I was reading about the Law of Thermodynamics, and the Second Law of Thermodynamics really interested me because the Law apparently stated that in any isolated system, the entropy of that system will increase.

Entropy, is the amount of energy not available for useful work. It can also be measured as an amount of disorder.

So, in a closed system, as the disorder increases, it needs external energies to be applied to it in order for the entropy to decrease, apparently.

Dr John Ross of Harvard University states:

… there are no known violations of the second law of thermodynamics. Ordinarily the second law is stated for isolated systems, but the second law applies equally well to open systems. … There is somehow associated with the field of far-from-equilibrium thermodynamics the notion that the second law of thermodynamics fails for such systems. It is important to make sure that this error does not perpetuate itself.

The source is: Chemical and Engineering News, 7 July 1980, p. 40;

Since the universe is a closed system, entropy will continually increase,and consequently, the disorder in our universe will be on an uphill run. How does evolution answer this? Do we have to change the law of entropy? Or is the Theory of Evolution flawed?

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    The universe is a closed system, but the Earth isn't. In fact it receives low entropy energy (light) during the day and it emits high entropy energy (thermal radiation) during the night. Plants, for example, use this to decrease their internal entropy through photosynthesis and so on. There is no reason why evolution wouldn't be permitted as long as this mechanism is in place. When the universe reaches thermal death, then evolution won't be possible.
    – Sklivvz
    May 7, 2011 at 9:58
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    I'm not sure by what good reason this is being voted down. He's just confused about physics. The nature of the question doesn't seem erroneous to me, I think we should be more welcoming.
    – Kit Sunde
    May 9, 2011 at 6:31
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    Did you read the answer Larian provided? By your understanding of theormodynamics, (as he said) "Going from an egg and sperm, to a full grown adult would seem to violate your understanding of the second law of thermodynamics."
    – JasonR
    May 11, 2011 at 12:24
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    Two things. I edited out the term "evolutionist" because it is not appropriate in this context. And again, you ought to read the answer. You seem to be deliberately ignoring the answer. In particular your poor understanding of thermodynamics (which as I said, wouldn't allow for a sperm and egg to eventually grow into an adult), seems to be at odds with reality. May 15, 2011 at 2:17
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    @Jim The current question is a-ok. But look at the original question and the discussion above and you’ll see that the OP was simply ignoring the answers and waving the arguments away. People resent that. The question in itself is actually a good question for Skeptics. Oct 30, 2011 at 11:18

5 Answers 5


This is a throughly debunked canard by creationists. Look up in the sky on a sunny day, and look at an incredible source of energy for the earth. For a basic primer on evolution, go to this page and then avail yourself of the many links available. You do seem to have a severe case of misunderstanding and just plain bad information that you have been exposed to.

As a UNIVERSE, things are indeed overall going to more entropy, but locally, we see entropy decreasing all the time. Or do you doubt that you were born? Going from an egg and sperm, to a full grown adult would seem to violate your understanding of the second law of thermodynamics. As has been repeated, the earth is not a closed system. Local entropy is decreasing all over the globe, all the time. Of course, on the whole, in our solar system, because of the way our sun works, and all the other elements of the universe, we are still seeing a net increase of entropy in the universe. And in several trillions upon trillions of years, the ultimate fate of the universe (as best as we can tell) will be ultimate entropy, known as heat death.

Since this is a tiresome canard, I shall refer to a rebuttal written by a Science Writer that goes by the pseudonym Calilasseia who has this to say (forgive the writing style, he is British, and slightly miffed at having to drag up such an inane argument) (Also, this large block of text is reproduced with permission at any location on the internet, as noted originally on the cited web page):

[27] Tiresome canards about evolution and the laws of thermodynamics.

And how tiresome these canards are. Not least because they've been debunked in the past, even without reference to relevant scientific literature, by people who pay attention to the scientific basics. Once the relevant scientific literature is consulted, these canards become visibly asinine.

