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2nd law of thermodynamics
please explain the creationist attack in detail

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2nd law of thermodynamics

Simple Occam
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Posted 07/08/08 - 01:47 PM:	#26
reincarnated wrote: Oh please. "Why" must life survive? Because the examples of life who didn't want to fight for their survival simply died out - leaving the examples of life who DID want to fight for their survival. That's what evolution is all about. With friends like you, why does evolution need enemies? I share your "oh please' moment about the quote from Yahadreas but your understnading of evolution seems almost as naive as Yahadreas'. You seem to think that it was a matter of which animals "want to fight for their survival", as if evolution were driven by will power and the animlas who "really wanted it" survived and those without such a strong desire to survive didn't. Tell that to the dinosaurs. Oh, wait a minute...there are no more dinosaurs because of an extraterrestrial object that impacted the earth 65 million years ago. Did the T-Rex will to survive have ANY bearing on that situation? I'm not trying to criticize you personally but your remark points to an answer to the original question here: ignorance. People generally don't even understand how Darwin's mechanism works. But the main reason for that is not because creationism is so convincing: it's not. Rather, it's because even biologists don't understand that evolutionary theory suffers from the causal incompleteness of physics itself. This incompleteness first arises with Newton's 2nd Law of Thermodynamics, the entropy law. It stands apart in a very significant way from his laws of motion in that the increase of entropy is observed only in a closed system. That is, it is a physical regularity that has a temporal and a spatial factor. The regulariries of the 2nd Law are not reversable in time as the laws of motion are. When the cue ball hits the rack the billiard balls are propelled around the table in a way that is completely predictable from the laws of motion and the angular momentum of the cueball striking the rack. If you reversed all those forces in time you would get back to the balls all racked up before the break. But even if you could reverse time, the water will not turn back into ice and the coffee will not get hot again...unless energy is introduced from outside the system. The 2nd Law cannot be reduced to the laws of motion or any more basic law. That's why its a target for creationists like Duane Gish. It's truly an empirical law since it is built up out of a series of observations that always turn out to be true but it is not derived from any more basic laws that explain WHY it always holds. Evolution is another "law" that does not admit of reversability because it relies on the 2nd Law to explain how free energy in a closed system can be used to do work. So it, too, is another "stand alone" regualrity that cannot be explained as deriviing more the more basic, reversable laws of motion or electromagentism. This "emergent" quality to regularities described by these laws is just the opening creationists need to advance their hypothesis that we must postulate another force from outside the system to explain the apparent "progression" toward more complex and intelligent life forms over time. Science can only say in response that evolution is accidental. Darwin's mechanism 'explains', after the fact, HOW these species evolved through natural selection of the most successful reproducers... not those with the strongest wills. I think a good understanding of biology, as is, debunks the creationist arguments. But the mechanism itself suffers from its irreducibility in the same way that the 2nd Law does and this means that the kind of meaning and purpose to life that creationists can explain is unavailable through science. Since we all want and need meaning and purpose in our lives, this accidentalist theory leaves us wanting another explanation, even though one does not seem to be at hand.

