In The Beginning There Was Metabolism, And Metabolism Said Let There Be Life

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You know, there was a person who found very convincing evidence of bacterial forms in meteorites. Let me see if I can find it...[searching]...

Couldn't find the one that I had read, but here is a different one:
Martins, Zita, et al. "Extraterrestrial nucleobases in the Murchison meteorite." Earth and planetary science Letters 270.1 (2008): 130-136.

So this seems like a common finding now.

Some biochemists try to explain life formation from a "primordial soup," but it actually looks like they no longer have to. However, someone now needs to explain how these were formed on other planets (impossible).

What is interesting about the extraterrestrial DNA bases is that they have a different carbon isotope ratio. These things are like 30% carbon-13. This is unusual, as the prevalence on earth is about 1%. But I am open to the possibility that the impact had something to do with this.

This meteorite impacted in 1969.

I know who you mean. and yes that's who I was referring to.

btw there's proof that the asteroid belt that these meteors come from originated from a previous planet in the solar system that was destroyed.

So that planet would be where the bacteria originated.
 

JKerx

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@Quequeg and @tara, I really do not think there is much of a difference at all "between saying that the laws of physics created the Universe from nothing and saying that the laws of physics organized the existing matter and energy into the Universe we know today". If we acknowledge that the laws of physics are indeed contingent upon there being a nature from which they gain being, then it really isn't possible to call them the necessary cause of life. Unlike a simple math equation like 2 and 2 making four, which is impossible to imagine otherwise and is logically necessary, we can imagine there being other laws of physics in the universe than the ones in which we are bound--we could imagine trees that literally pour out root beer upwards and against gravity naturally, for instance. Nature, and the laws and life that dwell therein, could have been otherwise, and nature is in that sense arbitrary. If any contingent thing has being, which our experience and observation indeed tell us that contingent things do indeed have being, there is necessarily a being which is not contingent, which is the source of all being (if being itself were contingent (possible to be or not be) it would mean that at some point being would not have been; as something cannot come from nothing (in the sense of non-being), being itself cannot be contingent (This is Aquinas's Third Way, which I think is originally from Aristotle). As being itself is upholding nature in existence, and the laws and matter and life therein, at each moment of those things existing, the only thing that should be deemed necessary as the cause of life is being itself, and these secondary causes (the laws of physics) should not be confused with being the primary cause of life.
 

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@JKerx

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JKerx

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@Dave Foster, I'm as difficult to understand as Heidegger? Honestly, give me some criticism I can work with.
 

DaveFoster

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@Dave Foster, I'm as difficult to understand as Heidegger? Honestly, give me some criticism I can work with.
You mention Aristotle, but I found your argument more Platonic, and certainly more ontological than Aristotelian dialectic. "Being" has no meaning outside of the context of the current universe and its laws.

Neither life's current manifestation, nor any asserted alternative manifestation can be fathomed without 1) the basic faculties required to perceive nature in its proposed alternative state, which necessarily disqualifies an alternative set of laws; and 2) the presence of life itself, for which we have only one known process, and there exists no evidence for an alternative process. Thus, it's an unwarranted assumption that reality can exist in a form divergent from its present state (point 2), except by way of our imagination, itself grounded in our limited faculties, or in a such a state that would necessarily disqualify human presence due to the inhospitality of such an environment to biological life (point 1).
 
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haidut

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I just wanted to clarify that the author is not saying that living systems violate the second law of thermodynamics as the second law only applies to closed systems. As you state, living organisms are open to the environment where they take in useful energy to do work. They thereby lower their internal entropy at the expense of their surroundings. The universe however is very different than a living system. It is the entirety of every existing system so by definition it must be a closed system; there is nothing else outside of it. Here the Second Law applies and entropy is always increasing.