I'll deal with the Second Law of Thermodynamics to start with, because that one is a creationist favourite, though when creationists parrot this specious nonsense, they merely demonstrate that they know nothing about the relevant physics, and certainly never paid attention to the actual words of Rudolf Clausius, who erected the Laws of Thermodynamics, and who was rigorous when doing so. Therefore, let us see what Clausius actually stated, shall we?

Rudolf Clausius erects this statement of the Second Law of Thermodynamics:

In an isolated system, a process can occur only if it increases the total entropy of the system.

Now Clausius defined rigorously what was meant by three different classes of thermodynamic system, and in his work, specified explicitly that the operation of the laws of thermodynamics differed subtly in each instance. The three classes of system Clausius defined were as follows:

[27a] An isolated system is a system that engages in no exchanges of energy or matter with the surroundings;

[27b] A closed system is a system that engages in exchanges of energy with the surroundings, but does not engage in exchange of matter with the surroundings;

[27c] An open system is a system that engages in exchanges of both matter and energy with the surroundings.

Now, Clausius' statement above clearly and explicitly refers to isolated systems, which, thus far, have been found to be an idealised abstraction, as no truly isolated system has ever been found. Indeed, in order to create even an approximation to an isolated system in order to perform precise calorimetric measurements, physicists have to resort to considerable ingenuity in order to minimise energy exchanges with the surroundings, particularly given the pervasive nature of heat. Even then, they cannot make the system completely isolated, because they need to have some means of obtaining measurement data from that system, which has to be conveyed to the surroundings, and this process itself requires energy. Physicists can only construct a closed system, in which, courtesy of much ingenuity, energy exchanges with the surroundings are minimised and precisely controlled, and to achieve this result in a manner that satisfies the demands of precise work is time consuming, expensive and requires a lot of prior analysis of possible sources of energy exchange that need to be minimised and controlled.

However, the Earth is manifestly an open system. It is in receipt not only of large amounts of energy from outside (here's a hint: see that big yellow thing in the sky?) but is also in receipt of about 1,000 tons of matter per year in the form of particles of meteoritic origin from outer space. Some of these 'particles' are, on occasions, large enough to leave craters in the ground, such as that nice large one in Arizona. That particular dent in the Earth's surface is 1,200 metres in diameter, 170 metres deep, and has a ridge of material around the edges that rises 45 metres above the immediate landscape, and was excavated when a meteorite impacted the Earth's surface, generating a blast equivalent to a 20 megaton nuclear bomb. Hardly a characteristic of an isolated system.

Indeed, physicists have known for a long time, that if a particular system is a net recipient of energy from outside, then that energy can be harnessed within that system to perform useful work. Which is precisely what living organisms do. Indeed, they only harness a small fraction of the available incoming energy, yet this is sufficient to power the entire diversity of the biosphere, and the development of organisms of increasing sophistication over time. Scientists have published numerous papers (twelve of which are known to me, and this is an incomplete inventory of the extant literature) in which calculations have been performed demonstrating that the utilisation of energy by the biosphere, and by evolution, is orders of magnitude too small to violate thermodynamic concerns. Relevant papers in question being:

Entropy And Evolution by Daniel F. Styer, American Journal of Physics, 78(11): 1031-1033 (November 2008) DOI: 10.1119/1.2973046

Natural Selection As A Physical Principle by Alfred J. Lotka, Proceedings of the National Academy of Sciences of the USA, 8: 151-154 (1922) full paper downloadable from here

Evolution Of Biological Complexity by Christoph Adami, Charles Ofria and Travis C. Collier, Proceedings of the National Academy of Sciences of the USA, 97(9): 4463-4468 (25th April 2000) Full paper downloadable from here

Order From Disorder: The Thermodynamics Of Complexity In Biology by Eric D. Schneider and James J. Kay, in Michael P. Murphy, Luke A.J. O'Neill (ed), What is Life: The Next Fifty Years. Reflections on the Future of Biology, Cambridge University Press, pp. 161-172 Full paper downloadable from here