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Posted 07/08/08 - 05:40 PM:	#27
Simple Occam wrote: ... But even if you could reverse time, the water will not turn back into ice and the coffee will not get hot again...unless energy is introduced from outside the system. A slight correction here ... because others might criticize you on it, (not that I disagree -- just nitpicking the details). First, if you reverse time, then you reverse entropy, therefore 2nd law is inverted, which is beyond our experience. Second, without reversing time, in a truly closed system, water WILL turn back into ice. In fact, everything should eventually freeze, (even your coffee), due to heat loss. We don't experience water turning back into ice, (unless you live in Minnesota), because room temperature is adding energy to the systems we observe. Simple Occam wrote: Evolution is another "law" that does not admit of reversability because it relies on the 2nd Law to explain how free energy in a closed system can be used to do work. So it, too, is another "stand alone" regualrity that cannot be explained as deriviing more the more basic, reversable laws of motion or electromagentism. This "emergent" quality to regularities described by these laws is just the opening creationists need to advance their hypothesis that we must postulate another force from outside the system to explain the apparent "progression" toward more complex and intelligent life forms over time. Science can only say in response that evolution is accidental. Darwin's mechanism 'explains', after the fact, HOW these species evolved through natural selection of the most successful reproducers... not those with the strongest wills. I think a good understanding of biology, as is, debunks the creationist arguments. But the mechanism itself suffers from its irreducibility in the same way that the 2nd Law does and this means that the kind of meaning and purpose to life that creationists can explain is unavailable through science. Since we all want and need meaning and purpose in our lives, this accidentalist theory leaves us wanting another explanation, even though one does not seem to be at hand. I think creationists tend to harp on the idea of "accidental" and trying to invent an attribute of "complexity" and confusing it with the idea of "order" in entropy, rather than energy levels. Given a certain starting point, evolution is more or less inevitable and predictable, if you knew those starting conditions. It really isn't up to one scientific theory to go around disproving other assertions and claims. It is up to the creationist to demonstrate and quantify the parameters of their argument and make predictions.
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simwaves1
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Posted 07/13/08 - 04:55 PM:	#28
swstephe wrote: ... without reversing time, in a truly closed system, water WILL turn back into ice. In fact, everything should eventually freeze, (even your coffee), due to heat loss. We don't experience water turning back into ice, (unless you live in Minnesota), because room temperature is adding energy to the systems we observe. I think you're misunderstanding how thermodynamics works.

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Posted 07/13/08 - 07:16 PM:	#29
simwaves1 wrote: I think you're misunderstanding how thermodynamics works. In heat theory, you can think of entropy as following along with heat flowing from hot objects to cold objects. When ice melts at room temperature, the heat in the room is flowing into the water, until the water is the same temperature as the room. Calsius restates the 2nd law of thermodynamics as "heat can not flow from a cold object to a warmer object without work being applied". We experience ice melting because we live at room temperature. If, instead, you place a glass of water in a freezer, the second law of thermodynamics says that the heat in the water will flow into the cold air of the freezer. The temperature of the air in the freezer will raise very slightly, but the temperature of the water will cool off until the water reaches its phase-transition temperature/pressure and freezes. I like the freezing part, because people who misunderstand the usage of "order" in the 2nd law would expect either water or ice to be more "ordered". The 2nd law of thermodynamics can be expressed as dS = dQ/T. The change in entropy is equal to the change in heat divided by the temperature of the system. Water will freeze if T is low enough and boil if it is high enough. All entropy says is that heat will flow between different objects until the whole system equalizes.
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Posted 07/14/08 - 07:49 AM:	#30
Legion wrote: Maybe the cretinists, I mean the creationists...

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Posted 07/14/08 - 11:13 AM:	#31
Ok I will attempt to outline an argument to show that the second Law somehow contradicts evolution. Here it goes:- 1) Order tends toward chaos (as per second law) 2) The proposed process of evolution creates order from chaos. C) Therefore evolution must be false. However as has been pointed out, there is a difference between net order/chaos and local order/chaos. If we are to have a successful argument, it seems we must show that the overall amount of chaos is reduced by the process of evolution:- 1) At all local points of the universe, as well as overall, order tends to become more chaotic as time progresses. 2) The process of evolution would cause a local drop in the increase of entropy. c) Therefore the process of evolution must be false. Still, this does not quite add up unless we contend that the second law must hold all over the universe at all times, with complete and strict uniformity. This would be a suppressed premise of this argument, and one I find wanting. If this were the case, we would see order decreasing at exactly the same rate everywhere, and this process would be unalterable. It would not be possible to increase or decrease the rate at which order is lost from a system: this does not match with experiment, and so we must charitably assume that no one who seriously studies science/advocates ID would make this claim. Let us again reformulate the argument with this in mind:- 1) When the universe is taken as a whole, matter tends to become more chaotic as time progresses. 2) An increase of chaos is equal to entropy (best to be clear I thought). 3) The process of evolution would cause a total drop in the entropy of the universe. c) Therefore the process of evolution must be false. Notice how this is no longer about any local drop in entropy, but about the total net entropy of the universe over time. This argument is valid (as in its conclusion follows logically from its premises), but the question remains as to how sound it is. I have done my best to come to a charitable version of what could be proposed by a proponent of ID who wished to say that the second law of thermodynamics invalidates the theory of evolution – I shall leave it up to you fine people to qualify it, argue against or for it, and judge its soundness.

