From: "Enzo Michelangeli" <em@who.net>
Date: Thu, 6 Aug 1998 17:53:22 -0700 (PDT)
To: <honig@sprynet.com>
Subject: Re: Noise source processing
Message-ID: <00bf01bdc19d$eb2c09c0$88004bca@home>
MIME-Version: 1.0
Content-Type: text/plain


-----Original Message-----
From: David Honig <honig@sprynet.com>
Date: Friday, August 07, 1998 1:58 AM


>>What about an analog filter placed before the digitizer?
>
>The engineering issue is this: no matter how great you filter out
>the junk, you don't have a perfect analog measurement to start with.
>(Note that filtering out junk reduces info content).

Well, linear analog filters are reversible, so, by themselves, they neither
destroy nor create information. In practice they may add some noise of their
own, drowning the original signal, but in our case this is good, not bad :-)

The relationship between entropy and reversibility is a deep one, of course.
That's also why reversible computing can, among other things, reduce the
power consumption without any theoretical limit.

Enzo