Natural Selection For Least Action by Ville R. I. Kaila and Arto Annila, Proceedings of the Royal Society of London Part A, 464: 3055-3070 (22nd July 2008) Full paper downloadable from here

Evolution And The Second Law Of Thermodynamics by Emory F. Bunn, arXiv.org, 0903.4603v1 (26th March 2009) Download full paper from here

All of these peer reviewed papers establish, courtesy of rigorous empirical and theoretical work, that evolution is perfectly consistent with the Second Law of Thermodynamics. I cover several of these in detail in this post, and it should be noted here that the notion that evolution was purportedly in "violation" of the Second Law of Thermodynamics was rejected in a paper written in 1922, which means that creationists who erect this canard are ignorant of scientific literature published over eighty years ago.

While covering this topic, it's also necessary to deal with the canard that entropy equals 'disorder'. This is a non-rigorous view of entropy that scientists engaged in precise work discarded some time ago. Not least because there are documented examples of systems that have a precisely calculated entropy increase after spontaneously self-organising into well-defined structures. Phospholipids are the classic example of such a system - a suspension of phospholipids in aqueous solution will spontaneously self-assemble into structures such as micelles, bilayer sheets and liposomes upon receiving an energy input consisting of nothing more than gentle agitation. In other words, just shake the bottle. Moreover, the following scientific paper discusses in some detail the fact that entropy can increase when a system becomes more ordered, a paper that was published in 1998, and hence, has been in circulation for over a decade now:

Gentle Force Of Entropy Bridges Disciplines by David Kestenbaum, Science, 279: 1849 (20th March 1998)

Kestenbaum, 1998 wrote:Normally, entropy is a force of disorder rather than organization. But physicists have recently explored the ways in which an increase in entropy in one part of a system can force another part into greater order. The findings have rekindled speculation that living cells might take advantage of this little-known trick of physics.

Entropy, as rigorously defined, has units of Joules per Kelvin, and is therefore a function of energy versus thermodynamic temperature. The simple fact of the matter is that if the thermodynamic temperature increases, then the total entropy of a given system decreases if no additional energy was input into the system in order to provide the increase in thermodynamic temperature. Star formation is an excellent example of this, because the thermodynamic temperature at the core of a gas cloud increases as the cloud coalesces under gravity. All that is required to increase the core temperature to the point where nuclear fusion is initiated is sufficient mass. No external energy is added to the system. Consequently, the entropy at the core decreases due to the influence of gravity driving up the thermodynamic temperature. Yet the highly compressed gas in the core is hardly "ordered".

STOP PRESS: as if to reinforce this point, my attention has just been drawn to this scientific paper:

Disordered, Quasicrystalline And Crystalline Phases Of Densely Packed Tetrahedra by Amir Haji-Akbari, Michael Engel, Aaron S. Keys, Xiaoyu Zheng, Rolfe G. Petschek, Peter Palffy-Muhoray and Sharon C. Glotzer, Nature, 462: 773-777 (10th December 2009)

The abstract is suitably informative here:

Haji-Akbari, 2009 wrote: All hard, convex shapes are conjectured by Ulam to pack more densely than spheres1, which have a maximum packing fraction of φ = π/∫18 ≈ 0.7405. Simple lattice packings of many shapes easily surpass this packing fraction2, 3. For regular tetrahedra, this conjecture was shown to be true only very recently; an ordered arrangement was obtained via geometric construction with φ = 0.7786 (ref. 4), which was subsequently compressed numerically to φ = 0.7820 (ref. 5), while compressing with different initial conditions led to φ = 0.8230 (ref. 6). Here we show that tetrahedra pack even more densely, and in a completely unexpected way. Following a conceptually different approach, using thermodynamic computer simulations that allow the system to evolve naturally towards high-density states, we observe that a fluid of hard tetrahedra undergoes a first-order phase transition to a dodecagonal quasicrystal7, 8, 9, 10, which can be compressed to a packing fraction of φ = 0.8324. By compressing a crystalline approximant of the quasicrystal, the highest packing fraction we obtain is φ = 0.8503. If quasicrystal formation is suppressed, the system remains disordered, jams and compresses to φ = 0.7858. Jamming and crystallization are both preceded by an entropy-driven transition from a simple fluid of independent tetrahedra to a complex fluid characterized by tetrahedra arranged in densely packed local motifs of pentagonal dipyramids that form a percolating network at the transition. The quasicrystal that we report represents the first example of a quasicrystal formed from hard or non-spherical particles. Our results demonstrate that particle shape and entropy can produce highly complex, ordered structures.

