Great cases, as U.S. Supreme Court Justice Oliver Wendell Holmes suggested a century ago, may make bad law. But great questions often make very good science. Some great questions get bigger over time, encompassing an ever-expanding universe, or become more profound, such as the quest to understand consciousness. On the other hand, many deep questions drive science to smaller scales, more minute than the realm of atoms and molecules, or to a greater depth of detail underlying broad-brush answers to past big questions. In 1880, some scientists remained unconvinced by Maxwell’s evidence for atoms. Today, the analogous debate focuses on superstrings as the ultimate bits of matter, on a scale a trillion trillion times smaller. Old arguments over evolution and natural selection have descended to debates on the dynamics of speciation, or how particular behaviors, such as altruistic cooperation, have emerged from the laws of individual competition.
Science’s greatest advances occur on the frontiers, at the interface between ignorance and knowledge, where the most profound questions are posed. There’s no better way to assess the current condition of science than listing the questions that science cannot answer. “Science,” Gross declares, “is shaped by ignorance.”