Cryonics is almost universally panned by scientists. Could there be any light at the end of the tunnel?
Cryonics, in short, is the freezing of a patient who can no longer be sustained by current medical technology in the hope that future medical advances will allow them to be reanimated.
The theory sounds like science fiction, and, at this stage, it is. The science of cryonics is met by staunch skepticism and a strong dose of derision.
But is it really so far-fetched?
Although the idea of freezing and reanimating humans after death has been in popular culture for some time, it was not until the 1960s when a physics teacher - Robert Ettinger - first presented cryonics as a genuine possibility.
Ettinger's book, The Prospect of Immortality, published in 1962, argues that diseases and conditions that are fatal today, might not be in the future. If we could freeze and store a recently (or almost) dead person, we might be able to fix their ailment further down the line and bring them spluttering back to life.
Cryonics in 2016
There are a small number of cryonics companies who take this area of investigation incredibly seriously. They will happily freeze you (or your pet) for a not-so-small fee. One of the largest cryonics companies charges upward of $200,000, plus a yearly subscription fee.
Globally, there are only four facilities set up to freeze bodies - three in the US and one in Russia; an estimated 250 humans have been cryogenically preserved as of 2015 and another 1,500 have signed up.
How does it work? In an ideal world, the cryonics company is able to reach the patient just after the heart has stopped beating but before the brain has died. This allows them to restart the heart and lungs, although the patient is clinically dead.
Initially, the body is dropped to 0°C in an ice bath while respiration and heartbeat are mechanically maintained; heparin is injected to prevent the blood from coagulating, along with a host of other chemicals.
Next, the blood is removed and replaced by cryoprotectants that defend cells from the damage caused by ice crystals developing between cells. This process leads to a state called "vitrification," in other words, crystallization during freezing is prevented and, instead, a "solid liquid" or "glassy state" is produced.
The body is eventually dropped to temperatures of -130°C and below using nitrogen gas. And there you will remain. Indefinitely.
The technology of freezing without damaging tissue has been the main thrust of cryonics research over the decades. But, of course, that is less than half of the battle; reversing the freezing and restoring life are the real stumbling blocks.
Cryonics has never enjoyed any popularity among the scientific populace, and, in the 1970s, its reputation took a substantial kick. The Cryonics Society of California, led by a former TV repairman - Robert Nelson - made it into the news for all of the wrong reasons.
Nelson's organization ran out of money and could no longer fund the preservation of the chilled cadavers it was storing. He was sued for leaving nine bodies to unceremoniously decompose.
The majority of mainstream scientists and medical professionals do not give cryonics researchers much favor. Some scientists simply mumble their dissent under their breath, others are vibrantly venomous, including neuroscientist Michael Hendricks, who refers to cryonics as:
"An abjectly false hope that is beyond the promise of technology and is certainly impossible with the frozen, dead tissue offered by the 'cryonics' industry. Those who profit from this hope deserve our anger and contempt."
Science does not seem to hold out much hope for the possibility of cryonics. It certainly has an incredibly long path ahead of it, and there is no telling whether that path leads to a pot of gold or a brick wall. However, there are some reasons to pass a sympathetic gaze over the field.
The shifting sands of death
The statement "a dead person cannot be revived" seems so obvious that it is hardly worth writing down, but when you look a little deeper, it is not so clear cut.
Could a dead person ever be revived?
A few decades ago, someone who suffered a cardiac arrest was considered irreversibly dead.
Move forward to today, and we routinely bring those people back from the brink. So, in some regards, our definition of what constitutes "dead" has shifted.
It is this kind of stance that cryonics researchers often take when faced with dissenters.
Their argument, whether you are prepared to run with it or not, is that death has already had its goal posts moved, so who is to say that they cannot be moved again?
Today, brain death, rather than cardiac death, is considered the stamp of finality. But even this, it might be argued, is not entirely infallible. For instance, in 1955, James Lovelock cooled a rat to just above 0°C. Its brain completely stopped its normal business. However, Lovelock managed to reanimate the rodent by warming it back up.
More recently, pigs were given the same freeze-to-death-warm-to-life treatment with an impressive degree of success. Even after having their blood almost entirely removed and their internal temperatures dropped to 10°C for 60 minutes, the majority survived.
In a similar experiment, pigs were also found to be neurologically normal after their ordeal. Their ability to learn new tasks was still intact, as was their ability to remember tasks learned prior to their "death."
Ice bath trauma care
Even more recently, in 2015, UPMC Presbyterian Hospital in Pittsburgh, PA, began a groundbreaking new treatment for victims of severe traumas, such as gunshot wounds and knife attacks.
The medical team replaces the patient's blood with a cold saline solution that rapidly cools the body and stops almost all cellular activity, including brain activity.
Cells at cooler temperatures need less oxygen, so a significant drop means that brain tissue can survive longer. This state of "induced hypothermia" gives surgeons more time to treat the injuries before returning the blood back to the system.