So as if the Kestenbaum paper on entropy driving ordered systems, and the empirical evidence from phospholipids were not enough, we now have this. Consequently, the message to creationists is simple: don't bother wasting your time posting the "evolution violates the Second Law of Thermodynamics" canard, because it is now well and truly busted.

Some creationists, however, erect a related, and in some respects, even more asinine canard, that evolution somehow violates the First Law of Thermodynamics. Guess who provided us with rigorous statements about this law? That's right, Rudolf Clausius again. Let's see what he actually stated with respect to this, shall we? The Clausius formulation of the First Law of Thermodynamics is this:

The increase in the internal energy of a system is equal to the amount of energy input into the system via heating, minus the energy lost as a result of the work done by the system upon its surroundings.

The mathematical expression of which is:

dU = δQ - δW

If the process is reversible, then this can be recast in terms of exact differentials by noting that δW is equal to PdV, where P is the internal pressure, and V the volume occupied, and that δQ is equal to TdS, where T is the thermodynamic temperature and S is the entropy of the system. Therefore this becomes dU = TdS - PdV.

Oh look. Clausius explicitly framed the First Law of Thermodynamics in terms of energy exchanges within a system. He did NOT assume constancy thereof. Indeed, the rigorous framing of the First Law of Thermodynamics explicitly takes into account the possibility of a system being a recipient of energy that can be used to perform useful work. Therefore creationist canards erected about the First Law of Thermodynamics are null and void for the same reasons as those erected about the Second Law of Thermodynamics - said canards not only ignore completely Clausius' original and rigorous formulations of those laws, and ignore completely that Clausius framed his formulations around energy exchanges between a system and its surroundings, but rely upon outright misrepresentations of those laws.

Indeed, Clausius had energy exchanges in mind with respect to the Second Law of Thermodynamics as well, which is why the statement on entropy was framed in terms of an isolated system, which engages in no such exchanges with the surroundings. When energy exchanges are taking place, the operation of the Second law of Thermodynamics within such systems is subtly different.

I also wanted to add a bit about your silly assertion that it's only a theory... Trust me, it's a fact, and is rejection of reality on a wholesecale level to assert anything but. The mechanisms by which evolution happen are also quite well understood, but there are fine points that are still being worked out. Evolution is a theory in the same way gravity is a theory, only that we actually know a great deal more about evolution than we do gravity.

6 Scientific theories are NOT guesses.

This is a favourite (and wholly duplicitous) canard beloved of creationists, and relies upon the fact that in everyday usage, English words are loaded with a multiplicity of meanings. This is NOT the case in science, where terms used are precisely defined. The precise definition apposite here is the definition of theory. In science, a theory is an integrated explanation for a class of real world observational phenomena of interest, that has been subjected to direct empirical test with respect to its correspondence with observational reality, and which has been found, via such testing, to be in accord with observational reality. It is precisely because scientific theories have been subject to direct empirical test, and have passed said empirical test, that they ARE theories, and consequently enjoy a high status in the world of scientific discourse. As a consequence of the above, anyone who erects the "it's only a theory" canard with respect to evolution will be regarded with well deserved scorn and derision.

If you want a good visualization of evolution, maybe this picture will help you with some shorthand: Evolution as a colour THAT is a logical process that seems to escape people who deny evolution. Again, I suggest you read up more at one of the earlier links provided.

