A teaching proposal for the didactics of Special Relativity: The spacetime globe

Special Relativity introduces students to Modern Physics, whose importance in the high school is increasing. Nevertheless its teaching and learning is a critical issue. Different solutions have been developed to overcome the encountered difficulties. In this paper we describe the spacetime globe, a mechanical instrument that allows to experience Special Relativity hands-on. We show how it is possible to treat all the main phenomena foreseen by Special Relativity with simple laboratory experiences, using the idea of Minkowski's spacetime diagrams. The aim is to develop the use of geometrical approach in learning Special Relativity in high schools.