Many long-range forecasts of technical feasibility dramatically underestimate the power of future technology because they are based on what I call the “intuitive linear” view of technological progress rather than the “historical exponential view.” It is not the case that we will experience 100 years of progress in the 22nd century; rather we will witness on the order of 20,000 years of progress (at today’s rate of progress, that is).

Careful consideration of the pace of technology shows that the rate of progress is not constant, but it is human nature to simply adapt to the changing pace, so the intuitive view is that the pace will continue at the current rate.

Even for those of us who have lived through a sufficiently long period of technological progress to experience how the pace increases over time, our unexamined intuition nonetheless provides the impression that progress changes at the rate that we have recently experienced.

One reason for this is that an exponential curve approximates a straight line when viewed for a brief duration. So even though the rate of progress in the very recent past (i.e., this past year) is far greater than it was 10 years ago (let alone 100 or 1,000 years ago), our memories are nonetheless dominated by our very recent experience.

It is typical, therefore, that even sophisticated commentators, when considering the future, extrapolate the current pace of change over the next 10 years or 100 years to determine their expectations. This is why I call this way of looking at the future the “intuitive linear” view.

But any serious consideration of the history of technology shows that technological change is at least exponential, not linear. There are a great many examples of this, of which the exponential growth of computing is just one. One can examine data on a wide variety of technologies, and on many different time scales, and see (at least) double exponential growth described by what I call the “law of accelerating returns.”

This observation does not rely on an assumption of the continuation of Moore’s Law but is based on a rich model of diverse technological processes. What it clearly shows is that technology advances (at least) exponentially and has been doing so since the advent of evolution on Earth. Most technology forecasts ignore altogether this “historical exponential view” of technological progress and assume instead the “intuitive linear view.”

That is why people tend to overestimate what can be achieved in the short term (because we tend to leave out necessary details) but underestimate what can be achieved in the long term (because we ignore the fact of exponential growth).This observation also applies to paradigm shift rates, which are currently doubling (approximately) every decade.

So, technological progress in the 22nd century will be equivalent to what would require (at *today’s* rate of progress) on the order of 20,000 years. In terms of the growth of computing, the comparison is even more dramatic.