X-Message-Number: 2394
Date: 31 Aug 93 13:28:56 EDT
From: "Steven B. Harris" <>
Subject: CRYONICS: Greg Benford Article

Here is a treat: an article on the workability of Cryonics from
this month's science column in the Magazine of Fantasy and
Science Fiction.  The author is physicist Gregory Benford, who
took over half of the regular column when Isaac Asimov died, and
this month's offering by Dr. Benford is based (with full credit
given) on an article of mine which is available in reprint from
Alcor, titled "Will Cryonics Work?"  This is how I'd have written
it if I wrote better <g>.

                        A SCIENTIST'S NOTEBOOK 
					  Gregory Benford 
4000 words 
Copyright 1993 by Abbenford Associates 
	Only the past is truly knowable. Sometimes, though, not even the  
past is available--seldom do we preserve good records of people and  
events. The present is a millisecond wide, the future a fog. 
	Or is it better to say that there is no single future? Rather,  
we can best regard the future as a set of possibilities. Science  
fiction is an entertaining game, aiming to make us aware of the vast  
ocean of potentiality we face. As fiction, it strives harder to  
entertain than to instruct. Is there a more orderly way to discuss the  
range of the probable? 
	This goal is not scientific, in the sense that the results  
cannot be checked right now. This is not the same as unscientific  
statements--those which have been tested and have failed. 
	Rather, ideas of the future are nonscientific. However  
systematically arrived at, they cannot be tested today. Someday they  
will be either disproved or not. But of course, like a tip about a  
horse race, they are most useful before you know whether they are  
	Consider cryonics. This idea, that properly freezing people  
immediately after they have crossed the threshold we call 'death' may  
allow them to be later reanimated, is an assertion about the future.  
It first figured in a Neil R. Jones sf story in the 1931 Amazing  
Stories, inspiring Dr. Robert Ettinger to propose the idea eventually  
in detail in The Prospect of Immortality (1964). 
	It has since been explored in Clifford Simak's Why Call Them  
Back From Heaven? (1967), Fred Pohl's The Age of the Pussyfoot (1969),  
and in innumerable space flight stories (such as 2001: A Space  
Odyssey) which use cryonics for long term storage of the crew. Fred  
Pohl became a strong advocate of cryonics, even appearing on the  
Johnny Carson show to discuss it. Robert Heinlein used cryonics as  
part of a time-traveling plot in The Door Into Summer. Larry Niven  
coined "corpsicle" to describe such "deanimated" folk. All these  
stories considered the long term aspects. 
	Sterling Blake's Chiller, which should appear this summer, is  
different. It treats cryonics as the field exists today, in a more  
mainstream, suspenseful plot structure. Chiller's armature is the  
adventures of a beleaguered band facing the present opposition to the  
idea. It is based on the three existing cryonics organizations and the  
considerable antagonism they face, much of it quite emotional. 
	This fervently felt resistance suggests a deep underlying  
uneasiness about death in our society. Imagine a scientist today being  
rejected from a scientific society because he wants to present  
research relevant to long-term preservation of whole organisms, not  
necessarily humans. Yet this continues, as well as widespread views  
that cryonics is inherently wrong, greedy, or else the work of con  
men. (This last assumption is universal among physicians.) 
	Of course, cryonics is a huge gamble. And many thoughtful people  
discount cryonics because they simply consider it fantastically  
implausible. This, despite the fact that Canadian painted turtles and  
four species of frogs routinely make it through the winter by  
freezing, then reviving. They respond to low temperatures by making up  
a cocktail of glucose, amino acids and a kind of naturally produced  
antifreeze, glycerol. They manage to move water out of their cells, so  
that ice crystals form outside delicate membranes. While these animals  
have special adaptations, their body chemistries are not bizarre.  
Their methods could be extended artificially to mammals, like us. 
   	Based on such reasoning, cryonics has gathered momentum, largely  
unnoticed by the world. The number of people who invest in cryonics as  
a rational gamble is increasing exponentially. Over forty are now  
suspended in liquid nitrogen, with hundreds signed up to be. 
