at first, but, with the understanding of heat and temperature that later developed, it's quite unremarkable.  The third law is a statement that absolute zero can't be reached by any finite number of Carnot cycles.<ref>[https://en.wikiversity.org/wiki/Carnot_engine Carnot Engine]</ref>  While true, its significance pales in comparison to that of the Second Law.)

Perhaps what makes the Second Law so remarkable is that it describes ''irreversible'' phenomena.  In particular, it describes the observed fact that heat energy, in bodies that are not being externally manipulated by compression, etc., flows only from a warmer body to a cooler one.  When a warmer body is placed in contact with a cooler one, heat energy will flow (always preserving total energy, of course) from the warmer one to the cooler one.  The warmer one will cool off as it releases its energy, and the cooler one will warm up.  This process will continue until the two bodies reach the same temperature, or "thermal equilibrium".

Perhaps what makes the Second Law so remarkable is that it describes ''irreversible'' phenomena.  In particular, it describes the observed fact that heat energy, in bodies that are not being externally manipulated by compression, etc., flows only from a warmer body to a cooler one.  When a warmer body is placed in contact with a cooler one, heat energy will flow (always preserving total energy, of course) from the warmer one to the cooler one.  The warmer one will cool off as it releases its energy, and the cooler one will warm up.  This process will continue until the two bodies reach the same temperature, or "thermal equilibrium".

Note that the Boltzmann constant has taken a value of 1 to simplify the maths.

Note that the Boltzmann constant has taken a value of 1 to simplify the maths.

So the state that we would expect to find the system in, the last one, has the highest entropy. However, the system could be in this state (10 in left, 10 in the right) and, just by chance, all the molecules could make their way to the left hand side of the box. This corresponds to a '''decrease''' of entropy. This example could be expanded up to a room, so why do we never see all the air in a room suddenly move to one end? The reason is that it is so unlikely, perhaps less than <math>10^{-10^{26}}</math>, that it essentially never occurs<ref>{{cite book

So the state that we would expect to find the system in, the last one, has the highest entropy. However, the system could be in this state (10 in left, 10 in the right) and, just by chance, all the molecules could make their way to the left hand side of the box. This corresponds to a '''decrease''' of entropy. This example could be expanded up to a room, so why do we never see all the air in a room suddenly move to one end? The reason is that it is so unlikely, perhaps less than <math>10^{-10^{26}}</math>, that it essentially never occurs.<ref>{{cite book

|author=Hugh D. Young and Roger A. Freedman

|author=Hugh D. Young and Roger A. Freedman

|title=University Physics with Modern Physics

|title=University Physics with Modern Physics

|pages=

|pages=

|quote=

|quote=

|language=English}}</ref>. Hence it may be '''assumed''' that for most systems entropy '''never''' decreases. This is  known as the [[fluctuation theorem]].

|language=English}}</ref> Hence it may be '''assumed''' that for most systems entropy '''never''' decreases. This is  known as the [[fluctuation theorem]].

==Thermodynamic definition of entropy==

==Thermodynamic definition of entropy==

==Entropy in popular culture&mdash;intuitive notions of entropy and "randomness"==

==Entropy in popular culture&mdash;intuitive notions of entropy and "randomness"==

The tendency toward disorder is something that is accessible on an intuitive level&mdash;shuffling a deck of cards destroys their order, rooms don't clean themselves up, and so on.  This phenomenon is often described by "popular science" writers, such as the Isaac Asimov quote at the beginning of this page.  As a further example of this, a Google search for "entropy" yields "lack of order or predictability; gradual decline into disorder"<ref>https://www.google.com/search?q=entropy&ie=utf-8&oe=utf-8</ref>, with synonyms like "deterioration" and "degeneration".

The tendency toward disorder is something that is accessible on an intuitive level&mdash;shuffling a deck of cards destroys their order, rooms don't clean themselves up, and so on.  This phenomenon is often described by "popular science" writers, such as the Isaac Asimov quote at the beginning of this page.  As a further example of this, a Google search for "entropy" yields "lack of order or predictability; gradual decline into disorder",<ref>https://www.google.com/search?q=entropy&ie=utf-8&oe=utf-8</ref> with synonyms like "deterioration" and "degeneration".

This is all very true, because the underlying phenomena of mathematical statistics are the same, but the difference in scale makes an enormous difference, and this can be misleading if one tries to draw thermodynamical conclusions from this intuitive notion.

This is all very true, because the underlying phenomena of mathematical statistics are the same, but the difference in scale makes an enormous difference, and this can be misleading if one tries to draw thermodynamical conclusions from this intuitive notion.

==Entropy and information==

==Entropy and information==

Information is in the eye of the beholder.  The first ten million digits of pi can be considerd to be a very precise and detailed piece of information, or they can be considered to be ten million digits of random garbage.<ref>The digits of pi are believed to be truly random.  They have passed every statistical test for randomness.  No patterns are known.</ref>  In the former case, the digits have an entropy of zero; in the latter case the entropy is 3.2 x 10^-21 Joules per Kelvin.