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Posted 07/14/08 - 05:14 PM:	#32
swstephe wrote: In heat theory, you can think of entropy as following along with heat flowing from hot objects to cold objects. When ice melts at room temperature, the heat in the room is flowing into the water, until the water is the same temperature as the room. Calsius restates the 2nd law of thermodynamics as "heat can not flow from a cold object to a warmer object without work being applied". We experience ice melting because we live at room temperature. If, instead, you place a glass of water in a freezer, the second law of thermodynamics says that the heat in the water will flow into the cold air of the freezer. The temperature of the air in the freezer will raise very slightly, but the temperature of the water will cool off until the water reaches its phase-transition temperature/pressure and freezes. I like the freezing part, because people who misunderstand the usage of "order" in the 2nd law would expect either water or ice to be more "ordered". The 2nd law of thermodynamics can be expressed as dS = dQ/T. The change in entropy is equal to the change in heat divided by the temperature of the system. Water will freeze if T is low enough and boil if it is high enough. All entropy says is that heat will flow between different objects until the whole system equalizes. What you described above is correct; however, this is not what I got from your previous post. It seems that your understanding of a "truly closed system," described in your previous post, is a system that can lose heat to its surroundings but not receive heat transfer. This is a misunderstanding of what a closed system is. The water in a closed system will only freeze if its surroundings are at a low enough temperature to accept enough of a heat transfer to reach fusion of water. It seems that your explanation ignores the fact that our planet has a constant heat transfer from the sun.

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Posted 07/14/08 - 05:40 PM:	#33
If I put gas in my car and drive it until I run out of gas, is the total entropy of the Universe greater or less? Since my car isn't 100% efficient, there has been heat loss and the "order", (that energy was stored in my gas), was reduced, (by producing work, the energy flowed into other forms), and entropy increased. Evolution, like my car, does work and produces some local "order", but the total entropy is always lost because nothing is 100% efficient. In a closed system, evolution would eventually run out of energy and stop. Maybe a better example, (which I'm "borrowing"), is that when a rabbit reproduces, it increases "order" and decreases entropy for its local environment and appears to violate the 2nd law of thermodynamics. Therefore, reproduction is impossible, right? But since rabbits aren't 100% efficient, the entropy of the solar system has increased slightly as the sunlight that produced carrots that made rabbits was a net loss that will never be regained. If we say that we observe rabbits reproducing, and having variations which are better or worse for their environment, then evolution necessarily follows, while obeying the 2nd law to the letter.
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Posted 07/15/08 - 12:55 AM:	#34
Simple Occam, This incompleteness first arises with Newton's 2nd Law of Thermodynamics, the entropy law. It stands apart in a very significant way from his laws of motion in that the increase of entropy is observed only in a closed system. That is, it is a physical regularity that has a temporal and a spatial factor. The regulariries of the 2nd Law are not reversable in time as the laws of motion are. When the cue ball hits the rack the billiard balls are propelled around the table in a way that is completely predictable from the laws of motion and the angular momentum of the cueball striking the rack. If you reversed all those forces in time you would get back to the balls all racked up before the break. But even if you could reverse time, the water will not turn back into ice and the coffee will not get hot again...unless energy is introduced from outside the system. The 2nd Law cannot be reduced to the laws of motion or any more basic law. That's why its a target for creationists like Duane Gish. It's truly an empirical law since it is built up out of a series of observations that always turn out to be true but it is not derived from any more basic laws that explain WHY it always holds. This isn't really accurate. First of all, the laws of thermodynamics are statistical mechanics laws. That is, they are laws about what happens on average, not rigid deterministic laws, like Newton's laws of motion. For example, the 2nd law is violated, even for closed systems, all the time. But this is nearly indetectable for anything other than extremely small systems being observed on very short time scales. Otherwise the probability of making such an observation becomes vanishingly small. Second, it is incorrect to say that we do not know why the 2nd law works, or that it cannot be derived from more basic laws. Quite the contrary, the 2nd law directly follows from Newton's laws, when applied to any complex system which, due to its complexity, involves approximately random exchanges of energy from one degree of freedom to another, via interactions. For example, if one takes a closed and perfectly insulated container of some ideal gas (individual perfectly spherical particles, with no adhesion or cohesion), an works out what Newton's laws say should happen, all the laws of thermodynamics immediately pop out. Given almost any set of initial conditions, the gas will go to state of approximately uniform temperature, which is also a state of maximal entropy for the amount of energy present. In principle, the laws of thermodynamics are nothing more than the application of basic principles of statistics to complex mechanical systems that behave randomly (or approximately randomly). There is nothing mysterious about it. DM
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Posted 07/15/08 - 07:16 AM:	#35
Makarismos wrote: 1) When the universe is taken as a whole, matter tends to become more chaotic as time progresses. Not matter, but the universe as a whole. 2) An increase of chaos is equal to entropy (best to be clear I thought). Entropy is the measure of chaos, not the increase in chaos. 3) The process of evolution would cause a total drop in the entropy of the universe. No. Instead it increases it. If you take a handful of clay, mix it with water, and play with it until you have a vase, you have decreased the entropy local to the clay and water mixture. But the energy you used in mixing the clay/water and modeling the vase increase the total entropy of the universe. c) Therefore the process of evolution must be false. Neyope!

