Altitude or height is defined based on the context in which it is used (aviation, geometry, geographical survey, sport, and more). As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context. Although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage.

Vertical distance measurements in the "down" direction are commonly referred to as depth.

Altitude in aviation and in spaceflight

In aviation, the term altitude can have several meanings, and is always qualified by either explicitly adding a modifier (e.g. "true altitude"), or implicitly through the context of the communication. Parties exchanging altitude information must be clear which definition is being used.

Aviation altitude is measured using either Mean Sea Level (MSL) or local ground level (Above Ground Level, or AGL) as the reference datum.

Pressure altitude divided by 100 feet (30m) is referred to as the flight level, and is used above the transition altitude ( in the US, but may be as low as in other jurisdictions); so when the altimeter reads 18,000 ft on the standard pressure setting the aircraft is said to be at "Flight level 180". When flying at a Flight Level, the altimeter is always set to standard pressure (29.92 inHg / 1013.25 mbar).

On the flight deck, the definitive instrument for measuring altitude is the pressure altimeter, which is an aneroid barometer with a front face indicating distance (feet or metres) instead of atmospheric pressure.

There are several types of aviation altitude:

Indicated altitude is the reading on the altimeter when the altimeter is set to the local barometric pressure at Mean Sea Level.

Absolute altitude is the height of the aircraft above the terrain over which it is flying. Also referred to feet/metres Above Ground Level (AGL).

True altitude is the elevation above mean sea level. In UK aviation radiotelephony usage, ''the vertical distance of a level, a point or an object considered as a point, measured from mean sea level''; this is referred to over the radio as altitude.(see QNH) Height is the elevation above a ground reference point, commonly the terrain elevation. In UK aviation radiotelephony usage, ''the vertical distance of a level, a point or an object considered as a point, measured from a specified datum''; this is referred to over the radio as height, where the specified datum is the airfield elevation (see QFE)

Pressure altitude is the elevation above a standard datum air-pressure plane (typically, 1013.25 millibars or 29.92" Hg and 15°C). Pressure altitude and indicated altitude are the same when the altimeter is set to 29.92" Hg or 1013.25 millibars.

Density altitude is the altitude corrected for non-ISA International Standard Atmosphere atmospheric conditions. Aircraft performance depends on density altitude, which is affected by barometric pressure, humidity and temperature. On a very hot day, density altitude at an airport (especially one at a high elevation) may be so high as to preclude takeoff, particularly for helicopters or a heavily loaded aircraft.

These types of altitude can be explained more simply as various ways of measuring the altitude:

Indicated altitude -- what the altimeter says

Absolute altitude -- altitude in terms of the distance above the ground directly below it

True altitude -- altitude in terms of elevation above sea level

Height -- altitude in terms of the distance above a certain point

Pressure altitude -- altitude in terms of the air pressure

Density altitude -- altitude in terms of the density of the air

Altitude regions

The Earth's atmosphere is divided into several altitude regions: Troposphere — surface to at the poles – at the equator, ending at the Tropopause. Stratosphere — Troposphere to Mesosphere — Stratosphere to Thermosphere — Mesosphere to Exosphere — Thermosphere to

High altitude and low air pressure

Regions on the Earth's surface (or in its atmosphere) that are high above mean sea level are referred to as high altitude. High altitude is sometimes defined to begin at above sea level.

At high altitude, atmospheric pressure is lower than that at sea level. This is due to two competing physical effects: gravity, which causes the air to be as close as possible to the ground; and the heat content of the air, which causes the molecules to bounce off each other and expand.

Because of the lower pressure, the air expands as it rises, which causes it to cool. Thus, high altitude air is cold, which causes a characteristic alpine climate. This climate dramatically affects the ecology at high altitude.

Relation between temperature and altitude in Earth's atmosphere

The environmental lapse rate (ELR), is the rate of decrease of temperature with altitude in the stationary atmosphere at a given time and location. As an average, the International Civil Aviation Organization (ICAO) defines an international standard atmosphere (ISA) with a temperature lapse rate of 6.49 K(°C)/1,000 m (3.56 °F or 1.98 K(°C)/1,000 Ft) from sea level to . From , the constant temperature is , which is the lowest assumed temperature in the ISA. The standard atmosphere contains no moisture. Unlike the idealized ISA, the temperature of the actual atmosphere does not always fall at a uniform rate with height. For example, there can be an inversion layer in which the temperature increases with height.

