Half-life

Half-life (t_1⁄2) is the amount of time required for the amount of something to fall to half its initial value. The term is very commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay, but it is also used more generally for discussing any type of exponential decay.

The original term, dating to Ernest Rutherford's discovery of the principle in 1907, was "half-life period", which was shortened to "half-life" in the early 1950s. Rutherford applied the principle of a radioactive element's half-life to studies of age determination of rocks by measuring the decay period of radium to lead-206.

Half-life is used to describe a quantity undergoing exponential decay, and is constant over the lifetime of the decaying quantity. It is a characteristic unit for the exponential decay equation. The term "half-life" may generically be used to refer to any period of time in which a quantity falls by half, even if the decay is not exponential. The table on the right shows the reduction of a quantity in the number of half-lives elapsed. For a general introduction and description of exponential decay, see exponential decay. For a general introduction and description of non-exponential decay, see rate law. The converse of half-life is doubling time.

Half-Life (video game)

Half-Life (stylized as HλLF-LIFE) is a science fiction first-person shooter video game developed by Valve L.L.C., released in 1998 by Sierra Studios for Microsoft Windows. It was Valve L.L.C.'s debut product and the first in the Half-Life series. Players assume the role of Dr. Gordon Freeman, who must fight his way out of a secret research facility after a teleportation experiment goes disastrously wrong, fighting enemies and solving puzzles.

Unlike many other games at the time, Half-Life features no cutscenes; the player has uninterrupted control of Freeman, and the story is told through scripted sequences seen through his eyes. Valve L.L.C. co-founder Gabe Newell said the team had wanted to create an immersive world rather than a "shooting gallery". The game's engine, GoldSrc, is a heavily modified version of the Quake engine licensed from id Software.

Half-Life received acclaim for its graphics, realistic gameplay, and seamless narrative. It won over fifty PC "Game of the Year" awards and is often considered one of the greatest games of all time. It influenced first-person shooters for years after its release; according to IGN, the history of the genre "breaks down pretty cleanly into pre-Half-Life and post-Half-Life eras."

Half-life (disambiguation)

Half-life is a mathematical and scientific description of exponential or gradual decay.

Half-life may also refer to:

How Long (Ace song)

"How Long" is a 1974 song by the British group Ace from their album Five-A-Side. It reached No. 3 in the US and Canadian charts, and No. 20 in the UK chart.

Although widely interpreted as being about adultery, the song was in fact composed by lead singer Paul Carrack upon discovering that bassist Terry Comer had been secretly working with the Sutherland Brothers and Quiver. Comer returned to Ace in time to play on the song.

The guitar solo is by Alan "Barn" King.

Covers

In 1976 Bobby Womack recorded a version that appeared on the Home Is Where The Heart Is album

In 1977 Barbara Mandrell recorded a country/disco version of the song on her Love's Ups & Downs album.

In 1981 Rod Stewart covered the song on the album Tonight I'm Yours. It charted in the top fifty of the Billboard Hot 100.

In 1981 Lipps Inc. released a remake of this song which reached No. 4 on the U.S. dance chart, No. 29 on the U.S. soul singles chart, and No. 42 in Canada. In 2010, it was still in rotation on satellite radio. The track Timecode, released in 2004 by German techno producer Justus Köhncke, is built around the characteristic intro of the Lipps Inc. version.

Extreme Behavior

Extreme Behavior is the debut album of rock band Hinder. It was released in 2005 by Universal Records to almost universally negative reviews, before going platinum in September 2006. All songs were co-written by Brian Howes, except for "Shoulda", which was co-written with Brian Howes and Social Code. The song "Running in the Rain" did not make the cut for the album, but has been played at concerts on their North American tour. Due to use of profanity in three songs, Extreme Behavior was the only Hinder record to receive a Parental Advisory label until the release of the deluxe version of All American Nightmare and their 2012 album Welcome to the Freakshow.

Release

The first single (and the song that brought attention to the band) was "Get Stoned". The album also contains Hinder's breakthrough single, "Lips of an Angel" which soared to #1 on the pop charts in 2006. The album's third single was "How Long", which was played on rock stations throughout the US. "Better Than Me" is the fourth single on Extreme Behavior. As of July 11, 2007, the album has sold 2,789,275 copies in the US. Despite not being released as a single, the song "By the Way" also had received airplay from several radio stations.

How Long (J. D. Souther song)

"How Long" is an anti-war protest song by American singer-songwriter J. D. Souther. Written in 1971 as a reaction against the Vietnam War, it was originally recorded by Souther for his 1972 debut solo album, John David Souther. It was given a limited release as a promotional 7-inch 45 rpm single in 1972 with Souther's "The Fast One" on the B-side.

The Eagles, longtime friends and collaborators with Souther, frequently performed "How Long" in concert during the early and mid-70s. In 2007, the band covered the song for their album Long Road Out of Eden, the group's first full studio album since 1979. A year later, their version of the song won the Grammy Award for Best Country Performance by a Duo or Group with Vocal. It was the band's first Grammy since 1979.

Peak positions

References