If the Universe is infinite then it cannot be considered a closed system. Yes, you can say it is the totality of all there is but if it is infinite then the concept of closeness is meaningless and the Second Law does not apply. A lot of assumptions built into physics break down when infinities are involved. Black hole singularities are another example (even though I do not think they exist). A singularity is just another word for an entity that current physics cannot describe. If singularities can be tossed around and ignored as if they are not really that big of a deal then I don't see how an infinite Universe violating the Second Law is much different. And remember, entropy is a completely subjective definition, it has no empirical/physical basis. It only follows that entropy will always increase IF AND ONLY IF elementary particles in the Universe have no position bias and one arrangement is as a good as another. So, with such an assumption entropy will increase simply because the fully random particle arrangement is the least biased one. But the evidence so far suggests that the Universe (and its laws) does have a bias, and it is for building more and more complex structures, not maximizing randomness.
http://bayes.wustl.edu/etj/articles/gibbs.vs.boltzmann.pdf
"...After the above insistence that any demonstration of the second law must involve the entropy as measured experimentally, it may come as a shock to realize that, nevertheless, thermodynamics knows of no such notion as the "entropy of a physical system". Thermodynamics does have the concept of the entropy of a thermodynamic system; but a given physical system corresponds to many different thermodynamic systems."
 

Queequeg

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If the Universe is infinite then it cannot be considered a closed system. Yes, you can say it is the totality of all there is but if it is infinite then the concept of closeness is meaningless and the Second Law does not apply. A lot of assumptions built into physics break down when infinities are involved. Black hole singularities are another example (even though I do not think they exist). A singularity is just another word for an entity that current physics cannot describe. If singularities can be tossed around and ignored as if they are not really that big of a deal then I don't see how an infinite Universe violating the Second Law is much different. And remember, entropy is a completely subjective definition, it has no empirical/physical basis. It only follows that entropy will always increase IF AND ONLY IF elementary particles in the Universe have no position bias and one arrangement is as a good as another. So, with such an assumption entropy will increase simply because the fully random particle arrangement is the least biased one. But the evidence so far suggests that the Universe (and its laws) does have a bias, and it is for building more and more complex structures, not maximizing randomness.
http://bayes.wustl.edu/etj/articles/gibbs.vs.boltzmann.pdf
"...After the above insistence that any demonstration of the second law must involve the entropy as measured experimentally, it may come as a shock to realize that, nevertheless, thermodynamics knows of no such notion as the "entropy of a physical system". Thermodynamics does have the concept of the entropy of a thermodynamic system; but a given physical system corresponds to many different thermodynamic systems."

My only point was that the author of the article you posted does not negate the second law of thermodynamics to explain how complexity arises in molecules but in fact uses it to explain his thesis. The decrease in entropy i.e. increasing complexity of molecules comes at the expense of the environment where useful energy is extracted and degraded as heat and thereby raising the entropy of the environment. Overall however the entropy of the system as a whole must increase since these processes are irreversible.

This is stated in the paragraph you quoted. "...The biophysicist Jeremy England made waves in 2013 with a new theory that cast the origin of life as an inevitable outcome of thermodynamics. His equations suggested that under certain conditions, groups of atoms will naturally restructure themselves so as to burn more and more energy, facilitating the incessant dispersal of energy and the rise of “entropy” or disorder in the universe.”

As for the universe, it is an open debate as to whether or not it is infinite. However I am not sure that even an infinite universe would negate the second law.
 
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Dhair

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My only point was that the author of the article you posted does not negate the second law of thermodynamics to explain how complexity arises in molecules but in fact uses it to explain his thesis. The decrease in entropy i.e. increasing complexity of molecules comes at the expense of the environment where useful energy is extracted and degraded as heat and thereby raising the entropy of the environment. Overall however the entropy of the system as a whole must increase since these processes are irreversible.

This is stated in the paragraph you quoted. "...The biophysicist Jeremy England made waves in 2013 with a new theory that cast the origin of life as an inevitable outcome of thermodynamics. His equations suggested that under certain conditions, groups of atoms will naturally restructure themselves so as to burn more and more energy, facilitating the incessant dispersal of energy and the rise of “entropy” or disorder in the universe.”

