The word space has many meanings, including:
The definition of space in physics is contentious. Various concepts used to try to define space have included:
- the structure defined by the set of "spatial relationships" between objects
- a manifold defined by a coordinate system where an object can be located
- the entity that stops all objects in the universe from touching one another
- the condition within the conceptual field of Existence that provides the 'ground' for any manifested form and as such it enables the movement and all physical dynamics
In classical physics, space is a three-dimensional Euclidean space where any position can be described using three coordinates. Relativistic physics examines spacetime rather than space; spacetime is modeled as a four-dimensional manifold.
See also: Spherical coordinates, Cartesian coordinates, Philosophy of physics
An issue of philosophical debate is whether space is an ontological entity itself, or simply a conceptual framework we need to think (and talk) about the world. Another way to frame this is to ask, "Can space itself be measured, or is space part of the measurement system?" The same debate applies also to time, and an important formulation in both areas was given by Immanuel Kant.
Immanuel Kant, in the Critique of Pure Reason, described space as an a priori notion that allows us (together with other a priori notions such as time) to comprehend sense experience. With Kant, neither space nor time are conceived as substances, but rather both are elements of a systematic framework we use to structure our experience. Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantify how far apart events occur.
Similar philosophical questions concerning space include: Is space absolute or purely relational? Does space have one correct geometry, or is the geometry of space just a convention? Historical positions in these debates have been taken by Isaac Newton (space is absolute), Gottfried Leibniz (space is relational), and Henri Poincaré (spatial geometry is a convention). Two important thought-experiments connected with these questions are: Newton's bucket argument and Poincaré's sphere-world.
See also: Philosophy of space and time
In mathematics, a space is a set, usually with some additional structure.
For examples, see Euclidean space, vector space, normed vector space, affine space, projective space, Banach space, inner product space, Hilbert space, topological space, uniform space, metric space, probability space.
The term space can refer to the relatively empty parts of the universe, outside the atmospheres of celestial bodies such as the earth. Space is referred to also as the "cosmos".
See outer space and Boundary to space.
The term inner space has sometimes been used to describe the contents of the human mind.
The memory space of a computer is often thought as a one dimensional array of memory cells.
The Space character (ASCII value 32) is used as the blank separating words (same as Orthographic space), and corresponds to the spacebar on the keyboard.
Space is a French electronic music band created in 1977. It was headed by Didier Marouani (also known as Ecama).
Space was also an ambient album by Jimmy Cauty of the KLF.
Space is also a Liverpool-based pop/indie band, popular in the late 90's.
Orthography / Typography
In some orthographies, a space is a blank area that serves as punctuation to provide interword separation.
In board games, space is often the term used to describe the divisions to which the result of the dice roll (or similar alternative) denotes the movement. For example, one would "land on that space", or "move five spaces". When the playing piece lands on a space, this often triggers an action which affects the player in control of the playing piece.
Space is a common shorthand reference to the Canadian specialty cable network, Space: The Imagination Station.