What Does Joules per Kelvin Imply About Entropy?

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Discussion Overview

The discussion centers on the physical interpretation of entropy, particularly its units of "Joules per Kelvin" and what this implies about energy distribution and internal energy in systems. Participants explore various interpretations and implications of entropy in both theoretical and practical contexts.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that entropy can be interpreted as a measure of the increase of internal energy with temperature, suggesting a relationship expressed by the formula S = U/T.
  • Others argue that if two bodies have the same temperature but different energy levels, the one with more energy has greater entropy.
  • A different perspective suggests that if two bodies have the same energy but different temperatures, the one with lower temperature has greater entropy.
  • Some participants challenge the traditional view of entropy as merely "disorder," indicating that this interpretation is outdated and not universally applicable.
  • A participant provides a link to resources that aim to clarify misconceptions about entropy, emphasizing that the standard formula S = k ln W is valid only under specific conditions, such as an isolated system at equilibrium.
  • Another participant suggests that the units of entropy imply how quickly energy is spreading in a medium, although this interpretation is not universally accepted.

Areas of Agreement / Disagreement

Participants express varying interpretations of entropy, with no consensus on a singular definition or understanding. The discussion remains unresolved regarding the physical implications of entropy and its representation in different contexts.

Contextual Notes

Some limitations include the dependence on specific conditions for the validity of certain formulas and the ongoing debate about the interpretation of entropy beyond the notion of disorder.

TimNguyen
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Hello.

I know that entropy equals the Boltzmann's constant times the natural log of the multiplicity but I do not know the physical interpretation of what "entropy" really is. I understand the units of it are "Joules per Kelvin" but what does that really mean?
 
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TimNguyen said:
Hello.

I know that entropy equals the Boltzmann's constant times the natural log of the multiplicity but I do not know the physical interpretation of what "entropy" really is. I understand the units of it are "Joules per Kelvin" but what does that really mean?

The most simple and direct interpretation

[tex]U = TS[/tex]

entropy is a "measure" of the increase of internal energy with temperature or

[tex]S = \frac{U}{T}[/tex]

If two bodies have the same temperature but one has more energy, then it has more entropy.

If two bodies have the same energy but one has less temperature, then it has more entropy.
 
Last edited:
TimNguyen said:
Hello.

I know that entropy equals the Boltzmann's constant times the natural log of the multiplicity but I do not know the physical interpretation of what "entropy" really is. I understand the units of it are "Joules per Kelvin" but what does that really mean?

Try this:

http://www.entropysite.com/

It has a good collection of basic articles, especially in dispelling the notion that entropy is nothing more than "disorder".

Zz.
 
ZapperZ said:
Try this:

http://www.entropysite.com/

It has a good collection of basic articles, especially in dispelling the notion that entropy is nothing more than "disorder".

Zz.

Nice link!

Effectively, the old (archaic) idea of entropy like disorder is not justified and would be abandoned of literature.

Moreover, the standard formula [tex]S = k \ ln W[/tex] often invoked in that old interpretation is valid only in the very special case of an isolated system at equilibrium.

That is reason that one would reasoning what is entropy from above formulas.
 
TimNguyen said:
Hello.

I know that entropy equals the Boltzmann's constant times the natural log of the multiplicity but I do not know the physical interpretation of what "entropy" really is. I understand the units of it are "Joules per Kelvin" but what does that really mean?
ans:
it really means how quickly the energy is spreding in medium.
 
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