The Second Law of Thermodynamics: Enough Already!One of the most tediously common creationist claims is the Second Law of Thermodynamics argument. It is wrong, and was wrong from the beginning; but despite the fact that it has been refuted countless times, it continues to circulate in anti-evolutionist organizations, inevitably accompanied by the claim that it presents an insurmountable problem for the theory of evolution. Nothing could be further from the truth, as this essay will demonstrate.

The Second Law of Thermodynamics is a fundamental principle of physics. It dealswith entropy, a term that has a precise mathematical definition. For this essay, it is sufficient to say that entropy corresponds to the amount of energy in a system available to do work. The more energy available for work, the less entropy there is, and vice versa. The Second Law of Thermodynamics (or 2LOT for short) says that the net entropy of a closed system must always increase.

To better understand the topic, a further explanation is worthwhile. The First Law of Thermodynamics, another well-established physical principle, says that the total amount of energy in the universe is constant; energy can never be created or destroyed. However, it can take many forms – kinetic, potential, electromagnetic, thermal, mechanical, and others. When you throw a ball, you areconverting chemical energy stored in your muscles, in the form of the cellular fuel ATP, into mechanical energy to move your arm, which is in turn transferred into kinetic energy in the ball. The leaves of green plants collect electromagnetic energy – light – and convert it into chemical energy in the form of sugar. Virtually every interaction involves an energy conversion of some kind.

The 2LOT states that no energy conversion is ever 100% efficient. Whenever energy is converted from one form to another, some of it is lost, in the form of waste heat. When electric current travels through wires, some of the energy is dissipated as heat by the resistance of the wire; when you move your body, some energy is dissipated as heat by friction in your joints, and so on.

Energy cannot be destroyed, but this waste heat is effectively lost. It spreads out into its surroundings, becoming diluted among all the available molecules until no temperature differential exists and it is stretched too thin to ever be recovered. Entropy has just increased. This is the heart of the 2LOT: in every reaction, usable-energy decreases and entropy increases, even if only by a small amount. The most common phrasing of the 2LOT is that in a closed system, net entropy alwaysincreases. A system is any collection of interactions; a closed system is one that exchanges neither matter nor energy with its surroundings.

Equivalently, entropy can be described in terms of disorder. In a system containing atoms at different temperatures, the low-entropy state would consist ofthose atoms segregated by temperature, for example, one reservoir of hot atoms and one reservoir of cold atoms. This temperature differential is what makes it possible for the system to do work. The high-entropy state would consist of atoms of all different temperatures randomly mixed together, so that the temperature of

any part of the system is on average the same as the temperature of the whole system. The high-entropy state is more disordered than the low-entropy state, in the sense that rearrangements of the system are less likely to change it importantly. When atoms are separated into hot and cold pools, any random rearrangement will probably mix the two pools together, increasing entropy; but when the atoms are mixed together in a homogeneous gas, any random rearrangement is far more likely to leave them as a homogeneous gas, producing no change in entropy. (This can be analogized by pouring ink into a glass of water.If one randomly stirs the glass immediately after pouring in the ink, the result will be to diffuse the ink throughout the water’s volume, but if one stirs the glass afterthe ink and water are well mixed, it is extraordinarily unlikely that the ink and water will unmix themselves and separate out; rather, they will remain mixed.)

It is important to note that an increase in entropy is not necessarily irreversible. If the system is left to itself, random chance makes it overwhelmingly likely that entropy will increase to the maximum and then stay the same, just as it is overwhelmingly likely that the ink will diffuse throughout the water and never spontaneously re-separate. However, if the system is not “left to itself” – if work isdone on it – the entropy of that particular system can decrease, although only at the cost of increasing the entropy of the system that did the work – and thus the total amount of entropy in the universe – by an even greater amount. Many kinds of human-built technology are designed to change a high-entropy state into a low-entropy state; one common example is a refrigerator.

