Among the first things you notice when you step into the corner office of Harvard University professor Joanna Aizenberg are the playthings. Behind her desk sit a sand dollar, an azure butterfly mounted in a box, a plastic stand with long fibers that erupt in color when a switch is pulled, and haphazard rows of toys. Especially numerous are the Rubik’s cubes—the classic three-by-three, of course, but also ones with four, five, six and even seven mini cubes along each edge. An eight-year-old would be in heaven.