# Spacetime |  | In physics, **Spacetime** is any mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing and understanding relativistic effects such as how different observers perceive where and when events occur. | |-|-| | | wikipedia:: [Spacetime](https://en.wikipedia.org/wiki/Spacetime) | Also "spatial"