The conference room window overlooks a line of floor-to-ceiling, gleaming steel flasks. The steel feels chilly but not cold; the warehouse-like space they inhabit is unheated in the Arizona "winter". But don't lift the inner styrofoam lid and stick your hand in: they are filled with liquid nitrogen, which boils at 77 degrees Kelvin (-196C). From a nitrogen storage tank, a pipeline snakes along the ceiling sending a runner to each flask - more correctly, "dewar" - to top it up.
Most of the dewars are occupied. This is a little eerie. We are at Alcor, the cryonics organisation. The dewars' 79 occupants were - possibly will have been - people with a dream: that given enough time, medical science will advance enough to cure them of whatever killed them. To pay for their decades - centuries, possibly - at temperatures cold enough to prevent decomposition, they bought life insurance policies of between $75,000 (£38,500) and $100,000. Legally, they are dead. To Alcor's staff, they are "patients".
Cryonics is a small community. The two largest cryonics organisations, Alcor and Michigan-based Cryonics Institute, together poll about 1,600 members. Alcor has 79 patients and 33 pets in cryopreservation; CI has 85 patients and 50 pets.
Grand dream
Science was always going to be slow to fulfill a dream as grand as this. First, cryopreservation techniques need to improve so patients' bodies - and especially their brains, the repositories of memory and personality - suffer minimal damage. Second, the medical techniques for revival, such as cures for Aids, cancer and heart disease, must be developed. Many cryonicists opt to preserve only their heads, hoping for revival technology good enough to give them new, younger bodies. However, there are not even animal experiments to bolster the idea. Nobody has yet frozen and revived any mammal.
But the dream no longer seems quite as lunatic as it did in 1962, when Robert Ettinger's The Prospect of Immortality launched the modern cryonics movement. But because cryonics is so small, it has little funding for research.
The area of most immediate concern to cryonicists is improvements in preservation techniques: less damage at the beginning means an easier eventual repair job. The key technique, which came into use in 2001, is vitrification.
Ice cream that's melted and refrozen develops ice crystals. So do human bodies, where crystals can tear through delicate tissues. As one cryonicist puts it: "We didn't evolve to be frozen." Vitrification avoids this by replacing the blood with a mixture of antifreeze-like chemicals known as cryoprotectants via a machine like the cardio-pulmonary bypass devices used in hospitals. The right mixture at the right temperature, between -90C and -130C, becomes a smooth solid, like glass - hence vitrification.
This process and the cryoprotectants used vary between Alcor and CI; Alcor's cryoprotectants were developed and published by 21CM, a media-shy Florida-based company whose website stresses vitrification's usefulness to organ banks. Published research has shown that vitirication preserves the brain's structure remarkably well.
The downside is that cryoprotectants are toxic. In addition, vitrified human flesh tends to fracture. These are, respectively, the key areas for ongoing research to Ben Best, CI's president, and Alcor. Tanya Jones, director of operations at Alcor, says the cause of the fractures isn't clear, but that at least a few large fractures are easier to repair than many small ones.
The other problem is that it's illegal to vitrify someone while they're medically alive. So the teams have to wait for someone to be declared dead before they can go to work with vitrification.
Meantime, medical research throws up a new and promising headline almost every day. Last year, scientists at the J Craig Venter Institute successfully transferred an entire genome from one bacterium to another. In Maryland recently, scientists built an entire microbial chromosome.
Or take, for example, the work being done by Lance Becker, director of the Penn Center for Resuscitative Medicine. Becker is not directly concerned with cryonics, but it's easy to see connections. Becker wants to extend today's five-minute window for successful resuscitation after the heart stops.
"Fundamentally," he says, "what we are focused on is bringing people back to life from death or near-death, and reinventing or revolutionising the way we approach that." Becker's key discovery is that cells don't die during that five-minute window. The real damage comes when the heart restarts and oxygen floods the tissues, a process known as reperfusion.
"It's pretty well accepted that at the point at which the usual human being gets pronounced dead, all their cells are alive. It's a very eerie question: if all their cells are alive, what is death?" says Becker. Besides, if all the patient's cells are alive, why can't the patient recover and walk out of the hospital? "With our current therapies we can't do it."
One option, says Becker, is cooling the patient - by a few degrees, not to cryonic extremes - to buy time, an idea he says has been around for thousands of years. In studies, dogs and mice cooled before reperfusion have recovered better. "We believe it prevents reperfusion injury."
Cooling, he adds, is much quicker if you cool the blood directly, either by injecting a slurry of micro-ice particles or by using a bypass machine. Imagine, he says, a soldier in the Iraq war, bleeding to death while you watch. "If you could zap, perfuse him, put him on a plane, wing him to a major hospital and fix him all up - that's not at all crazy."
Mad or prescient?
That idea is in fact close to Jones's vision. "If we succeed in our mission," she says, "cryonics will become a process carried out in hospitals by medical staff for much shorter times."
That in itself is a change from the early days, when cryonicists more often aspired to immortality, not just more life. In addition, the demographics are changing. Formerly, most cryonicists were young, male and geeky. Now, Alcor gets whole families.
The important unknown is: Can a cryosuspended brain, warmed and revived, retain the memories and personality of its owner? Until this is proven - in a dog, if not a human - cryonicists don't know if they're mad or prescient. How long before we know?
Best says: "I think within 30 years we'll see a successful revival, but the people revived then would be cryopreserved 30 years from now." Last in, first out: the earliest patients to be cryopreserved suffered the worst damage. James Bedford, who in 1967 became the first person ever to be cryonically suspended and who is now at Alcor, was barely perfused at all. "For the people being cryopreserved now, under the best conditions, my guess is 50 to 100 years." Given the current rate of medical progress and research into nanotechnology, says Jones: "If we haven't done it in 100 years, it's not going to work."
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