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Author Topic: Is theory of entropy correct?  (Read 4194 times)

Offline shufeng-zhang

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Is theory of entropy correct?
« on: 26/11/2010 19:50:37 »
We define heat engine efficiency η as: η= W/W1, that is, replacing Q1 in the original definition η=W/Q1 with W1, W still is the net work of the heat engine applied to the outside in one cycle, W1 is the work the heat engine applied to the outside in the cycle, then, we use Stirling cycle as the element reversible cycle, if ∮dQ/T =0 is tenable, we can prove ∮dW/T =0 and ∮dE/T =0.
If the formula ∮dQ/T=0,∮dW/T=0 and ∮dE/T=0 can really define new system state variables, it should come to the absurd result of such a definition. 
In fact, during the process of obtaining entropy, ∑[(ΔQ)/T)] becoming ∫dQ/T is untenable, therefore, the formula ∮dQ/T=0, ∮dW/T=0 and ∮dE/T=0 are all untenable.

Entropy:A concept that is not Physical Quantity
By shufeng-zhang          Email: uhsgnahz@126.com
College of Physics,Central-South University,China

newbielink:http://wenku.baidu.com/view/cd8704d5b9f3f90f76c61b82.html [nonactive]
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Offline Soul Surfer

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Is theory of entropy correct?
« Reply #1 on: 27/11/2010 00:09:51 »
To my mind the problem arises because entropy has two meanings one a precise physical meaning which allows you to calculate precisely how much useful work is obtainable from a heat engine operating between two clearly defined temperatures using clearly defined processes.  The other is a much more abstruse concept related to the flow of energy in a system (universe) coupled with an attempt to define a generalised term for the limits that exist.  I am afraid in english (and therefore most of science) we use the same word to describe both.  Perhaps we should introduce some sort of qualifier to distinguish between them.
 

Offline Bored chemist

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Is theory of entropy correct?
« Reply #2 on: 27/11/2010 18:20:35 »
S remains k ln(w)
 

Offline Soul Surfer

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Is theory of entropy correct?
« Reply #3 on: 28/11/2010 00:00:55 »
BC I agree that is the basic model of fundamental entropy but deciding on what all the independent states of the system are to define w is not easy and subject to argument.
 

Offline Bored chemist

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Is theory of entropy correct?
« Reply #4 on: 28/11/2010 10:45:58 »
I accept that it's not easy but there is, in principle, no argument.
You measure the entropy and that tells you w.
It's not a matter of opinion, it's a matter of fact.
No matter how many websites the OP posts his ideas on, as I said, S remains k ln(w).
 

Offline Soul Surfer

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Is theory of entropy correct?
« Reply #5 on: 28/11/2010 17:26:19 »
OK consider you were the last person alive as the universe died the heat death and your space suit heater ran out of energy and you froze down to the ambient of absolute zero what then is your entropy?
 

Offline Bored chemist

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Is theory of entropy correct?
« Reply #6 on: 28/11/2010 18:18:31 »
"you froze down to the ambient of absolute zero "
In this house we obey the laws of thermodynamics.

 

Offline Soul Surfer

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Is theory of entropy correct?
« Reply #7 on: 28/11/2010 23:49:12 »
LOL!!!  I was not suggesting anything against the laws of thermodynamics but pointing out with a satirical thought experiment that the final state of something may be along way from the idealised random structure.  So in your deciding of the number of states that anything has (w) to define its numerical entropy the route you take is important and the end points are not all the same Therefore the strict numerical entropy of something is not always single valued.

If you wish to think numbers it is far better to consider the normal differential entropy
 

Offline Bored chemist

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Is theory of entropy correct?
« Reply #8 on: 29/11/2010 14:07:59 »
The point I was making is that it jolly well does exist. It's difficult to calculate or measure in some cases, but it is real whatever shufeng-zhang says about it.
 

Offline JP

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Re: Is theory of entropy correct?
« Reply #9 on: 06/11/2012 18:21:30 »
shufeng-zhang, this is not the place to promote speculative theories, and posts that consist of nothing but links without discussion will be deleted.
 

Offline shufeng-zhang

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Re: Is theory of entropy correct?
« Reply #10 on: 11/11/2012 11:07:50 »
In fact, in thermodynamics, P-V figure should be P-V-T figure, that is, Carnot cycle should be drawn in P-V-T chart but not in P-V chart.

Please think the KEY STEP that  "deduced" entropy in P-V-T chart, you will know obviously that the KEY STEP is untenable at all.
 

Offline Bored chemist

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Re: Is theory of entropy correct?
« Reply #11 on: 11/11/2012 12:44:42 »
If it's fundamentally wrong, how come it works so well?
BTW, it's still k log (w)
 

Offline shufeng-zhang

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Re: Is theory of entropy correct?
« Reply #12 on: 12/11/2012 13:24:11 »
it works so well?
You don't know its self-contradiction?

On the other side:
Aristotle free-fall theory worked well for more than two thousand years.
Caloric theory、Phlogiston theory worked well for many years.
And so on.



 

Offline Bored chemist

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Re: Is theory of entropy correct?
« Reply #13 on: 12/11/2012 21:50:45 »
"Aristotle free-fall theory worked well for more than two thousand years."
Nope, it failed as soon as someone thought about it clearly.
"Caloric theory、Phlogiston theory worked well for many years."
Nope it was utterly inadequate to explain the experimental results. As soon as anyone checked on it, it failed.

What experimental evidence is there for a contradiction of entropy in thermodynamics?
 

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Re: Is theory of entropy correct?
« Reply #13 on: 12/11/2012 21:50:45 »

 

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