The idea of freezing a life form and bringing it back to life decades or centuries later has been a common plot line in science fiction for hundreds of years.
The earliest accidental freezing story was a French novel, 10,000 Years in a Block of Ice (1889), in which a man is accidentally trapped and frozen in a block of ice, only to be discovered and successfully thawed out by an advanced civilization thousands of years later.
The first story that talked about cryonically freezing someone was 1931's "The Jameson Satellite." Published in Amazing Stories, it follows Professor Jameson, who knows he is dying and requests that his corpse be launched into the absolute zero of outer space. It's found millions of years later by some evil cyborg-type creatures. The story actually inspired the godfather of cryonics, Robert Ettinger, who launched the cryonics movement in the 1960s.
That's where the "science" of cryonics belonged, many scientists and physicians believed. But preserving and re-animating a body (or, more economically, a brain) at a later date is moving from the remainder shelves of science fiction bookstores into serious scientific investigation.
The biggest reason for that is the massive expansion of knowledge about several heretofore mysterious subjects like death, the brain, and consciousness. The more we understand about the body, the mind, and the process of death, the more realistic cryonics becomes.
At least that's what the cryonics companies say.
Neuroscientist Ariel Zeleznikow-Johnston at Monash University in Australia wanted to find out what the medical community thought about cryonics. He and two of his colleagues surveyed 300 primary care doctors, intensive care providers, neurologists, anesthesiologists, and other specialists.
"While a little over one in four of these physicians (27.9%) reported that they believed it was 'plausible,' or even 'very plausible,' that cryonic preservation could potentially lead to some form of revival for patients one day, the data got really interesting when sliced by medical specialty," writes Gizmodo's Matthew Phelan.
When asked to weigh the probability that “critical psychological information” could be adequately preserved by whole brain preservation and revival, neurosurgeons were much more bullish on average, collectively giving the procedure a 72% median estimated probability of success. Zeleznikow-Johnston and his colleague’s entire pool of 334 physicians, by contrast, only granted this futuristic medical intervention a 25.5% median estimated probability of success.
And there’s a reason for this discrepancy, according to Zeleznikow-Johnston, who also serves as an to the nonprofit Brain Preservation Foundation. The foundation has been a wide variety of techniques beyond the more commonly known strategies like cryogenic freezing, including room temperature preservation methods via chemical fixation.
“A lot of physician hesitancy may come from simple unfamiliarity with the scientific basis of modern preservation methods,” Zeleznikow-Johnston explained in a press statement. “The doctors who have actually thought about this—and who regularly sit with dying patients—tend to be more receptive, not less.”
One of the biggest hurdles faced by doctors and patients who wish to have their bodies preserved is legal. Many of the ways that doctors prepare a body for preservation are currently barred by law. The survey asked doctors whether some of these procedures should be legalized, including the administration of the drug heparin, an anti-blood-clotting medication. Gizmodo notes, "70.7% of respondents said this 'probably or definitely should be allowed.' Only 11.7% of the doctors surveyed reportedly disagreed."
While cryonics is still in the realm of science fiction, we're at the point now where novelists were in the 1950s writing about a Moon landing. We knew it was possible and probably going to happen, but the exact method of execution remained unknown.
Imagining a future where cryonics is possible isn't completely beyond the possible. We just don't know how we'll get there.