Effects of high altitude on humans

Medicine recognizes that altitudes above start to affect humans, and extreme altitudes above cannot be permanently tolerated by humans. As altitude increases, atmospheric pressure decreases, which affects humans by reducing the partial pressure of oxygen. The lack of oxygen above can cause serious illnesses such as altitude sickness, High altitude pulmonary edema, and High altitude cerebral edema. The higher the altitude, the more likely are serious effects.

The human body can adapt to high altitude by breathing faster, having a higher heart rate, and adjusting its blood chemistry. It can take days or weeks to adapt to high altitude. However, above , (in the "death zone"), the human body cannot adapt and will eventually die.

For athletes, high altitude produces two contradictory effects on performance. For explosive events (sprints up to 400 metres, long jump, triple jump) the reduction in atmospheric pressure means there is less resistance from the atmosphere and the athlete's performance will generally be better at high altitude. For endurance events (races of 5,000 metres or more) the predominant effect is the reduction in oxygen which generally reduces the athlete's performance at high altitude. Sports organisations acknowledge the effects of altitude on performance: the International Association of Athletic Federations (IAAF), for example, have ruled that performances achieved at an altitude greater than will not be approved for record purposes.

Athletes also can take advantage of altitude acclimatization to increase their performance. The same changes that help the body cope with high altitude increase performance back at sea level. These changes are the basis of altitude training which forms an integral part of the training of athletes in a number of endurance sports including track and field, distance running, triathlon, cycling and swimming.

References

External links

Downloadable ETOPO2 Raw Data Database (2 minute grid)

Downloadable ETOPO5 Raw Data Database (5 minute grid)

Calculate true altitude with these JavaScript applications

Find the altitude of any place

See also

Acronyms and abbreviations in avionics

Flight altitude record

High altitude wind power

Organisms at high altitude

Category:Aerospace Category:Aviation terminology Category:Physical geography Category:Topography Category:State functions

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Coordinates	53°25′″N21°53′″N
Name	Cut Chemist
Background	non_vocal_instrumentalist
Birth name	Lucas C. MacFadden
Birth date	October 04, 1972
Origin	U.S.
Instrument	Turntables, sampler
Genre	Hip hop, turntablism
Occupation	DJ, record producer
Years active	1993–present
Associated acts	Ozomatli, Jurassic 5, DJ Shadow
Website	http://www.cutchemist.com/ }}

Lucas MacFadden (born October 4, 1972), better known as Cut Chemist, is an American DJ and record producer. He is a former member of the funk Latin band Ozomatli, and of hip hop group Jurassic 5. He has collaborated with fellow turntablist DJ Shadow on a number of projects.

Career

Cut Chemist became known through the Los Angeles-based rap group Unity Committee, and debuted on vinyl on the B-side of Unity Committee's 1993 single, "Unified Rebelution". The track, "Lesson 4: The Radio" was an ovation of Double Dee and Steinski's "Lessons 1-3."

Preceding the vinyl release, Unity Committee formed Jurassic 5, along with another group, Rebels of Rhythm. Cut Chemist contributed avidly to the group, adding "Lesson 6: The Lecture" to Jurassic 5's eponymous EP, and co-producing the entirety of the record. Between then and other releases, he explored remixing alongside DJ Shadow and Liquid Liquid, and performed doing outside work (sampling and scratching for Less Than Jake, and appearing with Ozomatli). From late 1996 to early 1997, Cut Chemist recorded his album debut, ''Live at Future Primitive Sound Session'', with Shortkut of Invisibl Skratch Piklz.

Cut Chemist did not appear on their latest album ''Feedback''. In May 2006, he indicated to ''Billboard'' that he had left the group.

Cut Chemist's first full-length solo album, ''The Audience's Listening'', was released on July 11, 2006. The album includes the pre-released song "The Garden", which features a bossa nova style, vocals from Astrud Gilberto's Brazilian song "Berimbau", and berimbau instrumentals.