As for the universe, it is an open debate as to whether or not it is infinite. However I am not sure that even an infinite universe would negate the second law.
Could there be a point in which entropy on a macro scale becomes subjective? If someone cannot recognize the universe as being purposeful and becoming gradually more complex, couldn't that person mistake it for randomness?
I understand that physicists and scientists in general are trained to recognize patterns, so the idea may seem ludicrous, but as haidut seemed to be implying , even the established laws seem to exist for the sole purpose of explaining away the advancement of an infinitely complex or "purposeful" universe. The matter of perspective could still apply to the Second Law of Thermodynamics at this level.
Just a thought.
 
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Queequeg

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Could there be a point in which entropy on a macro scale becomes subjective? If someone cannot recognize the universe as being purposeful and becoming gradually more complex, couldn't that person mistake it for randomness?
I understand that physicists and scientists in general are trained to recognize patterns, so the idea may seem ludicrous, but as haidut seemed to be implying , even the established laws seem to exist for the sole purpose of explaining away the advancement of an infinitely complex or "purposeful" universe. The matter of perspective could still apply to the Second Law of Thermodynamics at this level.
Just a thought.
I am not sure what you mean by subjective but if one thermodynamic system within the universe is "purposeful" or becoming more complex then it does so at the expense of its surroundings whose entropy must increase at an equal or greater amount than what was decreased by the "complexity." In other words increased complexity has a cost that must be settled by its surroundings.
 
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kyle

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Newton's world of force ran against the Aristotelian view that the elements (earth, fire, water, air) had a place where they were intrinsically moving toward (rest).

Unlike Aristotle, things do not have a Telos or a kind of aim or purpose.

Newton's ideas can be extended into a cosmology itself in every field of thought. Biology with its reductionist system of genes/natural selection and economics as an amoral science of objects and actors have a lot in common with the idea of atoms.
 

tara

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If we acknowledge that the laws of physics are indeed contingent upon there being a nature from which they gain being, then it really isn't possible to call them the necessary cause of life. Unlike a simple math equation like 2 and 2 making four, which is impossible to imagine otherwise and is logically necessary, we can imagine there being other laws of physics in the universe than the ones in which we are bound--we could imagine trees that literally pour out root beer upwards and against gravity naturally, for instance.
I don't acknowledge that. Being able to imagine something doesn't prove that it is possible. I don't know whether the laws of nature are contingent or not. I don't know whether there is any other way they could be. I might even currently be radically agnostic on the point (ie. I have my doubts about whether it is possible for anyone to know that/whether different laws of nature could exist).

Regardless of the above ...
If any contingent thing has being, which our experience and observation indeed tell us that contingent things do indeed have being, there is necessarily a being which is not contingent, which is the source of all being (if being itself were contingent (possible to be or not be) it would mean that at some point being would not have been; as something cannot come from nothing (in the sense of non-being), being itself cannot be contingent (This is Aquinas's Third Way, which I think is originally from Aristotle).
If I understand you, you seem to be confounding and conflating 'being' with 'life'.

The hypothesis referred to in the OP was that life was generated by the laws of physics from the energy and matter that existed. Not from nothing.

It's hard to define 'life' (it generally involves at least some self-sustaining processes - homeostasis, organisation, metabolism, growth, reproduction, adaptation, response to stimuli, ...). But the word has meaning, and applies to some physical organisms that exist now ( eg. plants, animals, fungi, protists, archaea, and bacteria), and which at some time in the past did not exist. It is possible to imagine that other forms of life might arise under other conditions - the forms of life might be contingent.

If there was something that went before the currently known forms of energy and matter, or before the currently operating laws of nature, you can call it 'being (or 'Being') in the sense of existing, and assign whatever religious/spiritual/metaphysical significance you like to it, but that doesn't make it 'life' in the normal meaning of the word.
 

Travis

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The burning of coal always increases entropy; but it's premature to assume that entropy, as a whole, must increase. I see photosynthesis as an decrease in entropy.

The Second Law of Thermodynamics is simply what happens when you let locomotive engineers define reality.
 
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You mention Aristotle, but I found your argument more Platonic, and certainly more ontological than Aristotelian dialectic. "Being" has no meaning outside of the context of the current universe and its laws.