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Posted 07/15/08 - 11:03 AM:	#36
philosopher8293 wrote: If a glass, an ordered object with low entropy is dropped and smashes, it's entropy increases because it is left as many shattered pieces. If you melt it down and reform it as a glass, it's entropy decreases again because it becomes a more ordered shape. However the energy transformed to do this spreads out through space, increasing the net entropy. The energy taken to create the first life will have spread out through space increasing the entropy. The universe started as an infinitely small point with all of the energy in the universe concentrated in it - infinite order and 0 entropy. Time started and space expanded and energy spread out to fill it, increasing the entropy of the universe. Everything that is ordered actually creates more disorder than the order that it is in. I don't see why the entropy in the initial singularity is 0. How can it be so if there is absolute uniformity? I tend to think that entropy has decreased as the universe expanded. Paul Davies explained somewhere how the expansion of the universe can make entropy decrease by creating differences in temperature. A friend of mine, physics and mathematics professor, told me once that the universe is not an isolated system because, by definition, there is no system without environment. The latter has never convinced me. As for Davies' opinion, I'd say that if he is right, it would only show that an expanding universe must be an open system. Regards

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Posted 07/15/08 - 12:01 PM:	#37
LauLuna wrote: I don't see why the entropy in the initial singularity is 0. How can it be so if there is absolute uniformity? I tend to think that entropy has decreased as the universe expanded. Paul Davies explained somewhere how the expansion of the universe can make entropy decrease by creating differences in temperature. A friend of mine, physics and mathematics professor, told me once that the universe is not an isolated system because, by definition, there is no system without environment. The latter has never convinced me. As for Davies' opinion, I'd say that if he is right, it would only show that an expanding universe must be an open system. Regards It is precisely because there was absolute unifority that entropy was 0, or unity. Absolute uniformity as a result of 0 dissociation implies 0 chaos. What Davies explained was a (one of several) hypothesis which attempts to account for the seemingly 'un-chaotic' clumping observed in the universe, in the form of relatively dense clumps of matter (galaxies) with huge spaces between them in a seemingly non-uniform distribution. This hypothesis (I forget the source) attempts to explain the conundrum that although one would expect the big bang to distribute matter more or less uniformly throughout the universe, in reality it's completely the opposite. Even so, that is still a case of local decrese in entropy. Overall entropy always increases. Discussions regarding the immutable direction of entropy always brings to mind Asimov's classic The Last Question.

