This article is about distance in time speed and distance concepts for cat pdf, physics, and computation. Distance is a numerical description of how far apart objects are. In most cases, “distance from A to B” is interchangeable with “distance from B to A”. In mathematics, a distance function or metric is a generalization of the concept of physical distance.
A metric is a function that behaves according to a specific set of rules, and is a way of describing what it means for elements of some space to be “close to” or “far away from” each other. Note that the shortest route appears as a curve rather than a straight line because this map is a Mercator projection, which does not scale all distances equally compared to the real spherical surface of the Earth.
Circular distance” is the distance traveled by a wheel, which can be useful when designing vehicles or mechanical gears. 1, then each revolution of the wheel is equivalent of the distance 2π radians. 2πƒ is often used, where ƒ is the frequency.
Manhattan distance” is a rectilinear distance, named after the number of blocks north, south, east, or west a taxicab must travel on to reach its destination on the grid of streets in parts of New York City. Chessboard distance”, formalized as Chebyshev distance, is the minimum number of moves a king must make on a chessboard to travel between two squares. Distance measures in cosmology are complicated by the expansion of the universe, and by effects described by the theory of relativity such as length contraction of moving objects.
The term “distance” is also used by analogy to measure non-physical entities in certain ways. In computer science, there is the notion of the “edit distance” between two strings. For example, the words “dog” and “dot”, which vary by only one letter, are closer than “dog” and “cat”, which differ by three letters.
In mathematics, a metric space is a set for which distances between all members of the set are defined. The notion of distance in graph theory has been used to describe social networks, for example with the Erdős number or the Bacon number, the number of collaborative relationships away a person is from prolific mathematician Paul Erdős or actor Kevin Bacon, respectively. In psychology, human geography, and the social sciences, distance is often theorized not as an objective metric, but as a subjective experience. Distance cannot be negative, and distance travelled never decreases.
Distance is a scalar quantity or a magnitude, whereas displacement is a vector quantity with both magnitude and direction. Directed distance is a positive, zero, or negative scalar quantity.
A to a point B should be distinguished from the straight-line distance from A to B. For example, whatever the distance covered during a round trip from A to B and back to A, the displacement is zero as start and end points coincide. In general the straight-line distance does not equal distance travelled, except for journeys in a straight line.
Directed distances are distances with a directional sense. They can be determined along straight lines and along curved lines. A is the starting point.