X-Message-Number: 3895 From: (Eli Brandt) Subject: Re: CryoNet #3882 - #3891 Date: Thu, 23 Feb 1995 13:18:21 -0800 (PST) > From: John K Clark <> > Subject: SCI.CRYONICS Uploading > > -----BEGIN PGP SIGNED MESSAGE----- > > Bruce Zimov" <> Wrote: > > >Why can't the simplest part of the mind change in N ways? > > Because then it could be replaced by something that had the > integer value of (1 + the logarithm base 2 of N) number of > subparts that change in only one way, so it couldn't be the > simplest part. Huh? If the simplest part of the brain is, as postulated, an N-state device, then... that is the simplest part of the brain. You're saying that it's equivalent to a bunch of 2-state devices, and going from there to claiming that it actually is that bunch of devices. If I show you a die, will you tell me it's three coins? The brain is also isomorphic to a very big number along with a function from the naturals to the naturals. It's isomorphic to an infinity of different things. I think you would say that any isomorph is an acceptable replacement, while some others are not sure of this. > >way.THAT is a switch, and I agree that we can use switches > >to replace brain parts. BUT THAT is not a bit of information. > > Well it is, but I don't want to be pedantic, I know your using > words like "bit" and "information" in non standard ways. Again: huh? The switch *is* a bit? I think this isomorphism/identity issue needs to be addresses if this discussion is to go anywhere. > Message #3890 > Date: Wed, 22 Feb 1995 21:20:27 -0800 > From: John K Clark <> > Subject: SCI.CRYONICS Uploading > The only other thing I can figure your talking about is the > cabal properties of dendrites, that is the passive spread of > electrical signals with no amplification from voltage gated > channels. Trouble is dendrites make terrible cables, They're good enough over the span of a small dendritic tree. Passive transmission *does* happen in the brain. In fact, it's the predominant sort of dendritic transmission. Any neurophysiology book should cover this, and I think the low-level discussion of uploading would benefit from understanding low-level neural processes. > That's true, but I'm sure you know there are 2 types of > channels, voltage gated ion channels and ligand gated ion > channels. There's a third: the gap junction. This is not a gated channel at all; it's a direct ionic coupling. As such, it's much faster than an electrochemical synapse, but doesn't do much information processing. But if you're talking about passive potentials, you can't ignore electrical synapses. > that signals can not be processed and transmitted from the > synapses to the axon hillock at anything close to light speed > and could benefit from a speed up as much as the action > potential would. Conduction in salt water isn't light-speed fast, but I fail to see how you're going to speed it up much. Eli Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3895