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 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=26335