Entropy

[peter]

Dr Jim Al-Khalili presented a program on BBC Four the other night entitled 'Order and Disorder', in which he examined the central role of entropy in the Universe. He went to great lengths to explain that entropy was in fact a measure of the state of disorder of a system (the Universe or whatever) and then in an attempt to explain why the entropy of the Universe always increases said that the reason was that there were an infinitely greater number of ways a system could be disordered rather than ordered and for this reason "if left to its own devices energy will always tend to move from a state of order toward one of disorder".

Ok ....... but why? Dr Khalil's explanation certainly tells us what is happening - but he skipped the bit where he tells us why it is that energy will always tend toward increasing disorder. Is there like a 'potential difference' gradient for entropy that makes it in the main always flow in one direction? And can someone explain to me what exactly this Universe in its early stages of low entropy (is high order) was like? Were all the atoms stacked in neat rows like colouring pencils in an art shop's display cabinets? Where exactly was the order that surpassed that we see on our Earth today: surely we inhabit a regional patch of order greater than anything we can point to in the known universe, extant or in the past?

[peter]

Thoughts on the above: we are the by products of the cascade of energy from order to disorder. But is there not a further paradox here: does not disorder, when taken to it's absolute extreme ultimately return to order. When every snowflake becomes equally different from every other will they then not all be the same?

[Mighara Sovmadhi]

There is a theory of entropy according to which increases in quantum entanglement correspond to the diffusion of energy, like as more and more particles, over time, become entangled, their probability radius increases, until eventually, in principle, it would be distributed evenly across all spaces into which the entangled particles could move---and this, from our macro viewpoint, looks like entropy.

[peter]

[Boy, am I in deep waters here, but I'll continue anyway at the possible expense of making myself look foolish - not a consideration that normally causes me any problem! ]

The second program in the series did seem to offer some answer as to why order always moves toward disorder rather than in the opposite direction - and that has to do with the difficult notion of information. Information it appears is as an inherent property of the Universe as energy. Any physical body that can exist in a binary state holds information - at least one bit - and information, like energy, can be converted from one form to another. This information is what is apparently used to create the localised order we experience from the one way cascade of entropy, but there is a price to pay. Any system has only so much 'memory' in terms of the amount of information it can store before it must begin to delete - and odd as it may seem it is apparently this deletion process, which is a fundamental of all physical system and is in itself an energy consuming process, which drives entropy to proceed in only one direction. The minimum amount of energy needed to erase one bit of information even has a name - the Landower Limit. In order to understand what is going on we have to ditch our idea of information being merely descriptive of the Universe, of reality, and start seeing it as inseparable from it - an inherent property of matter that can be tapped into in the same way that energy can, and as tightly bound to entropy as matter is to energy or space to time. We, it appears, do not create information but rather draw it from the Universe as water from an infinite well.

[wayfriend]

but he skipped the bit where he tells us why it is that energy will always tend toward increasing disorder.

Destruction vs Creation. It's easier to destroy than to create. Destruction releases energy, creation binds energy. Two asteroids collide, boom, that's disorder. Particles decay, that's disorder. So easy. What creates order? Gravity, occassionally. Life, usually. Both require gathering and binding energy. That's hard.

Energy is unevenly distributed in the universe. It's bound up in structures. It seeks to be evenly distributed. So structures decay. That's entropy. (Similar to Mighara's point, I think.)

[Vraith]

What creates order?[[[[snip]]]]. Life, usually.

Hmmm.

David Kaplan explains how the law of increasing entropy could drive random bits of matter into the stable, orderly structures of life.

https://www.quantamagazine.org/20160630 ... andomness/

[Cord Hurn]

Hey, stuff falls apart. I can't let it upset me too much.

[Avatar]

Yes, sorta like a diffusion gradient, where it moves from areas of high concentration to ones of low concentration.

Eventually all energy will be distributed evenly across space and everything will stop.

--A

[peter]

Nah - we'll stop it happening: it's what we do. We see a problem - and we fix it.

[Skyweir]

At the heart of England's idea is the second law of thermodynamics, also known as the law of increasing entropy or the "arrow of time." Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble; in short, energy tends to disperse or spread out as time progresses. Entropy is a measure of this tendency, quantifying how dispersed the energy is among the particles in a system, and how diffuse those particles are throughout space. It increases as a simple matter of probability: There are more ways for energy to be spread out than for it to be concentrated. Thus, as particles in a system move around and interact, they will, through sheer chance, tend to adopt configurations in which the energy is spread out. Eventually, the system arrives at a state of maximum entropy called "thermodynamic equilibrium," in which energy is uniformly distributed. A cup of coffee and the room it sits in become the same temperature, for example. As long as the cup and the room are left alone, this process is irreversible. The coffee never spontaneously heats up again because the odds are overwhelmingly stacked against so much of the room's energy randomly concentrating in its atoms.

