Every culture throughout recorded history had its seekers after agelessness, all of whom were deluding themselves. As science replaced alchemy the seekers remained just as prevalent, but adopted the superficial trappings of science in their futile quest. A few even adopted the scientific method, or emerged from the scientific community of the time, and were thus much more rapidly and reliably disappointed by the results of their experiments. The power of the scientific method lies as much in its ability to close off potential paths ahead as to open up new ones: it clears out wishful thinking and delusion for those willing to adopt its rigors.
Technology and other applications of scientific knowledge have steadily lengthened healthy life spans since the late 1700s, once the positive feedback loop of growth in wealth and knowledge really kicked in. For most of the past few hundred years much of that growth has stemmed from reducing the burden of infectious disease, not just a matter of reducing death rates in the young, but also lowering the damage load carried by those reaching middle age and older. Nowadays the continued growth in life span in the wealthier regions of the world is largely achieved through improvements in treating and preventing age-related disease. As before this is a very incremental process, however, with trends adding a year of life expectancy at 60 in every decade.
In the 1970s futurists were very enthused about the prospects for medicine, and especially in the prospects for their own personal longevity. They are all aged to death or near as gone now. They were absolutely wrong about how much could be achieved with then new and exciting applications of biotechnology. Yet so very much has been achieved. In comparison to the tools of today, 1970s biotechnology is clunky and expensive: halls of manually tended machinery have now shrunk to a single chip, and a graduate student today can accomplish tasks in a few weekends that would have strained the largest laboratory in the country for years back then.
So we're all pretty excited about what can be done today in medicine, and the prospects for our own personal longevity. When it comes to our understanding of biochemistry and ability to manipulate our cells, we are as far beyond the 1970s as the 1970s were beyond the gentlemen-scientists working at the end of the 19th century. Why, however, is it different this time? Why are the seekers after agelessness now rational scientists rather than another crop of self-deluded fools? This is a question that crops up. I can recall numerous conversations over the years in which I was informed that someone knew an older fellow who was, back in the day, quite confident in the forthcoming existence of longevity-enhancing therapies, and yet where are those treatments decades later? Nowhere in evidence, but here I stand telling you that now is the time, that the Strategies for Engineered Negligible Senescence (SENS) are a viable, plausible road to rejuvenation treatments that could indefinitely extend human life, and that given sufficient funding we could make enough progress in the next 20 years to hit actuarial escape velocity, the point at which medicine adds more healthy life faster than aging takes it away.
As an aside, there is an unfortunate tendency for successful futurists to be those who predict useful and interesting things to happen soon enough to catch the interest of the audience, regardless of the merits of that claim. Most of the really good communicators have also convinced themselves of their message. It is somewhat challenging for a non-technical person to tell the difference between the self-convinced fraud versus someone who happens to be right about an opportunity for development that happens to be in the near future. Many of these opportunities are in the range of 20-30 years distant, assuming funding goes well at each stage, far beyond the point at which you'll see a lot of corroboration in the form of investment in companies trying to achieve these goals directly.
So why is it different this time? For one there is SENS, a detailed plan of development leading to rejuvenation treatments that could be prototyped in mice given a billion dollars and ten years, give or take. No such plan could have been formed a century ago, and while much of the basic knowledge that informs the SENS viewpoint of aging as an accumulation of cellular and molecular damage existed in the 1970s, SENS could not have been proposed as a serious project at that time even had someone had the realization. There was simply no way to even guess at how much time and money it would have required to build the tools to build the tools to develop the validation of the theories so as to build the tools to build the tools to develop the therapies, and so forth: it would have been a project on the scale of going to the moon, and with far less certainty of success.
More importantly none of the proposed paths to add decades or more of healthy life put forward in past generations, now obviously naive and wrong, were in any way rigorous or supported by large fractions of the scientific community. Only now do we have that, built on the vast body of knowledge of biology accumulated over the last century, and on the new tools of biotechnology of the past few decades. Only now are large numbers of scientists putting their careers and their reputations into the extension of healthy life.
Why is it different this time? The fact that funding for various scientific establishment efforts to extend life is growing rapidly. Most of these are in fact not going to move the needle all that much, but that isn't the point. The point is that the consensus in a significant fraction of the scientific community and its surrounding institutions of funding and review is that the time has come. Investment and interest in any given field are cyclic, and this present cycle will see billions poured into this field, and old narrow views of the implausibility of life extension swept away. Scientists are the arbiters of truth in our culture, though this is sometimes hard to see, and the rest of the world will follow their lead when deciding whether to take something seriously. That will create a feedback loop of funding and progress in which, yes, a lot of less useful work will thrive, but so will significant approaches such as SENS.
None of this was the case for past generations of what turned out to be deluded optimism. It is the case now. The times have changed, and it is different this time around.