Entropy is NOT disorder (it really is not)

[sayak83]

It's one of the most perversely propagated scientific misunderstandings in the world. The concept of entropy has nothing to do with order or disorder whatsoever. It has to do with how many microscopic quantum states are accessible to the particles in the system at a given energy. There are many ways to put this but let's think of it in terms of economics.

Consider two nations with the same GDP(energy) but in one case we have a
1) Highly unequal society with centrally managed economy(North korea) . There all the money is concentrated in the hands of a few and, more ever one can only use the money to buy one and only type of state made product (one type of state made car, state made house, state made popcorn etc.). In such a society the distribution of money is very concentrated... it's in the hands of a few and distributed among the state approved products. If this were a nation of molecules, we would say that their energy can be distributed in a narrow set of options and hence it has low entropy.

2) Highly egalitarian and capitalistic nation(Sweden). The money is roughly equally distributed and an individual can invest it in lots and lots of possible products. If this were a gas, we would say energy is well distributed and each molecule can partition its energy into many modes. Such a system (which can be much richer and complex and vibrant than 1) will have a higher entropy.

So the 2nd law states that an isolated thermodynamic system in the universe evolves towards greater liberty and equality. Yay!

Notice that this has nothing to do with disorder and is completely inapplicable for determining order and disorder. Thus

1) A pack of shuffled cards have the Same entropy as a pack arranged in accordance to color suites
2) A bound book has the same entropy as a random arrangement of its torn up pages
3) An Egyptians mummy has lower entropy than a living human (has to do with water content)
4) Sun is losing entropy by radiation.
5) The concept of entropy applies to elementary particles and their quantum states only, does not apply to anything else (shuffled cards, messy rooms or North korea).
Etc.
The universe had lower entropy earlier simply because it was so dense and hence its matter and radiation were too crammed in to be "free". Think Japan, people have to live in tiny flats and can't spread out as there's no room.

More detailed explanation (with some math) in the link below

Elusive Entropy | Do the Math

Bottom line :- there should be a moratorium on scientists trying to connect everyday words with scientific terms.

Here's the same message from the royal society
What is entropy?

 

[Revoltingest]

So the 2nd law states that an isolated thermodynamic system in the universe evolves towards greater liberty and equality. Yay!

Actually, the 2nd Law says there will be an ever lessening ability to do work....& we'll be getting colder.

 

[sayak83]

Actually, the 2nd Law says there will be an ever lessening ability to do work....& we'll be getting colder.

It's an outcome of the second law. Work is any form of macroscopic energy not locked away in the internal states of molecules. So one implies the other.

Taking my social analogy, only when molecules are grumpy with all the income (energy) inequality and absence of free choice will they organize into macroscopic committees and start social (err molecular) movements. That's the work. Once they are all happy and rich they will just stay home happily ever after and all the societies, political parties, special interest groups (galaxies, planets, our bodies) will disband.

 

[siti]

If this were a gas, we would say energy is well distributed and each molecule can partition its energy into many modes.

And that's where order/disorder come into it. A highly ordered system has low entropy because it is, by virtue of its ordered-ness, not able to "partition its energy into many modes". Think of a random pile of sand grains - there are many ways that the grains can be rearranged without affecting the overall structure of the pile - you could dip your hands into it, grab a handful and pour it back on top randomly and the pile will be essentially the same - energetically and geometrically. But turn that sand pile into an intricate sand castle and you can't do that any more. There is, more or less, only one arrangement that can maintain the energy-distribution and geometry of the system. The energy is not now anywhere near so "well-distributed" - the grains at the top and the outside of the structure are in a very precarious situation and even left to its own devices, the structure will soon begin to collapse until it achieves the "well-distributed" - and less ordered - arrangement of the random pile.

 

[CogentPhilosopher]

It's one of the most perversely propagated scientific misunderstandings in the world. The concept of entropy has nothing to do with order or disorder whatsoever. It has to do with how many microscopic quantum states are accessible to the particles in the system at a given energy. There are many ways to put this but let's think of it in terms of economics.

Consider two nations with the same GDP(energy) but in one case we have a
1) Highly unequal society with centrally managed economy(North korea) . There all the money is concentrated in the hands of a few and, more ever one can only use the money to buy one and only type of state made product (one type of state made car, state made house, state made popcorn etc.). In such a society the distribution of money is very concentrated... it's in the hands of a few and distributed among the state approved products. If this were a nation of molecules, we would say that their energy can be distributed in a narrow set of options and hence it has low entropy.

