In my Physics and Philosophy course (Drake University, Spring 2018), I guided my students in the creation of a three-dimensional model of space-time. The campus maps printed on foam board are, of course, a familiar reality: a two-dimensional representation of the three-dimensional space that is a college campus. But in the model, these foam boards also represent “time-slices”, hour by hour, throughout a twelve-hour period. The vertical dimension of the model represents time. Each student wove their own colored ribbon, their personal “world-line” through each time-slice, tracing the path they took through space over the course of one particular day.
This project stimulated discussion and writing of a number of philosophical questions. What does it mean to “move” through space? Through time? What is motion and how do we recognize it? What does it mean for world-lines to intersect or not intersect? And more broadly: What are the benefits and drawbacks of models? What do they manage to communicate and what do they fail to represent?