Some 70 years ago, cybernetics was a hot field; 30 years ago, catastrophe theory was on everyone’s lips. Those Greek-derived words for disciplines that once brought hope of explaining human behavior now evoke a quaint nostalgia, like Polaroids of long-haired young people in bell-bottom jeans and tie-dyed T-shirts. The new buzzword nowadays is big data, the fashionable term for capturing and analyzing the vast collections of information that people reveal about themselves when shopping online at Amazon.com and Travelocity or when writing about themselves on Facebook and Twitter. Big data involves a mix of computer science, information technology, mathematics, and applied statistics. It is increasingly used to sell us products or to persuade us to vote for politicians by tailoring the products’ or politicians’ images to our particular data-generated personas. Some talking heads like to say that computer-aided analysis of patterns will soon replace our traditional methods of discovering the truth in many fields, including medicine, the social sciences, and physics.