2) Highly egalitarian and capitalistic nation(Sweden). The money is roughly equally distributed and an individual can invest it in lots and lots of possible products. If this were a gas, we would say energy is well distributed and each molecule can partition its energy into many modes. Such a system (which can be much richer and complex and vibrant than 1) will have a higher entropy.

So the 2nd law states that an isolated thermodynamic system in the universe evolves towards greater liberty and equality. Yay!

Notice that this has nothing to do with disorder and is completely inapplicable for determining order and disorder. Thus

1) A pack of shuffled cards have the Same entropy as a pack arranged in accordance to color suites
2) A bound book has the same entropy as a random arrangement of its torn up pages
3) An Egyptians mummy has lower entropy than a living human (has to do with water content)
4) Sun is losing entropy by radiation.
5) The concept of entropy applies to elementary particles and their quantum states only, does not apply to anything else (shuffled cards, messy rooms or North korea).
Etc.
The universe had lower entropy earlier simply because it was so dense and hence its matter and radiation were too crammed in to be "free". Think Japan, people have to live in tiny flats and can't spread out as there's no room.

More detailed explanation (with some math) in the link below

Elusive Entropy | Do the Math

Bottom line :- there should be a moratorium on scientists trying to connect everyday words with scientific terms.

Here's the same message from the royal society
What is entropy?

 

[sayak83]

And that's where order/disorder come into it. A highly ordered system has low entropy because it is, by virtue of its ordered-ness, not able to "partition its energy into many modes". Think of a random pile of sand grains - there are many ways that the grains can be rearranged without affecting the overall structure of the pile - you could dip your hands into it, grab a handful and pour it back on top randomly and the pile will be essentially the same - energetically and geometrically. But turn that sand pile into an intricate sand castle and you can't do that any more. There is, more or less, only one arrangement that can maintain the energy-distribution and geometry of the system. The energy is not now anywhere near so "well-distributed" - the grains at the top and the outside of the structure are in a very precarious situation and even left to its own devices, the structure will soon begin to collapse until it achieves the "well-distributed" - and less ordered - arrangement of the random pile.

This is not always true. For example molecules has internal rotational, vibrational and other quantum mechanical states where it can keep bits of its energy and which has nothing to do with disorder. Often a well ordered crystal would allow its molecules greater degree of internal freedom than a cramped crystal, making the orderly crystal have more entropy. Finally, entropy has nothing to do with structure but with energy. For systems of same energy, those which have greater no. of internal energy states will have greater entropy. While this is sometimes true for disorder, order and complexity may often possess greater no. of such states.

By the way check out the first link. It's very well explained.

 

[Skwim]

It's one of the most perversely propagated scientific misunderstandings in the world. The concept of entropy has nothing to do with order or disorder whatsoever. It has to do with how many microscopic quantum states are accessible to the particles in the system at a given energy.

Bottom line :- there should be a moratorium on scientists trying to connect everyday words with scientific terms.

entropy (noun.)
1868, from German Entropie "measure of the disorder of a system," coined 1865 (on analogy of Energie) by German physicist Rudolph Clausius (1822-1888), in his work on the laws of thermodynamics, from Greek entropia "a turning toward," from en "in" (see en- (2)) + trope "a turning, a transformation" (see trope). The notion is supposed to be "transformation contents." Related: Entropic.

It was not until 1865 that Clausius invented the word entropy as a suitable name for what he had been calling "the transformational content of the body." The new word made it possible to state the second law in the brief but portentous form: "The entropy of the universe tends toward a maximum," but Clausius did not view entropy as the basic concept for understanding that law. He preferred to express the physical meaning of the second law in terms of the concept of disgregation, another word that he coined, a concept that never became part of the accepted structure of thermodynamics. [Martin J. Klein, "The Scientific Style of Josiah Willard Gibbs," in "A Century of Mathematics in America," 1989]
Source: Online Entomology Dictionary

​

Think Rudy had the number of accessible quantum states in mind when he coined the term? Think he even knew what a quantum state is? Hell, do you think he even knew what "quanta" means in physics?