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Posted 07/15/08 - 09:58 PM:	#38
I don't think "chaos" is a good way to think of entropy. When a hurricane/typhoon/monsoon dissapates into the surrounding atmosphere, it becomes less "chaotic", but the entropy increases because the usable heat or energy got transferred into the surroundings. If the sun disappeared, (no outside energy), the atmosphere would lose its energy and become uniformly distributed while cooling, (losing heat as radiation). But uniformity isn't always the best indicator of an increase in entropy either. Look at planets -- they form as entropy transfers the energy from gravity into a lower state by being clumped together. The fate of the universe sometimes falls into 2 ultimate entropy scenarios -- where matter expands until it is beyond the reach of gravity or where it all collapses into the maximum entropy of the "big crunch". Either scenario is maximum entropy, but with very different results. Planets are also interesting when someone thinks of "order" implying low entropy. People look at planets and think they are perfectly ordered spheres, (or close enough an approximation). They think that because the human brain mistakes the aesthetic pleasure of looking at something symmetric as "ordered", when it is simply the lowest entropy for the energy and forces available. Gravity is the one force that always keeps us from having a nice simple Universe, but without it, we probably wouldn't have all the rest or be here to appreciate it.
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Posted 07/16/08 - 07:05 AM:	#39
Its true that the translation of entropy as chaos is orthodox, but accurate nonetheless. wikipedia wrote: Entropy, historically, has often been associated with the amount of order, disorder, and/or chaos in a thermodynamic system. The traditional definition of entropy is that it refers to changes in the status quo of the system and is a measure of "molecular disorder" and the amount of wasted energy in a dynamical energy transformation from one state or form to another.[31] In this direction, a number of authors, in recent years, have derived exact entropy formulas to account for and measure disorder and order in atomic and molecular assemblies. An interesting point you brought up with the case of the big crunch. I'm not entirely sure whether the big crunch would imply an increase, decrease, or no change in entropy. This would be wort looking into. Finally, swstephe wrote: People look at planets and think they are perfectly ordered spheres, (or close enough an approximation). They think that because the human brain mistakes the aesthetic pleasure of looking at something symmetric as "ordered", when it is simply the lowest entropy for the energy and forces available. That is pretty straghtforward and rational, yet profound at the same time, since it touches on the meaning of the phenomenon of beauty. Edited by Kurt_Godel on 07/16/08 - 07:11 AM

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Posted 07/16/08 - 07:17 AM:	#40
We need a working definition of "entropy" in this discussion, as well as some consensus on what the second law entails. It seems that these things are known, and are in the public domain - but that we don’t collectively understand them from the discussion so far on this thread. Surely entropy is simply the decrease of order? and the second law states that this order within the universe will decrease uniformly as time progresses? Are these the important implications of these ideas for the present debate, or are there others?

