From The Art and Popular Culture Encyclopedia
"By the railway space is annihilated, and only time remains."--French affairs – Letters from Paris. In: Two Volumes. Vol. II. Lutetia () by Heinrich Heine
In physics, spacetime is any mathematical model that combines space and time into a single construct called the spacetime continuum. Spacetime is usually interpreted with space being three-dimensional and time playing the role of the fourth dimension. According to Euclidean space perception, the universe has three dimensions of space, and one dimension of time. By combining space and time into a single manifold, physicists have significantly simplified a large amount of physical theories, as well as described in a more uniform way the workings of the universe at both the supergalactic and subatomic levels.
In classical mechanics, the use of Euclidean space instead of spacetime is appropriate, as time is treated as universal and constant, being independent of the state of motion of an observer. In relativistic contexts, however, time cannot be separated from the three dimensions of space because the rate at which time passes depends on an object's velocity relative to the speed of light, and also the strength of intense gravitational fields which can slow the passage of time, and as such is dependent on the state of motion of the observer and is therefore not universal.
- Basic introduction to the mathematics of curved spacetime
- Global spacetime structure
- Hole argument
- List of mathematical topics in relativity
- Local spacetime structure
- Lorentz invariance
- Mathematics of general relativity
- Metric space
- Philosophy of space and time
- Relativity of simultaneity
- Strip photography
- World manifold