How many singularities are near and how will they disrupt human history?

This paper reviews a large number of approaches that have been used for considering technologically driven profound societal change. We agree with Vinge's suggestion for naming events that are capable of rupturing the fabric of human history (or leading to profound societal changes) as a singularity. This is a useful terminology especially since a mathematically rigorous singularity seems impossible for technological and related societal change. The overview of previous work is done within the context of a broader look at the role of technological change within human history. The review shows that a wide variety of methods have been used and almost all point to singularities in the present century particularly in the middle of the century. The diversity of the methods is reassuring about the potential robustness of these predictions. However, the subjectivity of labeling events as singularities (even well studied past events) is a concern about all of the methods and thus one must carefully pause when relying in any way on these predictions. The general lack of empirical research in this area is also a concern. Quantitative considerations (by proponents and opponents) about past singularities or future singularities often confound two types of metrics. The first type is essentially related to diffusion of technologies (or bundles of technologies) where the logistic curve is empirically well established as the proper time dependence. The second type of metric is for technological capability where hyper-exponentials are empirically well established for their time dependence. In this paper, we consider two past singularities (arguably with important enough social change to qualify) in which the basic metric is alternatively of one type or another. The globalization occurring under Portuguese leadership of maritime empire building and naval technological progress is characterized by a metric describing diffusion. The revolution in time keeping, on the other hand, is characterized by a technological capability metric. For these two cases (and thus robust to the choice of metric type), we find that: People undergoing profound technologically-driven societal change do not sense a singularity. The societal impacts depend in complicated ways on human needs, institutional variables and other more uncertain factors and thus are particularly hard to project; The societal impact is apparently not determined by the rate of progress on either type of metric or by projections to mathematical points with either kind of metric. This finding supports the existing concept that social change due to technology is a more holistic phenomenon than can be characterized by any technical metric. In the final section, we use these empirical findings as the basis for exploring the possibilities for and nature of future singularities. In this we speculate that the potential for a future strong singularity based upon computational capability does not appear particularly probable but that one may already be occurring and is not fully noticed by those (us) going through it. Other possible 21st century singularities (life extension and fossil fuel elimination are two examples considered) may also be already underway rather than waiting for the predicted mid-century changes. (C) 2011 Elsevier Inc. All rights reserved.