How can life exist in an increasingly entropic universe?

[megacal]

TL;DR

How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Not sure to ask here or in Physics/Cosmology.
How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

 

[256bits]

Summary: How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Not sure to ask here or in Physics/Cosmology.
How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Are you making a only a global statement?

I can cool down water to form ice.
The entropy of the ice has decreased.

 

[Hornbein]

Summary: How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Not sure to ask here or in Physics/Cosmology.
How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

The idea is that the process which is evolution of life give off heat. So while a living form has less entropy than a random assortment of stuff, as a consequence of creating that living thing the system as a whole (the surface of the Earth, or if you like the Universe) has more entropy than it did before. Not only that, living things give off heat and so forth so they act to increase the entropy of the system pretty much continuously. If a book is written or a dam built the idea is that heat is given off during the process which results in more entropy in the system as a whole.

In short, the second law has nothing to say about open systems. Completely closed systems only. Local decreases in entropy happen all the time.

 

[malawi_glenn]

Let me quote my university teacher I had on introductory thermodynamics
"The Earth is not a F***ing thermos"

which means that the Earth is not an isolated system.

 

[Ibix]

according to the 2nd Law of Thermodynamics entropy always increases with time?

This is a sadly common but incorrect statement of the second law. The second law says that the entropy of a closed system (or an isolated system, as drmalawi puts it) always increases. The Earth is not a closed system, because the Sun pours huge amounts of energy into it every second, so the second law does not apply in such a naive way.

The Sun plus its emitted light plus the Earth can be thought of as a closed system (the energy input from distant stars is negligible) and you can apply the second law to that. The enormous entropy increase of the Sun fusing and radiating utterly dwarfs the decrease in entropy associated with evolution, so the entropy of the system increases.

 

[pinball1970]

Summary: How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Not sure to ask here or in Physics/Cosmology.
How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

@jim mcnamara has posted extensively on Abiogenesis.

Shorter version is that Earth had some basic building blocks for organic reactions to occur. Tonnes of material from space hit the Earth all year round. 1000s of organics have been isolated from meteorites (Google Murchison)
A nice medium for chemical reactions to occur, liquid water.
An energy source, the sun, electrical activity (Urey Miller) in the atmosphere or from deep sea vents (Google JPL Caltech, Russell)
Then you need some time.
I am never quite sure where the entropy thing comes into it. As long as the system is being fed with energy and available substrate I don't see why key reactions are not able to occur.
Maintaining gradients is one issue and the deep sea vents work looks at that.
Jim will have some good links.

 

[megacal]

The idea is that the process which is evolution of life give off heat. So while a living form has less entropy than a random assortment of stuff, as a consequence of creating that living thing the system as a whole (the surface of the Earth, or if you like the Universe) has more entropy than it did before. Not only that, living things give off heat and so forth so they act to increase the entropy of the system pretty much continuously. If a book is written or a dam built the idea is that heat is given off during the process which results in more entropy in the system as a whole.

In short, the second law has nothing to say about open systems. Completely closed systems only. Local decreases in entropy happen all the time.

OK...closed vs open. Got it.
Thanks!

 

[jim mcnamara]

@Ibix, @drmalawi gave good answers. The sun warms the earth, so that means the Earth is not a closed or "standalone" system. Not much more to say...

I like the thermos analogy, could have used it when I taught freshman biology.

 

[Demystifier]

Life is an organized disorder. Order decreases (that is, entropy grows), but organization (that is, complexity) increases. See the appendix in https://arxiv.org/abs/1703.08341
or just look at the picture

 

[malawi_glenn]

Life is an organized disorder. Order decreases (that is, entropy grows), but organization (that is, complexity) increases. See the appendix in https://arxiv.org/abs/1703.08341
or just look at the picture
View attachment 303888

You are supposed to drink beer, not look at it

 

[Demystifier]

You are supposed to drink beer, not look at it

This attitude explains why people don't understand how is life compatible with the 2nd law.

 

[BillTre]

I think the main reason for this continuing misunderstanding is that most people think of living things as separate items that seem like they should have an explanation of their own. This places them apart from their environment and leads to misunderstanding as they are considered independently from their environment.

just look at the picture

I think more of life as a complex organization that (once initiated) is propagated into the future.
The complexity of the coffee and cream mixing is just a case of entropy making a more disorganized mess of things over time. There is no hidden organization there. Life (when functioning) does the opposite. When considered separate from its environment, from which it harvests energy, negentropy, and resources, it appears as an affront to the second law.

A picture showing life's organizational "powers" might have the coffee/cream mix combined with some bacteria. After a few daysyou would have a bacterial culture, which might or might not look homogeneous, but would be full of highly structured little bacterial cells making more highly structured bacterial cells at the expense of its environment's increasing disorder.

You are supposed to drink beer, not look at it

My contrary anti-joke view:
A beer on the other hand, might start out looking homogeneous, but soon develop a head of foam as the excess gas comes out of solution. This might look more organized (due to the separation of the gas in the foam from the rest of the beer), but it would be approaching an equilibrium of the larger (or enveloping) system.
The beer may be gaining heat from its environment (if it started cold), which would further drive gas out of the solution (less soluble at higher temperatures).

 

[Jarvis323]

The idea is that the process which is evolution of life give off heat. So while a living form has less entropy than a random assortment of stuff, as a consequence of creating that living thing the system as a whole (the surface of the Earth, or if you like the Universe) has more entropy than it did before. Not only that, living things give off heat and so forth so they act to increase the entropy of the system pretty much continuously. If a book is written or a dam built the idea is that heat is given off during the process which results in more entropy in the system as a whole.

In short, the second law has nothing to say about open systems. Completely closed systems only. Local decreases in entropy happen all the time.

The second paragraph is right, but the first one is wrong isn't it?

 

[BillTre]

The second paragraph is right, but the first one is wrong isn't it?

How is the first paragraph wrong?

 

[Jarvis323]

How is the first paragraph one wrong?

Most of the heat given off by life on Earth is coming from the release of stored chemical and mechanical potential energy that originated from the Sun or from the heat of the Earth (with the exception of some life forms getting energy solely off potential energy in minerals). Doesn't the stored energy represent a reduction in entropy and the conversion of some or all of that energy into heat just add some or all of the entropy back into the system?

Edit: I may have misread the first paragraph.

 

[Lord Jestocost]

Summary: How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Not sure to ask here or in Physics/Cosmology.
How could life have begun much less evolve (or even planets form) if according to the 2nd Law of Thermodynamics entropy always increases with time?

Alex Kleidon and Ralph Lorenz in “Non-equilibrium Thermodynamics and the Production of Entropy Life, Earth, and Beyond” (Editors: A. Kleidon and R.D. Lorenz):

“The formulations from classical thermodynamics can be applied to non-equilibrium systems which are not isolated (e.g., Prigogine 1962). By exchanging energy of different entropy (or mass) across the system boundary, these systems maintain states that do not represent thermodynamic equilibrium. For these systems, the second law then takes the form of a continuity equation, in which the overall change of entropy of the system $dS/dt$ is determined from the local increase in entropy within the system $dS_I/dt$ and the entropy flux convergence $dS_E/dt$ (i.e., the net flux of entropy across the system boundary):

$dS/dt=dS_I/dt+dS_E/dt$ (1.1)

In steady State, with no change of the internal entropy $S$ of the system, the production of entropy within the system $\sigma$ that leads to the increase $dS_I/dt$ balances the net flux of entropy across the system boundary $dS_E/dt$. The second law in this form then states that $\sigma \geq 0$. A non-equilibrium system can maintain a state of low entropy by "discarding" high entropy fluxes out of the system.”