Spacetime

In physics, spacetime, also called the space-time continuum, is a 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. Until the turn of the 20th century, the assumption had been that the three-dimensional geometry of the universe (its description in terms of locations, shapes, distances, and directions) was distinct from time (the measurement of when events occur within the universe).

Extends: Spacetime, [Concepts in physics](https://wikipedia.org.ai/Concepts in physics), [Theoretical physics](https://wikipedia.org.ai/Theoretical physics), [Theory of relativity](https://wikipedia.org.ai/Theory of relativity), Time