AS A CHILD, Susan Hockfield took apart anything she got her hands on to figure out how it worked. One time it was a watch, another time her mother’s iron. Her interest in the anatomy of the physical world grew over time: She pursued a career in neurobiology, and went on to teach at Yale University, where she eventually became provost. In 2005 she became the first female president of the Massachusetts Institute of Technology — and its first biologist-president.