We now turn to the creationist argument. Typically, it goes something like this: Evolution predicts that organisms (biological systems) evolve from less complex to more complex (more highly ordered) states. The 2LOT predicts that all systems,including biological ones, inevitably degrade and break down into less ordered states. Therefore, evolution contradicts the 2LOT and must be wrong.

With the above explanation in mind, several things can be said about this. First, it is a common mistake to equate entropy with everyday notions of chaos or disorder, but it is a mistake nevertheless. Strictly speaking, entropy is equivalent to disorder only on the atomic level, in the technical sense discussed above. If theterms “order” and “disorder” are instead used in the way most people would understand them – the way creationists use them – then entropy can increase without there being any corresponding increase in disorder, and some processes that increase entropy actually increase order. For an example of the first condition, if you set up a heater in your bedroom and leave it running for several hours, you will have significantly increased the room’s entropy, regardless of whether the arrangement of items in the room has changed. The temperature of your bedroom, rather than whether your clothes are folded in the bureau or strewn about the floor, is the overwhelmingly important factor when determining the entropy of the room (see this Talk.Origins Post of the Month for an explanation); and this applies to every other macroscopic system as well.

As for the second condition, there are many physical processes that spontaneously increase order without in any way violating the 2LOT. For example, the process of crystallization produces highly ordered, complex structures such as geodes and snowflakes. Random weather interactions give rise to highly ordered

systems such as tornadoes and hurricanes. Evaporation can separate a mixture ofwater and salt; wave action on a beach can sort pebbles by size. Random processes of freezing and thawing can produce eerily regular geometric patterns of stones (Self-Organization of Sorted Patterned Ground; see also Stone circles explained). And finally, highly organized stars can form through the gravitational collapse of random clouds of hydrogen gas. None of these processes violate the 2LOT in any way.

When the true definition of entropy is used, rather than the creationists’ straw man, it is obvious that evolution in no way violates the 2LOT, regardless of whether it produces an increase in some vaguely-defined notion of order. For thermodynamics to be satisfied, the only requirement is that entropy increase, and it does. What energy is dissipated to cause this entropy increase? The answeris fairly obvious: the energy of the Sun. A small fraction of the energy the Sun emits reaches the Earth, where it is absorbed by living things and used for photosynthesis. The rest of the Sun’s energy is radiated into space and dissipated,causing a huge increase in entropy.

In other words, the Earth is an open system – it is not isolated, but rather is constantly receiving energy from the Sun. Therefore, there is no 2LOT constraint on what its net entropy gain or loss must be. (Living organisms, for that matter, are also open systems, since they continually take in energy.) Though the 2LOT, invarying formulations, does apply to all systems, it does not say that the net entropy of an open system must increase. On the contrary, the net entropy of an open system can either increase or decrease. This is because an open system canimport energy, as the Earth does, and export waste heat, so that the universe’s total entropy does increase “somewhere else”. Such is the case if one steps back and considers the larger system of the Earth and the Sun. Any small decreases in the entropy of the Earth are more than compensated for by the huge increases in entropy produced by the Sun each moment.

If evolution violates the 2LOT, there must be some specific step in the process of evolution that violates the 2LOT. Which step is this, according to creationists? It is not mutation; the process of replicating the genome uses up energy just like any other chemical reaction. It is not natural selection; for every one organism that emerges victorious and prospers, many more must die, dissipating their stored biochemical energy. It is not reproduction; all living things are dependent on the usable energy of the Sun, whether used directly for photosynthesis or passed along the food chain. There is no step in evolution that violates the 2LOT, which is why creationists cannot point to one. And if no single step in the process violates this law, then the process as a whole does not, either.