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    It's a pity, I liked that removed comment so much ;) I too understand and support both the comment and the removal ;))
    – user288
    May 7, 2011 at 14:04
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    @LarsH it's an ANALOGY. Be definition analogies are imperfect. It's meant to debunk the no transition canard (which just recently popped up), not energy states. Sorry if that was confusing. May 21, 2011 at 18:26
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    @Larian, although no analogy corresponds to reality in every detail, there's a difference between an analogy that validly supports the point it claims to support, and one that doesn't. This one claims to support the point that macro-evolution is obvious merely by extrapolation from micro-evolution; and fails, for the reason I stated. A better analogy is Dawkins' "Climbing Mount Improbable", which says that a high, steep mountain is climbable if there exists somewhere a gradual path from bottom to top.
    – LarsH
    Jun 16, 2011 at 4:38
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    @SonnyOrdell I intended it to address more that uniquely British ability (dare I say talent) to insult the intelligence of the person who asked the question without ever saying an insulting word. ;) Just in case anyone picked up on the total disdain the author has for creationists and their ilk. Nov 20, 2011 at 18:22
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    +1 for the brilliant red/blue text example. It clearly shows how evolution works, and also shows one answer for questions like "where are the missing links" and "when was the first human"
    – hdhondt
    Nov 5, 2012 at 23:05

The second law of thermodynamics states that the total entropy increases, it does not prohibit a local decrease of entropy that is offset by a larger increase in entropy somewhere else in the system. You can still have a local decrease in entropy even if the overall entropy is increasing.

A second point is that while the universe can be regarded as a closed system, the earth is certainly not a closed system. It gets a constant supply of energy from the sun, and is therefore no closed system.

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    Thank you for a civilized, clear answer that addresses the question without pummeling the asker.
    – LarsH
    May 20, 2011 at 21:26
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    @LarsH The sheer level of denial this questioner has shown is wholly and fully deserving of any pummeling he receives. He should be made to physically feel pain every time he ventures into such areas of denialism. He may as well ask if gravity violates thermodynamics for his motives (link to creation.com).
    – Skava
    Jun 16, 2011 at 0:22
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    @Skava: I think I'm going to frame that comment.
    – LarsH
    Jun 16, 2011 at 2:46
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    Thanks for a courteous answer to a questionable question. Also, I would point out that it's not just that the earth gets a constant supply of energy from the sun, but that the energy it does get is at high temperature, and it radiates to the rest of space at a very low temperature, so it is a classic heat engine doing work, including driving all the chemistry that evolves. Nov 20, 2011 at 21:50

Although the total entropy increases, the local entropy at some point in space can decrease, if that decrease is adeaqautely offset by an increase in entropy somewhere else.

Evolution on earth might reduce the entropy on earth, but this is more than offset by the increase in entropy in the sun. You can even do some back-of-the-envelope type calculations to get an idea on the numbers.

It is really sad that creationists keep repeating this thermodynamics argument and ignore that it is so plain wrong.

Please also note that evolution is a fact. It is not a theory. The theory you are referring to is called Theory of evolution by natural selection. Further, the everyday use of the word theory is different from how scientists use the term. For most people, it means "hunch, unproven statement". For scientists, a theory is the best currently available model explaining all the available observations pertaining to a certain field. Evolution is "just a theory" in the same sense that electromagnetism is "just a theory".

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    No worries. :) I have an entire web page dedicated to rebutting these sort of tired old arguments that have been debunked for nearly a century... May 7, 2011 at 3:24
  • As you say, "for scientists, a thoery is the best currently available model explaining all the available observations pertaining to a certain field" it's only the best available model, but not necessarily a fact. There are many 'best available models' for the atom, none of them are necessarily proven to be true.
    – Thursagen
    May 8, 2011 at 23:50
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    Yes, but we do know how atoms work. To precisely model it for a layman to understand would be well beyond what could be expected. If truth be told, we actually DO have proven models of atoms. It's just beyond any undergraduate level discussions (or do you have a PhD in particle physics?). Again, evolution is very well understood, say compared to gravity. Both have very observable phenomenon, yet only one of them do we have a good idea how those phenomenon happen (hint, it's not gravity). May 9, 2011 at 2:33
  • @Larian, do you have any references for back-of-the-envelope calculations on the amount of entropy gained by the sun and lost via evolution?
    – LarsH
    May 20, 2011 at 21:49
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    @LarsH that would probably make a great PhD project! The thing is, we do know how much of the sun's energy gets to earth (5.6 X 10^24 Joules per year). But I don't know what the biomass requirement for energy is. Furthermore, the human species is releasing about 10^18 Joules per year of stored solar energy (i.e. burning fossil fuels). Also, all that solar energy doesn't go to biomasses, but also to driving weather (which can ALSO affect evolution by the way). And yes, those numbers are almost so big as to be meaningless. May 21, 2011 at 18:29