Although entropy must increase over time in an isolated or "closed" system, an "open" system can keep its entropy low - that is, divide energy unevenly among its atoms - by greatly increasing the entropy of its surroundings. In his influential 1944 monograph "What Is Life?" the eminent quantum physicist Erwin Schrodinger argued that this is what living things must do. A plant, for example, absorbs extremely energetic sunlight, uses it to build sugars, and ejects infrared light, a much less concentrated form of energy. The overall entropy of the universe increases during photosynthesis as the sunlight dissipates, even as the plant prevents itself from decaying by maintaining an orderly internal structure.

Life does not violate the second law of thermodynamics, but until recently, physicists were unable to use thermodynamics to explain why it should arise in the first place. In Schrodinger's day, they could solve the equations of thermodynamics only for closed systems in equilibrium. In the 1960s, the Belgian physicist Ilya Prigogine made progress on predicting the behavior of open systems weakly driven by external energy sources (for which he won the 1977 Nobel Prize in chemistry). But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted.

David Kaplan explains how the law of increasing entropy could drive random bits of matter into the stable, orderly structures of life.

Besides self-replication, greater structural organization is another means by which strongly driven systems ramp up their ability to dissipate energy. A plant, for example, is much better at capturing and routing solar energy through itself than an unstructured heap of carbon atoms. Thus, England argues that under certain conditions, matter will spontaneously self-organize. This tendency could account for the internal order of living things and of many inanimate structures as well. "Snowflakes, sand dunes and turbulent vortices all have in common that they are strikingly patterned structures that emerge in many-particle systems driven by some dissipative process," he said. Condensation, wind and viscous drag are the relevant processes in these particular cases.

Very interesting .. so a theory where not all things dissipate and devolve. Very interesting

[peter]

It strikes me - that all examples of the second Law, of entropy increasing, are always formed in terms of energy of motion - and specifically in terms of the molecular/atomic motion that we describe as 'heat'. But there are of course other forms of energy - the positional energy of 'potential' energy, the chemical energy stored in atomic bonds, the very energy held in the form of matter, light, electrical, nuclear ... all interchangeable and all around all of the time.

So what form will this 'even distribution of energy' take in this final grey cold universe that the 2nd Law tends toward; will there be no matter, will all of the energy be radiant, running around as it were, all dressed up with nowhere to go. What will it be like? I'm struggling here because it seems to me that if one atom is left then there's a shit-load of energy tied up that is not evenly distributed - and the 2nd Law has failed?

[Skyweir]

But Pete if England is right under certain conditions matter self organises .. so if this is proven to be accurate.. meaning that therell be a party and everyones invited.

I thought it was interesting that he referred to snow, sand and turbulent vortices in example of possessing structural patterns.

So if hes right it challenges the typical criticism intelligent design proponents raise to poo poo evolution ... and use to support their creationist model... you know evolution is in effect devolution.

This guy is suggesting the opposite .. kinda evolution is organisation. If Ive correctly interpreted this lol ..

NOT A DOCTOR

[Vraith]

This won't solve the issue. It just shifts to a different [and maybe more tractable] kind of issue, but:

Could it be that Entropy and Disorder are NOT synonyms?
Yes.
It is sometimes conceptually convenient to consider them similar, or even identical.
But sometimes doing so creates paradoxes or barriers of misinformation.

[Fist and Faith]

I've always thought the most ordered state possible is complete entropy. That would mean everything is spread out in a perfect matrix. How is that not ordered? Clumps of different shapes and sizes here and there, gaps of different sizes and shapes separating them... That's a mess.

[Zarathustra]

There are several concepts being mixed about here. There is not just a question of order vs disorder, but also complexity. The concepts are defined mathematically, and I'm not a mathematician. But something that can be written as a simple formula, say a number consisting of a string of 2s repeating indefinitely, we could describe this very simply with a few symbols. It has order, but very low complexity. It's not random, but it's not complex.

All the really interesting things about life come from building up complexity, not merely triumphing over disorder.

[Skyweir]

Great post Z .. very apt.

I get that if you dont have a good grasp of the scientific elements it is probably easy to oversimplify the issues.

It really is all quite fascinating.. I look forward to reading and learning more from each of you on these issues.

Isnt patterned matter more complex than just matter? If matter not only self replicates but self organises are t those processes achieving higher levels of complexity? These may seem stupid questions and if so just disregard ..

[peter]

Isn't there something to do with degrees of freedom in entropy: sand in a pile has way more degrees of freedom than sand in a sand castle - and so the latter tends toward the former.....or something?

[Skyweir]

LOL .. Its obvious who the odd ones are in this group are isnt it ... ... hahaha


Spot the ones that are different to all the others

Sorry Pete .. youre probably in a whole different league than moi

[peter]

A league of one I suspect Sky!

[Vraith]

Isn't there something to do with degrees of freedom in entropy:

Yea. Degrees of freedom is much more accurate and useful than disorder.
I was just reading an article that was talking about the collapse of sandpiles [among other things]...thought it was at Quanta, but didn't see it...it was semi-relevant, and coincidental, but I've lost it now...