When confronted with this argument, creationists will usually speak vaguely about“the law of conservation of information” or “energy conversion mechanisms”, or say that only intelligence can “overcome” the 2LOT to produce an increase in order. These arguments are pure fabrication. No such concepts exist in the scientific formulation of the 2LOT or in the field of thermodynamics in general. Theequations of the 2LOT are called path independent, meaning that it is irrelevant for their purposes how an energy conversion is brought about. Intelligence has no privileged position in the equations; a human producing an ordered system no

more “overcomes” the 2LOT than a human who throws a ball up into the air overcomes the law of gravity. Nor do the equations of thermodynamics mention “information”, a term which creationists deliberately leave ill-defined and vague so that they can employ it in a manner convenient to them. Before such arguments can be entertained, creationists must first define exactly what “information” means in this context and provide a precise way to measure it.

There is one final point to consider: If the creationists’ arguments were correct and the 2LOT did indeed forbid evolution, then there should be a massive conflict between biologists and physicists. There is none. Even someone who has no understanding of entropy or thermodynamics can appreciate this point. If the clash were as obvious as it is made out to be, then every physicist in the world should be an anti-evolutionist, aware that the theory is a gross violation of one of their most basic laws. But since the community with the most comprehensive understanding of thermodynamics seems to see no conflict between it and evolution, the obvious conclusion is that the creationists have invented a problem where none exists.

Read more: http://www.patheos.com/blogs/daylightatheism/essays/the-second-law-of-thermodynamics-enough-already/#ixzz33i3eWKLA

Ok, I have warned you. Brace yourself. I am going to argue against what many believe to be the most fundamental law of physics. A sacrosanct law. A law that you experience everyday and that is so obviously true that no one should meddle with it. You all know this law. It's the law referred to as 'the second'. The second law of thermodynamics.

Ok, don't blow it hammock guy. You can argue against every concept in physics, but don't touch the second law of thermodynamics! You don't want to place yourself in this group, do you?

Has anyone ever dared to attack the second law of thermodynamics? I am not aware of even a single attempt. Eddington's famous remark on the second law of thermodynamics says it all. This law occupies a special position in physics and rules supreme. Beware the person who dares to meddle with it:

It was Rudolf Clausius, the inventor of the term 'entropy', who already told us that the entropy of the universe* can go only one direction: it can only increase. And once Ludwig Boltzmann and Claude Shannon were done, we became familiar with the true meaning of the term entropy, and it all started to make sense. Entropy simply is the information content of a physical system, the number of digits needed to fully describe the system down to its smallest details. So the second law tells us that the number of digits needed to describe the universe keeps increasing. Seems fair enough, right? The whole universe expands, so probably itsinformation content increases as well.

One-way UniverseWait a second. Take Newton's laws, or any other fundamental law of physics. All

these laws are reversible. They describe a two-way universe. Look at two elastically colliding billiard balls. Now consider the same collision reversed in time.This reverse collision is as valid as the collision going forward in time. Our laws of physics describe a two-way universe. A universe without an 'arrow of time'. This holds for all fundamental dynamical laws, including the las that describe the dynamics of atomic and subatomic particles.

Yet, our human experience that focuses on scales much larger than microscopic scales is vastly different. We seem to live in a one-way universe. Glass can brake, but it can't unbreak. You can turn a piece of wood into ashes, but no one has managed to reverse that process. We grow older, never younger. We all can remember the past but not the future.

What is the origin of this arrow of time? Why does time present itself as a one-wayroad?

Feynman contemplated these issues, and considered them of enough relevance tobring to the attention of undergraduate students at Caltech. In his 'Feynman Lectures on Physics' he points towards the big bang as the cause of the one-way-ness:

Many years later another Caltech physicist and science communicator, Sean Carroll, continues to study the puzzle of entropy increase breaking the two-way nature of our universe:

So the current consensus is that entropy increases simply because there are manymore configurations that require a large number of digits to describe them, then that there are configurations described by fewer digits. We all now that with four digits you can describe a total of 10,000 configurations, with two digits only 100. So statistically, a physical system will be likely to end up in configurations described by more digits. But as Sean Carroll stresses, that still leaves the question why the universe started in such a particular low entropy configuration described by very few digits.

