Exploring Entropy: Macro vs. Micro Reductionism and Separationism

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Discussion Overview

The discussion explores the relationship between macro and micro definitions of entropy, questioning whether entropy can be reduced from a macro area to micro components. Participants examine the implications of reductionism versus separationism in this context, alongside the statistical nature of entropy and its definitions in thermodynamics.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question whether entropy can be meaningfully reduced from a macro area to micro components, suggesting that such a process may be nonsensical.
  • Others argue that entropy is defined for any system with recognizable macrostates and microstates, implying that it can be applied to smaller systems.
  • A participant proposes that the natural tendency of entropy is to spread from a compact domain to a less compact one, relating this to energy equilibrium.
  • There is a discussion about the implications of reducing energy from larger particles to smaller ones, such as from protons to quarks, and how this relates to entropy and equilibrium states.
  • Mathematical definitions of entropy are presented, including a specific equation related to statistical ensembles, with references to Gibbs' entropy and Einstein's contributions to the concept.
  • Questions are raised about the relationship between phase transitions of ensembles and the mathematical definitions provided, as well as whether Gibbs' entropy is equivalent across different volumes.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of entropy to macro and micro systems, with some asserting that reduction is nonsensical while others maintain that entropy can be defined for smaller systems. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Limitations include the dependence on definitions of macrostates and microstates, and the unresolved nature of how entropy behaves in relation to different scales of systems.

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Can Entropy be reduced from a Macro Area (large quantity?), to a Micro Quantity, individual 'area' components?

If so would this process be reductionism or Separationism?
 
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It would be nonsense.Entropy is a statistical quantity defined on statistical ensembles...

Daniel.
 
It would be nonsense.Entropy is a statistical quantity defined on statistical ensembles...

This is not true, entropy is defined for any system for which we can recognize "macrostates" and "microstates".

You might have meant that the second law of thermodynamics would be nonsense if applied to a system other than a statistical ensemble.

Can Entropy be reduced from a Macro Area (large quantity?), to a Micro Quantity, individual 'area' components?

What exactly are you asking? Can entropy be defined for small systems (yes)? Could it be meaningful to consider the entropy of various subsytems (yes)? Please try and rephrase the question.
 
dextercioby said:
It would be nonsense.Entropy is a statistical quantity defined on statistical ensembles...

Daniel.

Of course the natural path for Entropy is to spread out from a compact domain, to one that is less compact, I believe the standard stance is:Energy, in whatever form, tends to Equilibriate from an out_of_equlibrium state, to one that is closer to Equilibrium.

A volume/area of matter that is close to an Equilibrium state, can only get closer to Equilibrium, by interaction with its surrounding Area/Volume.

So a small Area that has energy present, if it is reduced further, ie in Stringtheory for instance, the separation of Componant energy, actually increase's the Energy value.

Lets start to reduce an energy from a particle of certain size, to one of a lesser size, from a Proton to an individual Quark, or from an individual Quark to a single string?

In Entropy terms, this is creating a Non-Equilibriated starting point?..the potential of which can interact with the surrounding Area/..do you agree?

So the "nonsense" now becomes apparent..please enlighten me!

Define the stastistical ''quantity" for change of 'one_MACRO_AREA->to_one micro_area'.
 
[tex]S_{stat,class.stat.virtual ensemble}=:-k\langle \ln \rho\rangle _{\rho}[/tex] (1)

This is the definition.

The definition of [itex]\rho[/itex]...

[tex]\rho (x,0) =:\lim_{\Omega_{\mathcal{D}} \rightarrow 0 ,x\in \mathcal{D}} \frac{1}{\Omega_{\mathcal{D}}} \left(\lim_{\mathcal{N}\rightarrow +\infty}\frac{\mathcal{N}\left(\mathcal{D}_{t=0}\right)}{\mathcal{N}}\right)[/tex]


The dependence of the probability density of a classical miscrostate "x" of the macrostate is postulated.

Correctly

[tex]\rho=\rho\left(microstate,time;macrostate\right)[/tex]


Einstein did it.We may call (1) Gibbs' entropy,but Einstein provided the concept that definition relies on:virtual statistical ensemble...

Daniel.
 
Last edited:
dextercioby said:
[tex]S_{stat,class.stat.virtual ensemble}=:-k\langle \ln \rho\rangle _{\rho}[/tex] (1)

This is the definition.

The definition of [itex]\rho[/itex]...

[tex]\rho (x,0) =:\lim_{\Omega_{\mathcal{D}} \rightarrow 0 ,x\in \mathcal{D}} \frac{1}{\Omega_{\mathcal{D}}} \left(\lim_{\mathcal{N}\rightarrow +\infty}\frac{\mathcal{N}\left(\mathcal{D}_{t=0}\right)}{\mathcal{N}}\right)[/tex]


The dependence of the probability density of a classical miscrostate "x" of the macrostate is postulated.

Correctly

[tex]\rho=\rho\left(microstate,time;macrostate\right)[/tex]


Einstein did it.We may call (1) Gibbs' entropy,but Einstein provided the concept that definition relies on:virtual statistical ensemble...

Daniel.

Thanks, so the Phase transition of an Ensemble is governed by the above Equation?..is Gibbs Entropy equivilent for all Volumes?
 
Volume is an mechanical extensive parameter involved in the description of a macrostate of a closed (constant volume) thermodynamical system.So,yes,entropy is a function of volume.

Macroscopical volume...The volume of a domain in [itex]\mathbb{R}^{3}[/itex] ...

Daniel.
 

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