Regarding molecular entropy

"Examining the mixing process on a molecular level gives additional insight. Suppose we were able to see the gas molecules in different colors, say the air molecules as white and the argon molecules as red. After we took the partition away, we would see white molecules start to move into the red region and, similarly, red molecules start to come into the white volume. As we watched, as the gases mixed, there would be more and more of the different color molecules in the regions that were initially all white and all red. If we moved further away so we could no longer pick out individual molecules, we would see the growth of pink regions spreading into the initially red and white areas. In the final state, we would expect a uniform pink gas to exist throughout the volume. There might be occasional small regions which were slightly more red or slightly more white, but these fluctuations would only last for a time on the order of several molecular collisions.

In terms of the overall spatial distribution of the molecules, we would say this final state was more random, more mixed, than the initial state in which the red and white molecules were confined to specific regions. Another way to say this is in terms of ``disorder;'' there is more disorder in the final state than in the initial state. One view of entropy is thus that increases in entropy are connected with increases in randomness or disorder. This link can be made rigorous and is extremely useful in describing systems on a microscopic basis. While we do not have scope to examine this topic in depth, the purpose of this chapter is to make plausible the link between disorder and entropy through a statistical definition of entropy."
source

("A key idea from quantum mechanics is that the states of atoms, molecules, and entire systems are discretely quantized. This means that a system of particles under certain constraints, like being in a box of a specified size, or having a fixed total energy, can exist in a finite number of allowed microscopic states."
source)


.

​

 

[sayak83]

entropy (n.)
1868, from German Entropie "measure of the disorder of a system," coined 1865 (on analogy of Energie) by German physicist Rudolph Clausius (1822-1888), in his work on the laws of thermodynamics, from Greek entropia "a turning toward," from en "in" (see en- (2)) + trope "a turning, a transformation" (see trope). The notion is supposed to be "transformation contents." Related: Entropic.

It was not until 1865 that Clausius invented the word entropy as a suitable name for what he had been calling "the transformational content of the body." The new word made it possible to state the second law in the brief but portentous form: "The entropy of the universe tends toward a maximum," but Clausius did not view entropy as the basic concept for understanding that law. He preferred to express the physical meaning of the second law in terms of the concept of disgregation, another word that he coined, a concept that never became part of the accepted structure of thermodynamics. [Martin J. Klein, "The Scientific Style of Josiah Willard Gibbs," in "A Century of Mathematics in America," 1989]
​

Think Rudy had the number of accessible quantum states in mind when he coined the term? Think he even knew what a quantum state is? Hell, do you think he even knew what "quanta" means in physics?

.

​

No he did not. That was demonstrated by Boltzmann

 

[Skwim]

No he did not. That was demonstrated by Boltzmann

No he did not what?
Don't see any mention of Clausius demonstrating anything. What are you talking about.

.

 

[Revoltingest]

It's an outcome of the second law. Work is any form of macroscopic energy not locked away in the internal states of molecules. So one implies the other.

Taking my social analogy, only when molecules are grumpy with all the income (energy) inequality and absence of free choice will they organize into macroscopic committees and start social (err molecular) movements. That's the work. Once they are all happy and rich they will just stay home happily ever after and all the societies, political parties, special interest groups (galaxies, planets, our bodies) will disband.

I was extending your social analogy.....we'll all be unemployed & cold.

Btw, I look at entropy from a 19th century perspective, ie, heat flow.
So it's particularly irksome to hear recurring creationist arguments
that evolution violates the 2nd Law of thermodynamics. We have
plenty of heat supplied to our not-closed system (Earth's biosphere).

 

[Jayhawker Soule]

Bottom line :- there should be a moratorium on scientists trying to connect everyday words with scientific terms.

Yeah ... it's really hard to imagine a problem more deleterious to the fabric of society. (Seriously?)

My recommendation? Read this and get over it ...

... and perhaps take the time to applaud the efforts of science to employ everyday words to communicate with everyday people despite the inevitable loss of fidelity that such efforts entail.​

 

[Revoltingest]

Yeah ... it's really hard to imagine a problem more deleterious to the fabric of society. (Seriously?)

You neurotypicals clearly don't belong here.
This thread is for pedants & obsessive nerds!