Neither life's current manifestation, nor any asserted alternative manifestation can be fathomed without 1) the basic faculties required to perceive nature in its proposed alternative state, which necessarily disqualifies an alternative set of laws; and 2) the presence of life itself, for which we have only one known process, and there exists no evidence for an alternative process. Thus, it's an unwarranted assumption that reality can exist in a form divergent from its present state (point 2), except by way of our imagination, itself grounded in our limited faculties, or in a such a state that would necessarily disqualify human presence due to the inhospitality of such an environment to biological life (point 1).

yes reality can exist outside of its current state. why not? Your imagination is a sort of virtual reality with it's own laws of physics. just not as permanent as this one.
 

tara

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The burning of coal always increases entropy; but it's premature to assume that entropy, as a whole, must increase. I see photosynthesis as an decrease in entropy.

The Second Law of Thermodynamics is simply what happens when you let locomotive engineers define reality.
Yeah, photosynthesis is a decrease in entropy.
But I guess a star running down it's fuel supply might count as increasing entropy?
 

Queequeg

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The burning of coal always increases entropy; but it's premature to assume that entropy, as a whole, must increase. I see photosynthesis as an decrease in entropy.

The Second Law of Thermodynamics is simply what happens when you let locomotive engineers define reality.
Photosynthesis raises the entropy of the surroundings due to heat losses from the radiative energy, in other words not all the energy is converted to chemical potential and much is lost and degraded.

As for the Second Law many people have lost lots of money and some their minds trying to defy the second law with perpetual motion machines. Unless the cranks on Youtube have really come up with something, the second law provides a limit to how efficient any process can be, including photosynthesis.

and not just train engineers
"A theory is the more impressive the greater the simplicity of its premises is, the more different kinds of things it relates, and the more extended is its area of applicability. Therefore the deep impression which classical thermodynamics made upon me. It is the only physical theory of universal content concerning which I am convinced that within the framework of the applicability of its basic concepts, it will never be overthrown."
Albert Einstein
 

Travis

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Photosynthesis raises the entropy of the surroundings due to heat losses from the radiative energy, in other words not all the energy is converted to chemical potential and much is lost and degraded.
Some experiments have shown a quantum yield of unity at 600nm. Judging by the color of leaves, this is probably the main frequency absorbed.
McCree, Keith J. "The action spectrum, absorptance and quantum yield of photosynthesis in crop plants." Agricultural Meteorology 9 (1971): 191-216.

Some people people actually agree with me. Here is a quote from another article:
Though their final conclusion was that the overall photosynthetic process, due to its low quantum efficiency in vivo, does not seem to constitute an exception to the second law, this can not be assumed a priori. One obvious reason for this is the decrease in molecular entropy associated with glucose production. If the overall quantum efficiency is high enough, negative or zero entropy changes are able to be contemplated. These papers are rarely, or not at all, cited in thermodynamic studies on photosynthesis.
So if the quantum yield is low enough, the heat lost will raise the entropy of the environment more than the decrease created through the condensation of CO₂ and H₂O into glucose. So the validity of the Second Law rests on this number.

He goes on to conclude that a decrease of total entropy* occurs as a result of photosynthesis:
The above considerations demonstrate that the second law is violated by the core particles of both plant photosystems for primary charge separation.
Jennings, Robert C., et al. "Photosynthesis and negative entropy production." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1709.3 (2005): 251-255.


*On Earth. There could be a corresponding increase of entropy on the Sun (tara, 2017).
 
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Queequeg

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Some experiments have shown a quantum yield of unity at 600nm. Judging by the color of leaves, this is probably the main frequency absorbed.
McCree, Keith J. "The action spectrum, absorptance and quantum yield of photosynthesis in crop plants." Agricultural Meteorology 9 (1971): 191-216.

Some people people actually agree with me. Here is a quote from another article:
So if the quantum yield is low enough, the heat lost will raise the entropy of the environment more than the decrease created through the condensation of CO₂ and H₂O into glucose. So the validity of the Second Law rests on this number.