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Posted 07/16/08 - 10:58 AM:	#41
Entropy is only the increase of disorder if one takes a very particular (and probably peculiar) view of the reduction of thermodynamics to statistical mechanics. In thermodynamics, though I don't have any of my textbooks here with me, entropy is essentially a mathematical relationship that holds in order to ensure that no engine (a machine that carries out work based on heat exchange) can exceed a certain efficiency. It is a measure of the efficiency of heat exchange. Strictly speaking, in no reduction of thermodynamics to statistical dynamics does the second law of thermodynamics actually hold. The "law" is simply a behaviour expected given certain initial conditions that happen to be very, very common in what we identify as the past. (Now I think that the past we identify is actually correctly identified as a real past, but that's pretty much beside the point.)
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Posted 07/17/08 - 08:52 AM:	#42
I find entropy and dark matter to be similar in their un-definitness. More or less, they are remainders to equations. Is this accurate?
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Posted 07/17/08 - 12:35 PM:	#43
To some extent, I agree. Dark matter, in the sense used by the WMAP team, the distant supernova search teams, and most cosmological programs is fairly well defined in terms of its properties as an aggregate of particles at a given speed with a well defined range of mass and little electromagnetic interaction. This reference is used to search for the specific particles that comprise the aggregates of dark matter that can be detected through various means. However, it is often used to refer to any matter that is not currently detectable through emitted or reflected light. This use often confuses the issue, especially since the properties of the particles that comprise aggregated of dark matter (narrowly construed) are still a matter of speculation. "Entropy" is a well defined term in a number of different fields. There are good reasons to suppose that some of these definitions coincide and good reasons to suppose that others do not. For example, the entropy of information theory relates to the entropy of thermodynamics and statistical mechanics (in that these processes contribute to the entropy in the information theory context) but it would be incorrect to identify these terms.
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Posted 07/19/08 - 07:36 AM:	#44
Kurt_Godel wrote: It is precisely because there was absolute unifority that entropy was 0, or unity. Absolute uniformity as a result of 0 dissociation implies 0 chaos. What Davies explained was a (one of several) hypothesis which attempts to account for the seemingly 'un-chaotic' clumping observed in the universe, in the form of relatively dense clumps of matter (galaxies) with huge spaces between them in a seemingly non-uniform distribution. This hypothesis (I forget the source) attempts to explain the conundrum that although one would expect the big bang to distribute matter more or less uniformly throughout the universe, in reality it's completely the opposite. Even so, that is still a case of local decrese in entropy. Overall entropy always increases. Discussions regarding the immutable direction of entropy always brings to mind Asimov's classic The Last Question. I fail to see it: 1. Lack of uniformity in matter distribution shows (locally?) decreased entropy, still uniformity in the initial singularity means 0 entropy. The matter/energy occupied its most probable state in the initial singularity. Perhaps it could be said that, there being 0 degrees of freedom, the probability of the actual state was 1 and the entropy was infinite. According to Boltzmann's equation 'entropy = K*ln(number of possible states)', entropy must be as low as possible in the intitial singularity, where surely the number of possible sates is 1. 2. The general distribution of matter/energy in the universe is a case of local decrease of entropy: how can it be local if it is general? I think Davies was referring to a general increase of order in the universe. The passage you have in mind is perhaps from 'The Cosmic Blueprint' whereas the one I have in mind is from 'God and the New Physics', a book I have no longer at hand. I may easily be wrong since I am no expert. I'd be grateful for any corrections. Regards

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Posted 08/18/08 - 11:16 AM:	#45
DM DM wrote: This isn't really accurate. First of all, the laws of thermodynamics are statistical mechanics laws. That is, they are laws about what happens on average, not rigid deterministic laws, like Newton's laws of motion. For example, the 2nd law is violated, even for closed systems, all the time. But this is nearly indetectable for anything other than extremely small systems being observed on very short time scales. Otherwise the probability of making such an observation becomes vanishingly small. Second, it is incorrect to say that we do not know why the 2nd law works, or that it cannot be derived from more basic laws. Quite the contrary, the 2nd law directly follows from Newton's laws, when applied to any complex system which, due to its complexity, involves approximately random exchanges of energy from one degree of freedom to another, via interactions. For example, if one takes a closed and perfectly insulated container of some ideal gas (individual perfectly spherical particles, with no adhesion or cohesion), an works out what Newton's laws say should happen, all the laws of thermodynamics immediately pop out. Given almost any set of initial conditions, the gas will go to state of approximately uniform temperature, which is also a state of maximal entropy for the amount of energy present. In principle, the laws of thermodynamics are nothing more than the application of basic principles of statistics to complex mechanical systems that behave randomly (or approximately randomly). There is nothing mysterious about it. The laws of thremodynamics are interpreted as statistical laws because they cannot be understood as "rigid deterministic" laws of nature. But what would you have a "law" be, if not rigid and deterministic. You want flexible law or one where outcomes are not determined? A law that holds true some of the time is not a law. There's a 70% chance of rain tomorrow but it will either rain 100% or it won't; we don't get a 70% rain shower. Statistical laws are approximations about what we can expect to happen but the mechanisms that CAUSE rain operate infallibly and deterministically. Since they are NOT deterministic, regularities described by the 2nd law are either accidental generalizations or emergent causes... unless the laws of physics are not causally complete. It's not that the coffee really does heat back up again sometimes but it's so rare we don't notice it. The laws of thermodynamics are not mysterious because we see them confirmed everywhere we look. But the reversible, "rigid deterministic" laws of physics describe the same universe and explain the motion that underlies thermodynamic interactions. So the the disconnect between motion and heat is not trivial because heat IS a result of motion.It's clear, to me at least, that something must be missing in the physics of heat that would allow us to explain the irreversibility of theromodynamics.

