• The Science (and Science Fiction) of Cryonic Preservation

    Philip Jaekl on Robert Ettinger and the Eternal Promise of Escaping Death Through Freezing

    For around two hundred years, investigators ranging from John Hunter (in the 1700s) to Audrey Smith and James Lovelock (in the 1950s) attempted to suspend the animacy of living beings—from frogs to hamsters—in hopes of reviving them upon thawing. Hunter was determined to discover the essence of life—and also to bag a fortune in creating a means of time travel into the future by freezing oneself to stop the clock on aging and then eventually reanimating. Smith and Lovelock, more practically, aimed to advance medical practices. Regardless, in key respects the process was the same: freeze, wait, reanimate. Success, however, was never achieved. Smith and Lovelock’s failure in the 1950s to freeze and revive rabbits and monkeys marked formal science’s latest attempt to reanimate frozen mammals. Will it be the last?

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    With the 1960s came an increase in prosperity in the United States and an optimistic vision toward the future of scientific discovery. Outlandish aspirations like Optiman and the cyborg preceded actual scientific and engineering advancements, such as successfully traveling to the moon and back—achievements that had also seemed like science fiction just years before. Visions of the future went beyond making humans space-proof and greatly expanding the normal lifespan; they came to include the possibility of escaping death completely.

    At the time, the list of animals discovered to be capable of self-revival after withstanding freezing core body temperatures was growing. They could survive temperatures that would be fatal if encountered by mammals, including humans. By then it was well-known, for example, that the simple creatures known as tardigrades—one-millimeter-long, barrel-shaped anomalies with four pairs of legs, also known affectionately as “water bears” or “moss piglets”—could survive temperatures near –508°F (–300°C). Increasing in complexity from tardigrades, and probably to John Hunter’s dismay had he been alive, researchers discovered that wood frogs could tolerate freezing of up to 60 percent of their entire body while buried in mud during a long winter hibernation. During their period of stasis, they have no heartbeat, don’t breathe, and show no sign of brain activity. While frozen, these frogs are dead by all legal and clinical definitions existing today.

    What allows them to survive “death”? Basically, the answer involves antifreeze in the form of glucose, a type of sugar. The wood frog carries in its cells high amounts of glucose, which it generates to prevent the destructive effects of ice crystallization, which expands water’s volume—think of frozen water bursting a pipe. Truly enigmatic, however, is the frog’s ability to literally die and reanimate. In many ways, the current research is similar to John Hunter’s quest to understand the nature of life, beyond the beating of a heart and the respiration of lungs. What is the “vital essence”?

    Today, our understanding of this frigid frog mystery is the result of cryobiologic inquiry. But aside from inquisitions into the nature of life, cryobiology’s primary function lies largely in the life-saving purpose of organ and tissue preservation. The transplantation of organs, however, can save lives only if the donor organs are viable. Each year, thousands of potential organ recipients die because an organ can’t get to them soon enough due to a failure in preservation. The main challenge of this branch of science is to freeze biological tissue for the purpose of preservation, and to do so while maintaining its functionality after transplantation.

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    These efforts have seen some significant success. Today, many organs, tissues, and cells are preserved at low and even freezing temperatures and then are successfully thawed to resume their function after transplant. A human heart can be stored at around 41°F (5°C) for up to six hours, and blood, semen, and eggs can be stored indefinitely in liquid nitrogen at –320°F (–196°C). At that temperature all cellular processes cease, including those involved in decay. Essentially, liquid nitrogen can freeze time for biological material.

    The reproductive cells have a particular resilience after being frozen. Testicular and ovarian tissues can tolerate temperatures fatal to other tissues. Perhaps even you were entirely frozen at some point shortly after your conception. Embryos can be successfully frozen and stored for artificial insemination. In fact, freezing them is routine protocol because inseminations don’t always yield a fetus, and multiple attempts are often required.

    What defines death has already been obscured by medical technology.