Allow me to suggest that you never accept quotes from creationist literature.

The COMPLETE quote from Dr. John Ross now of Stanford is:

"SIR: I am referring to the article entitled 'Physical Chemistry,' C&EN, June 2, page 20. Toward the end of the article is stated: 'Another area where physical chemistry likely has important biological applications is the study of the properties of steady states far from equilibrium. These are stable systems that do not follow the second law of thermodynamics; instead they require a continual supply of energy from outside the system to maintain themselves.' Please be advised that there are no known violations of the second law of thermodynamics. Ordinarily the second law is stated for isolated systems, but the second law applies equally well to open systems. I recognize that it is very difficult to write an article on as broad a subject as physical chemistry in two pages, and ordinarily I would not bother to point out minor errors. However, there is somehow associated with the field of far-from-equilibrium phenomena the notion that the second law of thermodynamics fails for such systems. It is important to make sure that this error does not perpetuate itself."

The bold represents the creationist quote mine. Note that Dr. Ross is simply stating that the systems described in the article DO FOLLOW THE 2nd LAW BY REQUIRING A CONTINUAL SUPPLY OF ENERGY FROM OUTSIDE THE SYSTEM. The same can be said of the earth's bioshere. The continual input of energy from the sun allows seeds to grow into plants, fetuses to grow into babies and babies to grow into adults without violating the second law. This continual input of energy also allows evolution to occur. Any decrease in entropy experienced in the bioshere is more than offset by the increase in entropy in the sun

  • I would suggest this be a comment perhaps. Good info though! Aug 26, 2011 at 2:12
  • Thank you! I started to research that quote before getting this far in the answers, and got stymied because it isn't online any more. Larian, I think this counts as a partial answer - a complementary answer to yours - because it addresses one of the OP's claims in the question that had been left unaddressed. You show the OP was wrong. This shows Dr Ross, who was quoted by the OP, wasn't wrong.
    – Oddthinking
    Oct 31, 2011 at 15:35

The simplest answer to your question is that the theory of evolution does not claim that life will continue evolving forever. The "heat death of the universe" could well spell an end to life. If it does, that does not have any bearing on the theory of evolution, which is a theory about how life came to be and how it will continue to work. So in response to the question,

Since the universe is a closed system, entropy will continually increase,and consequently, the disorder in our universe will be on an uphill run. How does evolution answer this?

Evolution says, "Okay. That's fine." It isn't related to the phenomena evolution describes because the time scale on which cosmological considerations about entropy become important is hundreds of billions of years.

Nonetheless, it is an interesting question whether life can continue indefinitely. The only work I know on this is in the form of a talk given by Freeman Dyson. Dyson concludes that in an open universe (eternally expanding as it evolves according to general relativity), intelligent life could potentially continue creating and sharing ideas indefinitely. The talk is summarized on Wikipedia.

However, Dyson's work dates to 1979, before discovery of the acceleration of the universe, and I do not know of any attempts to update his work to reflect our latest understanding of cosmology.

  • not really answering the question.
    – matt_black
    Feb 23, 2012 at 17:11
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    @matt_black Yes, it does answer the question. I specifically quoted the question and replied to it. I said that the answer is no, the second law of thermodynamics does not contradict evolution. Feb 24, 2012 at 5:28

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