Information is in the eye of the beholder.  The first ten million digits of pi can be considered to be a very precise and detailed piece of information, or they can be considered to be ten million digits of random garbage.<ref>The digits of pi are believed to be truly random.  They have passed every statistical test for randomness.  No patterns are known.</ref>  In the former case, the digits have an entropy of zero; in the latter case the entropy is 3.2 x 10⁻²¹ Joules per Kelvin.

The entropy of the human genome, in each cell, is 6 x 10^-14 Joules per Kelvin when the base pairs are considered to be random, and zero when the base pairs are in a given human's specific genetic configuration.  The metabolism of 2.5 x 10^-22 grams of sugar, or one nanosecond of sunlight falling on one square centimeter, can provide the "entropy budget" to copy a cell's genome.  That is, it can turn the random base pairs floating in the intracellular fluid into a copy of an existing set of chromosomes.  This is done every time a cell divides.  Of course the process is far from 100% efficient.  10^-8 grams of sugar, or 4 seconds of sunlight falling on one square meter, are sufficient, under 100% thermodynamic efficiency, to copy the DNA of all the cells in one's body.  Avogadro's number really is very large.

The entropy of the human genome, in each cell, is 6 x 10^-14 Joules per Kelvin when the base pairs are considered to be random, and zero when the base pairs are in a given human's specific genetic configuration.  The metabolism of 2.5 x 10^-22 grams of sugar, or one nanosecond of sunlight falling on one square centimeter, can provide the "entropy budget" to copy a cell's genome.  That is, it can turn the random base pairs floating in the intracellular fluid into a copy of an existing set of chromosomes.  This is done every time a cell divides.  Of course the process is far from 100% efficient.  10^-8 grams of sugar, or 4 seconds of sunlight falling on one square meter, are sufficient, under 100% thermodynamic efficiency, to copy the DNA of all the cells in one's body.  Avogadro's number really is very large.

==Liberal abuse of the Second Law of Thermodynamics==

==Liberal abuse of the Second Law of Thermodynamics==

The Second Law of Thermodynamics is abused by many people, claiming that it buttresses their arguments for a wide variaty of things to which it simply doesn't apply.  It has become common in recent years for [[Environmentalism|environmentalists]] to claim that the Second Law of Thermodynamics implies limits to [[economic growth]]. Their reasoning is that because free energy in resources such as [[petroleum|oil]] decreases with time, then economic growth can only be finite.  (The supply of oil is finite, but the consequences of that are not consequences of the Second Law.)  However, this simplistic [[liberal]] reasoning ignores the [[false zero-sum game|non-zero sum]] nature of [[free market economics]], whereby improvements in technology deliver gains for all at no further cost. Indeed, one of the most vital economic goods, knowledge, or more generally information, can be said to be free from thermodynamic limitations entirely.<ref>[http://www.discovery.org/a/2053] Discovery Institute cofounder and futurist George F. Gilder put it eloquently as follows: ''Gone is the view of a thermodynamic world economy, dominated by "natural resources" being turned to entropy and waste by human extraction and use. Once seen as a physical system tending toward exhaustion and decline, the world economy has clearly emerged as an intellectual system driven by knowledge.''</ref> Liberals also vastly exaggerate the limitations that natural resources impose on human economies. Some estimate that the [[Earth]] can harbor 100 billion people. God Himself gives His explicit assurance that the Earth will be generous as long as the human race exists in [[Genesis]]: "And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth." (Gen. 1:28, KJV)

The Second Law of Thermodynamics is abused by many people, claiming that it buttresses their arguments for a wide variety of things to which it simply doesn't apply.  It has become common in recent years for [[Environmentalism|environmentalists]] to claim that the Second Law of Thermodynamics implies limits to [[economic growth]]. Their reasoning is that because free energy in resources such as [[petroleum|oil]] decreases with time, then economic growth can only be finite.  (The supply of oil is finite, but the consequences of that are not consequences of the Second Law.)  However, this simplistic [[liberal]] reasoning ignores the [[false zero-sum game|non-zero sum]] nature of [[free market economics]], whereby improvements in technology deliver gains for all at no further cost. Indeed, one of the most vital economic goods, knowledge, or more generally information, can be said to be free from thermodynamic limitations entirely.<ref>[http://www.discovery.org/a/2053] Discovery Institute cofounder and futurist George F. Gilder put it eloquently as follows: ''Gone is the view of a thermodynamic world economy, dominated by "natural resources" being turned to entropy and waste by human extraction and use. Once seen as a physical system tending toward exhaustion and decline, the world economy has clearly emerged as an intellectual system driven by knowledge.''</ref> Liberals also vastly exaggerate the limitations that natural resources impose on human economies. Some estimate that the [[Earth]] can harbor 100 billion people. God Himself gives His explicit assurance that the Earth will be generous as long as the human race exists in [[Genesis]]: "And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth." (Gen. 1:28, KJV)

== Creation Ministries International on the Second Law of Thermodynamics and evolution ==

== Creation Ministries International on the Second Law of Thermodynamics and evolution ==