The song "The Audience Is Listening Theme Song" from ''The Audience's Listening'' has been featured in a 2G Apple iPod nano advertisement.

More recently, Cut Chemist has opened for Shakira in 2007 on the European leg of her Oral Fixation Tour, and at the press conference held by car-maker SEAT to promote their sponsorship of the shows.

Cut Chemist made an appearance in the 2007 comedy ''Juno'', playing a high school chemistry teacher, playing on his "chemist" stage-name. His logo, an opened pair of scissors over a beaker, is drawn on the whiteboard behind him in the movie.

Cut Chemist joined DJ Shadow on a world wide tour to support their new mix ''The Hard Sell'' beginning in early 2008. Kid Koala opened for them. Dates included Dallas, New York, San Francisco, Melbourne, Toronto, Vancouver, London, Hamburg and Paris among others.

In October 2008, Cut Chemist's video for the song "What's the Altitude" featuring Hymnal was removed for violating a WMG copyright.

Cut Chemist is featured in the award-winning documentary ''This is the Life'', chronicling the music movement which was birthed at The Good Life Cafe in South Central Los Angeles. The Good Life is the open-mic workshop where he first performed with Unity Committee in the early 1990s and launched Jurassic 5.

Most recently, Cut Chemist was featured in the film ''Up In The Air'' under his name Cut Chemist as the conference DJ who introduces Young MC.

Discography

Releases

''Brainfreeze'' (CD)

''Live at Future Primitive Sound Session Version 1.1'' (CD)

''Product Placement'' (CD)

''Brain Freeze Original Sound Track'' 1979

''The Litmus Test'' (CD)

''Rare Equations'' (2xCD)

''The Audience's Listening'' (CD)

''The Hard Sell'' (CD)

Remixes

''The Re-Return Of The Original Art Form (12")''

''Midnight In A Perfect World (12")''

''Midnight In A Perfect World / The Number Song (12")''

''The Remix EP (12")''

''Midnight In A Perfect World / Number Song (CD5")''

''Number Song / Painkiller (12")''

''A2G EP (12")''

''Cut Chemist Suite (12")''

''Remixes (12")''

''Super Bowl Sundae (12")''

''The Art Of War: Who Dares Wins (2xCD)''

''Now, Listen! (CD)''

''Urban Theory Presents...Meltdown (2x12")''

''Urban Theory Presents: Meltdown (2xCD)''

''One To Grow On (CD)''

''Herbal Blend (2x12")''

''Solid Steel Presents The Herbaliser - Herbal Blend (CD)''

''The Document II (3x12")''

''The Document II (CD)''

''They Mixes (12")''

''Biz Markie ripped up megamix (7')''

Scratches

''The Funky Precedent (CD)''

''Later That Day (2x12")''

''Street Signs (CD)''

Production

''Jurassic 5 EP (2x12")''

''Jurassic 5 EP (12")''

''Concrete Schoolyard (12")''

''Improvise / Lesson 6: The Lecture (12")''

''Jayou / Action Satisfaction (12")''

''Jayou / Without A Doubt (12")''

''A2G (12")''

''A2G EP (2x12")''

''Jurassic 5 (LP)''

''Nia (3x12")''

''The Funky Precedent (CD)''

''The Litmus Test (CD)''

''Alphabet Aerobics -Blackalicious (12")''

DJ mixes

''Brainfreeze (CD)''

''Product Placement''

''The Litmus Test (CD)''

''The Hard Sell (CD)''

''The Hard Sell (Encore) (CD)''

Appears on

''Got What You Need (12")''

''The 5 O'Clock Shadow EP (12")''

''My Vinyl Weighs A Ton (CD)''

''My Vinyl Weighs a Ton (2x12")''

''Tale of Five Cities (12")''

''2001: A Rhyme Odyssey (3x12")''

''2001: A Rhyme Odyssey (CD)''

''No Categories 3:: A Ubiquity Compilation (2xCD)''

''Embrace the Chaos (CD)''

''Blazing Arrow (2x12")'' by Blackalicious

''Blazing Arrow (CD)''

