Decades ago, Cornell’s Dr. Joe Halpern wrote a book called “Reasoning with Uncertainty.” In this interview, we discuss alternative approaches to handling large-scale uncertainty - as might be applied to broad concerns such as environmental policy, or the management of hard-to-predict emerging technologies.   Through thought experiments and some philosophical exploration, Prof. Halpern explains some potential alternatives to “probabilities,” and opens up the door to other, potentially more robust methods of managing large, uncertain, important questions for humanity’s future.