Your link really doesn't help anyone who isn't grounded in thermodynamics &
statistical mechanics (both of which have long since faded from my memory).
This is partly because the analogy presented (piles of bricks) can be looked
at in 2 incompatible ways. The classical thermodynamic view would be that
the piles each have the same entropy, whether neatly stacked or just dumped.
The quantum view.....well, that's still poorly illustrated.

Useful simplified view....
The practical side of the 2nd Law is about the simple real world friendly concept
of heat. Temperature differences cause heat to flow from hot to cold, resulting
in temperatures equalizing. With less of a temperature difference, less work can
be done. (This is rooted in the history of steam engine efficiency & design.)
"Entropy" is a measure of this temperature equalization, ie, the inability to do work.
Since entropy can only increase, it means that things must always run down,
unless you bring energy in from elsewhere.
Disturbing implication:
If our universe is a closed system, it will run down....no life, no stars.

(For simplicity of concept, the above doesn't address other energy forms, eg, chemical.)

 

[Revoltingest]

Back in the last millennium, when I took thermodynamics courses, we
had a really odd chapter in the middle of an otherwise great textbook.
The authors reasoned that the predicted heat death of the universe
was utterly unacceptable, so something had to reduce its entropy.
Their solution....
God
This was not on any of the tests.

 

[sayak83]

No he did not what?
Don't see any mention of Clausius demonstrating anything. What are you talking about.

.

I was agreeing with you. Clausius did not have to concept of quantum micro states when he was defining entropy.

 

[sayak83]

entropy (noun.)
1868, from German Entropie "measure of the disorder of a system," coined 1865 (on analogy of Energie) by German physicist Rudolph Clausius (1822-1888), in his work on the laws of thermodynamics, from Greek entropia "a turning toward," from en "in" (see en- (2)) + trope "a turning, a transformation" (see trope). The notion is supposed to be "transformation contents." Related: Entropic.

It was not until 1865 that Clausius invented the word entropy as a suitable name for what he had been calling "the transformational content of the body." The new word made it possible to state the second law in the brief but portentous form: "The entropy of the universe tends toward a maximum," but Clausius did not view entropy as the basic concept for understanding that law. He preferred to express the physical meaning of the second law in terms of the concept of disgregation, another word that he coined, a concept that never became part of the accepted structure of thermodynamics. [Martin J. Klein, "The Scientific Style of Josiah Willard Gibbs," in "A Century of Mathematics in America," 1989]
Source: Online Entomology Dictionary

​

Think Rudy had the number of accessible quantum states in mind when he coined the term? Think he even knew what a quantum state is? Hell, do you think he even knew what "quanta" means in physics?

Regarding molecular entropy

"Examining the mixing process on a molecular level gives additional insight. Suppose we were able to see the gas molecules in different colors, say the air molecules as white and the argon molecules as red. After we took the partition away, we would see white molecules start to move into the red region and, similarly, red molecules start to come into the white volume. As we watched, as the gases mixed, there would be more and more of the different color molecules in the regions that were initially all white and all red. If we moved further away so we could no longer pick out individual molecules, we would see the growth of pink regions spreading into the initially red and white areas. In the final state, we would expect a uniform pink gas to exist throughout the volume. There might be occasional small regions which were slightly more red or slightly more white, but these fluctuations would only last for a time on the order of several molecular collisions.

In terms of the overall spatial distribution of the molecules, we would say this final state was more random, more mixed, than the initial state in which the red and white molecules were confined to specific regions. Another way to say this is in terms of ``disorder;'' there is more disorder in the final state than in the initial state. One view of entropy is thus that increases in entropy are connected with increases in randomness or disorder. This link can be made rigorous and is extremely useful in describing systems on a microscopic basis. While we do not have scope to examine this topic in depth, the purpose of this chapter is to make plausible the link between disorder and entropy through a statistical definition of entropy."
source

("A key idea from quantum mechanics is that the states of atoms, molecules, and entire systems are discretely quantized. This means that a system of particles under certain constraints, like being in a box of a specified size, or having a fixed total energy, can exist in a finite number of allowed microscopic states."
source)


.

