"There is an element of uncertainty in every complicated engineering endeavor. “In July 2003, in the Pacific, a Japanese fishing boat was sunk by a flying cow,” Robert Bea told me. Bea is a professor of civil and environmental engineering at the University of California, Berkeley, and a leading scholar of risk; he also spent many years working in research and management at Shell. The cow, it turned out, was part of an illegal cattle shipment bound from Anchorage to Russia; as the plane approached its destination the smugglers became nervous about their cargo and began shoving it out of the plane. “No risk analysis can ever be complete. No one can predict a flying cow.”"