X-Message-Number: 2185 From: R.Ettinger Subject: CI Progress Here is the latest news from Robert Ettinger on recent progress at Cryonics Institute and also comments on CryoNet messages through April 22. Kevin Q. Brown ----- April 27, 1993 > From: R. Ettinger > To: Correspondents, via good offices of Kevin Q. Brown > Subject: Not-so-cold experiments and other matters The following are draft versions of material for THE IMMORTALIST May issue. NOT-SO-COLD EXPERIMENTS Andy Zawacki (as time allows) has been conducting the Cryonics Institute experiments we promised, looking into the feasibility of storage in the vicinity of -130o C, in case this should finally be agreed to be useful in reducing cracking. Preliminary indications are that it is feasible, as we have previously guessed, although at increased cost. Details elsewhere in this issue. The gist of it, so far, is that it will be rather easy to maintain stable temperatures by relying on stratification; convection does not appear to be a problem. We may not even need pontoons. With the reconfigured HSSV-1, at the -130 stratum, there isn't even any appreciable temperature variation between reloadings of nitrogen. A LOX PROBLEM? This is not the delicatessen variety, but liquid oxygen, and the (possible) problem--aired on Cryonet--arises from the fact that liquid nitrogen, used in our cryostats and those of other cryonics organizations, is not perfectly pure, but contains some small amount of liquid oxygen. Liquid oxygen, unfortunately, is both denser than liquid nitrogen and has a higher boiling point. This suggests that, in a mixture, it might tend to sink to the bottom and to boil off less rapidly. So it might gradually accumulate. Eventually, it might conceivably become a bit of a fire hazard, since oxygen supports combustion, and in very unusual circumstances even an explosion hazard. We don't want to overstate this. First, liquid oxygen, in itself, would not constitute any apparent danger to the patients or to the cryostats. Any danger would arise from the possibility of an accidental fire or spark burning faster than normally, in an atmosphere containing more than the usual 20% oxygen. But even if the cryostats contained pure liquid oxygen, the air in the room would not develop an excessively high oxygen content. (To see this, without doing any calculations, just remember that the air in our rooms at present does not contain any noticeable excess of nitrogen, even during loading periods, because the boiloff is not large compared to the volume of air in the room, and the ventilation is adequate.) Remember also that--for example--when you are trying to distill alcohol from a mixture of water and alcohol, even though the alcohol is less dense and has a lower boiling point, it isn't easy to separate the two; you have to condense and recycle repeatedly. I'm not even sure there is any real stratification tendency--liquid oxygen settling toward the bottom. They may be essentially totally miscible, as alcohol and water. Water settles under oil, but not under alcohol. In that case, the oxygen might still boil off less rapidly, and increase its concentration, but would remain dispersed. Further, any tendency for oxygen to accumulate would imply that the overall boil-off rate would gradually diminish a bit, other things equal. This has not been noticed. Finally, we have not heard of any problem like this in commercial or scientific cryogenic opera- tions, including biological cryostats, some of which have been in use for many years. Even so, we intend to monitor the situation, if further checking of the facts warrants. We can sample the liquid at the bottom of the cryostats to estimate the oxygen content and its rate of increase, if that is noticeable. If there is a problem, we could siphon off from the bottom occasionally; or we could stir up the liquid to bring more oxygen near the surface to increase its boiloff. Anyway, we're glad we have paranoid (or just nervous or alert) people in our organizations, always smelling out possible dangers. No matter how paranoid we get, we will still fail to foresee some of the problems ahead--but hopefully not too many. ON THE CRYONET The E-Mail discussions continue, and we continue indebted to Kevin Q. Brown for keeping us posted. Brian Wowk, Dr. Steven Harris, Tim Freeman, Michael Darwin, and others continue to brainstorm on the cold room that some Alcor members would like to have built--a room-sized storage region for use near -130o C. They think this would save money over present types of storage, and, more importantly, would significantly reduce cracking of tissues. Most of our readers know that Cryonics Institute people are not yet convinced there is good evidence that this kind of storage would really improve the patient's chances appreciably. In a recent Cryonet posting, Mike Darwin seems to concur, and to agree with our feeling that building such an installation now would be premature. He says there is no evidence that frozen patients cooled to near the glass transition point remain unfractured. As previously noted, we have seen expert opinion that cracking is significantly reduced by storage at this higher temperature--but is "significantly" enough? If the remaining cracking is still substantial, then we might still need just as much in advanced technology--maybe full- fledged nanotech--for repair, and nothing would really be gained. This conclusion is reinforced if Dr. Ralph Merkle is right in saying that the low-temperature cracks are "clean" and thus would allow relatively easy reassembly of the "jigsaw puzzle" of a brain with cracks. At some point, depending on the answers to several other questions, the proposed not-so-cold room might be desirable just on the basis of reduced maintenance cost. In the short to intermediate term, however, such storage will be more expensive, not less. Cryonics Institute research should tell us, fairly soon, just how much more expensive it might be. We will also be doing biological research, looking for the effect of such storage on sheep heads. When we have some of these answers, we will decide whether or not to offer the not-so-cold option to CI members. R.E. ----- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2185