Over at the Longevity Meme, I recently pointed to very good commentary on the implications of Ray Kurzweil's predictions for our life spans - how close are we to agelessness attained through advanced technology? With regard to the varied predictions, economist Arnold Kling seems to be on much the same page as I am; his recent piece at Tech Central Station reminded me of arguments I've made in the dim and distant past on the pace of development. He says:
In comparing the predictions that turned out to be conservative with the predictions that turned out to be optimistic, I detect a clear pattern. Generally speaking, the more open-ended the problem and the more adaptive that the machine needs to be to provide a solution, the less far along we are in arriving at a technological solution. One way to put this is that we can construct tools, but we cannot construct agents.
In other words, progress towards general (and/or strong) artificial intelligence - a grail for many transhumanists and other futurists - has been slower than we'd like. The level of difficulty has been consistently underestimated in the past, and I see this as one part of a larger underestimation of any form of complexity management. You may recall seeing this idea put forward in a variety of 1990s writing on the topic of nanotechnology; the production of millions of nanorobots wasn't thought to be as hard as the process of controlling and managing those nanorobots in a useful fashion - strategies for information processing are as much the key to future medical technologies as nanoscale and molecular manufacturing. Complexity is hard, both to manage and estimate in advance.
Now replace "nanorobot" with "human cell" and that's where we are today with biotechnology. Biological systems - such as your body, or even just a small piece of it - are immensely complex. The reason researchers can make meaningful progress today with medical technology such as gene therapies and stem cell research is that they are, effectively, tweaking settings on existing machinery that largely handles the complexity management itself. Our grasp of how things work - based on our ability to process information and build the tools required to gather information and effect change - is now adequate for this task, just as it is almost adequate to guide existing biological machinery to build replacement tissue and organs in a useful, controlled manner. But it seems to me to be a very large leap - in terms of managing complexity - to go from where we are today to reach the point of, for example, replacing biochemically complex systems within the body with artificial substitutes. Or reverse-engineering the brain, that sort of thing.
People are working on making this future a reality, the technologies of information processing are advancing by leap and bound, and science will get there eventually. The bigger question to my mind - being a first things first sort of person - is whether the first generation and intermediary technologies of healthy life extension, each better than the last, prove to be effective stepping stones. Will early SENS or regenerative medicine therapies enable us to live healthily for long enough to see a Kurzweilesque tomorrow? Or live healthily for long enough to to use the next, nore effective therapy that will take us into Kurzweil territory? Will these working anti-aging medical technologies be developed at all? That is, as I have often said, up to us.