Friday, June 18, 2010

Entropy, Conservation of Energy, Order, and Life

Carl Sagan has claimed that life (1) is in fact entropic and that a decrease in order in the sun compensates for an increase in order in earthly systems that receive energy from the sun, specifically living systems. This, he said, proves that life is entropically possible and moreover is likely driven by entropic forces.

Mathematicians have followed this route, using entropy as a force for motion, and since evolution is also declared a motion, then deriving a mathematical justification for an entropic cause for evolution. This has received a certain amount of play in the media and some traction with evolutionists.

In order to examine these propositions, it becomes absolutely necessary to understand exactly what entropy is and is not, and to what the second law of thermodynamics actually refers.

Entropy is an energy based concept, which refers to reversible / irreversible systems. According to thermodynamic system theory, a system cannot use all of the energy it contains due to losses. This means that no system is reversible if it depends upon its own self-contained energy.

If a system receives energy from the outside, it can become reversible, unless it becomes unstable and is destroyed. Stability is achieved when the useful energy in the reversing system plus the waste energy equals the input energy. Excess input energy either is turned into waste energy or it builds in the system somehow as potential or kinetic energy. If it builds in the system too long, destruction occurs.

Entropy only secondarily describes order in a system. It does this by describing the amount of disorder that a system, open or closed, produces. And every system, regardless of whether it is open or closed, produces excess disorder. The equation for conservation of energy in a system looks like this:

Einput + Epotential + Ekinetic internal + Ekinetic output + Ewaste = KeSystem

Entropy merely states that Ewaste is never zero. In other words, entropy is merely a metric which is used to measure system energy loss to disorder.

From this equation we see that when Einput = 0, Ekinetic output = 0, and Ewaste = 0 (non-lossy), in other words, an ideal closed system doing no work, then,

Epotential + Ekinetic internal = KeSystem (a constant).

So when Ekinetic is minimum, Epotential is maximum; conversely when Ekinetic is maximum, then Epotential is minimum. Just like the pendulum.


This means that an ideal system can reverse itself from all kinetic energy to all potential energy.

If external energy, Einput, is added to a perfect, ideal, non-lossy system, then,

Einput + Epotential + Ekinetic internal = KeTotal

So, assuming the potential energy to be limited, the kinetic energy would increase beyond its original values by the amount of energy input, and the total system energy increases also. With unlimited energy input over time, then the kinetic energy would also be unlimited.

But that is not a feature of nature. Here’s what happens in reality, where all systems incur losses, Ewaste:

Einput + Epotential + Ekinetic internal + Ewaste = KeTotal (assuming no work done by the system)

So in reality, the extra input energy from the input is turned into waste energy at ever increasing levels, while the system continues reversing itself.

If work is being done, Ekinetic external, then the relationship becomes:

Einput + Epotential + Ekinetic internal + Ekinetic external + Ewaste = KeTotal

Where Ekinetic external is work. Work is defined as energy expended over a given time.

In natural systems, such as a rolling boulder hitting another boulder and dislodging it, thereby doing “work”, a series of energy conservation equations can be written, and combined into a single system equation. The work done then becomes a completely internal energy issue, and the energy wasted remains a positive value. There is nothing to suggest that natural, material systems ever develop more energy than they consume. Nor is there anything about entropy that suggests that work in a material open system ever creates more order than is lost to waste.

There is nothing about entropy that even suggests that order is being swapped around. What is clear is that disorder is created from order in varying amounts by inputting varying amounts of input energy. This is true whether the system is closed or open.

In addition, the energy that is radiated from the sun is in the form of subparticles and photons, the entropic degradation products of fusion from hydrogen to helium. When this energy is finally input into living systems, mostly via photosynthesis, it is done at the electron level. There is nothing about this energy input to living systems that suggests that anentropy could be expected as a result, or that order would be increased in defiance of thermodynamics.

This is a direct contradiction to Sagan’s claim that increasing disorder on the sun allows for more order to be created in an earthly system. Sagan has taken scientifically illegitimate liberties with the concept of entropy.

Again, entropy is a merely metric for loss in natural systems, whether open or closed. And it defines an increasing disorder only, not any possibility of increasing order. To claim otherwise betrays either an ignorance of physics and specifically thermodynamics, or an intent to deceive using fuzzy physics for obfuscation.

Either way, entropy is not a force that can be used because it is a definition of wasteful disorder, and it cannot be a force for increasing complexity as is suggested by the evolutionists and mathematicians. It is a logarithmic measure of system loss. No matter how fancy the math, if it is based on incorrect premises then it cannot produce correct theorems.

