It is said that one of the things that make us human is our sense of our own mortality, and almost as long as we know we will die one day we have been wondering if we can wake up again. Stories of resurrection and immortality can be found in countless religions and myths, and in recent years many of these stories have been based on the idea of cryonic preservation: freezing a body and then resuscitating it in the future. If it worked for Han Solo, Captain America and Fry from Futurama, why can't it work for us?
"(For) most cryonists there are two things you will find. We are science fiction enthusiasts, of course. We are optimists too, & # 39; & # 39; said Dennis Kowalski, president of the Cryonics Institute, a nun. profit organization in Michigan and one of the few companies to offer its service offering worldwide.
That optimism is important, because cryonic preservation and resuscitation is "100 percent not possible," Kowalski said. However, he says, "we are not at the peak of all our knowledge at this point, and we certainly have more to learn and discover in the future." Kowalski, a former paramedic, cites modern life-saving interventions such as cardiac defibrillation and resuscitation as examples of how science can change dramatically – throughout most of human history, people have generally agreed that there is no way to save someone whose heart has stopped. "And now," he says, "it's quite a routine."
Based on that premise – that science will one day find solutions to biological damage that is irreparable by today's standards – the goal of cryonics is to keep bodies in a stable, preserved state until the necessary medical technology arrives. Even for its most loyal followers cryonics is no guarantee; Kowalski describes it as "an ambulance journey to a future hospital that may or may not exist". But he sees the field as sort of a Pascal bet – we're definitely going to die, so if there's even an outside chance of extending life through cryonics, there's nothing to lose and potentially a second life to be won.
How the cryonic process works
When someone who has arranged to cryonically store their remains is pronounced dead, a medical team cools the body with ice water and keeps the body tissues from oxygen using CPR and oxygen masks. The icy body is placed in a hermetically sealed container and flown to the cryonics facility. (A note on nomenclature – freezing a cadaver is cryonics, not cryogenics. Cryogenics is the science and engineering of super-low temperatures.)
At the cryonics facility, the team places the body on a machine similar to a heart-lung bypass, circulating blood and maintaining oxygenation. They pump in a vitrification solution that acts like antifreeze to keep the body's tissues from turning into ice crystals, hoping to minimize structural damage. They then slowly cool the body to -320 ℉ in a vapor chamber with liquid nitrogen. Once it is cold enough, the body is transferred to a thermos-like tank of liquid nitrogen, where it will stay for the foreseeable future. The fees of the customers (about $ 28,000 per person) maintain the institute's endowment to keep the organization running forever.
The bodies will wait in these tanks until medical technology can (hopefully) revive them. Kowalski says there are three challenges to this future technology that must be overcome: he must repair the damage caused by frostbite, heal any ailments that originally killed the subject, and reverse the aging process so that the subject has a young, healthy body to to enjoy. in their second round. Nobody knows what that technology could look like; Kowalski's best bet is tissue engineering and molecular nanotechnology that will be able to repair and replace damaged tissues.
Kowalski and his fellow cryonics advocates recognize that it is a tall order. But if you study cryonics, most cryobiologists – scientists who study the effects of freezing temperatures on living tissues for procedures like in vitro fertilization, stem cell therapy, and organ transplantation – will just shake their heads.
What can go wrong
"There is absolutely no current way, no proven scientific way, to actually freeze an entire human to that temperature without completely destroying the tissue – and I mean erasing it -" said Shannon Tessier, a cryobiologist at Harvard. University and Massachusetts General Hospital. When scientists try to freeze a sample of living human tissue, such as a slice of liver, “the tissue is completely obliterated, the cell membrane is completely destroyed. So there is really no evidence that you keep anything, and that's because the science just isn't there yet. "
There are animals that can survive when frozen and thawed, such as Canadian wood frogs, but these organisms have evolved specifically to handle the pressures of freezing temperatures in a way that our bodies just haven't. Tessier says it's hard to imagine how our tissues could even endure the process of heating up, even with the benefit of a few centuries of scientific advancement. “We did an experiment in the lab a few years ago. We tried to glaze a pig's heart, a whole pig's heart. And of course, the technology currently doesn't exist to heat up the heart fast enough and, literally, the whole heart broke in half. "
Our tissues' ability to physically resist freezing and thawing is just the beginning, says John Baust, a cryobiologist at Binghamton University, SUNY. When our tissues are cooled, the part that freezes is usually pure water – the cells, salts, and organic materials that make up our fluids are excluded. The remaining cells undergo severe molecular stress. "There are genetic changes that occur," says Baust, "that say to the cell,"Die. & # 39; & # 39; These instructions for cell death, called apoptosis, begin well before freezing temperatures are reached.
"For those of us who work in the field of freezing biological material – mammal cells, tissues, we've tried organs, and so on – there are simply insurmountable problems," Baust says.
Cryonics like Kowalski are well aware of this criticism. He argues that while these problems are insurmountable for us today, they may be solvable in the future. It's a point that is definitely impossible to rule out – almost as if it definitively proves there is no such thing as unicorns. "I don't think anyone can really deny what the future holds," said Baust. 'I don't have all the answers. But I think skepticism is very reasonable. "
& # 39; nothing to lose & # 39;
Aside from arguments about what is possible or could be possible in the future, one more question lingers: even if you could be brought back, would you want to? After all, you would have been stranded in a strange world, separated from everything that made your life worth living.
Anders Sandberg, a philosopher at Oxford University's Future of Humanity Institute, compares the prospect of revival to “ a temporary refugee – you can't survive in the present, your only chance is some kind of exile. to go in a foreign land & # 39 ;. But for Sandberg, a cryonics advocate who wears a medallion every day with his cryonics instructions: & # 39; Life is worth living. I really enjoy living. As long as that's true, I want to try and hang out. But of course it is a gamble. "
& # 39; You have nothing to lose, everything to gain. Except for some life insurance money. And to me it is worth it. It gives me peace of mind, ”said Kowalski, who along with his wife and sons has been signed up for cryonic preservation. "Even if it doesn't work, we're still pushing the science forward and figuring out what doesn't work. And when it works, oh my God, we just came across a cure for death, at least temporarily."