Blocking the symmetry of motion and the second law

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Discussion Overview

The discussion revolves around the implications of a new material that blocks molecular motion in one direction while allowing it in another, as reported in an article. Participants explore how this concept relates to the second law of thermodynamics, questioning whether it presents a violation or misunderstanding of thermodynamic principles.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant suggests that the ability to block motion in one direction while allowing it in another contradicts the second law of thermodynamics, proposing that this could lead to infinite energy production in an open system.
  • Another participant questions whether the phenomenon is merely a small-scale ratchet mechanism and seeks clarification on the nature of the material's response to motion.
  • A different participant argues that the original article does not imply any violation of the second law, stating that the material's behavior is simply a unique property without suggesting perpetual motion or infinite energy generation.
  • One participant references Feynman's lectures on ratchets and the second law, indicating that there is established discussion on this topic that may provide further insights.

Areas of Agreement / Disagreement

Participants express disagreement regarding the implications of the material on the second law of thermodynamics, with some asserting that there is no violation while others believe there may be a misunderstanding of the principles involved.

Contextual Notes

There are unresolved assumptions regarding the interpretation of the material's properties and their implications for thermodynamics. The discussion also reflects varying levels of understanding of the original article and its scientific context.

Who May Find This Useful

Individuals interested in thermodynamics, materials science, and the implications of new materials on established physical laws may find this discussion relevant.

Papatom
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Hi,

The article below states that they made a material that blocks the motion of molecules in only one way but passing the other way is possible. See the article.

https://physicsworld.com/a/blocking-the-symmetry-of-motion/

This seems to me in contrast with the second law. You can for example make the pressure higher in one compartiment without using energy. Than you use the difference in pressure to produce electricity or motion or whatever. If you would have a closed system the temperature would drop. If you do not have a closed system you can produce energy infinite.

Can somebody explain to me what my mistake is?
 
Science news on Phys.org
Is this more than a small scale ratchet mechanism?
The introductory passage "A mechanical metamaterial that responds strongly to motion" is a bit confusing. What sort of "response" is involved?
Papatom said:
You can for example make the pressure higher in one compartiment without using energy.
How would you achieve this? Would you not need an initial pressure difference to produce motion? You may be reading more into this than the Nature article seems to imply. The Physics World journalist's interpretation of what he read may not be the best source for the 'facts'. The original work could produce useful practical applications without violating thermodynamics laws.
 
Papatom said:
This seems to me in contrast with the second law.
The article said nothing about violating the 2nd law. You are just making that up. From what the article described the material is stiffer in one direction than in the opposite direction. That is strange and potentially useful, but no violation of the 2nd law.

Papatom said:
You can for example make the pressure higher in one compartiment without using energy. Than you use the difference in pressure to produce electricity or motion or whatever. If you would have a closed system the temperature would drop. If you do not have a closed system you can produce energy infinite.
This is also not even remotely implied by the article. You are completely fabricating this.

We do not discuss perpetual motion machines here. Thread closed
 

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