From: gusenet@gmx.net   
      
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   > Another recreational impossibility, a la Douglas Adams.   
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   > Heat flows from hot to cold because in statistical mechanics, the ratio    
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   > of the probabilities (basically the state densities) favours that    
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   > direction by so large a factor that it's overwhelmingly probable that no    
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   > vaguely macroscopic hot object has ever got hotter by spontaneous heat    
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   > transfer from a colder object in the entire history of the universe.   
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   > I haven't slogged through Gerhard's example, but the usual ways that    
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   > people cock up radiative transfer calculations are failing to take into    
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   > account the change in the speed of light due to changing refractive    
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   > index (which gives erroneous numbers for the flux and the energy    
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   > density) or ignoring total internal reflection.   
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   > Cheers   
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   > Phil "Heard it all before" Hobbs   
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   Thanks for your response. Both points are very important.   
   Regarding the speed of light: In this setup the speed is not important at all.   
   In principle there are two blackbodies and in between some transparent media.   
   The flux from blackbody A to B will (after a short time) only depend on the   
   number of generated    
   beams at A per time period and the probability that a beam from A will reach B   
   any ant time. The time for the beams from A to reach B is irrelevant. And vice   
   versa.   
   I considered the total internal reflection, since is one of the important   
   facts from this setup. The transparent sheet in the middle has a lower   
   refractive index than the other two sheets left and right. Therefore the beams   
   with an angle arger than the    
   critical angle with respect to the normal to the surface will be reflected.   
   Interestingly when one blackbody is not parallel to this middle sheet, then   
   this effect will occur.   
   Best regards,   
   Gerhard   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)