X-Message-Number: 26335
From: "John de Rivaz" <>
References: <>
Subject: Re: long lived fruit flies, fungus and PCM recordings
Date: Wed, 15 Jun 2005 12:05:02 +0100

There is a  debate about whether it is worthwhile trying experiments to
extend the lives of fruit flies, or investigations as to whether fungi can
exist indefinitely, do have some merit.

The reason is that if such things can be proven, then it is a proof of
principle. No longer can theories which suggest that accumulated noise will
"get us in the end" be considered as reasons why a quest for indefinite
lifespan is as sensible as quests for perpetual motion. [ But we can still
have much longer life, just as the motion of galaxies can be regarded as
near being perpetual as you are likely to get ]

There is an analogy in communications and recording. Suppose you have a pair
of very good analogue tape recorders, such as the Revox. You use them to
make a copy of a tape, and then copy the copy and so on. Distortions rapidly
accrete.

If on the other hand you use a pair of digital recorders and make recordings
using the digital connectors, then the copies always remain faithful -- at
least in theory. In practise if you did this for many years - centuries
maybe -- the odd passing cosmic ray may turn a "one" into a "zero" or the
other way round, and errors creep in. But simple 1930s style PCM [
http://www.alecharleyreeves.com ] may not be the "be all and end all" of
recording. There are probably mathematical techniques that can ensure
faithful recording and elimination of errors - some may even be used in
modern CD recorders.

It would be interesting, though, to know whether there is any mathematical
technique and proof that would illustrate once and for all that a digital
recording could be copied for all eternity and never lose fidelity.

-- 
Sincerely, John de Rivaz:  http://John.deRivaz.com for websites including
Cryonics Europe, Longevity Report, The Venturists, Porthtowan, Alec Harley
Reeves - inventor, Arthur Bowker - potter, de Rivaz genealogy,  Nomad .. and
more

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