Clock

A clock is an instrument to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a striking mechanism has traditionally been known as a timepiece. In general usage today a "clock" refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one's person are often distinguished from clocks.

The clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia. A sundial shows the time by displaying the position of a shadow on a flat surface. There are a range of duration timers, a well-known example being the hourglass. Water clocks, along with the sundials, are possibly the oldest time-measuring instruments. A major advance occurred in Europe around 1300 with the invention of the escapement, which allowed construction of the first mechanical clocks, which used oscillating timekeepers like balance wheels. Spring-driven clocks appeared during the 15th century. During the 15th and 16th centuries, clockmaking flourished. The next development in accuracy occurred after 1656 with the invention of the pendulum clock. A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time-keeping for navigation. The electric clock was patented in 1840. The development of electronics in the 20th century led to clocks with no clockwork parts at all.

Clocks (song)

"Clocks" is a song by British alternative rock band Coldplay. It was written by all members of the band for their second album, A Rush of Blood to the Head. Built around a piano riff, the song features cryptic lyrics of contrast and urgency themes. Several remixes of the track exist and its riff has been widely sampled.

"Clocks" debuted to critical and commercial success, with critics mainly commenting on the song's piano melody. It was released in the United Kingdom as the third single from A Rush of Blood to the Head, where it reached number nine in the UK Singles Chart. It was released in the United States as the album's second single, it reached number 29 on the Billboard Hot 100 and number 9 on Billboard's Modern Rock Tracks chart. It won the Grammy Award for Record of the Year. Due to its success in the US, the radio cut version of the song serves as the final track of the 2003 compilation album Now That's What I Call Music! 13

Background and writing

"Clocks" was composed during the late stages of production of Coldplay's second album, A Rush of Blood to the Head. A riff popped into Chris Martin's mind late one night in Liverpool when he came in to the studio, where he then developed it on piano. According to Martin, "Clocks" was inspired by the English rock band Muse. Martin presented the riff to the band's guitarist Jonny Buckland who then added a layer of guitar chords to the basic track: "He picked up his guitar [a sure sign that he likes a song] and played these brilliant chords ... It was like a chemical reaction process." (The syncopated piano arpeggio that gives the song its signature sound also bears a similarity to a syncopated arpeggio that is repeated several times in Alex De Grassi's 1981 instrumental "Clockwork.")

Diaphragm (optics)

In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a field stop or flare stop for other uses of diaphragms in lenses). The diaphragm is placed in the light path of a lens or objective, and the size of the aperture regulates the amount of light that passes through the lens. The centre of the diaphragm's aperture coincides with the optical axis of the lens system.

Most modern cameras use a type of adjustable diaphragm known as an iris diaphragm, and often referred to simply as an iris.

See the articles on aperture and f-number for the photographic effect and system of quantification of varying the opening in the diaphragm.

Iris diaphragms versus other types

A natural optical system that has a diaphragm and an aperture is the human eye. The iris is the diaphragm, and the opening in the iris of the eye (the pupil) is the aperture. An analogous dev in a photographic lens is called an iris diaphragm.

Iris (1987 film)

Iris is a 1987 Netherlands film directed by Mady Saks and starring Monique van de Ven.

Plot

A young woman, Iris, runs away to the big city on her eighteenth birthday. She moves in with an architect and decides to become a veterinarian. With an inheritance she buys an existing clinic in a backwoods town where Iris is leered at by the men, scorned by the women. Cruel jokes and gossip eventually lead to violence.A local thug breaks in her house while she is out. When she returns home late night, he attacks her, drag her to the wooden stairs, ties her hands, stretch her legs wide apart and ties to the railing of stairs and rapes her brutally.

References

External links

Iris (EP)

Iris is Miranda Sex Garden's second release, and first EP.

Track listing