	Many others regard cryonics as creepy and pointless. Even  
science fiction writers fascinated by its long-term aspects (Simak,  
Heinlein) never made arrangements to be "suspended", as the  
cryonicists say. I know of no sf writer who has publicly endorsed  
cryonics as a plausible possibility, with the exception of a  
deposition Arthur C. Clarke made several years ago to support a court  
	Of course the notion calls up images of the cold grave, zombies,  
etc. Still, as eerie ideas go, being frozen strikes me as less  
horrific than turning into food for worms, or being cremated. (When  
cremation started out commercially, bodies were burned during a church  
service. The businesses quickly added organ music, because mourners  
wondered about the loud bang that often interrupted the funeral. It  
was the skull of the deceased, exploding.) 
	So if not especially creepy, is it none the less pointless? That  
is, are cryonicists making a reasonable bet? 
	That depends on many factors. Any vision of the future does. To  
analyze them in more than an arm-waving way, I'll work out here a  
simple method for quantitatively thinking about future possibility. 
	The simplest way to consider any proposed idea is to separate it  
into smaller, better-defined puzzles. This atomizing of issues is  
crucial to science, since it is easier to ponder one problem at a  
time. This approach has been applied to nonscientific questions, many  
closely allied to science. 
	The central question of SETI, the Search for ExtraTerrestrial  
Intelligence, is the calculation of how many technological  
civilizations may exist in our galaxy now. Estimating this factors out  
such issues as how likely it is that a star has livable planets, and  
how long a civilization lasts, on average. Nobody expects the estimate  
to be a hard, concrete result. It is really a way of discussing the  
elements which entered into the past, not the future, to yield the  
present density of radio-using aliens. 
	The same techniques can be applied to future possibilities. This  
was first done for cryonics by Dale Warren, an engineer, and sharpened  
by a UCLA physician, Steve Harris. 
	I'm going to have to use equations here, but they'll be simple.  
So will my method. If every issue I raise is independent of the other  
questions, then we can simply multiply all the probability estimates  
together at the end to get the total likelihood of cryonics working. 
	What kind of concerns enter here? I'll break them down into  
three categories--the metaphysical, the social, and the technical.  
Most sf has dealt with the social aspects, because that generates the  
most interesting stories, but the other matters are equally vexing. 
	First, the metaphysical. To preserve people's minds, we  
naturally think of saving their brains. What are the chances that the  
brain carries the mind? This is the materialistic world view, and the  
chances that it is correct I'll label with a probability M. I'm a  
solid materialist, so I'd say that M=.99, i.e., 99% chance that some  
vital soul does not leave the body when metabolism stops. There is  
evidence for this, actually. People cooled down to a state of clinical  
death on operating tables, for brain surgery, revive with their sense  
of self intact. 
	Next, what are the odds that our brain structure tells the whole  
story? That is, that your Self is not the product of continuing  
electrical activity in the brain. Here, too, the cooled patients seem  
to show that though their brain rhythms cease, they persist when  
	Further, some people have gotten jolts of heavy current which  
completely swamped their delicate internal electrical circuits. This  
happens to hundreds of people struck by lightning every year in the  
U.S., and occurred in routine shock treatments earlier in this  
century. They survived with memory intact, except for short term  
recall. Our minds, then, are something like hardwired, though  
rewritable programs inscribed in the cells of our brains. So I'll set  
this probability that our Essence is in brain cells, not momentary  
brain activity, at E=.99. 
	Finally, there is chance that your Self can make it through the  
process of being frozen down to liquid nitrogen temperatures. The  
trick is to get to the brain quickly, before it degrades. Several  
years ago a boy survived drowning in a cold lake, reviving after an  
hour spent clinically dead. Even if cryonically suspended immediately- 
-which means being perfused with a glycerol-type solution to minimize  
damage while being cooled--there lurk the huge unknowns of what this  
perfusion does to your memories. Studies show that the most damage is  
done when brains are rewarmed. Neuronal membranes are ripped, pierced.  
Even so, experimental animals revive with memories intact. And the  
perfusion technology will certainly improve. Let's be optimistic and  
put the probability that the Self will persist through this Transition  
process, T, at T=0.9. 
