Challenger - Return Home   A Science Fiction Fanzine   Winter 2003

Gregory Benford is a professor of physics at the University of California Irvine, the author of Deep Time and many SF classics, and a frequent contributor to these pages. He was one of our nominators for DUFF, and even if he hadn't written the following gem for these pages, would have my deathless gratitude. Hmm ... "deathless" ...



Cryonics as a Gamble

copyright 2002 by

Gregory Benford



art by Charlie Williams

       For many, the most startling news of this summer was that the American baseball legend, Ted Williams, had been frozen. A close relative turned Williams' body over to a firm that suspends its "patients" in liquid nitrogen. A firestorm of media attention followed.

       The USA is the only nation with a thriving industry in "cryonics." The underlying hope, that properly freezing people immediately after they have crossed the threshold we call "death" may allow them to be later reanimated, is a bold assertion about the future.

       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 non-scientific. However systematically arrived at, they cannot be tested today.

       Cryonics opens a window into the American mind. It is utopian and pragmatic, since the essential argument is to freeze people with carefully tailored cryo-protectants distributed through the bloodstream into their cells. The technology to "resurrect" by warming the body and curing their disease must lie in the far future, perhaps a century away. This demands optimism few can muster, a faith that the future will both care and be able to work what to use would be medical miracles.

       Response to the very idea is quite emotional, a fervently felt resistance suggesting a deep underlying uneasiness about death in modern 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.) Critics usually fail to note that the procedure, which costs between $25,000 and $60,000, is paid by the "patients."

       Of course, cryonics is a huge gamble. Many thoughtful people discount cryonics because they simply consider it fantastically implausible. But Canadian painted turtles and four species of frogs routinely make it through the winter by freezing, then reviving. These creatures 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. Over sixty are now suspended in liquid nitrogen, with many hundreds signed up to be.

       Many others regard cryonics as creepy and pointless; 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 method can work on many ideas.

       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.


       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. This probably is not true, but to do better one must know the future in detail.

       What kind of concerns enter here? I'll break them down into three categories--the metaphysical, the social, and the technical.

       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, like most scientists, 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 revived.

       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 somewhat 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 0.9.

       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 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 (a professor named Bedford, incidentally) is still coasting along at 77 degrees above absolute zero after 35 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 science, or 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. Probably in Europe this number should be much lower.

       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 suspended patients.

       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, a la Enron. 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 over the last decade has made it the favored mechanism for cryonics. Nanotech 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 bit 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 went 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 (0.5)(0.9)(0.5)(0.9) = 0.2.

       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. It is very rough. 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.


       Science fiction invented cryonics; it is, after all, 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.

       But even science fiction writers fascinated by it (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, except for Charles Platt, with the further marginal exception of a deposition Arthur C. Clarke made several years ago to support a court case.

       Why do even those intrigued not gamble? Maybe writers without much cash think it's too chancy an investment. 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% by our estimate here) times the expected return (a million dollars, earned by the revived person). 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 (about 75 years) and divide it by the expected gain in years if they are revived in the future. This would be perhaps 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.

       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) 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 50/50 range.


       Of course, numbers don't tell the whole tale. Ray Bradbury once 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 told me, he wouldn't take the option at any price.

       Still, he came into this world without all those associations. And further, why assume that nobody else would go with him? 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 through.

       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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