Evolution and 2nd law of thermodynamics

(Tooba Waheed) #1

Hi, i just read your blog post
in which you say 2nd law of thermodynamics does not affect life because we are considering life on earth and earth is an open system…hence it is possible ffor complex molecules to from from simpler ones on earth…
"With biological evolution however, the system being considered is not the universe, but the Earth. And the Earth is not an isolated system. This means that an increase in order can occur on Earth as long as there is an energy input — most notably the light of the sun. Therefore, energy input from the sun could give rise to the increase in order on Earth including complex molecules and organisms. "

So basically you are saying 2nd law of thermodynamics does not apply to the earth??? being an open system and all??? I mean, its not just life that is recieving that solar energy, everything else is as well, including the carcass of a living being??? Please do answer i could not find a comment section over there so i posted a link…

The Second Law (and Discovery Institute) Defeat Evolution Once Again
Evolution and the Second Law of Thermodynamics
(Ralph Dave Westfall) #2

It is often argued that the Second Law of Thermodynamics does not represent a valid argument against evolution. However I think such claims might not be valid because they ignore the following considerations from a research paper I found online:

[A] Adding energy to a system can overcome the Second Law’s “spontaneous tendency” and lead to increasing structure. However, the way in which energy is added is critical. Gasoline in the engines of construction equipment can construct a building out of raw steel and concrete, while the same gasoline in a bomb can reduce a building to a mass of raw steel and concrete.

[B] In the context of biomechanical systems, Kugler and Turvey [7] suggest that self-organization can be reconciled with second-law tendencies if a system includes multiple coupled levels of dynamic activity. Purposeful, self-organizing behavior occurs at the macro level. By itself, such behavior would be contrary to the second law. However, the system includes a micro level whose dynamics generate increasing disorder. Thus the system as a whole is increasingly disordered over time. Crucially, the behavior of elements at the macro level is coupled to the micro level dynamics.

Entropy and Self-Organization in Multi-Agent Systems
H. Van Dyke Parunak and Sven Brueckner
Proceedings of the International Conference on Autonomous Agents (Agents 2001), 124-130

My thoughts and questions:
The first paragraph above [A] shows that entropy can be decreased in an open system if there is a mechanism in place to import and harness external energy (gasoline in this case). In the absence of such a mechanism(s), the added energy will increase the entropy of the whole system. However the existence of such mechanisms is in itself problematic. Wouldn’t they require either: 1-an infinite regress of such mechanisms? Or 2-a self-organism of such an initial mechanism to a degree that can not be demonstrated by non-living results in nature or through experimental simulations?

The second paragraph suggests that organization could increase (an entropy decrease) within a part of a closed system without violating the Second Law of Thermodynamics, if the entropy increase in the remainder was large enough to produce a net increase. However wouldn’t the self-organization of a non-trivial system that could produce that require a mechanism which would also be subject to the caveats above?

The preceding is well “above my pay grade” so I’d welcome feedback from those who know a lot more about the issues in physics and biology.

(Jan De Boer) #3

Hello Toba and Ralph

Reading your discussion on the 2nd law of thermodynamics I would like to give you some background on thermodynamics.
As subject I choose water/steam in a very simplified power plant. First you bring the water under high pressure with a pump. Then you insert heat into the water. It does not matter whether you use a nuclear reactor or burners using fossil fuel, and you get steam which has a high pressure and a high temperature. You feed that steam into a turbine where the heat is converted into mechanical energy and the steam goes to a condenser where it is restored into water. The water goes back to the pump for the next cycle. In this process you have to do with
pressure, with enthalpy, with temperature and with entropy.
Pressure is force against a surface. Easy to understand and measured with instruments
called manometers.
Enthalpy is the quantity of heat stored in the water/steam. You calculate the quantity if you design the process but you do not measure it.
Temperature is a very interesting property. Everyone knows what temperature is. Really? Are you sure that you know what temperature is? Well then please explain it to me in simple words. You will find that you are unable to explain temperature. And you measure the temperature with a thermometer isn’t it? No that is not true. A thermometer does not measure the temperature but the expansion of material due to temperature increase. And as far as I know there is no way to measure a temperature directly.
Last but not least we come to entropy. Entropy is not a real property of a material but an invented, artificial, mathematical property that cannot be measured at all. But it makes life very easy if you have to design and calculated a thermodynamic process.
Then it can be calculated, that is with limitations. You can determine the value of the entropy, if you know the pressure, and the temperature, and the state, steam or water. It is impossible to
determine the entropy of a water/steam mixture.
If you really want to understand entropy, you have to do a course in thermodynamics, which requires that you are a beta person and as fluent in the mathematics of differentiation and integration as in your native language, and that you do a few hundred mathematical exercises on thermodynamics. And then suddenly the coin drops and you know what is all about.
And you also suddenly know that anything said about entropy without the proper mathematical backup is pure nonsense.
The Dutch expression for the abstract philosophical musings of alpha people about the increase of entropy is “borrel prietpraat”, which my translator converts into “drink twaddle”. Another expression is “they heard the clock ring but do not know where clapper hangs”.
Defenitely no offense intended, I just try to emphasize that their words make no sense to me.

