Re: Pizza Example

From: Chris Hoess <choess_at_stwing.upenn.edu>
Date: Tue, 20 Apr 2004 05:12:09 +0000 (UTC)
Message-ID: <slrnc89c98.3hk.choess_at_force.stwing.upenn.edu>


In article <CbzHNpBGVwgAFwaa_at_thewolery.demon.co.uk>, Anthony W. Youngman wrote:
>
> Who gives a sh*t about "standards" when there's a scientific law that
> says you can't do it?
>
> I do appreciate what you're saying, about how database integrity
> standards are rigorous, but the scientific equivalent of what you
> propose is not separating the results into "90% good, 10% bad"; it is
> claiming that you have just invented a perpetual motion machine. In the
> real world, IT CANNOT BE DONE. PHYSICS FORBIDS IT.

Invidious nonsense. The Second Law of Thermodynamics tells us that the entropy of an *isolated system* must increase with every thermodynamic change. But your computer is not an isolated system! It requires input of energy to increase or maintain order in the system, which comes via electricity; the increase in entropy or destruction of information occurs in the combustion of fuel at the power plant. Besides, there is a simple counterexample: if every change we made to information on a computer caused entropy to increase, we could never save files! After all, a blank hard disk is essentially random 0s and 1s, and storing a file on it orders some portion of that.

(For that matter, I think the discussion of "decomposition" that started this subthread is a red herring; it's the tables that are being decomposed, not the data.)

-- 
Chris Hoess
Received on Tue Apr 20 2004 - 07:12:09 CEST

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