Post by Progenitor A on Mar 26, 2011 8:52:57 GMT 1
There has been great confusion and contradiction about entropy
Not thermodynamic entropy - I think that everyone is agreed that when work is done, some energy is always 'wasted' and much of that wasted energy is converted into unusable forms
This law is normally couched in terms of 'closed' thermodynamic systems - that is systems in which the total energy remains constant, no 'new' energy is introduced and no energy is lost; some of the energy within that closed system is usable, some is not.
The reason for introducing the concept of a 'closed' system is quite straightforward, it simplifies the concept of thermodynamic entropy and does not allow distraction from the central concept of thermodynamic entropy that is hence starkly defined
Exactly the same thermodynamic entropy the 'wastage' of energy occurs in 'open' systems too, but the 'usable' energy may increase because new energy may be introduced. (Of course energy may also be lost from an 'open' system, increasing the entropy rate!)
All this accords with our experience, our intuition and our common sense
Unfortunately all these reliable indicators of soundness-of-mind and reliability of idea simply evaporate when we move away from thermodynamic entropy and consider entropy in terms of order-to-disorder.
Why is this?
Why is order-to disorder entropy apparently so much more difficult to understand than thermodynamic entropy?
Why is order-disorder entropy apparently riddled with contradictions whereas thermodynamic entropy is not?
Some quite intelligent people absorb these contradictions and yet claim to 'understand' order-to-disorder entropy. If any other physical theory contradicted itself these same people would laugh it out of court.
The real apparent contradiction of order-to disorder entropy is that we see all around us contradictory evidence
We see everywhere the opposite, disorder-to-order.
The normal response to this contradictory evidence of disorder-to-order is that it 'only occurs in 'open' systems'
But a small pause to consider this riposte shows that it is nonsensical. Disorder-to-order occurs in both 'open' and 'closed' systems.
Perhaps the problem is that no-one has payed particular attention to the definition of 'order'. Cox did attempt to on his recent TV programme, and that has been forwarded on these boards - that is that order is defined as the improbability of a structure.
That seems good enough to me in fact
So some apparent contradictions about order-to disorder entropy must be accepted and challenged and some misleading shibboleths abandoned
The biggest barrier that I see to gaining a coherent understanding of order-to-disorder entropy, the shibboleth that should be abandoned as a mantra of obfuscation is the use of 'open' and 'closed' thermodynamic systems when discussing order-to-disorder entropy
Of course order-to -disorder entropy is related to, is a function of, thermodynamic entropy, but neither have anything to do with open or closed thermodynamic systems
So, let's close the book on 'open' and 'closed' systems.
They were introduced to simplify the concept of thermodynamic entropy, and can be dispensed with once we understand thermodynamic entropy
There is an explanation of order-to-disorder entropy as a function of thermodynamic entropy that does not depend upon mantras that lead to contradiction
Not thermodynamic entropy - I think that everyone is agreed that when work is done, some energy is always 'wasted' and much of that wasted energy is converted into unusable forms
This law is normally couched in terms of 'closed' thermodynamic systems - that is systems in which the total energy remains constant, no 'new' energy is introduced and no energy is lost; some of the energy within that closed system is usable, some is not.
The reason for introducing the concept of a 'closed' system is quite straightforward, it simplifies the concept of thermodynamic entropy and does not allow distraction from the central concept of thermodynamic entropy that is hence starkly defined
Exactly the same thermodynamic entropy the 'wastage' of energy occurs in 'open' systems too, but the 'usable' energy may increase because new energy may be introduced. (Of course energy may also be lost from an 'open' system, increasing the entropy rate!)
All this accords with our experience, our intuition and our common sense
Unfortunately all these reliable indicators of soundness-of-mind and reliability of idea simply evaporate when we move away from thermodynamic entropy and consider entropy in terms of order-to-disorder.
Why is this?
Why is order-to disorder entropy apparently so much more difficult to understand than thermodynamic entropy?
Why is order-disorder entropy apparently riddled with contradictions whereas thermodynamic entropy is not?
Some quite intelligent people absorb these contradictions and yet claim to 'understand' order-to-disorder entropy. If any other physical theory contradicted itself these same people would laugh it out of court.
The real apparent contradiction of order-to disorder entropy is that we see all around us contradictory evidence
We see everywhere the opposite, disorder-to-order.
The normal response to this contradictory evidence of disorder-to-order is that it 'only occurs in 'open' systems'
But a small pause to consider this riposte shows that it is nonsensical. Disorder-to-order occurs in both 'open' and 'closed' systems.
Perhaps the problem is that no-one has payed particular attention to the definition of 'order'. Cox did attempt to on his recent TV programme, and that has been forwarded on these boards - that is that order is defined as the improbability of a structure.
That seems good enough to me in fact
So some apparent contradictions about order-to disorder entropy must be accepted and challenged and some misleading shibboleths abandoned
The biggest barrier that I see to gaining a coherent understanding of order-to-disorder entropy, the shibboleth that should be abandoned as a mantra of obfuscation is the use of 'open' and 'closed' thermodynamic systems when discussing order-to-disorder entropy
Of course order-to -disorder entropy is related to, is a function of, thermodynamic entropy, but neither have anything to do with open or closed thermodynamic systems
So, let's close the book on 'open' and 'closed' systems.
They were introduced to simplify the concept of thermodynamic entropy, and can be dispensed with once we understand thermodynamic entropy
There is an explanation of order-to-disorder entropy as a function of thermodynamic entropy that does not depend upon mantras that lead to contradiction