I have long found it curious that Ray Kurzweil's public position on radical life extension omits support of specific ongoing research aimed at producing therapies for aging, such as the SENS program of rejuvenation biotechnology. This may be because he prefers to think in terms of broader trends rather than try to pick winners from present initiatives. Alternatively it may be because he sees the machine phase of medicine - the use of swarms of nanorobots capable of maintaining or replacing our biology - as emerging sooner rather than later.
As for me, I don't think that an early arrival of machine phase medicine is plausible: from where I stand it looks as though the medicine of the next four decades will be almost entirely based on control and manipulation of cells, alongside the design of proteins that complement our existing evolved set of protein machinery. We will augment and direct our own molecular biology using more molecular biology for decades before we get to the point of designing and using nanomachines that are as complex as cells without being biological at all.
So programs that are logical outgrowths of present day medicine - like SENS, pushing for repair therapies for cells and clearance of waste products - are the next step in human longevity. It's not a matter of skipping straight to nanorobotic cell replacements of the sort envisaged by Robert Freitas and others.
Most of us accept that our lives are limited. We'll have a certain number of years - more than 75, we hope, but probably fewer than 100 - and then we'll die. The world will go on without us. An awareness of our own mortality, we tell ourselves, is part of what makes is human. Not Ray Kurzweil. A renowned computer scientist and inventor, Kurzweil, 65, decided decades ago that mortality wasn't for him. He didn't have to die, and he wasn't going to, if he could help it. Fortunately, he believes he can help it - and he's been working feverishly at the task of staying alive ever since.
"How long do you think you will live?" I asked Kurzweil in a recent phone interview. He rarely misses a beat in conversation, but he was quiet for just a moment before replying. "I think I have a good chance - I would put it at 80 percent - of getting to the point where it becomes indefinite, because you'll be adding more time than is going by to your remaining life expectancy."
Technological advances won't transpire steadily over time, but rather exponentially, so that each year brings more change than the last. In fact, this is what's been happening for decades in the realm of computer processors, where it's known as Moore's law. Kurzweil believes similar laws of accelerating growth govern all forms of information technology. And he believes that all technology will eventually become a form of information technology. Ergo, technological progress is about to get really, really fast.
So why hasn't average life expectancy - or even the age of the oldest human alive - budged much over the last few decades? Kurzweil says we're just approaching what he calls "the knee of the curve." That's the point at which an exponential function starts to rocket upward. Longevity, Kurzweil explains, "is going to transform from having been a hit-or-miss affair where progress was linear ... to where it is now an information technology and therefore subject to my law of accelerating returns."