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Posted 08/18/08 - 12:31 PM:	#46
LauLuna wrote: I fail to see it: 1. Lack of uniformity in matter distribution shows (locally?) decreased entropy, still uniformity in the initial singularity means 0 entropy. The matter/energy occupied its most probable state in the initial singularity. Perhaps it could be said that, there being 0 degrees of freedom, the probability of the actual state was 1 and the entropy was infinite. According to Boltzmann's equation 'entropy = K*ln(number of possible states)', entropy must be as low as possible in the intitial singularity, where surely the number of possible sates is 1. Using Boltzmann's equation, since the number of microstates within the singularity can reasonably be assumed to be 1 (no separate microstate, or microstate is the macrostate), entropy of the singularity S = K ln (1) = 0. LauLuna wrote: 2. The general distribution of matter/energy in the universe is a case of local decrease of entropy: how can it be local if it is general? I think Davies was referring to a general increase of order in the universe. The passage you have in mind is perhaps from 'The Cosmic Blueprint' whereas the one I have in mind is from 'God and the New Physics', a book I have no longer at hand. I may easily be wrong since I am no expert. I'd be grateful for any corrections. Regards I too am referring to the hypothesis from 'God and the New Physics'. My understanding is that Davies explains the clumping of matter/energy as a localized decrese in entropy, even though the overall entropy of the universe still increases. An analogy is that living beings represent systems with localized entropy decrese, even though the environment they live in always has a net increase in entropy.

derekc153
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Posted 08/18/08 - 11:22 PM:	#47
Makarismos wrote: We need a working definition of "entropy" in this discussion, as well as some consensus on what the second law entails. It seems that these things are known, and are in the public domain - but that we don’t collectively understand them from the discussion so far on this thread. Entropy is given by the equation: S = kln(W), where S is entropy, k is the Boltzmann constant, "" denotes multiplication, ln is the natural logarithm, and W is the number of microstates corresponding to the macrostate whose entropy one wishes to calculate. A macrostate is the macroscopic state of a system, such as the total number rolled on a pair of 6-sided dice. A microstate is the specific configuration of the microscopic elements which constitute the macroscopic system. In the previous example using dice, the microstate of the seven rolled on a pair of 6-sided dice might be a roll of 6 on the first die and 1 on the second die. As this example makes clear, multiple microstates may give rise to the same macrostate. The more microstates correspond to a given macrostate, the greater the entropy of that macrostate. Thus, rolling a seven on a pair of 6-sided dice is the maximum entropy macrostate of that system because there are more ways to roll a seven--more microstates corresponding to that macrostate--than any other number.
"There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy." -Shakespeare's Hamlet "If God does not exist, then all things are permitted." -Fyodor Dostoyevsky

Death Monkey
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Posted 08/19/08 - 05:07 AM:	#48
Simple Occam, The laws of thremodynamics are interpreted as statistical laws because they cannot be understood as "rigid deterministic" laws of nature. Scientific laws are simply observed rules that the world appears to follow. In this particular case, the "rules" refer to what tends to happen on average in complex systems with random and/or apperantly random interactions occuring. They are not "interpreted" as statistical laws. They are statistical laws, by definition, because they are formulated in terms of statistics. They are, in fact, a part of statistical mechanics. But what would you have a "law" be, if not rigid and deterministic. Again, a scientific laws is a observed rule that the world appears to follow. Such rules can be formulated in terms of determinism (such as Newton's laws), or statistically (such as the laws of thermodynamics). It all depends on what the rule is actually claiming about the world. You want flexible law or one where outcomes are not determined? A law that holds true some of the time is not a law. There's a 70% chance of rain tomorrow but it will either rain 100% or it won't; we don't get a 70% rain shower. Statistical laws are approximations about what we can expect to happen but the mechanisms that CAUSE rain operate infallibly and deterministically. Since they are NOT deterministic, regularities described by the 2nd law are either accidental generalizations or emergent causes... unless the laws of physics are not causally complete. It's not that the coffee really does heat back up again sometimes but it's so rare we don't notice it. The laws of thermodynamics are not mysterious because we see them confirmed everywhere we look. But the reversible, "rigid deterministic" laws of physics describe the same universe and explain the motion that underlies thermodynamic interactions. I don't see your point. Sure, the laws of thermodynamics can be used to describe complex deterministic systems. They can also be used to describe systems with random interactions. So what? The laws are statistical ones. They describe what happens on average. So the the disconnect between motion and heat is not trivial because heat IS a result of motion.It's clear, to me at least, that something must be missing in the physics of heat that would allow us to explain the irreversibility of theromodynamics. Even in classical physics, the irreversibility of thermodynamics is no problem to explain. Again, thermodynamics does not say anything about how a specific microstate will evolve over time. It describes how we expect a macrostate to evolve, on average, over time. Sure, under Newtonian mechanics there are microstates which belong to high entropy macrostates, but which will evolve to microstates belonging to lower entropy macrostates. But such a microstate represents an extremely tiny subset of the macrostate it belongs too. The vast majority of the microstates corresponding to that macrostate will evolve to microstates belonging to higher entropy macrostates. That is what the second law actually claims. It does not say that every microstate will always evolve to a microstate with higher entropy. That would not even make any sense, because entropy is not defined for microstates. It says that, on average, a system in a particular macrostate will tend to evolve to a macrostate with higher entropy. DM
Pseudoscience makes Baby Jesus cry.

