Some investors are going further: PayPal founder Peter Thiel, for example, recently pledged up to $3.5 million to an organization headed by the British longevity guru Aubrey De Grey, a Cambridge-educated Ph.D. who is experimenting with mice to see if the aging process can be reversed by cellular regeneration. That sum is just a part of the millions De Grey has raised from a variety of donors to expand his research into what he calls “strategies for engineered negligible senescence,” or SENS, which are based on the idea that aging as we know it can be “cured” by arresting the destructive metabolic forces that cause it and manipulating genes to renew themselves. De Grey’s work competes, in a way, with that of the Ellison Medical Foundation, financed by Oracle co-founder Larry Ellison. The foundation, which has received about $300 million from Ellison since its startup, funds basic biomedical research into aging with an eye toward treating age-related diseases, though it adamantly distances itself from the notion that aging can be cured. For his part, Kurzweil invests heavily in his beliefs, helping finance De Grey’s efforts and the pioneering work of Dr. Robert Freitas, a nanobot researcher at the Institute for Molecular Manufacturing in Palo Alto, California. Kurzweil is also in the longevity business himself, partnering with Terry Grossman, a Denver antiaging doctor, to produce, among other things, a line of supplements sold under the Ray & Terry label.

The longevity field is splintered between people like De Grey, who think a cure for aging is a realistic goal, and those like the researchers at Ellison, who argue that medical science will indeed be able to extend life, but not eternally. (Since 1970, the average U.S. life span has crept up by four years, to 77.9, not the kind of increment that the immortalists have in mind.) “We’re all going to croak,” says Richard Sprott, the Ellison Medical Foundation’s director, who expects that humans may eventually live as much as 30 years longer, but only in the distant future. As for the rest of it, including cryonics, Sprott says, “I don’t know how anybody takes some of this stuff seriously.”

Such skepticism explains why Peter Thiel, now head of Clarium Capital Management, a $2.7 billion hedge fund, has raised some eyebrows with his very public funding of De Grey’s immortality work. After announcing his investment in 2006, he discussed it further at the annual Singularity Institute for Artificial Intelligence conference—in front of hundreds of the nation’s digerati. (Tech bloggers later went after Thiel, dismissing Aubrey De Grey as a crackpot.) In Thiel’s view, “Aubrey is the rare combination of a first-rate scientist with an out-of-the-box thinker. In just the past five years, the notion of radical life extension has moved from the fringes to the mainstream, and he’s been one of the central figures in bringing about that shift. Every myth on this planet tells people that the purpose of life is death. It’s time for us to move beyond mythology and try to find a real cure for this universal disease.”

Neutral observers suggest that the interest in longevity or immortality research among many high-powered business executives is stoked by the same fire, optimism, and ego that made them successful in the first place. “Many of them are masters of the universe in terms of creating great funds and profit, and they think any problem is solvable,” says Ari Kiev, a psychiatrist who has worked with Steve Cohen, founder of SAC Capital Advisors, the Stamford, Connecticut, hedge fund. “That they would get involved in this is not so far removed from their ability to create outsize dreams and go for it. It has to do with risk taking, dealing with the unknown.”

It's hardly surprising, however, that some investors on the fringe of longevity research don’t want to talk about their involvement. The science can easily turn into spectacle. Recall the lurid estate fight, back in 2002 and 2003, over the body of baseball great Ted Williams, whose written wishes were to take a swing at immortality by surrendering his remains to the Alcor Life Extension Foundation in Scottsdale, Arizona. The Associated Press filed this report: “Ted Williams was decapitated by surgeons at the cryonics company where his body is suspended in liquid nitrogen, and several samples of his DNA are missing.... The head is stored in a can filled with liquid nitrogen.... Williams’ body stands upright in a 9-foot-tall cylindrical steel tank, also filled with liquid nitrogen.”