Circle

A circle is a simple shape in Euclidean geometry. It is the set of all points in a plane that are at a given distance from a given point, the centre; equivalently it is the curve traced out by a point that moves so that its distance from a given point is constant. The distance between any of the points and the centre is called the radius.

A circle is a simple closed curve which divides the plane into two regions: an interior and an exterior. In everyday use, the term "circle" may be used interchangeably to refer to either the boundary of the figure, or to the whole figure including its interior; in strict technical usage, the circle is only the boundary and the whole figure is called a disk.

A circle may also be defined as a special ellipse in which the two foci are coincident and the eccentricity is 0, or the two-dimensional shape enclosing the most area per unit perimeter squared, using calculus of variations.

Terminology

Circles (film distributor)

Circles was a feminist film and video distribution network in the UK, which was set up out of a desire to distribute and screen women's films on their own terms. It was founded in 1979 by feminist filmmakers Lis Rhodes, Jo Davis, Felicity Sparrow and Annabel Nicolson, publishing a 1980 catalogue including about 30 films, and it closed in 1991, largely due to funding issues that also prompted the merger of Circles and Cinema of Women, which led to the formation of Cinenova. A previous funding crisis in 1987, when funding by Tower Hamlets council had been withdrawn, had been resolved with replacement funding from the British Film Institute.

Origins

According to Jenny Holland and Jane Harris, "Circles started in 1979, partly as a response to an Arts Council of Great Britain exhibition on experimental film. Feeling that their work on women's involvement in this field was being marginalised, the women on the exhibition committee withdrew their painstakingly researched work and issued an explanatory statement. In many ways, this research was the cornerstone of Circles, which went on to distribute the films by Alice Guy, Germaine Dulac, Maya Deren, and Lois Weber which were to have been discussed in the exhibition." The statement, "Women and the Formal Film," was published in the "Film as Film" exhibition catalogue and acted as a manifesto for the distribution collective that emerged.

Circles (George Harrison song)

"Circles" is a song by English musician George Harrison, released as the final track of his 1982 album Gone Troppo. Harrison wrote the song in India in 1968 while he and the Beatles were studying Transcendental Meditation with Maharishi Mahesh Yogi. The theme of the lyrics is reincarnation. The composition reflects the cyclical aspect of human existence as, according to Hindu doctrine, the soul continues to pass from one life to the next. Although the Beatles never formally recorded it, "Circles" was among the demos the group made at Harrison's home, Kinfauns, in May 1968, while considering material for their double album The Beatles.

Harrison revisited "Circles" during the sessions for his 1979 album George Harrison before he finally recorded it for Gone Troppo. Over this period, Harrison had softened the spiritual message in his work and had also begun to forgo the music business for a career as a film producer with his company HandMade Films. The song was produced by Harrison, Ray Cooper and former Beatles engineer Phil McDonald, with recording taking place at Harrison's Friar Park studio between May and August 1982. The track features extensive use of keyboards and synthesizer, with Billy Preston, Jon Lord and Mike Moran among the contributing musicians.

Atlas

An atlas is a collection of maps; it is typically a map of Earth or a region of Earth, but there are atlases of the other planets (and their satellites) in the Solar System. Furthermore, atlases of anatomy exist, mapping out the human body or other organisms. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geographic features and political boundaries, many atlases often feature geopolitical, social, religious and economic statistics. They also have information about the map and places in it.

Etymology

The word atlas dates from 1636, first in reference to the English translation of Atlas, sive cosmographicae meditationes de fabrica mundi (1585) by Flemish geographer Gerhardus Mercator, who might have been the first to use this word in this way. A picture of the Titan Atlas holding up the world appeared on the frontispiece of this and other early map collections.

History

The first work that contained systematically arranged woodcut maps of uniform size, intended to be published in a book, thus representing the first modern atlas, was De Summa totius Orbis (1524–26) by the 16th-century Italian cartographer Pietro Coppo. Nonetheless, this distinction is conventionally awarded to the Flemish cartographer Abraham Ortelius who in 1570 published the collection of maps Theatrum Orbis Terrarum.

Atlas (topology)

In mathematics, particularly topology, one describes a manifold using an atlas. An atlas consists of individual charts that, roughly speaking, describe individual regions of the manifold. If the manifold is the surface of the Earth, then an atlas has its more common meaning. In general, the notion of atlas underlies the formal definition of a manifold and related structures such as vector bundles and other fibre bundles.

Charts

The definition of an atlas depends on the notion of a chart. A chart for a topological space M (also called a coordinate chart, coordinate patch, coordinate map, or local frame) is a homeomorphism from an open subset U of M to an open subset of Euclidean space. The chart is traditionally recorded as the ordered pair .

Formal definition of atlas

An atlas for a topological space M is a collection of charts on M such that . If the codomain of each chart is the n-dimensional Euclidean space and the atlas is connected, then M is said to be an n-dimensional manifold.

October 2013 North American storm complex

The October 2013 North American storm complex was a blizzard and tornado outbreak that affected the Northwest, Rockies, and much of the Midwest. 22 tornadoes were confirmed as the system moved eastward across the eastern half of the United States, including two that were rated as EF4 on the Enhanced Fujita scale.

Summary of events

On October 3, 2013, the National Weather Service issued a blizzard warning for Rapid City and the Black Hills in advance of the storm urging people to delay or cancel travel plans.

The snow incident trapped over six dozen people inside of their automobiles and tornadoes injured 17 people in Iowa and Nebraska.Rapid City, the second largest city in South Dakota, was engulfed in close to two feet of snow, which exceeds the amount of snow that the city has ever recorded during any whole month of October. Furthermore, on October 4, 2013, the city received over 1.5 feet (0.46 m) of snow, which exceeded the previous one day record in October by more than six inches. Over 20,000 people lost electricity in Black Hills, where more than a meter of watered down, dense snow had fallen. The storm system also included thunderstorms that brought iced precipitation, significant rain and over half a dozen tornadoes to Nebraska and Iowa. Two of these tornadoes were violent enough to be rated EF4 on the Enhanced Fujita scale. Over 200 miles (320 km) of Interstate 90 was shut down from South Dakota to Wyoming.