What Does Joules per Kelvin Imply About Entropy?

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Entropy, measured in Joules per Kelvin, quantifies how energy disperses within a system. It is defined by the relationship S = U/T, indicating that higher energy at the same temperature results in greater entropy. The traditional view of entropy as mere disorder is outdated; instead, it reflects the distribution of energy states. The formula S = k ln W applies specifically to isolated systems at equilibrium, emphasizing the need for a nuanced understanding of entropy. Ultimately, entropy represents the rate at which energy spreads through a medium.
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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

U = TS

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

S = \frac{U}{T}

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.
 
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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?

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 S = k \ ln W 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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