    So, if it’s possible to carefully and indefinitely freeze an embryo, what about an entire, fully formed human? After all, in the simplest of terms, we are only composed of more cells, right?

    Cryopreservation below freezing seems to only work for cellular preservation and for relatively small amounts of tissue, nothing near an entire body. More than that and the process is likely to generate significant, widespread damage. Sure, you can easily freeze a whole person, but there’s no chance they’ll live after thawing.

    The more relevant question is whether an entire human body can be frozen in a way that minimizes the cellular damage caused by the freezing process.

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    Some futurists deem this possibility likely. They believe that achieving the necessary level of damage control is a relatively minor detail, and that in the years, maybe centuries, ahead, technology will enable successful reanimation after freezing. Although the notion may sound like far-fetched science fiction, current medical advances have not only enabled the successful freezing and thawing of cells, tissues, and organs; they have procured means of reviving people from hypothermic states in which, by all conventions, they would be declared dead, with no heartbeat and no measurable brain activity. Remember Anna Bågenholm, the skier? What defines death has already been obscured by medical technology. Similar to the wood frog, can a hypothermic human with no vital signs always be considered dead?

    That said, none of these futurists have volunteered to be frozen while alive, in the manner akin to animals that are capable of surviving freezing core body temperatures. Rather, it seems that such optimism begins with the idea of preservation after death. A person would have to rely on the invention of technology that could successfully recover them from their frozen state, and could also cure what killed them in the first place. Ideally, such technology would essentially restore youth. After all, someone who dies in advanced age after suffering the ravages of numerous ailments would likely prefer not to be restored to their preexisting condition.


    One such futurist was Robert Ettinger, the late originator of cryonics, the preservation and freezing of human corpses with the speculative hope of revival in the future. Ettinger was born in 1918 in Atlantic City, New Jersey. A fan of science fiction as a youth, he found one story particularly thought provoking: The Jameson Satellite, written by Neil R. Jones and published in Amazing Stories magazine in 1931. In the story, Professor Jameson arranges for his corpse to be launched into space in hopes of preserving it as it orbits Earth indefinitely at temperatures approaching absolute zero (−459.67°F or −273.15°C). After no less than forty million years, when the human race is extinct, Jameson is discovered by an advanced race of aliens. Their brains are similar to those of humans, but they have transcended organic bodies for mechanical ones, which allow them to replace broken parts when needed, thereby living indefinitely.

    Later in life, Ettinger reflected on how this story inspired him, writing, “It was instantly obvious to me that the author had missed the main point of his own idea! If immortality is achievable through the ministrations of advanced aliens through repairing a human corpse, then why should not everyone be frozen to await later rescue by our own people?”

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    And thus, cryonics was conceived.

    As a young adult, he served as an infantryman during World War II. Severely wounded in battle while in Germany, he received the Purple Heart award. His wounds may have been fatal had it not been for cutting-edge bone-grafting techniques. The procedure was considered experimental at the time, and Ettinger was counted as a success story. Undergoing successful surgery thanks to advanced medical technology and receiving the Purple Heart inspired Ettinger to seriously consider the idea of preservation after death. The hope was that future medical advancements could revive and repair a human’s body, returning him or her to a comfortable and indefinite state of being. Ettinger assumed that someone, perhaps a scientist, would advocate the idea, turning it into an area of research without the need for any active involvement on his part.

    He went on to study mathematics and physics and became a professor at Wayne State University and at Highland Park Community College. By 1960, at age forty-two, he began to consider his own mortality. As far as he knew, nobody else had realized his idea for escaping death. If he wanted to pursue the possibility of saving his own life, he’d have to act right away. And so he wrote down his conception of frozen stasis and reversible death and sent the paper out to two hundred people—recipients whom he’d carefully selected from a list of movers and shakers culled from Who’s Who in America. After his attempt failed to conjure any significant support, he wrote that, to his astonishment, “a great many people have to be coaxed into admitting that life is better than death, healthy is better than sick, smart is better than stupid, and immortality might be worth the trouble!”

