des, epidemics and interactions: Dirk Helbing, “Globally Networked Risks and How to Respond,” Nature, 2013, 51-59. 15 Scientists who study networks: D. Achlioptas, R. M. D'souza, and J. Spencer. "Explosive Percolation in Random Networks." Science, 2009, 1453-455. 16 And because the nature of terrorism: See Ant