Space

The room is a "container " for matter and fields in which play all physical processes. This deliberately somewhat imprecise understanding of the term "space" is widespread since Isaac Newton and was only detected by Einstein questioned.

This corresponds to that one in the human experience " already always knows what the space is ," for example, that it is determined by the three mutually orthogonal dimensions height, width and depth or distance, direction and height. Space allows all material objects an extension, he himself exists as a fundamental model of order "a priori of the existing objects in it ", according to current understanding, but only in relation to them. If the concept of space is formed in this sense, it makes no sense to speak of an "empty " space.

For the physical description of formal properties of various mathematical areas, most of Euclidean space can be used. The notion of space has changed considerably in the history of physics.

Space in classical mechanics

In classical mechanics, the space defined by Isaac Newton applies:

• The space is absolute, immutable and unaffected by the physical processes which take place in it.
• The space is Euclidean and three-dimensional.

Herein, the dimensions of a space realized by him Cartesian coordinates, usually expressed in the x-, y -and z- direction. These are called space coordinates and the plane spanned by them dimensions as spatial dimensions, with no spatial dimension one point, one space dimension a straight line or curve and two spatial dimensions correspond to an area. The determination of the reference point of a coordinate system requires real objects. Most of the focus of a large mass such as the Earth or the Sun is taken to.

Space and time

The discovery that the velocity of light is the same for all observers, required a modification of the concept of space. Albert Einstein swore in his special theory of relativity the groundwork so that Hermann Minkowski space and time could be combined into a common structure, the space-time. Thus, the room is no longer absolute, but by the observer (more precisely: the inertial frame ) dependent. This manifests itself, for example, in the Lorentz contraction, according to observers moving relative to each measure a different length for the same object.

In special relativity, the room is dependent on the observer, but not of the physical processes in it. He is still Euclidean for each observer. The changes in the general theory of relativity. In this gravitation is described by the curvature of space- time, which also means a curvature of space. The geometry of space-time depends on the energy -momentum tensor, ie the available space in the particles and fields. The space is therefore only locally Euclidean.

Modern theories of space-time

The Kaluza-Klein theories and string theories, which aim to unify gravity with the other fundamental forces, the space-time add additional dimensions. However, these extra dimensions are not like the famous four space-time dimensions ( almost ) infinite extended into; rather they are of a dimension of less than one atom core diameter. In addition, it is believed that they are periodically " rolled up " and that they (eg the so-called quintessence ) " flow into " as additional degrees of freedom into the existing space-time.

One goal of these theories is not to postulate the room with its properties as something given, but to justify it in a comprehensive theory together with the known fundamental forces and elementary particles.

A dissenting opinion is presented by the constructivist protophysics, is determined in geometry and chronometry through standards for measuring instruments.