Second Law of thermodynamics vs. Evolution

Discussion in 'Physics & Math' started by Saint, Apr 6, 2020.

  1. Saint Valued Senior Member

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    When all systems taking part in a process are included, the entropy either remains constant or increases. In other words: No process is possible in which the total entropy decreases, when all systems taking part
    in the process are included. This is an alternative statement of the second law of thermodynamics in terms of entropy.

    How can species develop from simple life to more complex life and become more ordered in the process?
     
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  3. exchemist Valued Senior Member

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    By rejecting waste heat and high entropy metabolic byproducts to the surrounding environment, and thus increasing its entropy by more than the decrease in entropy of the developing organism.

    In other words there is a net increase in entropy associated with development of an ordered living system.

    P.S. This so-called "thermodynamic argument" is one of the more stupid ones used by creationists. It is some years since I have come across it, presumably because even the creationists have worked out why it's wrong.
     
    Last edited: Apr 6, 2020
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  5. James R Just this guy, you know? Staff Member

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    Another way to put it is that the second law only applies to closed systems. The Earth, taken by itself, is not a closed system. It is constantly getting energy from the Sun and emitting waste heat back out into space.
     
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  7. Saint Valued Senior Member

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    but the single cell organism is a closed system, increase in entropy will increase its disorderness.
     
  8. James R Just this guy, you know? Staff Member

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    No. A cell isn't a closed system. It gets nutrients and energy from outside and expels waste.
     
  9. exchemist Valued Senior Member

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    Don't be silly. Do you breathe? Do you eat? Do you defaecate? And you are made of cells, right?

    If a cell does not exchange nutrients, gases and waste products with the outside environment it rapidly dies. Please try to think.
     
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  10. James R Just this guy, you know? Staff Member

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    Don't get your hopes up.
     
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  11. Saint Valued Senior Member

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    Thermo Law II also has external heat reservoirs, input and output.
     
  12. exchemist Valued Senior Member

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    Only in Carnot's formulation of it, which is for heat engines. You might notice that a living cell is not a heat engine.
     
  13. Saint Valued Senior Member

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    Thermo II law is about all processes, such as when you open a bottle of perfume, the fragrance will will the air, some of it evaporated into the air, you can't put it back into the bottle, the process is irreversible, entropy is increased.
     
  14. exchemist Valued Senior Member

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    True, but you do not use Carnot's formulation of the 2nd Law to describe diffusion processes, as they do not involve heat moving between reservoirs.
     
  15. billvon Valued Senior Member

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    Life increases entropy. It takes food and disorders it, increasing entropy overall for the system (organism + food.)

    Same is true for a great many purely inorganic processes. Go to Giant's Causeway someday. Acres of perfect hexagonal tiles, about as orderly as you can get - created because they were a lower energy state than the original molten lava. Again, entropy.
     
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  16. Saint Valued Senior Member

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    Other than entropy, evolution also cannot explain how can human's intelligent brain be evolved from much much simpler organism?
     
  17. CptBork Valued Senior Member

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    You can still put the perfume back in the bottle as long as a low-entropy heat sink absorbs some heat in the process, and the total entropy of the universe still increases as required. Any source of energy capable of performing mechanical work can be used to lower the entropy of one system at the expense of another.

    What makes you think evolution can't explain that? What physical property of the brain is there that can't be theoretically produced by evolution? In theory evolution can produce anything in the universe that obeys the laws of physics, as long as you have sufficient amounts of time, resources and selection pressures.
     
  18. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Beats me

    We have come a long long way from a handful of mud

    Can't get amuch simpler organism than a handful of mud

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  19. exchemist Valued Senior Member

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    Of course it can.

    But at least you are no longer pretending entropy considerations forbid evolution, which I suppose is something.
     
  20. billvon Valued Senior Member

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    Of course it can. Gradual improvement is the primary way evolution _works._* The difference from a mouse brain to a human brain is only size and complexity; we have exactly the same basic structures.

    (* - there are many cases of punctuated equilibrium causing rapid change, but by and large it's gradual.)
     
  21. Saint Valued Senior Member

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    Ape evolved into homo sapiens is decrease of entropy. Which is impossible.
     
  22. exchemist Valued Senior Member

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    Posts 2and 3 have already explained why this is wrong. By restating it, you simply expose your own foolishness.
     
  23. James R Just this guy, you know? Staff Member

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    Why would that involve a decrease in entropy? That's not at all obvious to me.

    Also, why are you ignoring the fact that entropy can decrease in an open system? This has already been explained to you.

    As a lecturer in mechanics, did you never study entropy? What are your actual qualifications?
     
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