X-Message-Number: 4703 Date: Wed, 2 Aug 1995 14:46:02 +0200 (MET DST) From: Eugen Leitl <> Subject: Re: Rebooting a suspendee Brian Wowk wrote on 29 Jul 1995: [ rebooting a suspendee question snipped ] > I'm wondering what "detailed schemes" you have seen, > since most of the ones I'm aware of (even Drexler's > 1981 PNAS paper) do deal with this problem explicity. > Solutions include: > > a) Selective blocking and unblocking of enzyme active > sites to inhibit unwanted reactions during the > rewarming phase. Excuse me, I thought we had an inpermeable glass solid to start with, reaction sites being inaccessable? Even if the patient is flash-defrosted with RF (btw is bond stiffness in ice sufficiently different from that in liquid so we can fine tune the microwave to ice bond resonance? Does anyone know? But microwave is probably still unviable for large specimens.. so it's still rf) we have a great many reactive sites to identify and reach within very tight time constraints. The time window width depends on temperature, of course. The operation of high concentrations of nanomachines operating at high speed will need large amounts of energy (which has to be delivered and de-delivered) and dissipate large amounts of heat in small volumes. a) is very easily to state but terribly hard to accomplish > b) Crosslinking everything in place until rewarming > is complete. (Leaving the crosslinks in place > after rewarming also gives the option of true room > temperature biostasis.) It is not easy to crosslink a phospholipide membrane. Since we will have large amounts of freeze damage, cell membranes being littered with holes. At the same time we will have extreme spatial concentration modulation, resulting in large osmosis gradients. Once rewarming is started, we have to be quite quick to collect the shards. In fact, slicewise body break up and reconstruction in a sliding zone few nm across should be easier. But this is virtually uploading with scan/reconstruction collapsed into one process and not standard postcryo resurrection. You are sure we will still have/need bodies in the sense of the word once this level of control and tech sophistication is achieved? We are talking magic here, after all. > c) Continuous repair and reversal of unwanted reactions > on the way back up. This is conceptually equivalent Repair is good, but one has to know how the original structure looked like. There _is_ such thing as information lossage. You'll end up inventing plausible structure for substitute. Speaking of that, how smart do you expect the nanoagents to be? Apart from navigation, propulsion, energy harvesting and atomic manipulation units (I skip the "self" code store and error checking machinery since we are using nonselfreplicating nanoagents for safety and efficiency reasons) we also need a very, very powerful computer and extensive sensory machinery. Since we have to use molecules for bit representation (one cannot read crystal lattice defects directly nor making computations with them, alas) and a 1d metal network (I skip ridiculous diamond rod logic here) infrastructure those bits are not so very tiny. And we need lots of them. What I wanted to say: intelligence is bulky, will need lots of energy and will almost certainly be _the_ bottleneck for nanoagents. This magical reaction reversal: we need to know (and this costs energy thus influencing the system) what is happening and where. Well, there might be technological magic, but we should also watch out for the natural law cops. > to progressive "redesign" of your metabolism so that > it is optimized for operation at whatever temperature > you are at-- essentially what Drexer meant in his This has _very_ tight constraints. Moreover, what is it good for? Are you expecting to operate the machinery you keep driving up the entropy gradient? > PNAS paper when he spoke of "modifying metabolism > to resemble that of freeze-tolerant species." > > Look, in the worst possible case, once you are repaired > we can use rf heating to take you from -130'C to body > temp in a matter of minutes (the approach now being > used by organ preservationists to avoid devitrification > and cryoprotectant toxicity in cryopreserved organs during > rewarming). That leaves at worst a few minutes of > ischemic injury to fix. One should not be ignoring the very extensive freeze damage and also the original death cause, which will _not_ be easy to fix. Major system deterioration due to old age and disease is still the major cryonist death cause, I presume? > To summarize: Taken in the context of the > difficultly of the overall repair problem, the rewarming > problem is TRIVIAL. This should be obvious after the > most modest amount of thought. The main problem: we have a whole throng of them closing in at the same time. Problem crowding, so to speak. Some problems are unavoidable since they come from the spacetime fabric we live in. Each operation reduces the degrees of freedom we have thus reducing the operation window. Problems do not get added up merely arithmetically. They breed explosively. > >This is of course yet another argument in my opinion > >for uploading - > > Aye, and there's the rub. I don't think you > gave this problem much thought because you simply saw > it as an opportunity to post some uploading propaganda. Now this was not fair. I could have accused you of taking advantage of cryonet's average reader low scientific background (or am I wrong, here?), spiring away many problems while making some appear trivial. This is not sound policy. This, in fact, is the main reason, why cryonics is considered utter trash by the majority of scientific community. The argument cuts both way: now you are preaching nanoresurrection cryonics propaganda ;) Though this probably has been restated countless times on cryonet: uploading is much simpler to accomplish than nanorepair ressurection of cryopatients. I could post megabytes of arguments why, but to keep the noise level down: There is no need in nanotech (some simple molecular circuitry, maybe) in scanning, damage repair or operator whatsoever. There are no timing constraints involved in scan whatsoever. (... lots of etc.....) > Forgive me, but after years of being told > that cryonics is obsolete and uninteresting because > we are going to have uploading *real soon now*, I'm > starting to develop a real disdain for uploaders. Cryonics, I thought, is the belief and according action, in conservation of information constituting each individual's uniquity in vitreus cryostorage and in future technological progress and motivation sufficient to revive the patient in some unspecified form sometime in the future. In this case, I believe in cryonics. On the other hand, it is ridiculous to expect to emerge from cryostorage as verbatim person. In fact, I would not wish to. Perpetuating existance without personal growth into eternity might hold promise for some. But not enough for me. Remember Vinge's "Marooned in realtime"? > I do agree with you, though, that uploading (when > it becomes available) will mostly likely be done with > the brain in some kind of biostasis. This is of course > yet another argument in my opinion for cryonics. :) Uploading _is_ a fraction of cryonics. The only difference is the amount of reconstruction necessary and the final product, which, adimittedly, does not resemble the thing we started with very much ;) -- Eugene P.S. BTW, Joe Strout got the uploading (neural simulation, actually) mailing list off ground. We will have to converge on the FAQ and the details first, though, so don't subscribe yet. After we have grinded out the details we let you know. > ---Brian Wowk > > ---------------------------------------------------------------------- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4703