WIE: Though we may fear death, and wish we could avoid it, most people have never taken the idea of immortality seriously. It seems that if such a thing were to become possible, it would be a change far beyond any change that has ever occurred in human history, with almost unimaginable psychological, social, cultural, economic, and spiritual implications. Is humanity ready for this kind of change?

RK: Psychologically, we're not equipped to live five hundred years. So if we were talking only about conquering disease and aging, and then just living on as human beings in our current form for hundreds or thousands of years, that would lead to a serious problem. I think we would develop a deep ennui, a sort of profound despair. We would get bored with the level of intelligence we have and the level of experience we have available to us. I think in order to make this viable, we need not only radical life extension but radical life expansion. We need to expand our intelligence and our capacity for experience as well, which is exactly what these new technologies will enable us to do. Then an extended life span would become not only tolerable but a remarkable frontier where we could pursue the real purpose of life, which is the creation and the appreciation of knowledge. And I mean knowledge in the broader sense, including music and art and literature and science and technology and relationships. We're going to profoundly expand our ability to do that.

My next book, The Singularity Is Near: When Humans Transcend Biology, addresses the far-reaching implications for human life of these overlapping revolutions of genetics, nanotechnology, and robotics. For example, there are already feasibility designs showing that we could develop solar panels and nano-engineered fuel cells that could convert sunlight efficiently enough to meet all of our energy needs. Nanotechnology will also enable us to create any physical product at virtually no cost from very inexpensive raw materials and information. And nanobots are going to be permeating our bodies, brains, and environment—doing our work for us, transforming our environment, cleaning up pollution from earlier eras, and vastly expanding our intelligence. As we merge with our technology, we will have billions or trillions of nanobots in our bloodstreams keeping us healthy, interacting with our biological neurons, and providing, for example, full-immersion virtual reality incorporating all of the senses. If you want to be in real reality, the nanobots will just sit there and do nothing. If you want to be in virtual reality, they'll shut down the signals coming from your real senses, replace them with the signals that you would be experiencing if you were in the virtual environment, and your brain will feel like it's in that virtual environment. You can move your virtual body there and have any kind of encounter you want, incorporating all of the senses.

But most importantly, this intimate merger of our biological intelligence with nonbiological intelligence will vastly expand human intelligence as a whole. I mean, once it gets a foothold in our brains, our thinking will really be a hybrid of the two, and ultimately, the nonbiological portion will be much more powerful, and may give us access to new forms of intelligence that are very different than anything we've experienced.

This also relates to longevity, because the reality of longevity for nonbiological systems is different than for biological systems. Right now, the software of our lives is the information in our brains. I estimate it to be thousands of trillions of bytes, which represents all of our memories and experiences and skills and just the whole state of our brain. So that's software, and it's inextricably tied up with our hardware. When the hardware of our brain crashes, the software dies with it. Our whole concept of life and death has those intertwined; they're not separable.

But we have already experienced a different type of reality where they are separable, and that's our software files. If you buy a new computer, you don't throw all your files away—your files have a longevity that's independent of the hardware. Our lives are also information files, which I call our mind file. So eventually, the information in our brains will be independent of the hardware substrate that it's running on, just like software is today. That's the nature of immortality some decades from now, as our lives increasingly become dominated by the software of our mind file.

In envisioning the future, people frequently will take one change and consider how it would impact today's world as if nothing else is going to change. Most futurist movies are like that. In Spielberg's Artificial Intelligence, for example, you have human-level cyborgs, but everything else is the same—the coffee makers, the cars, no virtual reality. But you really have to look at all the different changes. If a very prescient futurist in 1900 had said, “We have a third of the population today working on farms, but I can see that will be less than two percent in a century from now,” people would have said, “Oh my god, everybody's going to starve.” But not only are we not starving, America's a major food exporter. How did that happen? Because new technologies, largely information-based, have improved productivity not only of food but of everything else.

WIE: Given our current struggles with overpopulation, many have pointed out that if such technologies were to become widely available, we would pretty quickly be faced with a choice between having more children and securing our own immortality. Do you agree?

RK: I don't think it's going to be a problem. Yes, radical life extension will enlarge the population. But soon, all of our products and foods will be manufactured by nanotechnology replicators that can make essentially any physical product at almost no cost. So this will lead to a radical increase in prosperity around the world. And we've seen that as nations become more prosperous, they lower their population growth. The most advanced countries have negative population growth. Now that will reverse again when we dramatically reduce the death rate. The birth rate will then exceed the death rate once again, and population will grow. But how quickly is it going to grow? It's not going to double every year, it's going to add a few percent every year. So compared to this very slow expansion of the biological population, the wealth creation from nanotechnology is going to expand at explosive rates. We're going to be able to keep up very easily.

WIE: One criticism of the life extension movement has been that these technologies are only going to be available to the rich, and therefore, their pursuit will intensify the class gap between the haves and have-nots—those who can afford to live forever and those who can't. Will we end up with a divided world of immortals and mortals?

RK: That's a misconception also. The law of accelerating returns says that there's fifty percent deflation annually in information technology so that you can buy the same digital camera today for half what it cost to buy it a year ago. The typical cycle is that a product starts out unaffordable and actually not working very well—remember when mobile phones barely worked and only the elite could afford them? Then it becomes merely expensive and works better, and then it becomes inexpensive and works very well, and eventually it's almost free and it's really perfected. So it's only at the point where technology doesn't work very well that only the rich can afford it.

Look at the AIDS drugs. They started out costing tens of thousands of dollars per patient and actually didn't work very well. Now, at least in the poorer countries, say, in Africa, it's about a hundred dollars a patient. It's still too much, and yes, we need to do a lot more. But actually, we have the opportunity to save millions of people, because the drugs are only a hundred dollars a person, and they actually work pretty well now. We're not where we need to be, but the technology has moved in the right direction. And that progression is going to accelerate. Ultimately, we'll be able to meet the material needs of the entire population at almost no cost.