​

I am completely in agreement with the math. The problem is the linkage of disorder with greater number of internal microstates for each energy level of the system. Sometimes this is not the case. That's the point. A good example is the transition from uniform flow to transitional flow with lots of eddies and vortices in a liquid or a gas. Such complex flows have enormous amount of structure and order at multiple scales, but since this order is not captured by an average property like mean velocity, the entropy is also higher. Another example would be how the sound from a tuning fork, transmitted at a single frequency (and hence a single wavefront) will have lower entropy than the sound of a symphony (which will be a Fourier integration of multiple octaves). There is a disjunction between what one means by order and chaos and what entropy represents.

 

[Guy Threepwood]

It's one of the most perversely propagated scientific misunderstandings in the world. The concept of entropy has nothing to do with order or disorder whatsoever. It has to do with how many microscopic quantum states are accessible to the particles in the system at a given energy. There are many ways to put this but let's think of it in terms of economics.

Consider two nations with the same GDP(energy) but in one case we have a
1) Highly unequal society with centrally managed economy(North korea) . There all the money is concentrated in the hands of a few and, more ever one can only use the money to buy one and only type of state made product (one type of state made car, state made house, state made popcorn etc.). In such a society the distribution of money is very concentrated... it's in the hands of a few and distributed among the state approved products. If this were a nation of molecules, we would say that their energy can be distributed in a narrow set of options and hence it has low entropy.

2) Highly egalitarian and capitalistic nation(Sweden). The money is roughly equally distributed and an individual can invest it in lots and lots of possible products. If this were a gas, we would say energy is well distributed and each molecule can partition its energy into many modes. Such a system (which can be much richer and complex and vibrant than 1) will have a higher entropy.

So the 2nd law states that an isolated thermodynamic system in the universe evolves towards greater liberty and equality. Yay!

Notice that this has nothing to do with disorder and is completely inapplicable for determining order and disorder. Thus

1) A pack of shuffled cards have the Same entropy as a pack arranged in accordance to color suites
2) A bound book has the same entropy as a random arrangement of its torn up pages
3) An Egyptians mummy has lower entropy than a living human (has to do with water content)
4) Sun is losing entropy by radiation.
5) The concept of entropy applies to elementary particles and their quantum states only, does not apply to anything else (shuffled cards, messy rooms or North korea).
Etc.
The universe had lower entropy earlier simply because it was so dense and hence its matter and radiation were too crammed in to be "free". Think Japan, people have to live in tiny flats and can't spread out as there's no room.

More detailed explanation (with some math) in the link below

Elusive Entropy | Do the Math

Bottom line :- there should be a moratorium on scientists trying to connect everyday words with scientific terms.

Here's the same message from the royal society
What is entropy?

2.Entropy

lack of order or predictability; gradual decline into disorder.
"a marketplace where entropy reigns supreme"
synonyms: deterioration, degeneration, crumbling, decline, degradation, decomposition, breaking down, collapse; More

 

[sayak83]

2.Entropy

lack of order or predictability; gradual decline into disorder.
"a marketplace where entropy reigns supreme"
synonyms: deterioration, degeneration, crumbling, decline, degradation, decomposition, breaking down, collapse; More

Common English word usage has little to do with science which is universal and not beholden to any language or culture.

 

[Kilgore Trout]

Entropy isn't a disorder. Then again, most things listed in the DSM aren't really either.

 

[Skwim]

Common English word usage has little to do with science which is universal and not beholden to any language or culture.

Are you saying that once a scientific word becomes commonly used it looses its standing in science? That in science "atom" no longer refers to "the smallest constituent unit of ordinary matter that has the properties of a chemical element"?
Source: various sites

Or that in science "calorie" no longer refers to "the amount of heat required at a pressure of one atmosphere to raise the temperature of one gram of water one degree Celsius that is equal to about 4.19 joules"?
Source: Merriam-Webster Dictionary

.

 

[sayak83]

Are you saying that once a scientific word becomes commonly used it looses its standing in science? That in science "atom" no longer refers to "the smallest constituent unit of ordinary matter that has the properties of a chemical element"?
Source: various sites

Or that in science "calorie" no longer refers to "the amount of heat required at a pressure of one atmosphere to raise the temperature of one gram of water one degree Celsius that is equal to about 4.19 joules"?
Source: Merriam-Webster Dictionary

.

No. I am saying that when discussing science one should stick with how science defines it rather than how it's used in any language. Since the debate here is whether it's proper to connect the scientific property entropy with the concept of order and disorder, quoting an English language dictionary does not help.