Shannon Entropy for Black Holes

rickman wrote:

   ...

> Don't let this confuse you.  In reality "lost" energy is still energy. 
> But it is lost in the sense that you can't do anything useful with it. 
> It becomes spread out evenly as heat otherwise known as "disorder". 
> Only "orderly" forms of energy can be used.  
> 
> Heat is only useful (orderly) if there is more of it here than there,
> then you can get some useful work from it by tapping it as it flows from
> here to there.  But then both here and there are at the same temperature
> and you can do no more work with that energy.  In that sense, it is
> "lost".  

Nicely put. A corollary is that when everything is at the same
temperature, nothing can be seen. Some electric ovens have a covered
eye hole so that one can see what's happening by swinging aside the flap
and peering in. There is often enough glow from the hot walls to show
the work. The work disappears at equilibrium, when it reaches the
temperature of the walls.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
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