Re: [Phys-l] Greenhouse effect / 2nd law

[Stefan Jeglinski <jeglin@4pi.com>]

>  > I have been involved in a few discussions of global warming.  There
> >  seems to be a school of thought that has concluded that second law
> >  precludes the greenhouse effect.  They are convinced that IR cannot
> >  go from a cold object to a hot object.

By way of comparison, this seems reminiscent of 
the argument that the 2nd law precludes 
life/evolution: "2nd law says disorder must 
increase; life/evolution is order; hence there 
can be no life/evolution." This is still a 
cornerstone for at least some creationists. You 
might point this out as an example of how the 2nd 
law can be misinterpreted, esp in terms of 
defining disorder (I'm def in the camp that 
order/disorder should be barred from the 
discussion), or in terms of confusing energy with 
entropy, not to mention any concept of "flow."


>  > For example, here is one incarnation ...
> >
>  > "Over and over again the interpretation goes something like thisŠ..
>  > A hot object transfers heat to a colder surface for example 100J.
> >  The colder surface transfer heat to the warmer surface say 99J.
>  > This they say satisfies the second law of thermodynamics.
> >  Their reasoning is that the NET HEAT is from hot to cold.
>  > I hope by now everyone who has paid attention knows that this is nonsense."

I'm struggling to understand the scope of this 
argument as written. It sounds from the last line 
that the arguer is citing the argument as bogus? 
Or is it /you/ referring to the argument and then 
saying "this is nonsense." ? Who is arguing what?

I don't see why you couldn't find a way to 
arrange this scenario. I prefer to think of it in 
terms of power - so the hotter surface radiates 
100W and the colder 99W, but it doesn't sound 
like equilibrium to me. What does the rest of the 
argument you cite entail - any notion of 
equilibrium at all, or what that implies or does 
not imply?


Stefan Jeglinski