He goes on to conclude that a decrease of total entropy* occurs as a result of photosynthesis:

Jennings, Robert C., et al. "Photosynthesis and negative entropy production." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1709.3 (2005): 251-255.


*On Earth. There could be a corresponding increase of entropy on the Sun (tara, 2017).
It looks like Jennings left out a major term in his equations. Two scientists rapped his knuckles on it.

Commentary on: “Photosynthesis and negative entropy production” by Jennings and coworkers - ScienceDirect
Abstract
This commentary argues against the view that photochemical energy conversion violates the second law of thermodynamics, as expressed in a recent paper [R.C. Jennings, E. Engelmann, F. Garlaschi, A.P. Casazza, G. Zucchelli. Photosynthesis and negative entropy production. Biochim. Biophys. Acta 1709 (2005) 251-255]. The basic principles of free energy conversion by a photo-electrochemical cell are outlined, emphasizing the fact that the potential depends on the relative population of the excited state and thus on the illumination intensity.

7. Negative entropy production?
This erroneous claim by Jennings and coworkers stems from their postulate that the thermodynamic treatment using chemical potential (i.e., Eq. (7)) and dealing with ensembles (i.e., many molecules or a single molecule for a long period of time), does not apply to photochemical conversion. They focus on the story of an absorbed photon on a single photosystem and find that the losses due to thermalization of the vibrational energy levels (related to the Stokes shift) are small. Since this is the only dissipation mechanism allowed in their scheme, it follows that the free energy stored by P* is close to 0, so that the entropy lost by the radiation field is not compensated. One certainly can accept that the ΔS0 of the excitation transition is negligible, so that the internal energy, or standard enthalpy (assuming a negligible volume change) is essentially 0. But the free energy of the system also comprises the entropic RT ln[P*]/[P] term. When dismissing this contribution as irrelevant, the authors ignore the statistical essence of the problem. There is no justification for excluding the interaction of matter with light from common thermodynamics: the theory of black body emission, which was at the origin of the quantum revolution, was precisely elaborated to meet this demand

Entropy production and the Second Law in photosynthesis - ScienceDirect
Abstract
An assertion that the primary photochemistry of photosynthesis can violate the Second Law of thermodynamics in certain efficient systems has been put forward by Jennings et al., who maintain their position strongly despite an argument to the contrary by Lavergne. We identify a specific omission in the calculation of Jennings et al. and show that no violation of the Second Law occurs, regardless of the photosynthetic efficiency.
 
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Travis

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Jennings denies having left out an entropic term in his rebuttal to Lavergne's rebuttal. His re-rebuttal.
and ξ is the thermodynamic efficiency of the absorbed photon. This term takes into account all energy changes from photon absorption to primary charge separation. ΔSpc is the entropy decrease associated with primary photosynthetic photochemistry.
...and calls into question Lavergne's use of even mentioning the macroscopic Carnot Cycle:
Firstly, we argue that the widely used “chemical reaction analogy”, while not being incorrect in itself, is unsuitable for a thermodynamic analysis of single photosystems. It is too macroscopic. Secondly, our “single photon-single photosystem approach” is correct for this microscopic level, as can be demonstrated by the almost identical results obtained when using radiation flux parameters and specific intensity of entropy radiation.
They also called support from a 1968 article written by two theoretical physicists:
In fact, these authors state in their final conclusions, “We conclude that the Second Law will be valid, provided the efficiency is < 0.88.” In other words, if the efficiency were greater than 0.88, then the Second Law would not be valid. For the above example of the tungsten light source (Tᵣ = 2800 K, T = 300 K), the global entropy change using Eq. (8) is negative for η ≥ 0.88, in very close agreement with our conclusion. Eq. (8) was derived by Yourgrau and van der Merwe using the light flux parameters and specific intensity of entropy radiation, i.e. an approach which is very different from the entropy balance considerations which we used.
Van der Merwe is a respectable physicist and was even a the founding editor of a journal: Foundations of Physics Letters. Here are some quotes from Van der Merwe's 1968 article:
As was emphasized, notably by Schrödinger, energy alone is incapable of sustaining the life of a plant or any other organism: moreover, there must be a continuous influx of enough negative entropy to at least balance the increase of entropy that inevitably accompanies the irreversible processes occurring inside the organism; otherwise, it would rapidly decay into the lifeless state of maximum entropy. Green plants acquire this negative entropy, along with energy, in the course of photosynthesis from the sunlight incident on their leaves.
The all seem to cite Schrödinger in the opening paragraph to lend authority to their ideas, although Nobelist Ilya Prigogine isn't normally mentioned (but he should be).
We conclude that the Second Law will be valid, i.e., ΔS > −ΔS,, provided η < 0.88. Experimentally, the efficiency of photosynthesis in red light is 59 per cent, so that the above requirement is certainly satisfied.
The Greek letter η (eta) is the amount of radiation absorbed by the leaf chromophores and is used to make glucose. The value 1−η is reflected. This shouldn't be confused with Jenning's themodynamic efficiency, given by ξ.