Since his 1989 book 'The Emperor's New Mind', Roger Penrose has been drawing the attention of the wider public to the remarkable low entropy of the big bang. In his magnum opus 'The Road to Reality' he revisits the issue, and finally in his latest book 'Cycles of Time' he presents a whole new cosmology aimed at explaining the low entropy beginning of our universe.

In my last blog post I discussed 'Cycles of Time' and made the statement that the big bang must have had a low entropy, but that very fact should not surprise us. The best way to explain this is by studying a simple toy model.

Fibonacci UniverseImagine a universe much simpler than ours. A universe in which time progresses in discrete steps. At each tick this universe jumps into a newspatial configuration. The physicists living in this universe have managed to describe these configurations, down to their most minute details, in terms of simple numbers. They discover that at a certain step theiruniverse is in a configuration that can be described by the number 4,298,034,510. One tick later the universe is in configuration 6,954,365,922. Then in 11,252,400,432, and next in 18,206,766,354. Scientists study these numbers and try to find a pattern. "If we find the mathematical law that generates these numbers,we will have a theory of everything" they exclaim. "We will know the mind ofGod!"

They readily observe that all numbers are even, and coin this 'the first law'. They also recon that the numbers keep growing, this provides them with their 'second law'. Next they discover how to quantify this growth: each next number appears to be about 1.618034 times the previous number.

Based on experiments in their particle accelerators the scientists start contemplating how the Second Law of configuration number growth would apply to an anti-universe obtained by replacing all particles by anti-particles. It is not before long that theorists come up with a growth rule for anti-universes: each nextconfiguration number in an anti-universe will be -1.618034 times the previous number. The negative sign causes negative configuration numbers to appear, but the second law will still hold as the configuration numbers would not just oscillate but also grow in size. There is a lot of discussion about the meaning of the minus sign in the growth number. However, this discussion subsides when the scientists start realizing that growth laws can only be an approximation to a deeper truth. Simple reason being that a repetitive multiplication by a non-integer number can'tproduce pure integers. Many scientists frantically try to find out how exactly each integer determines the next. No one succeeds.

Then a young scientist starts toying with the idea that a law that determines the next configuration based solely on the previous one might not exist. Could it be that two or more subsequent configurations are needed to determine the next? He immediately stumbles upon an amazingly simple pattern in which each number is nothing more the sum of the previous two numbers.

This hits the scientific community like a bomb shell.The scientist now realize they were pursuing the wrong approach by assuming the state of the universe requiresonly one configuration number. So they start considering pairs of subsequent configuration numbers as describing the universe:

It is as if the number of dimensions of the universe they live in have doubled overnight! For reasons no one remembers, the scientist start referring to the space of configurations described by pairs of numbers as the phase space. This todistinguish it from the configuration space that carries only a single number.They next discover that the anti-universe to their own universe is obtained simply by changing the sign of one of the numbers in the phase-space pair. So

would describe the anti-universe of

and vice versa. By applying the 'add-the-last-two' rule to the numbers appearing in subsequent pairs, they can reproduce the observed evolution in terms of the configuration pairs:

and they can do the same for the anti-universe:

A new riddle has appeared. Why do a universe and its anti-partner evolve differently? This can't be right as universes and their anti-universes are related by a simple sign change in the configuration pairs.

It doesn't take long before a bright mind realizes a universe and its anti universe both evolve according to the 'add-the-last-two' rule, but they do so in opposite directions in time.