General Discussion:

Here is how the man who defined entropy in the first place describes it:

Max Planck:

”“Whether reversible processes exist in nature or not, is not a priori evident or demonstrable. There is , however, no purely logical objection to imagining that a means may some day be found of completely reversing some process hitherto considered irreversible: one, for example in which friction or heat-conduction plays a part. But it can be demonstrated that if, in a single instance, one of the processes here declared to be irreversible should be found to be reversible, then all of these processes must be reversible in all cases. Consequently, either all or none of these processes are irreversible. There is no third possibility. If those processes are not irreversible, the entire edifice of the second law will crumble. None of the numerous relations deduced from it , however many may have been verified by experience, could then be considered as universally proved, and theoretical work would have to start from the beginning… It is this foundation on the physical fact of irreversibility which forms the strength of the second law. If therefore, it must be admitted that a single experience contradiction that fact would render the law untenable , on the other hand, any confirmation of part supports the whole structure, and gives to deductions, even in seemingly remote regions, the full significance possessed by the law itself.”(2)
[emphasis added].

There are no reversible processes seen in nature. Using the admittedly flawed inductive process we can say that entropy is universal: there are no “back eddy anentropic natural processes”. We can also say that purposefully moving a rock back uphill is anentropic. As Bertrand Russell pointed out, catching a train is against the determinate laws of nature. Determinate physical processes are not the same as non-determinate intentionality. Living things convert energy into higher forms of existence. Animate living things, especially higher forms, can go up hill, by first wanting to go there, then by purposefully implementing energy conversion into an increase in altitude. They can take rocks up hill by wanting to do that, then implementing that, intentionally.

On the other hand, atoms forming into molecules, crystals, etc. are finding lower energy levels at which to exist; they deterministically obey laws of physics, not self-intent. Intent is a capability accompanied by sentience, life and includes defying physical laws as in purposefully using certain laws of nature (e.g. leverage) to defy other laws of nature (e.g. gravity).

Crystal formation and molecular chains form under entropic law. Such molecules are not “more organized” than individual atoms. They are merely atoms connected together in lower energy combinations, when they find physical positions that satisfy that criterion. The properties are those of self-description, i.e. water is “wet” in the sense that it adheres to surfaces giving those surfaces a different quality of friction, refraction, and evaporation changes surface temperatures, all of which are in obedience to physical laws. This is eminently predictable under those physical laws.

Living things that exhibit intent and sentience can and do violate physical laws. Their behaviors are not predictable under any law of physics.

Here is an assortment of non-mathematical definitions of entropy:

Entropy:
1. “There is a tendency in nature to proceed toward a state of greater molecular disorder.” [not restricted to closed systems]. (3)

2. 100% conversion of heat into mechanical work is not possible by any form of engine.(4) [Specific]

3. There is a tendency in nature to proceed toward a state of greater molecular disorder. This one-sidedness of nature produces irreversible processes. (5) [General]

Notes:
(1) http://isotope.colorado.edu/~geol3300/Sagan%20Definitions%20of%20life.pdf Sagan also defines life as the focus of several viewpoints, with the idea of obscuring the fundamental characteristics. An example is the claim that automobiles give the appearance of life due to metabolizing fuel. This obscures the totality of living things which demonstrate all the physical characteristics plus one: life itself, which only comes from other life, and once it is gone, it is gone. Sagan has an objective: apologetics for evolution, which supports his Atheism.

(2)Max Planck, “The Second Law of Thermodynamics”; World Treasury of Physics, Astronomy, and Mathematics, Ferris, Ed.; Little Brown & Co. pubs; 1989; pg 343.

(3) Modern University Physics, Richards, Sears, Wehr, Zemansky, Addison-Wesley Pub., 1960.

(4) http://pespmc1.vub.ac.be/ASC/SECOND_THERM.html; Sears and Zemansky, p 342,

(5) http://pespmc1.vub.ac.be/ASC/SECOND_THERM.html; Sears and Zemansky, p 347,

8 comments:

Unknown said...

*sigh*

Ironic, because entropy does not "disprove" life at all, especially since life decays. Entropy does disprove God, however.

Stan said...

Ginx, if you think I said that entropy disproves life, you completely misunderstood the post. And life doesn't decay, body elements such as individual cells decay and are replaced by the "life" component within the entity. Life is intact until death. It is binary.

And you assert without details or proof the disproof of God:

Your commitment to anti-rationalism and anti-logic does seem to dominate your thinking.

Unknown said...

I am no expert on entropy, nor do I know exactly what Sagan's claims were... but here are two comments: first, a minor point: that increase in system entropy is only an inviolable law in classical physics. In QM, there is no reason why order cannot increase in a system - it is simply that it is overwhelmingly likely not to.

Second, and this addresses what I think Sagan was getting at: according to my understanding, entropy in all current classical and QM formulations is time-independent. That is to say, your statement:

"Again, entropy is a merely metric for loss in natural systems"

Is true - not just moving forwards in time within a system, but BACKWARDS in time as well. There is no theoretical reason why entropy should increase towards the future, but decrease towards the past. According to all current formulations of entropy, it should increase towards the past as well... Of course, to the best of our knowledge and our empirical observations, this is not the case in our universe. The old analogy (I think given by Brian Greene) is that we assume in our universe that the melting ice cubes in your drink came from whole ice cubes, and didn't spontaneously assemble a moment before from liquid water molecules in your drink - even though (completely counterintuitively) quantum mechanics suggests that the latter is actually a far more reasonable scenario than the former.

