Maxwell's Demon: What Do You Think?

AI Thread Summary
The discussion centers on the concept of "Maxwell's Demon" and its implications for thermodynamics. Participants argue that the paradox assumes a classical model, which does not accurately reflect molecular behavior. It is suggested that the demon would need energy to operate and measure molecular speeds, which complicates the scenario. Additionally, modern quantum models provide a more accurate understanding of molecular interactions, contradicting classical assumptions. Overall, the conversation highlights the limitations of classical physics in explaining molecular dynamics.
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.
 
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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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