The photosynthetic reaction itself has negative entropy. From a different article:*
P(S₀) = ΔS(glu) + 6 ΔS(O₂) − 6 ΔS(CO₂) − 6 ΔS(H₂O) − ΔS(SR₀) = − 0.8337 kJ/Kmol
This numerical result clearly violates the 2nd Law of Thermodynamics...
Some people would scrap the Second Law right there, but not this guy. He goes on:
Hence, a photosynthesis process of this type cannot exist.

Jennings used experimental data from Raman spectroscopy in his paper. Lavergne attacked him on purely theoretical grounds. He makes assumptions about the time spent in the exited state:
Taking ∼20 ns for the natural lifetime of Chllorphyll*, we reason that every second a chlorophyll is excited once and remains so for ∼20 ns, which means that [P*]/[P] ≈ 2 × 10⁻⁸. Therefore:
These values are absolutely essential for Lavergne to salvage the Second Law the way he does. If the ratio of the the exited state over the ground state [P*]/[P] is much higher, the value plummets. The natural logarithm of one is zero. He is using the value of the gas constant in electron volts, so it is: 8.63 x 10⁻⁵ eV/K·atom.

The fluorescent lifetime that he used was measured using free chlorophyll in pyridine, methathol, toluene, and diethyl ether.† His choice of fluorescent lifetime (∼20 ns) seems to have been chosen based purely on the number he wanted to arrive at. The values actually reported by Connolly were quite different and are effected by both solvent and concentration.
photo.png


Moreover, Lavergne gave no justification for assuming that that this excitation will happen only once per second. Increasing the frequency of excitation will change the ratio [P*]/[P] as the denominator increases.

Schrodinger, Erwin. What is life?. University Press: Cambridge, 1943.
*Keller, J. U. "Thermodynamic Analysis of Photosynthesis."
Yourgrau, Wolfgang, and Alwyn Van Der Merwe. "Entropy balance in photosynthesis." Proceedings of the National Academy of Sciences 59.3 (1968): 734-737.
Jennings, Robert C., et al. "Photosynthesis and negative entropy production." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1709.3 (2005): 251-255.
Lavergne, Jérôme. "Commentary on:“Photosynthesis and negative entropy production” by Jennings and coworkers." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1757.11 (2006): 1453-1459.
Jennings, R. C., et al. "Reply to “Commentary on photosynthesis and negative entropy production by Jennings and coworkers” by J. Lavergne." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1757.11 (2006): 1460-1462.
†Connolly, John S., A. Frederick Janzen, and Edward B. Samuel. "Fluorescence lifetimes of chlorophyll a: solvent, concentration and oxygen dependence." Photochemistry and Photobiology 36.5 (1982): 559-563.
 
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Queequeg

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Jennings denies having left out an entropic term in his rebuttal to Lavergne's rebuttal. His re-rebuttal.
...and calls into question Lavergne's use of even mentioning the macroscopic Carnot Cycle:

They also called support from a 1968 article written by two theoretical physicists:

Van der Merwe is a respectable physicist and was even a the founding editor of a journal: Foundations of Physics Letters. Here are some quotes from Van der Merwe's 1968 article:

The all seem to cite Schrödinger in the opening paragraph to lend authority to their ideas, although Nobelist Ilya Prigogine isn't normally mentioned (but he should be).

