# space

"Space isn't remote at all. It's only an hour's
drive away if your car could go straight upwards."

– Fred Hoyle.

In astronomy, space is the part of the Universe lying outside of the limits of Earth's atmosphere. More generally,it is the volume in which all spatial bodies move.

In physics, space is the three-dimensional theater in which things as we know them can exist or in which events can take place. In the Einsteinian worldview, space and time are united inextricably in a spacetime continuum and there is also the possibility of higher dimensions. See also fourth dimension.

In mathematics, a space
is any unbounded or bounded extent. According to Euclidean
geometry, space is uniform and infinite, so that we may talk of
a line of infinite extent or a polygon of infinite area. In Riemannian
geometry, however, all lines are of less than a certain, finite
extent; and in **Lobachevskian geometry**, there is a similar
maximum area.

There are additionally many other types of space, most of them too abstract
to imagine or to describe accurately in a few sentences. Generally,
a mathematical space is a set of points with additional features. In
a topological space every
point has a collection of neighborhoods to which it belongs. In an **affine
space** (see affine geometry),
which is a generalization of the familiar concepts of a straight line,
a plane, and ordinary three-dimensional space, a defining feature is
the ability to fix a point and a set of coordinate axes through it so
that every point in the space can be represented as a "tuple," or ordered
set, of coordinates. Other examples of mathematical spaces include vector
space, **measure spaces**, and metric
spaces.