(Tooba Waheed) #4

Thank you for that concept,i really am not from a physics bafkground atall… i dont know much abt entropy and laws of thermodynamics… if you had asked me to define temeperature, i would have said measure of degree of hotness or coldness, but that would be a simplistic definition, just like in biology we define species as a group of organsisms organsisms ahle to interbreed and produce fertile offsprings, but we know this definition has so many problems… i m asking from a completely lay man point of view, you seem to know quiet a bit about thermodynamics, please give me answers to my questions in simple terms, to apersonwith no knowledge of thermodynamics, does 2nd law apply to living beings at all??? in any form or any organismal level??? And how rrue is the claim that 2nd law can not be applied to open systems??? Does open system rule also not apply to a building, which recieves sunlight almost half the time of its existance and gives back radiation, and a carrot decaying, with its roots and leaves on, and a river and sea… please in simple lay man terms, because the article that claimed this was also written without any maths, a simple statement that open systems are exempt, hense living beings are exempt, now i m simply asking other examples of open systems that are very actively cited in every article i read abt 2nd law… are they for explaining purpose only then???


The 2nd law of thermodynamics can only be applied to close systems. (A system in which energy cannot escape or enter)

A person walking around does not need to obey the 2nd law, a rotting corpse does not need to obey the 2nd law, Living things which obtain their energy from outside sources do not need to obey the 2nd law, a building sitting in the sun does not need to obey the 2nd law.

(Tooba Waheed) #6

Thankyou… is it a consensus among all biophysicists then??? I mean the research cites by RalphDavewestfall in his point B above, even in that way 2nd law thermodynamics can not be applied to living beings??? Also is it safe to then say that these examples of a rotting building or decaying food given to explain 2nd law are only for explaining purposes… ?


The second law of thermodynamics is just a consequence of the statistical fact that there are more possible ways for a system to be in a state of disorder than there are possible ways for a system to be in a state of order.

Imagine you have a jar of red and green marbles which are the same size and weight? Initially they are separated into two distinct layers: red marbles filling the bottom half of the jar and green marbles on top of them. After shaking the jar, the two layers begin to mix up (we say that entropy of the system is increasing). If you keep shaking the jar, how likely is it that it will return to the state that it once occupied? If you said: Incredibly unlikely, you would be correct. Now think about why that is: Why is it so easy to mix things up but much harder to get things back into a state of order?

The answer simply has to do with statistics: There are more possible ways for the jar of marbles to be disordered than there are possible ways for the jar to be neatly separated out into two layers. As you jumble the jar you are effectively switching the jar between different possible states. Because there are many billions more ways for the jar to be jumbled, the chance of you accidentally stumbling upon an ordered state is almost 0.

Now it is very easy to show that a system that isn’t closed can undergo a decrease of entropy. Imagine I told you that you were allowed to stick your hand in the jar and separate the marbles out manually. By increasing entropy in other ways (in your muscles), you can decrease entropy in the jar.

So to answer your question: Anybody that understands the concept of entropy and the second law will understand that it only applies to closed systems since it is very easy to demonstrate decreasing entropy by allowing outside influences to affect the system.

So yes there is a consensus amongst people who understand what entropy is.

(Jan De Boer) #8

Hi Tooba
How would you explain
colors to a blind person?
SF-writer Robert Heinlein
wrote somewhere in his book “Time enough for Love” that “If you
can’t express it in mathematics, it ain’t science”.

I believe that this is
true for thermodynamics.

The 2nd law applies to any
thermodynamical process, but if you want to draw conclusions, you
have to express that process in mathematics, solve the equation and
you have your conclusion.
The physical processes of
living beings are chemical processes, not thermodynamical processes.
Our muscles convert chemical energy to mechanical energy. So the 2nd
law does not apply because it only applies to thermodynamic
processes, not chemical processes…
Open systems may have
thermodynamical processes. And these processes are subjected to the
2nd law, but 2nd law does not apply to the whole open system, only to
the thermodynamical parts. Aside from that, you can not apply
mathematics on an open system, you have to draw a box around the part
you want to study, decide what goes out and what goes in the box,
express that in mathematics, solve the equation and then you can
start thinking about conclusions.
It is a very sad thing,
but many of the so-called experts really don’t know what they are
talking about.

cited some statements that are all wrong.
Ad [A] constructing
a building is not a thermodynamic process.
Ad [B] I consider
this a perfect example of abstract philosophical musings of alpha
Ad his thoughts and
questions: none of the processes are thermodynamic, so the 2nd does
not apply.

(system) #9

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