	Then the metaphysical factors, MET=(.99)(.99)(.9), or just about  
	Next, the social issues. First, what are the odds that your  
brain (and body, presumably--but the Self is in the brain, remember)  
will make it to some far off revival time without some accident  
thawing you out. Call this S, the chances for Survival of your brain. 
	Many issues enter here. Presently, all cryonics patients are  
kept indoors, in steel containers, carefully watched. This hasn't  
always been so; financial failures doomed several to thawing in the  
two decades after Ettinger's pioneering book. But none have been lost  
in over a decade, and the first man frozen (named Bedford,  
incidentally) is still coasting along at 77 degrees above absolute  
zero after 26 years. Given that cryonics is far more sturdy now, let  
me set the brain survival odds S=0.9. 
	Sure, one can say, but what about the odds that society as a  
whole will make it through for, say, a century? Call this factor O,  
the Odds against civilization itself being rich enough to not make  
cryonics impossible. This includes the chances that society will turn  
irrational, or break down (war, economic depression), or will take a  
fervent dislike to cryonics itself. 
	The economics of cryonics are modest. Liquid nitrogen is the  
third cheapest fluid, after water and crude oil, and is widely useful,  
so it will probably be available in even damaged economies. Of course,  
even democracies can decide to suppress those arrogant enough to spend  
their money on a chancy voyage across time into an unknown future. So  
I will set the Odds of social continuity allowing cryonics at O=.8. 
	Ah, but what if the cryonics organizations themselves don't  
last? This is a real worry, because the collapse of Cryonic Interment  
Inc. in California during the mid-1970s lost those earlier suspended  
	The longest lived institutions in human history have been  
religious, with the Catholic church arguably holding the record at  
nearly 2000 years. Cryonics has some of the aura of a religion, with  
deeply persuaded people sustaining a long-range hope of personal  
salvation. Maybe that will help. 
	Still, greedy corporate directors could someday simply find it  
more profitable to keep tapping the assets left behind by the  
patients, rather than investing in reviving them. (See Simak's Why  
Call Them Back From Heaven? for a plausible argument that this would  
indeed occur.) 
	Or somebody could simply embezzle the funds. The more popular  
cryonics becomes, the bigger will be the spoils. Call this probability  
of cryonics organization failure C, and my guess is that C=0.5--a  
fifty-fifty chance that the whole shebang will go under. After all, we  
're talking about a wait that could be a century. How many of today's  
corporations are that old? About one percent. 
	These social factors I estimate at SOC=(0.9)(0.8)(0.5)=0.36, or  
a bit better than a third. 
	I can hear the tech types impatiently asking, can it be done at  
all? And there's the rub. From the METaphysical to SOCial factors we  
come to the issues which blend the two--is revival technically  
possible, given the social and philosophical assumptions? 
	Cryonics began with no clear idea of how revival could be done.  
That gave rise to a standard joke, about how many cryonicists it took  
to screw in a light bulb. The answer was none--they just sit in the  
dark and wait for the technology to improve. 
	The rise of nanotechnology at the hands of Eric Drexler over the  
last decade has made him the patron saint of cryonics. Drexler  
envisions self-replicating machines of molecular size, programmed with  
orders to repair freezing damage, bind up torn membranes, and  
generally knit together the sundered house of a frozen brain. 
	There appears to be no fundamental physical reason why such tiny  
machines can't be made on the scale of a billionth (nano-) of a meter.  
The rewards of developing such handy devices would be immense, a  
revolution in human society (which is why the SOC issues intertwine  
with the tech ones, as I'll discuss below). 
	Not only must this marvelous technology appear, but we must  
survive its flowering. This is tricky; runaway use of nanotech could  
produce virulent diseases or everything-eaters that could wipe us out.  
Modern, Promethean technology, like nuclear physics, shares this  
daunting property. 
	I suspect that we will take at least fifty years, and more  
plausibly a century, to develop nanotech able to repair freezing  
damage. The good thing about being frozen is that you aren't going  
anywhere; you can afford to wait. 
	Given these immense uncertainties, I put the chances that the  
Technology will arrive and we will survive it at T=0.5. 
