Any of various processes and phenomena associated with the surface discharge of molten rock or hot water and steam, including volcanoes, geysers, and fumaroles. Most active volcanoes occur where two plates converge and one overrides the other (see plate tectonics). Volcanism can also occur along the axis of an oceanic ridge, where the plates move apart and magma wells up from the mantle. A few volcanoes occur within plates, far from margins. Some of these are thought to occur as a plate moves over a “hot spot” from which magma can penetrate to the surface; others appear to result from an extremely slow form of plate spreading.
Learn more about volcanism with a free trial on Britannica.com.
Ability of a substance to rotate the plane of polarization of a beam of light passed through it, either as crystals or in solution. Clockwise rotation as one faces the light source is “positive,” or dextrorotary; counterclockwise rotation “negative,” or levorotary. Louis Pasteur was the first to recognize that molecules with optical activity are stereoisomers (see isomerism). Optical isomers occur in pairs that are nonsuperimposable mirror images of one another. They have the same physical properties except for their effect on polarized light; in chemical properties they differ only in their interactions with other stereoisomers (see asymmetric synthesis).
Learn more about optical activity with a free trial on Britannica.com.
Performance by an animal of an act inappropriate for the stimulus or stimuli that evoked it. It usually occurs when an animal is torn between two conflicting drives, such as fear and aggression. Displacement activities often consist of comfort movements (e.g., grooming, scratching).
Learn more about displacement activity with a free trial on Britannica.com.
Number expressing the ratio of a substance's chemical activity to its molar concentration (see mole). The measured concentration of a substance may not be an accurate indicator of its chemical effectiveness as represented by the equation for a particular reaction; in such cases, the activity is calculated by multiplying the concentration by the activity coefficient. In solutions, the activity coefficient is a measure of how much the solution differs from an ideal solution.
Learn more about activity coefficient with a free trial on Britannica.com.
Radio-Activity is a 1975 concept album by Kraftwerk. It was also released under the German name of Radio-Aktivität. Unlike Kraftwerk's later albums, which featured language-specific lyrics, only the titles differ between the English and German editions.
The hyphenated album title displays Kraftwerk's typical deadpan humour, being a pun on the twin themes of the songs, half being about radioactivity and the other half about activity on the radio. More word plays are evident in the track listing: the cleverly titled "Ohm Sweet Ohm", and "Radio Stars", which as a title could refer to pop stars, but upon listening is revealed to be about quasars and pulsars.
This was the first Kraftwerk album to be entirely self-produced by Hütter & Schneider in their Kling Klang studio, and the first one to be performed by the "classic" Hütter/Schneider/Bartos/Flür line-up. All the music was written by Hütter/Schneider, with Emil Schult collaborating on lyrics. Schult also designed the artwork – a modified illustration of a late-1930s 'Deutscher Kleinempfänger' radio.
It was the first Kraftwerk album to feature use of the distinctive Vako Orchestron keyboard (choir, string and organ sounds), which the group had purchased on their recent US Autobahn tour. The band's custom-built electronic percussion also featured heavily in the sound, and extensive use was made of the vocoder. The usual synthesizers were present (including Minimoog and ARP Odyssey), and Ralf's Farfisa electronic piano made a return on "Transistor". For the first time the group did not use flute, violin or guitars.
By 1975, Hütter and Schneider's previous publishing deals with Capriccio Music and Star Musik Studio of Hamburg had expired. The compositions on Radio-Activity were published by their own newly set up Kling Klang Verlag music publishing company, giving them greater financial control over the use of songwriting output. Also, the album was the first to bear the fruit of Kling Klang as an established vanity label under the group's new licensing deal with EMI. The album reached #59 in Canada, in February 1976.
The title track "Radioactivity" was released as a single, and became a hit in France after it was used as the theme to a popular music show. The song was later re-recorded by Kraftwerk for their 1991 album The Mix. It was further remixed, for subsequent single release, by William Orbit and François Kevorkian.
2 - 4 written by Hütter/Schneider/Schult
1, 5 & 6 written by Hütter/Schneider
1 - 4 written by Hütter/Schneider/Schult
5 & 6 written by Hütter/Schneider
|Germany||December 1975||EMI-Electrola||Vinyl||1C 062 82 087||With insert sheet of 'Radio-Aktivität' stickers|
|December 1975||EMI-Electrola||Cassette||1C 244 82087|
|February 1986||EMI-Electrola||CD||CDP 564 7 46132 2|
|United Kingdom||December 1975||Capitol||Vinyl||E-ST 11457|
|December 1975||Capitol||Cassette||TC E-ST 11457|
|June 1987||EMI||CD||CDP 7 46474 2|
|United States||January 1976||Capitol||Vinyl||ST-11457||With insert sheet of 'Radio-Activity' stickers|
|1985||Capitol||CD||CDP 7 46473|
Leisure Activities and Cognitive Impairment in Late Life-A Selective Literature Review of Longitudinal Cohort Studies
Sep 01, 2007; Abstract Objectives: To selectively review longitudinal cohort studies examining the relationship of leisure activities to...
Physical Activity Trends -- United States, 1990-1998.(survey indicates that the amount of physical activity during leisure time has changed little)
Mar 09, 2001; Physical activity is associated with numerous health benefits , and increased participation in various types of...