Forecasting is really hard, especially when it involves the future - or so they say. One of Ray Kurzweil's more noteworthy achievements has been, I think, to help popularize the idea that technological progress can be predicted fairly well at the level of general capabilities (as opposed to specific implementations). This is not a new idea, but despite - or because of - the sweeping, glittering changes transforming our society, at a pace that is only getting faster, it hasn't achieved any great adoption in the public eye, at least beyond some few narrow and often misquoted instances such as Moore's law for computing power.
If the outcome of technological progress only meant smaller widgets and brighter lights, then I probably wouldn't be as interested in it as I am. In the grand scheme of things, does it much matter that you can be modestly confident in predicting whether widgets will be half the size and a tenth of the cost in twenty years versus forty years? If you're in the widget business for the long haul, it matters. If not ... well, everyone has their own specialty to attend to.
There is one branch of technology which is now of great importance to everyone, however, and that is medicine. We stand on the verge of being able to extend human life by reversing the underlying biological damage that causes aging. "On the verge" means that either you die just a little later than your parents, or you live for centuries or longer, depending on whether or not you live long enough to benefit from the first therapies capable of actual rejuvenation. The early rejuvenation therapies will be poor in comparison to what comes afterwards, but they will give you time to wait for better treatments: you just have to be young enough at the outset to stay ahead of the curve of improvement.
This is vastly more important than widgets: being able to more or less predict the course of electronics, computing, or space flight gives you an idea of what you might see before you die. Predicting the course of capacities in medicine even at a very high level may show you whether you will have to age to death at all, should things progress as expected. On this topic, here is an open access paper that delves into historical technologies to suggest that progress is predictable:
Forecasting technological progress is of great interest to engineers, policy makers, and private investors. Several models have been proposed for predicting technological improvement, but how well do these models perform? An early hypothesis made by Theodore Wright in 1936 is that cost decreases as a power law of cumulative production. An alternative hypothesis is Moore's law, which can be generalized to say that technologies improve exponentially with time. Other alternatives were proposed by Goddard, Sinclair et al., and Nordhaus.
These hypotheses have not previously been rigorously tested. Using a new database on the cost and production of 62 different technologies, which is the most expansive of its kind, we test the ability of six different postulated laws to predict future costs. Our approach involves hindcasting and developing a statistical model to rank the performance of the postulated laws. Wright's law produces the best forecasts, but Moore's law is not far behind. We discover a previously unobserved regularity that production tends to increase exponentially. A combination of an exponential decrease in cost and an exponential increase in production would make Moore's law and Wright's law indistinguishable, as originally pointed out by Sahal.
We show for the first time that these regularities are observed in data to such a degree that the performance of these two laws is nearly the same. Our results show that technological progress is forecastable, with the square root of the logarithmic error growing linearly with the forecasting horizon at a typical rate of 2.5% per year.
I point you to the research quoted above as a form of reassurance: progress will continue in medicine, and via efforts such as the Methuselah Foundation and SENS Research Foundation the medical research community is presently being brought around to the idea of extending human life via rejuvenation biotechnology. The uncertainty in timelines at present all lies in how long it will take for SENS-style rejuvenation research to gather a firm, mainstream, well-funded position: once that happens then progress is inevitable and tends to unfold as outlined above. Prior to that point there is much uncertainty, with things progressing in fits and starts - the standard tyranny of progress under minimal funding and participation.
Thus the present goal for advocates is to persuade enough people and funds to make progress inevitable from that point on. The sooner that happens, the higher the fraction of those presently alive who will live to see and benefit from human rejuvenation. If you're in mid-life like I am, you only have forty years or so of grace - and less if you're not taking care of your health, or are just plain unlucky in the cancer lottery. Four decades is probably only enough time if things go very well over the next ten to twenty years, and SENS or SENS-like programs colonize a large enough chunk of the life science research community in a short enough space of time.
So: hope or help. One of the two, but the letter is generally a better plan.