Even in a real life situation - cold water drowning - similar findings have been described. A young girl was resuscitated after an astonishing 66 minutes of total submersion in freezing water.
After an hour under water, most people would consider the individual irreversibly dead. We now know this is not always the case. Importantly, her memories and personality were still intact.
This is not the only case of people "surviving clinical death." In 1999, 29-year-old Anna Bågenholm spent 80 minutes trapped in ice after a skiing accident; she survived and fully recovered from a core body temperature of 13.7 °C. Cases like these have spawned a saying in some emergency rooms:
"Nobody is dead until warm and dead."
Frozen rabbit's brain
In early 2016, a company called 21CM managed to freeze a rabbit's brain to -135°C using a process called aldehyde-stabilized cryopreservation. This was nothing new, but, for the first time, the organ was unfrozen without damage.
For the first time, a mammal brain has been frozen and thawed intact.
The team brought the brain back to room temperature and, under electron microscope investigation, the cellular structure of the brain was fully intact.
All of a sudden, cryonics seems less like sci-fi and much more like a (very) distant possibility.
There is evidently a great deal of distance to travel before the reanimation of a long-dead frozen body becomes a regular process, but it is not such a leap of imagination to consider it as, at the very least, a remarkably far-flung possibility.
Additionally, when you consider that healthy human cells - sperm, eggs, blood - are routinely frozen and work perfectly well once reheated and reused, the concept is given another dose of reality.
But, before we get too carried away and sign up at our nearest cryonics lab, it is important to realize we are still incredibly far from making this a viable intervention.
What's in a name?
At this point, it seems relevant to briefly mention the importance of the nomenclature of cryonics. In reality, what name we assign to a medical procedure or discipline should not matter, but in some cases, where discrepancies arise, it is important to know your terminology.
In common usage, the freezing of a body with a plan to reanimate him or her in the future is often referred to as "cryogenics." This is incorrect. Cryonics is the science of freezing and reanimation; cryogenics is the physics behind the production and effects of very low temperatures.
The tone and capitalization in the following statement, taken from the Cryogenic Society of America's website, gives us an idea of the general mood:
"Body Freezing is NOT Cryogenics. It's cryonics, and cryonics is NOT the same as cryogenics. We wish to clarify that cryogenics, which deals with extremely low temperatures, has no connection with cryonics, the belief that a person's body or body parts can be frozen at death, stored in a cryogenic vessel, and later brought back to life. We do NOT endorse this belief, and indeed, find it untenable."
One of the scientists involved in the trauma research at UPMC Presbyterian Hospital, mentioned above, makes the following insightful remark in an interview with New Scientist:
"We are suspending life, but we don't like to call it suspended animation because it sounds like science fiction. So we call it emergency preservation and resuscitation."
The company 21CM - of frozen rabbit brain fame - develop the cryoprotectants for one of the major players in the cryonics industry - Alcor. But, on 21CM's website, they are swift to distance themselves from the potential furore. They do mention "suspended animation" in passing, but they are clearly not overly keen on being tarred with the "weird science" stick.
No one, it seems, wants to be associated with the cryonics guys.
The technical problems with cryonics
Cryonics researchers use the examples mentioned earlier to give their area of research more credence, and, to a certain extent, it does.
Cryonics has an infinitely long path ahead of it.
However, there are some mighty hurdles that cryonics needs to scramble over if it is ever to become a reality.
As we have briefly touched upon, human cells are regularly frozen and revived. This process does not scale up easily.
Numerous problems are encountered when a larger lump of tissue is frozen and thawed out.
Even a larger organ, like a human kidney, has multiple regions, all of which would need to be treated slightly differently in order to preserve the structure. Researchers have investigated the viability of vitrification for use in the storage of complex human organs for future use, but it is plagued with difficulties.
Researchers have successfully managed to vitrify a rabbit kidney, but a human kidney has proven too technically challenging by far. Both freezing and thawing large objects while maintaining structure is, for now, totally impossible.
Another major issue is that frozen humans tend to rupture significantly. Although vitrification helps keep things neat on a cellular level, vitrified human flesh is prone to large fractures, and no one knows why.
By far and away the tallest hurdle to cryonics is, of course, bringing someone back to life. Even if cryonics investigators manage to preserve a body perfectly without damaging it at all, even if the reason the person died in the first place has since become treatable, even if the thawing out of the body is done with perfect, non-disruptive accuracy, the problem remains - how do we breathe life back into a corpse?
Many cryonics researchers believe future nanoscale technologies may hold the answers to reanimation, but that is, quite clearly, nothing more than conjecture at this stage.
The stumbling blocks to cryonics are numerous, varied and titanic in stature, but when one looks back at humanity's speed of technological advance, it is difficult not to wonder whether one day technology like this might be plausible.
If we were to look 1,000 years into the future, and assume that we manage to reliably freeze and not damage a body, could it be possible? Only time will tell, and it will be a good long time at that.