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Entropy and the second law of thermodynamics

  1. Aug 3, 2005 #1
    I'm not sure if this is the right place for this thread, so i'm sorry if it isn't; well, I have a question about Entropy and the second law of thermodynamics, if supposedly we can't remember the future because our brain has to use up energy to create memories and thus increases the entropy and disorder in the system which therefore accounts for the direction in which we perceive time, couldn't one suggest that given the fact the brain is organizing new memories then there is less disorder???????????????
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  3. Aug 3, 2005 #2
    You can 'reverse' entropy by doing work, intellegent work at least. For example, if you have a pile of bricks in a truck, all nice and neat, and the bricks fall off, it goes to a state of high entropy. But what if the truck stops and the driver piles the bricks back into the truck? He did work to reverse the entropy process. Your brain consumes sugars to function, so it can do that. Also, Im not entirely sure of this, but I think memories arent really organized perfectly, they just are randomly used by brain cells, I dont think it is organized like books in a library.

    Also I dont quite get what you mean by remembering the future, the future cant be known because that wouold change the past. I would think of it as the future being a shadow of the present. If you can see into the future, then you would have the ability to change it. (Whereas is you dont like the look of the shadow, then you can change the appearance of that as well.) Therefore the future can never be known, I believe time travel is more plausible. If time travel were, then I belive it would involve travel between parallel universes, not within our own. (BTW, anyone that reads this, I also mean time travel into the 'past' not by the effects of time dialation.)
  4. Aug 3, 2005 #3
    If one looks at the events in everday relative spacetime, you can perform tasks in three-dimensional space. Say if you are sitting at chair, reading the daily-blogs, and you reach over to a table for a cool drink, you can do this without actually looking directly at the table and drink. As you placed the glass down earlier, your memory remembers the location of this with respect to you sitting at the chair.

    It ranges in 3-D space, now lets say you are sitting on a revolving chair, and you friend with you spins your chair around faster and faster..then stops you in one go. Your momentum pulls you off the chair, you fall to ground. You get up off the floor, and try to reach for the Glass, even looking at it, you will have great difficulty in grasping the Glass off the table. Its not until you remain still for a while are you able to grasp your drink.

    The brain has to equlibriate the present-time, out of the past-time (Disorder-spinning event)..in order to progress into an action of the future, in this case the reaching out and grasping the cold drink!

    Waiter..order please! :biggrin:
  5. Aug 3, 2005 #4

    Claude Bile

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    The OP uses an argument presented by Stephen Hawking to argue that the so called psychological arrow of time and the thermodynamic arrow of time were one and the same.

    This argument turned up in "A Brief History of Time" as I recall. Though, with no offense to the OP, Hawking's argument was a little more compelling, even if I can't remember exactly what it was.

    I think he simplified the argument by using computers as an anology of the human mind. If I remember I'll look this up when I get home.

  6. Aug 4, 2005 #5
    Irreversible phenomena increase disorder in closed systems. But brain is not a closed system, and irreversible phenomena (second law) in a open system can generate both order and structures. Those structures, frequentely, are not cited in basic physics textbooks on thermal phenomena, but a Nobel Prize for chemistry was awarded to Ilya Prigogine: they are dissipative structures.

    One can check that brain is a dissipative structure easily. A dissipative structure disappears when the flow of energy and matter is stopped. When a man passes away, natural flows of energy and matter stop and dissipative structures, e.g. brain disappear progresively. However, other structures, non dissipative ones, (e.g . bones) remain.

    Moreover, brain is a higghly correlated system. In CPS: physchem/0309002 was proposed a new thermodynamical framework for the study of that kind of systems (standard thermodynamics does not work).

    That generalization of thermodynamics generated the novel concept of epsilon structures. Those structures may play an important role on brain behavior. More information will be available on www.canonicalscience.com in brief.
    Last edited: Aug 4, 2005
  7. Aug 4, 2005 #6


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    Hi Dexed25;
    The main reason that the mind can't remember the future is that it hasn't happened yet! Precognition is impossible, because it implies 'predetermination'. That is specifically ruled out by quantum mechanics as well as common sense.
  8. Aug 4, 2005 #7
    Forming a memory of something requires that we be exposed to it in some way shape or form. Your question assumes some kind of previous exposure to the future, or at least information about the future, but you have glossed over this extremely important point, and neglected to explain how anyone might have any information about the future to remember in the first place.

    How is it that anyone might have been exposed to the future to form a memory of it?

    You are right, I think, to argue that forming new memories decreases the entropy of the brain (software-wise, anyway); the information is, in fact, ordered. The success or failure of our memory, though, is a much more complicated problem that goes way beyond the second law.
  9. Aug 4, 2005 #8

    Well, I believe you have raised a very valid question, but I must answer that according to the arrow of time theory, we perceive time in a direction going from "past" to "present", precisely because our brain needs to gain entropy to create memories, in fact all procceses evolve from a low entropy state to a high entropy state progressively thus determining the direction in which the flow of time moves (not actually admitting that time is linear, but is only perceived that way, would make it easier to understand). Then again, if we can suppose the brain actually goes from a disordered state to a more ordered one when creating memories, then wouldn't this mean that the arrow of time has been in a sense reversed as we go forward.

