Mitchell_Porter comments on A proposal for a cryogenic grave for cryonics - Less Wrong

17 [deleted] 06 July 2010 07:01PM

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Comment author: Mitchell_Porter 12 July 2010 08:30:26AM 0 points [-]

If you want something that flies, the simplest way is for it to have wings that still exist even when it's on the ground. We don't actually know (big understatement there) the relative difficulty of evolving a "persistent quantum mind" versus a "transient quantum mind" versus a "wholly classical mind".

There may also be an anthropic aspect. If consciousness can only exist in a quantum ontological unit (e.g. the irreducible tensor factors I mention here), then you cannot find yourself to be an evolved intelligence based solely on classical computation employing many such entities. Such beings might exist in the universe, but by hypothesis there would be nobody home. This isn't relevant to persistent vs transient, but it's relevant for quantum vs classical.

Comment deleted 12 July 2010 11:02:13AM *  [-]
Comment author: Mitchell_Porter 13 July 2010 09:38:15AM -2 points [-]

This is, first of all, an exercise in taking appearances ("phenomenology") seriously. Consciousness comes in intervals with internal continuity, one often comes to waking consciousness out of a dream (suggesting that the same stream of consciousness still existed during sleep, but that with mental and physical relaxation and the dimming of the external senses, it was dominated by fantasy and spontaneous imagery), and one should consider the phenomenon of memory to at least be consistent with the idea that there is persistent existence, not just throughout one interval of waking consciousness, but throughout the whole biological lifetime.

So if you're going to think about yourself as physically actual and as actually persistent, you should think of yourself as existing at least for the duration of the current period of waking consciousness, and you have every reason to think that you are the same "you" who had those experiences in earlier periods that you can remember. The idea that you are flickering in and out of existence during a single day or during a lifetime is somewhat at odds with the phenomenological perspective.

Cryopreservation is far more disruptive than anything which happens during a biological lifetime. Cells full of liquid water freeze over and grow into ice crystals which burst their membranes. Metabolism ceases entirely. Some, maybe even most models of persistent biological quantum coherence have it depending on a metabolically maintained throughput of energy. To survive the freezing transition, it seems like the "bio-qubits" would have to exist in molecular capsules that weren't penetrated as the ice formed.

Comment deleted 13 July 2010 09:58:34AM *  [-]
Comment author: Mitchell_Porter 13 July 2010 11:21:15AM 0 points [-]

I must have been, at some point, but a long time ago and don't remember.

Clearly there are situations where extra facts would lead you to conclude that the impression of continuity is an illusion. If you woke up as Sherlock Holmes, remembering your struggle with Moriarty as you fell off a cliff moments before, and were then shown convincingly that Holmes was a fictional character from centuries before, and you were just an artificial person provided with false memories in his image, you would have to conclude that in this case, you had erred somehow in judging reality on the basis of subjective appearances.

It seems unlikely that reliable reconstruction of cryonics patients could occur and yet the problem of consciousness not yet be figured out. Reliable reconstruction would require such a profound knowledge of brain structure and function, that there wouldn't be room for continuing uncertainty about quantum effects in the brain. By then you would know it was there or not there, so regardless of how the revivee felt, the people(?) doing the reviving should already know the answers regarding identity and the nature of personal existence.

(I add the qualification reliable reconstruction, because there might well be a period in which it's possible to experiment with reconstructive protocols while not really knowing what you're doing. Consider the idea of freezing a C. elegans and then simulating it on the basis of micrometer sections. We could just about do this today, except that we would mostly be guessing how to map the preserved ultrastructure to computational elements of a simulation. One would prefer the revival of human beings not to proceed via similar trial and error.)

In the present, the question is whether subjectively continuous but temporally discontinuous experience, such as you report, is evidence for the self only having an intermittent physical existence. Well, the experience is consistent with the idea that you really did cease to exist during those 3 hours, but it is also consistent with the idea that you existed but your time sense shut down along with your usual senses, or that it stagnated in the absence of external and internal input.

Comment deleted 13 July 2010 12:18:34PM *  [-]
Comment author: Vladimir_Nesov 13 July 2010 03:13:25PM 1 point [-]

The remaining unsolved problems in this area seem to be related to the philosophy of computations-in-general, such as "what counts as implementing a computation" or anthropic/big world problems.

Which is to say, decision theory for algorithms, understanding of how an algorithm controls mathematical structures, and how intuitions about the real world and subjective anticipation map to that formal setting.

Comment deleted 13 July 2010 04:21:31PM [-]
Comment author: Vladimir_Nesov 13 July 2010 04:28:57PM *  0 points [-]

Well, that's one possible solution. But not without profound problems, for example the problem of lack of a canonical measure over "all mathematical structures" (even the lack of a clean definition of what "all structures" means).

Logics allow to work with classes of mathematical structures (not necessarily individual structures), which seems to be a good enough notion of working with "all mathematical structures". A "measure" (if, indeed, it's a useful concept) is aspect of preference, and preferences are inherently non-canonical, though I hope to find a relatively "canonical" procedure for defining ("extracting") preference in terms of an agent-program.

Comment deleted 13 July 2010 04:44:16PM [-]
Comment author: JoshuaZ 13 July 2010 12:41:24PM 0 points [-]

It seems unlikely that reliable reconstruction of cryonics patients could occur and yet the problem of consciousness not yet be figured out.

I don't agree with this claim. One would simply need an understanding of what brain systems are necessary for consciousness and how to restore those systems to a close approximation to pre-existing state (presumably using nanotech). This doesn't take much in the way of actually understanding how those systems function. Once one had well-developed nanotech one could learn this sort of thing simply be trial and error on animals (seeing what was necessary for survival, and what was necessary for training to stay intact) and then move on to progressively larger brained creatures. This doesn't require a deep understanding of intelligence or consciousness, simply an understanding of what parts of the brain are being used and how to restore them.