Countdown

A countdown is a sequence of backward counting to indicate the time remaining before an event is scheduled to occur. NASA commonly employs the term "T-minus" during the preparation for and anticipation of a rocket launch, and even "E-minus" for events that involve spacecraft that are already in space, where the "T" could stand for "Test" or "Time", and the "E" stands for "Encounter", as with a comet or some other space object. Other events for which countdowns are commonly used include the detonation of an explosive, the start of a race, the start of the New Year, or any anxiously anticipated event. An early use of a countdown once signaled the start of a Cambridge University rowing race. The first known association with rockets was in the 1929 German science fiction movie Die Frau im Mond (English: Woman in the Moon) written by Thea von Harbou and directed by Fritz Lang in an attempt to increase the drama of the launch sequence of the story's lunar-bound rocket.

Rocketry

A countdown is a carefully devised set of procedures ending with the ignition of a rocket's engine. Depending on the type of vehicle used, countdowns can start from 72 to 96 hours before launch time.

AC

AC, A.C. or Ac may refer to:

Computing

Entertainment

A.C.T

A.C.T (Swedish pronunciation: [ækt]) is a Swedish progressive rock band formed in 1995 under the name ‘Fairyland’, in Malmö. The band has been through several personnel changes; with the current line-up featuring Herman Saming (vocals), Ola Andersson (guitar), Peter Asp (bass), Jerry Sahlin (keyboards) and Thomas Lejon (drums).

History

Initially under Ola Andersson on guitars, Tomas Erlandsson on drums, Jens Appelgren on vocals and Jerry Sahlin on both keyboards and drums, Fairyland was started by members of a music school in Malmö. Amongst various line-up changes, Fairlyland changed its name into A.C.T in 1995. In 1996 A.C.T first came into the public eye when it made its way to the final of a Swedish music competition, although it did not win.

In 1997 a new demo was recorded and the band toured extensively in Sweden, eventually recording its debut album, ‘Today’s Report’, released in 1999. Following the release of this album, A.C.T embarked on a Scandinavian tour with the progressive rock band Saga.

Dance

Dance is a performance art form consisting of purposefully selected sequences of human movement. This movement has aesthetic and symbolic value, and is acknowledged as dance by performers and observers within a particular culture. Dance can be categorized and described by its choreography, by its repertoire of movements, or by its historical period or place of origin.

An important distinction is to be drawn between the contexts of theatrical and participatory dance, although these two categories are not always completely separate; both may have special functions, whether social, ceremonial, competitive, erotic, martial, or sacred/liturgical. Others disciplines of human movement are sometimes said to have a dance-like quality, including martial arts, gymnastics, figure skating, synchronized swimming and many other forms of athletics.

Performance and participation

Theatrical dance, also called performance or concert dance, is intended primarily as a spectacle, usually a performance upon a stage by virtuoso dancers. It often tells a story, perhaps using mime, costume and scenery, or else it may simply interpret the musical accompaniment, which is often specially composed. Examples are western ballet and modern dance, Classical Indian dance and Chinese and Japanese song and dance dramas. Most classical forms are centred upon dance alone, but performance dance may also appear in opera and other forms of musical theatre.