Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>> And I'm still not convinced you can actually destroy information. At the 
>> quantum level, time is reversible, which means that information at that 
>> level does *not* get destroyed.
> 
>   I don't understand how time could be reversible, because that would imply
> that an increase in entropy (of an isolated system) would also be reversible,
> which is against the law.

Because the law is statistical, and if you get sufficiently few degrees of 
freedom, then the statistics work out such that the probability *does* 
reverse on occasion.

Take a perfect frictionless billiards table. Rack the balls. Throw one ball 
into the middle. Watch them bounce around a while. Will they ever re-rack? 
No, that's entropy.  Is every interaction reversible?  Yes.  Is it 
*possible* the balls will bounce around enough to eventually come back 
together with exactly the right velocities that they'll all rerack? Certainly.

Take a tank of water. Put two atoms of ink in it. Let them diffuse until 
they're one on each side of the tank. Is it possible they'll ever randomly 
come together to where they're both very close to each other at one corner 
of the tank? Sure.  How long before 10^20 selected atoms of ink do that at 
random? A long, long time. Is it impossible? No.

-- 
Darren New, San Diego CA, USA (PST)
   Serving Suggestion:
     "Don't serve this any more. It's awful."

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