Death Monkey
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Posted 08/19/08 - 05:16 AM:	#49
Simple Occam, The laws of thremodynamics are interpreted as statistical laws because they cannot be understood as "rigid deterministic" laws of nature. Scientific laws are simply observed rules that the world appears to follow. In this particular case, the "rules" refer to what tends to happen on average in complex systems with random and/or apperantly random interactions occuring. They are not "interpreted" as statistical laws. They are statistical laws, by definition, because they are formulated in terms of statistics. They are, in fact, a part of statistical mechanics. But what would you have a "law" be, if not rigid and deterministic. Again, a scientific laws is a observed rule that the world appears to follow. Such rules can be formulated in terms of determinism (such as Newton's laws), or statistically (such as the laws of thermodynamics). It all depends on what the rule is actually claiming about the world. You want flexible law or one where outcomes are not determined? A law that holds true some of the time is not a law. There's a 70% chance of rain tomorrow but it will either rain 100% or it won't; we don't get a 70% rain shower. Statistical laws are approximations about what we can expect to happen but the mechanisms that CAUSE rain operate infallibly and deterministically. Since they are NOT deterministic, regularities described by the 2nd law are either accidental generalizations or emergent causes... unless the laws of physics are not causally complete. It's not that the coffee really does heat back up again sometimes but it's so rare we don't notice it. The laws of thermodynamics are not mysterious because we see them confirmed everywhere we look. But the reversible, "rigid deterministic" laws of physics describe the same universe and explain the motion that underlies thermodynamic interactions. I don't see your point. Sure, the laws of thermodynamics can be used to describe complex deterministic systems. They can also be used to describe systems with random interactions. So what? The laws are statistical ones. They describe what happens on average. So the the disconnect between motion and heat is not trivial because heat IS a result of motion.It's clear, to me at least, that something must be missing in the physics of heat that would allow us to explain the irreversibility of theromodynamics. Even in classical physics, the irreversibility of thermodynamics is no problem to explain. Again, thermodynamics does not say anything about how a specific microstate will evolve over time. It describes how we expect a macrostate to evolve, on average, over time. Sure, under Newtonian mechanics there are microstates which belong to high entropy macrostates, but which will evolve to microstates belonging to lower entropy macrostates. But such a microstate represents an extremely tiny subset of the macrostate it belongs too. The vast majority of the microstates corresponding to that macrostate will evolve to microstates belonging to higher entropy macrostates. That is what the second law actually claims. It does not say that every microstate will always evolve to a microstate with higher entropy. That would not even make any sense, because entropy is not defined for microstates. It says that, on average, a system in a particular macrostate will tend to evolve to a macrostate with higher entropy. DM
Pseudoscience makes Baby Jesus cry.

Simple Occam
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Posted 08/19/08 - 01:07 PM:	#50
OK, so you don't see a problem for physics to be causally incomplete?

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