	But of course, a future society must have the desire to apply  
the technology to cryonics. If we do not yield to a kind of temporo- 
centric insulation, and cease to be curious about representatives from  
a century before, I suspect we will have the cultural Energy to work  
out nanotech for cryonics purposes. (After all, much of it will be  
useful in curing and repairing ordinary, living people.) So I put this  
cultural Energy probability, E, at E=0.9. 
	Still, will they pay the bill? The first few revived cryonicists  
will probably get onto the 22nd century's talk shows. Famous suspended  
people, too. (Wouldn't you pay a few bucks to talk to Benjamin  
Franklin? He was the first American to speculate on means for  
preserving people for later revival. And the philosopher Francis Bacon  
died of pneumonia caught experimenting with suspension of animals.)  
But if there are ten thousand cryonicists waiting to be thawed... 
	This is a major, imponderable problem. Humanitarians will argue  
that spending money on the living is always morally superior to  
spending it on the dead-but-salvageable. Will this argument win the  
day? Or, in the fullness of time, will nanotech make revival so cheap  
that the cost factor, C, becomes a non-issue? You can argue it either  
way--and science fiction writers already have. 
	Given such uncertainties, I'll guess that the cost probability  
factor C=0.5. 
	Finally, there is the truly unknowable factor, H, which stands  
for the contrariness of Humans. Some powerful social force may emerge  
which makes cryonics reprehensible. After all, many think it's creepy,  
a kind of Stephen King idea. 
	Maybe people will utterly lose interest in the past. I doubt  
this, noting that the world was fascinated with the frozen man found  
in the Alps in 1991. Considerable expense is going into careful  
examination of this remarkably preserved inhabitant of about 4000  
years ago, and his clothing and belongings will tell us much about his  
era--but still, he can't speak, as a revived cryonicist could. 
	Or perhaps some other grand issue will captivate human society,  
making cryonics and the whole problem of death irrelevant. Maybe we'll  
lose interest in technology itself. Factor in also the Second Coming  
of Christ, or arrival of aliens who spirit us all away--the choices  
are endless. 
	But all rather unlikely, I suspect. I'm rather optimistic about  
Humanity, so I'll take the odds that we'll still care about suspended  
cryonicists to be fairly large, perhaps H=0.9. 
	This means that the TECH issues multiply out to  
	All this homework done, we can now savor our final result. The  
probability that cryonics will work, delivering you to a high-tech  
future, blinking in astonishment, is 
	MET x SOC x TECH = 0.07 
A 7 percent chance. 
	Do I "believe" this number? Of course not. Such calculations are  
worth while only if they sharpen our thinking, not as infallible  
guides. Some decry numerical estimates as hopelessly deceptive, too  
exact in matters which are slippery and qualitative. True, for some,  
but the goal here is to use some simple arithmetic means of assessing,  
then planning. This does not rule out emotional issues, it merely  
places them in perspective. 
	Still, to wax numerical a bit more, suppose you regard cryonics  
purely as an investment. Does it yield a good return? 
	Well, what's a person worth? Most Americans will work about  
fifty years at a salary in the range of around $20,000 to $30,000 per  
year--that is the national average today. In other words, they will  
make somewhere between one and two million dollars in their lifetime. 
	One crude way to size up an investment is to take the  
probability of success (7% in our estimate here) times the expected  
return (a million dollars). Then compare with the amount you must  
invest to achieve your aim. This yields $70,000, which is in the range  
of what cryonics costs today. (Cryonicists buy a life insurance policy  
which pays off their organization upon their death; they don't finance  
it all at once.) 
	The goal of cryonics is not money but time--a future life.  
Another way to see if cryonics is a rational gamble is to take a  
person's expected life span (75 years) and divide it by the expected  
gain in years if they are revived in the future. This would be at  
least another 75 years, but if the technology for revival exists,  
people may quite possibly live for centuries. Then the ratio of gained  
years to present life span is, say, 150 years divided by 75 years, or  
a factor of 2. It could be higher, of course. 
