Physicists, stamp collectors, human mobility forecasters

Abstract

One of the two reviewers studied in high school to be a physicist. In the end,
he became something else, but he never lost his awe of physics. The other
reviewer never intended to become a physicist, but he sometimes asks himself
why he didn’t become one. Today, they are both sociologists who practice
their science on an action theory basis and believe that regularities exist in the
world of social actions which can be perceived, understood, explained – and
even used for making predictions.