    There lies my contradiction.
  10. Aug 4, 2005 #9


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    As has been said already, there is no contrdiction because the brain is not a closed system and its operation does increase the disorder of the universe.
  11. Aug 4, 2005 #10
    Claude Bile mentioned "arrow of time" in connection with Hawking, so I assume that's where you got this idea.

    I've never read Hawking myself and don't understand why he might be arguing that the creation of memory by a gain in entropy would suggest a hidden non-vectored time that we are somehow mispercieving as vectored past to present. If our brains move from low to high entropy, and if all processes move from low to high entropy, what prompts the suspicion of non-linearity of time?
  12. Aug 5, 2005 #11


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    It's at least a decade since I read any Hawking ('A Brief History of Time' when it was first published), so I can't allude to any of his statements. The only thing that I can think of that might be relevant is that in particle physics some processes are considered to be 'time reversal invariant'. It's just a way of saying that if a film of the particular interactions was to be played backward and considered to be based upon antimatter rather than normal matter, there would be no way to tell that it wasn't being played forward. I really need a particle physicist to help me out here, but I think that's the essential idea of it. (Astronuc... Lisa!... Arildno... HELP!)
  13. Aug 5, 2005 #12
    We, living organism, may well be objects which have time extension, i.e.....we may exist in a certain stripe of time, instead of living in an instant of time as is usual to conceive, in the same manner that we exist with extension in the three spatial dimensions. If we have time extension, then it is in principle possible that we are exposed to what in our opinion may be called the future. Turn this dicussion into a spatial metaphore: Our sentive apparatus (lets concentrate on the eyes first) is located in our upper part. So, regarding the vertical dimension, our eyes have more condition to be aware of what happens near to our eyes altitude than to what happens near to out foot, or even what happens below the ground. We may talk about spatial perspective. it seems possible that there could exist a time pespective.

    Note that, although our eyes are located at an specific height, it can receive light (information) from things which are located at different heights. Ears may also fit in this analysis. Time perception may be concentrated at some narrow stripe of time dimension, but it seems conceivable that our universe may send informatio from the not so distant future to us. Distant future physical reallity seems to be something which is somewhat fuzzy. But near future may have concrete existence.

    Best Philosofical Regards

  14. Aug 6, 2005 #13


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    No offense intended, but the physical senses that you alluded to have nothing to do with temporal perception. They all are evolved to detect things (within specific ranges) that exist at the time of perception. The 'future' exists only as a concept until it becomes the 'present' and immediately thereafter the 'past'. One can extrapolate what is almost certain to occur in the immediate future, but it's completely theoretical until it actually happens.
  15. Aug 6, 2005 #14
    ok, but let me go a bit further in this metaphore and imagine thing a little bit more:
    When we look at a clock we get somewhat satisfied by seeing its arms in well defined positions. Now, supose the existence of the same clock in the same physical universe but in which we, human beings, have a time extension of say two hours instead of being "almost instantaneous living beings". What the clock would look like to us ? I would say that the hour arms we be sensed as a cloudy object with the shape of a typical slice of pizza (its internal angle being 60 degrees) and the minute arms would look like a cloudy disk.

    This visual, mechanical perceptions can lead us to infer time perception (with the help of a physical model of course).

    Sorry if it is too much fiction for this thread.

    Best Regards,

  16. Aug 6, 2005 #15
    He goes on to argue why these two arrows must point in the same direction, and further states that if entropy decreased with time...
    Last edited: Aug 6, 2005
  17. Aug 7, 2005 #16
    Thanks ?llipse. That says that the notion of "remembering the future" is just a kind of gedanken fiction that only applies to his gedanken people whose psychological "arrow of time" is going backwards, because the entropy of their gedanken universe in decreasing.

    He has never actually proposed that anyone ought to be able to remember the future or that we're being prevented from doing so by an increase in entropy associated with memory formation.
  18. Aug 7, 2005 #17


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    Memory formation in fact demonstrates a decrease in local entropy. Every new neuronal connection (chemical, since the physical is already in place) adds to the complexity of the brain structure. As Russ pointed out, however, the brain is not a closed system. Oxydative and glycolitic phosphorilation, cyclic AMP production, the manufacture and expenditure of Adenosine Triphosphate (ATP), the 'sodium pump' ionic mechanism, etc. all require the intake of fuel and oxygen from the bloodstream, which in turn gets it indirectly from the air that we breathe and the food that we eat. While the storage of memories significantly increases the order of things within the brain, it requires an increase of entropy in the universe as a whole.
  19. Aug 16, 2005 #18
    Why isn't the thermoidynamic arrow of time thought of as going from high entropy to lower entropy, in the opposite direction to the psychological arrow, towards what we think of as the past?
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