orientation

orientation, in architecture, the disposition of the parts of a building with reference to the points of the compass. From remote antiquity the traditional belief in the efficacy of religious ceremonials performed at dawn toward the rising sun has influenced the orientation of temples and other sacred structures. In Mesopotamia and Egypt, in Mayan Central America, even at Stonehenge in England, entrances and other important architectural features were designed to point toward the east; the temples of Greece and Rome often, though not invariably, faced the rising sun. In medieval Europe and, consequently, in modern Europe and the Americas, it became customary to have the congregation and the priest at the altar facing east. So strong was this custom that "west front" came to be a generic term for the facade of a church. Some churches were so built that a central line of the axis of the church pointed exactly to the rising sun on the day of the saint for whom the church was named. Such orientation was, however, by no means universal. St. Peter's at Rome, continuing an earlier tradition, faces in the opposite direction. Important secular buildings in the West often face toward the cardinal points of the compass, and the gridiron pattern of a city's streets is frequently so laid out. Practical problems also govern orientations. The disposition of a building in relation to the prevailing wind or to the sun has long been an important consideration in construction. Early commentators on the problem were Xenophon and Vitruvius. Examples of the concern for climatological orientation can be found in ancient Rome, where there were laws regarding the placement and heights of buildings, or in Puebla, Mexico, where in 1554 the streets were planned so that winds would not sweep through the city. Although orientation in accordance with climatic conditions was in many instances ignored in the 19th cent., modern architects have considered it and have tended to design their buildings accordingly.

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orientation

In architecture, the position of a building on its site. In Mesopotamia and Egypt, as well as in pre-Columbian Central America, a building's important features, such as entrances and passages, faced the rising sun. Mosques are oriented so that the mihrab faces Mecca. Christian churches have usually been oriented with the apse or altar at the eastern end. Orientation is frequently planned to take maximum advantage of daily and seasonal variations of sunlight. A structure's optimal orientation is usually a compromise between its function, location, and the prevailing environmental factors of solar radiation, light, humidity, and wind that make up the site's microclimate.

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orientation

In typography, the direction of print across a page. See portrait.

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orientation

1. position or positioning with relation to the points of the compass or other specific directions

2. Chiefly US and Canadian

a. a course, programme, lecture, etc., introducing a new situation or environment

b. (as modifier): an orientation talk

3. Psychol the knowledge of one's own temporal, social, and practical circumstances in life

4. Biology the change in position of the whole or part of an organism in response to a stimulus, such as light

5. Chem the relative dispositions of atoms, ions, or groups in molecules or crystals

6. Archit the siting of a church on an east-west axis, usually with the altar at the E end

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orientation [‚ȯr·ē·ən′tā·shən]

(crystallography)

The directions of the axes of a crystal lattice relative to the surfaces of the crystal, to applied fields, or to some other planes or directions of interest.

(electromagnetism)

The physical positioning of a directional antenna or other device having directional characteristics.

(engineering)

Establishment of the correct relationship in direction with reference to the points of the compass.

(mathematics)

A choice of sense or direction in a topological space.

An orderingp₀,p₁, …,p_nof the vertices of a simplex, two such orderings being regarded as equivalent if they differ by an even permutation.

For a simple graph, a directed graph that results from assigning a direction to each of the edges.

(physics)

The direction of some vector or set of vectors, such as the direction of the electric vector and the propagation direction of plane polarized light, or the direction of a preponderance of nuclear spins in a crystal near absolute zero, relative to some other directions of interest.

Any process in which vectors associated with atoms or molecules in the substance are organized relative to some direction, rather than pointed at random; examples include dipole moments of polar molecules in an electric field, and nuclear spins in a crystal in a magnetic field at temperatures near absolute zero.

(physical chemistry)

The arrangement of radicals in an organic compound in relation to each other and to the parent compound.

(psychology)

Determination of one's relation to the environment.