    His next step caused the stir he was looking for. He wrote a book. After a preliminary copy was promoted by Isaac Asimov, The Prospect of Immortality sold exceedingly well. Ettinger became an overnight celebrity. Reviewers considered the book profound. It was covered in the New York Times, Newsweek, Paris Match, Der Spiegel, and (appropriately enough) Time. He appeared on radio and television talk shows and was interviewed by David Frost, Johnny Carson, and Steve Allen.

    Later, reflecting on why it had taken him so long to write his book, Ettinger said, “For the simple reason that I had, and have, no credentials worth mentioning, being only a (now retired) teacher of college physics and math. It is precisely this that prevented me, for so long, from doing more: I knew I carried no weight, had no formal qualifications, and was not suited for a leadership role. But as the years passed and no one better came forward, I finally had to write.”

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    Despite his self-effacement, Ettinger was in fact a fantastic candidate to advance a far-out idea. An academically credible war veteran, he was an articulate spokesperson who fit the creative and optimistic spirit of the 1960s.

    Over the next couple of years, various cryonics-centered organizations were born. The first, called Life Extension Society, was founded in 1964. (It wasn’t until 1965, however, that an industrial engineer and cryonicist in New York by the name of Karl Werner invented the term “cryonics” by fusing cryo- and bionics.)

    Other groups formed in California and Michigan, where Ettinger was president of the Cryonics Society of Michigan. Yet something crucial was missing: the first patient!

    Choosing cryonics seemed so obvious and logical. If you like life today, why not take the steps toward a world where each new day brings with it the possibility of another?

    Evan Cooper, who founded the Life Extension Society after reading Ettinger’s book, made extensive efforts to promote cryonics to both scientists and the public at large. Dismayed by the lack of appeal generated after two years, he wrote, “Are we shouting in the abyss? How could 110 million go to their deaths without one, at least trying for a life in the future via freezing? Where is the individualism, scientific curiosity, and even eccentricity we hear so much about?” The Life Extension Society even offered to freeze the first volunteer free of charge.

    The excitement, motivation, and eagerness displayed by the advocates of cryonics were aimed at catapulting the theory into practice in hopes that it would spur the world into realizing that immortality was within the limits of science. Choosing cryonics seemed so obvious and logical. If you like life today, why not take the steps toward a world where each new day brings with it the possibility of another? Surely any chance is better than a guarantee of rotting or turning to dust if there’s no afterlife.

    Although many cryonics promoters held this attitude, they advocated the slow, gradual process of science—experimental testing and formal research conducted according to a rigorous, skeptical standard—to achieve their aims.

    In 1967, a golden opportunity presented itself. A series of events that would generate worldwide news about cryonics was about to unfold. The first volunteer had arrived. A patient diagnosed with terminal cancer expressed interest in being frozen. Of course, the actual science of cryonics as a practice was still in its infancy.

    The stage was set with a call between Robert Nelson, an ex-TV repairman who was president of the Life Extension Society, and Robert Ettinger. Nelson recalled, “Well, I called Robert Ettinger that night, and I told him what had happened. And he said, oh my god, this is the biggest thing that’s happened in the cryonics program. And so Ettinger said, we need to go ahead and do it. And I said, but we’ll lose the scientific advisory council. He said, maybe not all of them. And if we do, we’ll get them again. He said, there’s nothing that will push the program of cryonics forward [faster] than the freezing of the first man.”


    From Out Cold: A Chilling Descent into the Macabre, Controversial, Lifesaving History of Hypothermia by Philip Jaekl, copyright © 2021. Reprinted by permission of PublicAffairs., an imprint of Hachette Book Group, Inc.

    Philip Jaekl
    Philip Jaekl
    Philip Jaekl is a cognitive neuroscientist and science writer. Aside from his academic publications he has written on topics related to neuroscience for The Atlantic, The Guardian, and Wired. He's also written for New York Magazine and has contributed feature-length essays to Aeon. Jaekl now lives in Tromsø, Norway.

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