John,

I think you are misreading Stan’s comments a little.  [Stan:  please correct me 
if I am wrong about that.]  I think it would be fair to say that older car 
engines were less well fit "between the energy gradient and the system 
attempting to utilize it”.  Another way of saying this is that the older car 
engine mechanism was less efficient in dissipating that gradient, which 
translated into low gas mileage.  Those engines had to work harder in 
delivering the same outcome (say driving 1 mile) than the newer, more efficient 
engines.  The capacity of the new engines to work harder than old engines does 
not mean they work harder to produce the same outcome.  I don’t see the flaw in 
saying that working harder to achieve a constant outcome degrades more energy.  
Clever design and selection can indeed utilize information to yield greater 
efficiencies, which can only approach the limit imposed by the 2nd law.  It 
looks to me like you and Stan are really in agreement here.  Am I missing 
something?

Cheers,

Guy

On Sep 4, 2014, at 1:06 PM, John Collier 
<colli...@ukzn.ac.za<mailto:colli...@ukzn.ac.za>> wrote:

S: In decline in the actual material world that we inhabit.  That is, the local 
world -- the world of input and dissipation.  I think the information problem 
may be advanced if we try to explain why the energy efficiency of any work is 
so poor, and gets worse the harder we work. This is the key local phenomenon 
that needs to be understood.

JC: Information can be used to improve efficiency.

SS: That is not same question.  Which is: Why is any work constitutively poor 
in energy efficiency?  I wrote a little essay ( Entropy: what does it really 
mean?  General Systems Bulletin  32:5-12.) suggesting that it results from a 
lack of fittingness between energy gradient and the system attempting to 
utilize it -- that is, that it is an information problem.

Actually, it is part of the same question. As I have said many times, you 
trivialize the idea of maximum entropy production if you relativize it to all 
constraints. Howard has made this sort of point over and over as well.

But you are right that the important factor is an information problem.

I was once asked to referee a paper that argued that we could get around 2nd 
law degradation by using the exhaust heat in a clever way, and keep doing this 
ad infinitum. I pointed out (sarcastically) that we could do this, but only if 
we could make smaller and smaller people to use the energy (apologies to Kurt 
Vonnegut).

We get much more work out of gasoline engines than we used to, even though most 
are smaller and work harder. So, no, it is not in general true that harder work 
degrades more energy. Clever design (and selection) can make a difference that 
is more significant.

John


_______________________________________________
Fis mailing list
Fis@listas.unizar.es<mailto:Fis@listas.unizar.es>
http://listas.unizar.es/cgi-bin/mailman/listinfo/fis

_______________________________________________
Fis mailing list
Fis@listas.unizar.es
http://listas.unizar.es/cgi-bin/mailman/listinfo/fis

Reply via email to