The normal explanation for this phenomena - the so-called 'arrow of time', unneeded in any modern theory of physics but demanded by empirical evidence, that is responsible for entropy increasing towards the future but decreasing towards the past - is that, just like melting ice cubes came from lower-entropy whole ice cubes in the past, the universe itself evolved from a low-entropy past state - specifically, that the universe at the moment of the big bang was in a state of very low entropy. (this is part of what QM physicists like Stephen Hawking mean when they say 'time began at the Big Bang').

I think this might have been part of what Sagan had in mind: that the Earth-Sun system evolved from a past state of lower entropy. I agree this does not in any way suggest a TRANSFER of order from one part of the system to the other. I think Sagan might have been thinking that the complexification of life on Earth was evidence that the Earth today was more ordered than it was in the past. If that was his thought, I would disagree - I think that heat loss from the Earth via radiation alone probably accounts for enough entropy gain in the Earth-system to account for the order present in living organisms. In short, I agree - Sagan was wrong :)

Unknown said...

hehe, missed the link to Sagan's article at the bottom...

After reading it, I don't believe he was making any claim that order was being transferred from the sun to the Earth, or about any order-transferring mechanism at all.

I think his point was to argue that the development of life (which appears to increase order over time) does not provide refuting evidence against the law of entropy or the potential heat-death of the universe, because all known life depends on sunlight. Therefore, any closed system containing life must also contain the sun - and within this system, there is more entropy gain (eg. from the sun) than there is entropy loss via the development of life.

(never mind my last post, then :) - doesn't seem to be relevant to Sagan's article...)

Stan said...

The point made in the article by Planck is that any natural system displays positive entropy. There is no reason to assume that there are backwashes of negative entropy in any natural system, open or closed.

The open or closed system part is a recent modification of the concept of entropy, which I suspect has been made specifically to accommodate life, because life defies the real meaning. The desperate need to accommodate life as a material "thing" necessitated the bastardization of the concept.

But other than life, what other natural systems produce pockets of high order that continually increases over time?

The only reason to modify the meaning of entropy is to preserve Philosophical Materialism, which philosophically denies exceptionalism to life. That makes the closed system issue a religious issue.

lolz anonymous said...

How would you answer this :

quote
The common argument used to explain this is that, locally, entropy can be lowered by external action, e.g. solar heating action, and that this applies to machines, such as a refrigerator, where the entropy in the cold chamber is being reduced, to growing crystals, and to living organisms.[2] This local increase in order is, however, only possible at the expense of an entropy increase in the surroundings; here more disorder must be created.[2][15] The conditioner of this statement suffices that living systems are open systems in which both heat, mass, and or work may transfer into or out of the system. Unlike temperature, the putative entropy of a living system would drastically change if the organism were thermodynamically isolated. If an organism was in this type of “isolated” situation, its entropy would increase markedly as the once-living components of the organism decayed to an unrecognizable mass.[11]
unquote
http://en.wikipedia.org/wiki/Entropy_(order_and_disorder)

Stan said...

My answer would be that this is an example of the bastardization of the meaning contained in the definition of entropy. Entropy is a mathematical model. Definitions which violate the model are incorrect. In this case, "putative entropy" is added to the model, and since there is no such thing as "putative entropy" then the addition is both incorrect and unnecessary... except as a philosophical bandage for the incorrect understandings of Philosophical Materialism.

Geoff said...

I have always believed that evolution violated 2LOT but it is hard to explain exactly why. Stan's article was interesting enough to make me try again.

I'll have a go. Lets say I go tidy my shed. Lets imagine it is a special shed in which no energy enters or exits.I enter the shed and start work. As I tidy I give off heat so that the amount of heat I give off exceeds the amount of work I do in tidying (due to wastage). As the shed is heated disorder increases due to the increased motion of various molecules due to heating. Thus although the shed appears lower in entropy overall entropy in the shed has increased. The significance of the closed system is that the increase of entropy is easily measured. Nevertheless entropy always increases in any system open or closed due to the wastage I have mentioned and can never reverse.

If you doubt this reconsider my shed. Now it is heated by the sun as in reality. I go in and tidy as before. However entropy actually increases even more in this situation. Added to my body heat is the heat of the sun which causes greater heating and more disorder. Nothing has changed from the original situation; I give off more energy than I use in tidying. It is a zero-sum game.

Could some of the sun's energy be harnessed directly to tidy the shed? Never. The heat energy coming from sun is very entropic it's self. It would need to be converted by an energy converting apparatus into the useful work required.

This is the problem with evolution. It requires an intentional energy converting mechanism to make it work.