Gas considered as lots of molecules

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    Gas Molecules
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Discussion Overview

The discussion revolves around the approximation of gases as collections of molecules that interact through collisions, exploring the underlying assumptions and forces involved in this model. Participants examine the justification for simplifying complex molecular interactions into a more manageable framework, touching on concepts from statistical mechanics and kinetic theory.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants question the basis for approximating gas molecules as "beach balls" and seek justification for this simplification.
  • Others argue that this approximation is an accurate description of molecular behavior, particularly for monatomic gases, while noting that diatomic and polyatomic gases exhibit more complex interactions.
  • There is discussion about the forces at play during molecular collisions, with some asserting that only Coulomb forces are relevant, while others mention the insignificance of magnetic forces in this context.
  • Participants highlight the role of statistical mechanics in managing the complexity of calculating forces among a vast number of particles.
  • One participant introduces the Lennard-Jones potential to describe interactions between neutral atoms, noting that at high temperatures, the potential can be approximated as zero when atoms are far apart.
  • There are inquiries about the nature of the potential field involved and whether it accounts for magnetic forces, with some clarifying that electromagnetic forces dominate the interactions.
  • The discussion includes a mathematical exploration of momentum changes during elastic collisions with walls, emphasizing the implications for force calculations in a gas system.

Areas of Agreement / Disagreement

Participants express differing views on the validity and accuracy of the "beach ball" model, with some asserting it as a valid approximation while others highlight its limitations. The discussion remains unresolved regarding the completeness of the forces considered in molecular interactions.

Contextual Notes

Participants acknowledge the complexity of molecular interactions and the limitations of the models used, including the dependence on temperature and the empirical nature of the Lennard-Jones potential. There is also recognition of the need for statistical approaches to simplify the analysis of large numbers of particles.

  • #31
anirudh215 said:
... how do I [we?] learn further from here?
Another, shorter-term suggestion for you:

Besides Physics Forums, you could look online at wikipedia or hyperphysics. A few topics to look for are:

The Schrödinger Equation (the time-dependent and also time-independent versions)
wavefunctions
eigenvalues, eigenvectors, and eigenfunctions​

These are some of the fundamental building blocks to learning quantum mechanics.

As for me, if I had the time I'd probably look for journal articles dealing with the possible measurements we have been discussing here. But my current, personal interests are to learn more about electric motors, power generation, and thermodynamics.

Good luck to you.
 
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  • #32
Redbelly98 said:
Another, shorter-term suggestion for you:

Besides Physics Forums, you could look online at wikipedia or hyperphysics. A few topics to look for are:

The Schrödinger Equation (the time-dependent and also time-independent versions)
wavefunctions
eigenvalues, eigenvectors, and eigenfunctions​

These are some of the fundamental building blocks to learning quantum mechanics.

I know what eigenvalues/ functions are. My Linear Algebra is not too bad and getting better. I don't know much about the other two though. I'll look into those. I am currently to learn about classical statistical mechanics and quantum mechanics and that is where all these questions popped up from. Texts always seem to leave many holes in my understanding.

Good luck to you.

Thanks for all your help! Does anyone else have comments on this?
 

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