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Posers and Puzzles

Posers and Puzzles

  1. 29 Apr '05 12:38
    I'm wondering why it is that generally, but especially during Carnivals or other big celebrations in cities, people don't tend to gather in the same place at the same time. Or perhaps they do but on the whole distribution seems to be relatively even. A friend told me that it was probably connected to the phenomenon which stops air molecules from gathering in one spot, thus preventing us from choking to death. Am I missing the obvious?
  2. Standard member Bowmann
    Non-Subscriber
    29 Apr '05 13:15
    Probably.
  3. 01 May '05 20:32
    Originally posted by agoekjian
    I'm wondering why it is that generally, but especially during Carnivals or other big celebrations in cities, people don't tend to gather in the same place at the same time. Or perhaps they do but on the whole distribution seems to be relatively even. A friend told me that it was probably connected to the phenomenon which stops air molecules from gathering in one spot, thus preventing us from choking to death. Am I missing the obvious?
    the second law of thermodynamics (aka: entropy) applied to crouds, nothing more.

    question: in more direct application, can entropy be dified?
    the second law of thermodynamics is not really a 'law' per se, so is it possible to intentionaly and repeatedly reverse it?
  4. 07 May '05 10:03
    Originally posted by fearlessleader
    the second law of thermodynamics (aka: entropy) applied to crouds, nothing more.

    question: in more direct application, can entropy be dified?61
    the second law of thermodynamics is not really a 'law' per se, so is it possible to intentionaly and repeatedly reverse it?
    This is the subject of Asimov's short story - "The Last Question". As the end of the universe draws nearer, the most sophisticated computer on earth is asked how to save humanity with the following question - Can the second law of thermodynamics be reversed?

    Apparently he thought it the best story he wrote.
  5. Standard member royalchicken
    CHAOS GHOST!!!
    07 May '05 10:07
    Originally posted by agoekjian
    This is the subject of Asimov's short story - "The Last Question". As the end of the universe draws nearer, the most sophisticated computer on earth is asked how to save humanity with the following question - Can the second law of thermodynamics be reversed?

    Apparently he thought it the best story he wrote.
    With the possible exception of 'The Holmes-Ginsbook Device', it is the best story he wrote.
  6. Subscriber AThousandYoung
    It's about respect
    07 May '05 20:02
    Originally posted by agoekjian
    This is the subject of Asimov's short story - "The Last Question". As the end of the universe draws nearer, the most sophisticated computer on earth is asked how to save humanity with the following question - Can the second law of thermodynamics be reversed?

    Apparently he thought it the best story he wrote.
    At that point the computer is no longer on Earth.

    It is a pretty clever story.
  7. Subscriber AThousandYoung
    It's about respect
    07 May '05 20:07
    Originally posted by agoekjian
    I'm wondering why it is that generally, but especially during Carnivals or other big celebrations in cities, people don't tend to gather in the same place at the same time. Or perhaps they do but on the whole distribution seems to be relatively even. A friend told me that it was probably connected to the phenomenon which stops air molecules from gathering in one spot, thus preventing us from choking to death. Am I missing the obvious?
    If you look at the planet from space, humans are not randomly distributed. More are in cities than elsewhere, for example.

    If you look at a big celebration, people are also not randomly distributed. People will be more likely to be at a bar, near the stage, near the rides, near the food, etc.

    There are similar processes going on with the people and the air molecules. However the laws of physics which describe why air particles are evenly distributed assume a homogenous environment. If there were some sort of factor like a hole to a vacuum on one side of a box then the air particles would not be evenly distributed. Similarly, humans encounter many things in their environment which affect how the humans will move, keeping them from moving completely randomly.
  8. Subscriber AThousandYoung
    It's about respect
    07 May '05 20:08
    Originally posted by fearlessleader
    the second law of thermodynamics (aka: entropy) applied to crouds, nothing more.

    question: in more direct application, can entropy be dified?
    the second law of thermodynamics is not really a 'law' per se, so is it possible to intentionaly and repeatedly reverse it?
    No, as far as I know, the 2nd Law cannot be defied. Entropy will increase in a closed system, period. The only way to decrease entropy is to increase it even more somewhere else.
  9. Donation richjohnson
    TANSTAAFL
    07 May '05 21:57
    Originally posted by AThousandYoung
    No, as far as I know, the 2nd Law cannot be defied. Entropy will increase in a closed system, period. The only way to decrease entropy is to increase it even more somewhere else.
    http://prola.aps.org/abstract/PRA/v39/i10/p5378_1?qid=862748786df953f8&qseq=1&show=10

    maybe heat death isn't inevitable after all...
  10. 09 May '05 19:05
    Originally posted by richjohnson
    http://prola.aps.org/abstract/PRA/v39/i10/p5378_1?qid=862748786df953f8&qseq=1&show=10

    maybe heat death isn't inevitable after all...
    interesting article...but wouldn't the Maxwell 'Demon' have to be able to get around that pesky Heisenberg Uncertainty Principle in order to determine when exactly to operate his shutter?

    My feeling is that if you propose something that ends up violating the second law, then it's time to scrap that proposition and propose something else.
  11. Donation richjohnson
    TANSTAAFL
    09 May '05 21:58
    Originally posted by davegage
    interesting article...but wouldn't the Maxwell 'Demon' have to be able to get around that pesky Heisenberg Uncertainty Principle in order to determine when exactly to operate his shutter?

    My feeling is that if you propose something that ends up violating the second law, then it's time to scrap that proposition and propose something else.
    I tend to agree with you, but some recent experiments have shown that the second law may be violated on a microscopic scale, which may have some interesting implications for nanotechnology.

    See:

    http://www.aip.org/enews/physnews/2002/split/598-1.html

    http://prola.aps.org/searchabstract/PRL/v89/i5/e050601?qid=36507ec175959a75&qseq=1&show=10
  12. Standard member Alcra
    Lazy Sod
    10 May '05 05:50
    Originally posted by royalchicken
    With the possible exception of 'The Holmes-Ginsbook Device', it is the best story he wrote.
    I had thought I had at least read all his books - but I have never seen this one. Anyone know where I can get a copy?
  13. 19 May '05 15:31
    Originally posted by davegage
    interesting article...but wouldn't the Maxwell 'Demon' have to be able to get around that pesky Heisenberg Uncertainty Principle in order to determine when exactly to operate his shutter?

    My feeling is that if you propose something that ends up violating the second law, then it's time to scrap that proposition and propose something else.
    can you give a better explination of maxwell's demon?