This means that by knowing a configuration pair, it is not only possible to computeforward in time, but also to trace back the history of their universe. And the amazing thing is: this can be done by using the very same 'add-the-last-two' rule, provided one changes the configurational pair into the corresponding anti-pair andreverses the order of the two numbers in the pair (an operation referred to as timereversal):

Now all pieces of the puzzle have fallen in place. By transforming universes in their anti universes and back again, the scientists can compute the phase-space state of the universe forward and backward in time. They can now answer the mother of all questions "how did it all start?". So they begin computing back in time. Starting from the pair

they reach lower and lower numbers:

No small task given the rudimentary computational resources in their rather limited universe. But they keep calculating and reach still lower numbers:

The computations continue further. And further. The numbers reduce in size to 3-digit and then 2-digit numbers. Then something remarkable happens, the numbers start growing in size:

Did they make an error? They check their calculations, and check them again. Everything seems right. What is happening here? Have they stumbled upon an

exception to the second law? If the numbers grow in size when going backwards in time, they shrink going forward in time. But the second law forbids this. And this law rules supreme. Or does it?

Big BouncePick a cellular automata rule, take the Hotel Boltzmann dynamics, use Langton's ant, or construct a much more complicated dynamics based on Loop Quantum Gravity. It doesn't matter which model of the universe you create. As long as you create a model that is reversible and that grows without bounds, the very same behavior is observed: a bounce. The bit size of your reversible model universe willgo through a contracting phase followed by an expansion phase.

The conclusion seems inevitable: if the second law of thermodynamics doesn't hold true for any of these simple model systems, it is probably neither true for ourown universe. One could argue that all of this just means the second law of thermodynamics holds true only at one side of the bounce. That would be compatible with the observed entropy increase following the big bounce that we refer to as the big bang.

This is a too restrictive view. It is much more insightful to start from a timeless description and to view an unbound reversible dynamics as a chain of states that never retraces its steps and that therefore has no beginning and no end. In terms of the length of the description of the states (the entropies of the states), such a chain can not be monotonic. The entropy of the states has to feature a bounce. This is inevitable, simply because the length of the descriptions can't drop below zero. With a bounce, the direction of entropy increase at either side of the bounce is pointed away from the bounce. And as low entropy states can not carry the memory of high entropy states, a temporal direction with an unknown future results.**

Where does this leave us with the Second Law? Clearly when expressed a-la Clausius "The entropy of the universe can only increase" does not hold true. However, we can redefine the Second Law such that it does cover the observed bounce behavior:

"The entropy of the universe is a convex function of time."

With S(X) denoting the entropy of the universe in state X, Clausius formulaition of the second law reads:

if B comes after A

The above findings suggest a replacement of the form:

for any states A and B

Is this the correct formulation of the second law? I don't know. But I do know that when considering model systems, this convexity formulation makes more sense than the standard formulation. Also this new formulation, in contrast to Clausius' formulation, makes no use of an ordering of events, and fits naturally with reversible laws of physics.

An important corollary of a convex function or bounce-description of the second law is that one should not wonder about the smallness of the entropy of our universe about 13.7 billion years ago. If the universe does not retrace its steps, it has to have a minimum entropy at some point. That point we refer to as the big bang, but that should be more appropriately be referred to as the big bounce.

Assuming that the big bang represents a temporal singularity that marks the startof time is an unnecessary assumption. An assumption that gets you in all kind of trouble and forces the question why the starting point was so special and had such a low entropy.

A big bounce seems to me a cleaner description that more easily survives Occam's razor than a big bang singularity. Let's remind ourselves of the fact that there is no single piece of evidence that would make us believe that our universe is in any way bounded, either in spatial extend or in time. For all we know, the universe will keep expanding indefinitely in all directions. Similarly, the universe can extend in both time directions without limit. There is no reason to believe thatour universe won't reach everywhere and everywhen.

Only when we know the ultimate theory, will we know for sure the character of thestate referred to as the big bang. In the meantime, you have to make a choice in what answer you are going to give to the question "what was there before the big

bang?". Will your answer be the traditional

A) "This is a nonsense question, you might as well have asked what is south of theSouth Pole!".

Or will it rather be a bounce-inspired

B) "An universe that is a mirror universe to our own, consisting of anti-particles moving back in time and mirrored in space."