Amid all the excitement about specific technological advances, it’s easy to lose sight of how emerging technologies are more than particular new techniques and tools. Rather than viewing them simply as a collection of specific examples (valuable though that is), much is to be gained by seeing them also as a general phenomenon. From this perspective, what is most striking is that “emerging technologies” have become a distinctive social world, a peculiar "speculative space" found at the edges of technological systems, where innovations are being most actively constructed and transformed. Characteristics of that speculative space include revolutionary rhetoric, scientific and technological practices, new institutional arrangements, and the politics of decisionmaking.