In 1989 the physicist and science-fiction writer Gregory Ben-ford was asked to take part in a series of US Department of Energy work-groups studying the prospects for nuclear waste storage in the New Mexico desert. Perhaps “studying” is not the right word: their charge, emanating ultimately from a congressional oversight committee, was to consider how best to make and mark a site that would safely contain deadly radioactive materials for at least the next ten thousand years. 1 This is a period longer than all recorded history and longer, certainly, than one could realistically imagine the United States of America persisting in anything like its current form. To project coherent risk narratives forward into such an explosively ramifying mass of uncertainty could only be pure speculation—something closer to what Benford does as a novelist than as a scientist. Only Congress, the man who called to hire him wryly noted, could concoct a task at once so earnestly practical and so far beyond belief, and then fund it. Nonetheless Benford, author of a classic fiction of environmental catastrophe, Timescape (1980), with its own take on questions of toxic waste and the passage of time, agreed to take part.

Determining the probabilities of accidental intrusion into the site was daunting enough; they amply confirm Ulrich Beck’s account of the present as a “world risk society” driven increasingly by a dynamic of nonknowledge, where the ever more avid calculation of probabilities is beset by the continual multiplication, in that very process, of positive uncertainties. 2 More broadly, whereas science was once thought of as a way of reducing ignorance, it now generates an uncontrollable array of unknowable technological side effects cascading into and back from the future. Living in the knowledge of this nonknowledge, inhabitants of the risk society can also be said, according to Beck, to be living in a time of “reflexive modernity,” when the consequences of modernization have become a source of widespread worry. 3 Long gone is the time when