Each December for the past fifteen years, the literary agent John Brockman has pulled out his Rolodex and asked a legion of top scientists and writers to ponder a single question: What scientific concept would improve everybody’s cognitive tool kit? (Or: What have you changed your mind about?) This year, Brockman’s panelists agreed to take on the subject of what we should fear. There’s the fiscal cliff, the continued European economic crisis, the perpetual tensions in the Middle East. But what about the things that may happen in twenty, fifty, or a hundred years? The premise, as the science historian George Dyson put it, is that “people tend to worry too much about things that it doesn’t do any good to worry about, and not to worry enough about things we should be worrying about.” A hundred fifty contributors wrote essays for the project. The result is a recently published collection, “What *Should* We Be Worried About?” available without charge at John Brockman’s edge.org.