Space and time play a special role in all physical theories, because they are implicitly assumed in all physical theories. Physical theories can only be applied in practice if we know what 'here' and 'now' mean.

Werner Ahrendt and Tom Becker attribute the puzzling phenomenon that most elementary particles are identical to themselves only after a 720° rotation to a four-dimensional shape of the universe.

The modern mathematical description of physics focuses on symmetries. Physical theories are considered beautiful because of their symmetries. What are these symmetries and where do they come from?

Classical mechanics is based on the everyday understanding of space and time that everyone can observe. According to it, space and time form the stage of world events, where space is three-dimensional, homogeneous, and isotropic in all directions. Time is one-dimensional and progresses uniformly.

In the common narrative of the history of science, one finds the story that classical mechanics was replaced by Einstein's theory of relativity and is contained in the theory of relativity as a special case for small velocities. On closer inspection, however, this narrative is not quite right.