Atmosphere

An atmosphere (from Greek ἀτμός (atmos), meaning "vapour", and σφαῖρα (sphaira), meaning "sphere") is a layer of gases surrounding a planet or other material body of sufficient mass that is held in place by the gravity of the body. An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low.

The atmosphere of Earth is mostly composed of nitrogen. It also contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis. The atmosphere helps protect living organisms from genetic damage by solar ultraviolet radiation, solar wind and cosmic rays. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

The term stellar atmosphere describes the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Stars with sufficiently low temperatures may form compound molecules in their outer atmosphere.

Atmosphere (unit)

The standard atmosphere (symbol: atm) is a unit of pressure defined as 101325 Pa (1.01325 bar). It is sometimes used as a reference or standard pressure.

History

In 1954 the 10th Conférence Générale des Poids et Mesures (CGPM) adopted standard atmosphere for general use and affirmed its definition of being precisely equal to 1,013,250 dynes per square centimetre (101325 Pa). This value was intended to represent the mean atmospheric pressure at mean sea level at the latitude of Paris, France, and does reflect the mean sea level pressure for many industrialized nations that are at broadly similar latitudes.

In chemistry and in various industries, the reference pressure referred to in “Standard Temperature and Pressure” (STP) was commonly 1 atm (101.325 kPa) but standards have since diverged; in 1982, the International Union of Pure and Applied Chemistry (IUPAC) recommended that for the purposes of specifying the physical properties of substances, “standard pressure” should be precisely 100 kPa (1 bar).

Atmosphere (Joy Division song)

"Atmosphere" is a song by English post-punk band Joy Division. It was originally released in March 1980 by record label Sordide Sentimental as "Licht und Blindheit", a France-only limited edition single featuring the track "Dead Souls" as the B-side. Following Ian Curtis's death two months later, it was re-released as a 12" single by record label Factory with "She's Lost Control" as the B-side.

The single was re-released in 1988 to coincide with the release of the compilation album Substance, and a music video was produced for the song.

Release

The song was originally released on 18 March 1980 by record label Sordide Sentimental as a France-only single under the title "Licht und Blindheit" (German for "Light and Blindness"). It was limited to 1578 copies and featured the track "Dead Souls" as the B-side.

Following the death of lead singer Ian Curtis in May 1980, "Atmosphere" was released as a single with "She's Lost Control". "Atmosphere" was the A-side for the UK release but the B-side for the USA release. "She's Lost Control" is an alternative version of the one that appears on the band's début album Unknown Pleasures. The single peaked at number 1 in New Zealand in August 1981, and it would later re-chart there in July 1984 (number 17) and when it was reissued in August 1988 (number 5). "Atmosphere" also hit number 34 in the UK Singles Chart during June 1988.