	Then even if the probability of success is 1%, say, the probable  
yield from the investment of your time would be 2 x 1% = 2%. It would  
make sense to invest 2% of your time in this gamble. Then 2% of your  
lifetime earnings (a million dollars) would be at least $20,000, which  
you could use to pay your cryonics fees. Or you could choose to invest  
2% of your time--half an hour a day--to working for cryonics. Make it  
a hobby. You would meet interesting people and might enjoy it. Most  
people spend more time than that in the bathroom. 
	Take another angle. Probability estimates should tell us the  
range of outcomes, not just an average number like 7%. To be a  
flagrant optimist, I could go back and take all the loosely technical  
issues to be must more probable, so that TECH=0.9, say. Then we get  
29% probability. 
	This is just about the upper end of the plausible range, for me.  
I could be a gloomy pessimist, with equal justification, and take the  
social issues to be SOC=0.05, say. Then my original 7% estimate  
becomes less than one percent. 
	So the realm of plausible probabilities, to me, is between one  
percent and about 30%. 
	Low odds like one percent emerge because we consider many  
factors, each of which is fairly probable, but the remorseless act of  
multiplying them together yields a final low estimate. This is  
entirely natural to us. Studies show that most people of even  
temperament, considering chains of events, are invariably optimistic.  
We don't atomize issues, but look for obliging conditions. This seems  
to be built into us. We humans will always lose cash in crap games;  
it's a habit of the species. 
	I've dwelled on using this simple probability estimate to show  
some properties of the method. The deeper question is whether it truly  
makes sense to break up any future possibility into a set of mutually  
independent possibilities. 
	This comes powerfully into play in the SOC factors. Once the  
TECH issues look good, people will begin to change their minds about  
cryonics. The prospect of longer life may well make society more  
stable so O gets larger. Cryonics organizations will fare better, so C  
improves. The slicing up into factors assumes that the general fate of  
humankind is the same for the folk of the freezers, and this may not  
be so. 
	Cryonicists are a hard-nosed, practical lot, in my experience.  
They have many technical skills. Society might even crash badly, and  
they would keep their patients suspended through extraordinary effort.  
They have already done so. Police raided a cryonics company in the  
late 1980s (Alcor of Riverside, California--the same town where  
Heinlein put his cryonics firm in The Door Into Summer) and demanded  
that a recently frozen patient be handed over for autopsy. Someone  
spirited away and hid the patient until Alcor could get the police and  
district attorney off their back, but not before the police hauled  
five staff members off to jail and ransacked the facility. 
	Perhaps a better way to analyze this is to note that the biggest  
uncertainties lie in the intertwined SOC and TECH factors. A techno- 
optimist might say that cryonics will probably work on technical  
grounds, but social factors lessen the odds, maybe to the fifty-fifty  
	Of course, numbers don't tell the whole tale. When Ray Bradbury  
visited my campus (University of California at Irvine) last year to  
speak, a fan asked him how he felt about cryonics. I had introduced  
Ray as a forward-thinking, adventurous writer, perhaps the best known  
sf author in America, so I was rather surprised by his answer. 
	Ray said he was interested in any chance of seeing the future,  
but when he thought over cryonics, he realized that he would be torn  
away from everything he loved. What would the future be worth without  
his wife, his children, his friends? No, he wouldn't take the option  
at any price. 
	When he and I were talking later, I pointed out that he had come  
into this world without all those associations. And further, I asked,  
why did he assume that nobody else would go with him? He looked  
surprised for a moment, then answered that he doubted if any of his  
friends would want to go. So his argument still stood. 
	This is an example of the "neighborhood" argument, which says  
that mature people are so entwined with their surroundings, people and  
habits of mind, that to yank them out is a trauma worse than death.  
One is fond of one's own era, certainly. But it seems to me that  
ordinary immigrants often face similar challenges and manage to come  
	Still, if you truly feel this way, no arithmetic argument will  
dissuade you. For many, I suspect, the future isn't open to rational  
gambles, because it is too deeply embedded in emotional issues. 
	So it must be with any way of thinking quantitatively about our  
future. We cannot see the range of possibilities without imposing our  
own values and views, mired in our time, culture, and place. 
	Often, these are the things which we value most--our  
idiosyncratic angles on the world. 

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