Then, to keep the body as close to its living state as possible, they will hook his corpse up to an IV and administer anticoagulants, pH buffers, and so-called free-radical inhibitors (free radicals are agents that damage cells and are thought to speed aging) plus anesthetics, which Alcor scientists say work as a preservative, particularly on the brain. Thorp’s blood will be drained and replaced with a cryoprotectant, which keeps the tissue from being damaged by cold temperatures. Next step: storage in the nitrogen container, called a Dewar, which is kept at –196°C.

Thorp admits this process gets tricky if he dies suddenly—say, in an accident—far from Alcor’s minions. That’s why Alcor advises all its clients to file living wills that state a religious objection to an autopsy, which often damages vital organs, notably the brain.

When the tough questions are put to Thorp—Why do you think you’d want to live in a world that could be transformed for the worse? Do you really believe this has a chance of succeeding?—he’s pretty candid in his responses.

True, “you could wake up and the language could be different,” he says. “Osama bin Laden could have nuclear weapons. There’s just no telling what could happen.” But while cryopreservation may be an extreme bet, such bets “have paid off for me in the investment world,” he adds.

As for his actual chances of coming back? “Five percent,” Thorp says. “It’s like buying a lottery ticket.”

Thorp may want to live forever, but most new investment in longevity research is going to less extreme areas, which adherents say have great promise to extend life now. Aside from De Grey’s cure-for-aging movement and the more mainstream work of the Ellison Medical researchers, a host of advocates are lobbying for other life-extension approaches: the calorie restrictors; the low-body-temperature enthusiasts; the hormone-replacement, supplement, and diet supporters. Some of these seem like a sideshow—the low-body-temperature theory, for example—but all of them have funding, passionate supporters, and just enough legitimate science in them that they aren’t going away.

Calorie restrictors, backed by an organization called the Calorie Restriction Society, repeat as their mantra “fewer calories, more life.” (The Ellison Medical Foundation also sees promise in some aspects of calorie-restriction research.) It’s actually an old idea, born of research conducted at Cornell University in 1934, which showed that rats that ate half as much as a control group lived twice as long. Similar studies of fruit flies in 1988 seem to show similar results. But calorie restriction vaulted to new prominence in 2004 when researchers at the Washington University School of Medicine in St. Louis reported that a restricted-calorie diet—eating about 45 percent less than the average adult consumes—lowered cholesterol and blood pressure. About the same time, independent researchers noted that a pill form of resveratrol—the antioxidant found in red wine—mimicked the effects of calorie restriction in rats that weren’t on a diet. Problem: Given the amount of resveratrol in red wine, and after adjusting for body weight and metabolism, humans would have to drink a huge amount of wine each day to get the same results. Still, big money is chasing the idea: The findings were provocative enough to allow Sirtris, a biotech startup co-founded by a Harvard M.D. and his venture capitalist partner, to raise about $60 million from an initial public offering to try to produce a pill with a highly concentrated amount of resveratrol.

Then there are the low-body-temperature advocates, emboldened by research showing that a reduction in body temperature slows metabolism and decreases wear and tear on the body and thus logically could extend life. Cooling theory is already part of conventional medicine: In recent years, doctors have taken to putting patients in a state of induced hypothermia as a way of slowing down their metabolism, thereby reducing risk during complicated surgeries. No mainstream studies show that cooling actually promotes longevity, but that hasn’t stopped Alen Salerian from vigorously pursuing the theory. Salerian, a Turkish-born psychiatrist in Washington, D.C., and the onetime head of the F.B.I.’s Mobile Psychiatric Emergency Response Team, fell from grace at the bureau when he was fined by Maryland medical authorities for leaking information to the press in the Robert Hanssen spying case. Salerian says he has unearthed statistics suggesting that people in temperate climates have longer life spans than those in hot climates, and he posits the notion—which he admits is just a notion—that humans could extend their lives by 10 to 20 years simply by lowering their core body temperature by 1°C.