The Greek letter η (eta) is the amount of radiation absorbed by the leaf chromophores and is used to make glucose. The value 1−η is reflected. This shouldn't be confused with Jenning's themodynamic efficiency, given by ξ.

The photosynthetic reaction itself has negative entropy. From a different article:*

Some people would scrap the Second Law right there, but not this guy. He goes on:


Jennings used experimental data from Raman spectroscopy in his paper. Lavergne attacked him on purely theoretical grounds. He makes assumptions about the time spent in the exited state:
These values are absolutely essential for Lavergne to salvage the Second Law the way he does. If the ratio of the the exited state over the ground state [P*]/[P] is much higher, the value plummets. The natural logarithm of one is zero. He is using the value of the gas constant in electron volts, so it is: 8.63 x 10⁻⁵ eV/K·atom.

The fluorescent lifetime that he used was measured using free chlorophyll in pyridine, methathol, toluene, and diethyl ether.† His choice of fluorescent lifetime (∼20 ns) seems to have been chosen based purely on the number he wanted to arrive at. The values actually reported by Connolly were quite different and are effected by both solvent and concentration.
View attachment 6368

Moreover, Lavergne gave no justification for assuming that that this excitation will happen only once per second. Increasing the frequency of excitation will change the ratio [P*]/[P] as the denominator increases.

Schrodinger, Erwin. What is life?. University Press: Cambridge, 1943.
*Keller, J. U. "Thermodynamic Analysis of Photosynthesis."
Yourgrau, Wolfgang, and Alwyn Van Der Merwe. "Entropy balance in photosynthesis." Proceedings of the National Academy of Sciences 59.3 (1968): 734-737.
Jennings, Robert C., et al. "Photosynthesis and negative entropy production." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1709.3 (2005): 251-255.
Lavergne, Jérôme. "Commentary on:“Photosynthesis and negative entropy production” by Jennings and coworkers." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1757.11 (2006): 1453-1459.
Jennings, R. C., et al. "Reply to “Commentary on photosynthesis and negative entropy production by Jennings and coworkers” by J. Lavergne." Biochimica et Biophysica Acta (BBA)-Bioenergetics 1757.11 (2006): 1460-1462.
†Connolly, John S., A. Frederick Janzen, and Edward B. Samuel. "Fluorescence lifetimes of chlorophyll a: solvent, concentration and oxygen dependence." Photochemistry and Photobiology 36.5 (1982): 559-563.

Jennings' claim of a Second Law violation applies only to the photoexcitation of electrons and not to photosynthesis as a whole which Jennings freely admits.

“of course, under normal photosynthetic conditions, where CO2 is being fixed, and both photosystems are required, the thermodynamic efficiency falls into the range of 0.02–0.1 and ΔStot [Δentropy] has positive values”.

I would also add that even in this hypothetical system he needs to assume an efficiency greater than the Carnot efficiency which in itself is already a violation of the Second Law. This is basically a tautological argument and is why Keller states that you can’t have a system like this; it breaks the second law.
Van der Merwe is a respectable physicist and was even a the founding editor of a journal: Foundations of Physics Letters. Here are some quotes from Van der Merwe's 1968 article:
“As was emphasized, notably by Schrödinger, energy alone is incapable of sustaining the life of a plant or any other organism: moreover, there must be a continuous influx of enough negative entropy to at least balance the increase of entropy that inevitably accompanies the irreversible processes occurring inside the organism; otherwise, it would rapidly decay into the lifeless state of maximum entropy. Green plants acquire this negative entropy, along with energy, in the course of photosynthesis from the sunlight incident on their leaves.”
Van der Merwe’s is not saying that photosynthesis as a whole is a negative entropic process. He is only saying that the plant lowers its entropic state through photosynthesis. The proper thermodynamic system to analyze must include the sunlight hitting the leaf, whose entropy is increased more than the leaf's is decreased.

It's called a Law for a reason.
 
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