Maxwell's Demon: What Do You Think?

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Discussion Overview

The discussion revolves around Maxwell's Demon and its implications for thermodynamics and molecular behavior. Participants explore the paradox presented by Maxwell's Demon, questioning the assumptions underlying its classical interpretation and considering modern perspectives on molecular behavior.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions the significance of Maxwell's Demon, suggesting that if the system's walls are perfect insulators, the demon would need energy to move a molecular-sized door for each transition, implying a limitation to the demon's effectiveness.
  • Another participant acknowledges the energy requirement for the demon to measure molecular speeds, indicating that measurement itself alters molecular energy, which complicates the paradox.
  • A participant asserts that the paradox is based on classical models, which do not accurately describe molecular behavior.
  • In response to a question about molecular behavior, it is noted that quantum models provide a more accurate description, as classical laws have been inadequate for over a century.

Areas of Agreement / Disagreement

Participants express differing views on the relevance and implications of Maxwell's Demon, with some supporting classical interpretations while others advocate for quantum models. The discussion remains unresolved regarding the implications of these differing perspectives.

Contextual Notes

The discussion highlights limitations in classical models and the transition to quantum descriptions, but does not resolve the implications of these shifts for the paradox of Maxwell's Demon.

KingNothing
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This came up in another topic, but rather than talk on about it there, I created a new thread as it would be too far off subject for the said other thread.

I don't see the big deal about "Maxwell's Demon". Assuming the walls and everything in the system are perfect insulators, wouldn't (grossly oversimplifying here) the door, being the size of a molecule, have to be made of at least 1 molecule, and the 'creature' require enough energy to move this 1 molecule back and forth for each molecule/transition that must occur?

What does everyone think?
 
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KingNothing said:
This came up in another topic, but rather than talk on about it there, I created a new thread as it would be too far off subject for the said other thread.

I don't see the big deal about "Maxwell's Demon". Assuming the walls and everything in the system are perfect insulators, wouldn't (grossly oversimplifying here) the door, being the size of a molecule, have to be made of at least 1 molecule, and the 'creature' require enough energy to move this 1 molecule back and forth for each molecule/transition that must occur?

What does everyone think?

Yes, that is one of the explanations that has been given to this paradox. Anotherone is that the demon would require energy to "measure" the speed of the molecules. The action of measuring would also modify the molecule´s energy.

The paradox is based in a completely classical model, and molecules do not behave classically. The paradox has no sense in a modern microscopic description of matter.
 
Last edited:
altered-gravity said:
The paradox is based in a completely classical model, and molecules do not behave classically.

Oh, so how do molecules behave?
 
KingNothing said:
Oh, so how do molecules behave?

Quantum models describe their behaviour. Molecules are systems of particles, electrons and nuclei. Classical laws failed to describe them a hundred years ago.
 

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