In common usage, a dimension (Latin, "measured out") is a parameter or measurement required to define the characteristics of an object—i.e. length, width, and height or size and shape. In mathematics, dimensions are the parameters required to describe the position and relevant characteristics of any object within a conceptual space —where the dimensions of a space are the total number of different parameters used for all possible objects considered in the model. Generalizations of this concept are possible and different fields of study will define their spaces by their own relevant dimensions, and use these spaces as frameworks upon which all other study (in that area) is based. In specialized contexts, units of measurement may sometimes be "dimensions"—meters or feet in geographical space models, or cost and price in models of a local economy. For example, locating a point on a plane (e.g. a city on a map of the Earth) requires two parameters — latitude and longitude. The corresponding space has therefore two dimensions, its dimension is two, and this space is said to be 2-dimensional (2D). Locating the exact position of an aircraft in flight (relative to the Earth) requires another dimension (altitude), hence the position of the aircraft can be rendered in a three-dimensional space (3D). If time is added as a 3rd or 4th dimension (to a 2D or 3D space, respectively), then the aircraft's estimated "speed" may be calculated from a comparison between the times associated with any two positions. For common uses, simply using "speed" (as a dimension) is a useful way of condensing (or translating) the more abstract time dimension, even if "speed" is not a dimension, but rather a calculation based on two dimensions. Adding the three Euler angles, for a total 6 dimensions, allows the current degrees of freedom —orientation and trajectory —of the aircraft to be known.

Theoretical physics often experiments with dimensions - adding more, or changing their properties - in order to describe unusual conceptual models of space, in order to help better describe concept of quantum mechanics —ie. the 'physics beneath the visible physical world.' This concept has been borrowed in science fiction as a metaphorical device, where an "alternate dimension" (ie. 'alternate universe' or 'plane of existence') describes Extraterrestrial places, species, and cultures which function in various different and unusual ways from human culture. Materials of sculpture through history Throughout most of history, the purpose of creating sculpture has been to produce works of art that are as permanent as is possible. So to that end, works were usually produced in durable and frequently, expensive materials, primarily bronze and stone such as marble, limestone, Porphyry, and granite.

More rarely, precious materials such as gold silver, jade, and ivory were used for chryselephantine works. More common and less expensive materials were used for sculpture for wider consumption, including woods such as oak, Buxusbox and Tilialime, terra cotta and other ceramics, and cast metals such as pewter and spelter. Sculptors are constantly searching for new ways to make art and for new materials to use. Andy Goldsworthy is notable as a sculptor for his use of almost entirely natural materials in natural settings and for creating sculptures much more ephemeral than is typical. Other artists, including Jim Gary used less conventional media including automobile parts, tools, machine parts, and hardware in sculpture as well as glass. Pablo Picasso used bicycle parts for one of his most famous sculptures. Despite durability being the usual objective, some sculpture is deliberately short lived -- for example, ice and sand sculptures or gas sculptures. Sculptors often build small preliminary works called maquettes of ephemeral materials such as plaster of paris, wax, clay, and even plasticine, as Alfred Gilbert did for 'Eros' at Piccadilly Circus,London.