Spacetime

:See Space-time theories of consciousness for the philosophy topic.

Related Topics:
Space-time theories of consciousness - Philosophy

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In physics, spacetime is a model that combines space and time into a single coordinate system called the space-time continuum. In our universe, this continuum has three dimensions of space and one dimension of time. Here, time is expressed in the same units as space by multiplying time measurements by the speed of light.

Related Topics:
Physics - Space - Time - Coordinate system - Universe - Dimension - Units - Measurements - Speed of light

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Spacetime is vital to the theories of special relativity and general relativity.

Related Topics:
Theories - Special relativity - General relativity

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Space-time continua are the arenas in which all physical events take place — for example, the motion of planets around the Sun may be described in a particular type of space-time, or the motion of light around a rotating star may be described in another type of space-time.

Related Topics:
Planet - Sun - Light - Star

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A point in space-time is usually referred to as an event. An example of an event may be the explosion of a star. The worldline of a particle or light beam is the path that this particle or beam takes in the space-time, the shortest path between any two points being called a geodesic (of the spacetime). In classical physics, geodesics are timelike or null (light-like).

Related Topics:
Point - Worldline - Geodesic - Classical physics - Geodesics

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