''The Private Press (Limited Edition) (2xCD)''

''Freestyle (Steinski's Additive Remix) (12")''

''Later That Day... (CD)''

''Make Yourself (CD)''

''Chemical Calisthenics (CD)

''Jennifer's Body''

Tracks appear on

''Audio Alchemy (Experiments In Beat Reconstruction) (2x12")''

''Audio Alchemy (Experiments In Beat Reconstruction) (CD)''

''Scratchmasters Volume #3 (CD)''

''Return Of The D.J. Vol. 1 (CD)''

''Return Of The DJ Vol. 1 (2x12")''

''Deep Concentration (2xCD)''

''The Funky Precedent (CD)''

''Urban Revolutions The Future Primitive Sound Collective (3x12")''

''Bunky's Pick (CD5")''

''Bunky's Pick (12")''

''Product Placement (2x12")''

''Slinky Presents Superclub DJ's (2xCD)''

''In The Mix / Live (12")''

''Later That Day... (CD)''

''The Ultimate Lessons (2x12")''

''The Ultimate Lessons (CD)''

''The Ultimate Lessons 2 (2x12")''

''The Ultimate Lessons 2 (CD)''

''Nat King Cole RE: Generations (CD)''

References

External links

Cut Chemist

Synthesis Magazine interview

Category:American electronic musicians Category:Hip hop DJs Category:1972 births Category:Living people

es:Cut Chemist fr:Cut Chemist ja:カット・ケミスト pl:Cut Chemist pt:Cut Chemist ru:Cut Chemist

Coordinates	53°25′″N21°53′″N
name	Laura Izibor
background	solo_singer
birth name	Laura Elizabeth Arabosa Izibor
born	May 13, 1987Dublin, Ireland
instrument	Vocals, piano
genre	R&B;, soul, pop
occupation	Singer–songwriter, pianist, producer, arranger, composer
years active	2000–present
label	Jive, Atlantic
website	www.lauraizibor.com }}

Laura Elizabeth Arabosa Izibor (born 13 May 1987) is an Irish recording artist, musician and producer. She won the RTÉ 2fm song contest while still in secondary school. She went on to win an award at the 2006 Meteor Music Awards. She also performed at that year's Electric Picnic music festival and Music Ireland 2007. Izibor has opened for Aretha Franklin, India.Arie, Estelle, Maxwell and John Legend on tour.

Her debut album, ''Let the Truth Be Told'', was released in Ireland on Friday 8 May 2009, and in the UK on Monday 18 May with a U.S. release to follow on 16 June.

Izibor is currently featured in The CW television show, ''One Tree Hill''., where she plays Erin Macree.

Life and career

1987–2003: Early life and career beginnings

Laura Elizabeth Arabosa Izibor was born in 13 May 1987 in Dublin, Ireland. She is the fourth of five children born to Irish mother Trish and Nigerian father Saul and brother Evan. Izibor's parents separated when she was seven and she was raised by her mother. As a child, she faced racial discrimination. She recalled being "paranoid about one teacher in particular, who I think was a racist" as well as "a few kids who made stupid little comments here and there". After singing "When You Believe", a duet by Mariah Carey and Whitney Houston, in her drama class, she discovered her interest for music; she began writing songs at age 13 and taught herself how to play the piano at 14. At age 15, public service broadcaster Raidió Teilifís Éireann (RTÉ) held a song competition by radio station RTÉ 2fm, which Izibor won. Her winning song, "Compatible", received constant airplay after she won the competition; RTÉ also filmed a documentary of Izibor after winning the competition.

2004–present: ''Let the Truth Be Told''

At age 17, Izibor was signed to Jive Records and dropped out of school to record her debut album. After a dispute with the label, she signed with Atlantic Records and subsequently moved to New York after her mentor, Steve Lunt, was offered a job at the label. She won an award at the 2006 Meteor Music Award and became the first unsigned recording artist to receive a nomination. Izibor's debut album, ''Let the Truth Be Told'', was released in May 2009. The album debuted at number two on the Irish Albums Chart.

Film and television

Her song "From My Heart to Yours" featured in an episode of Grey's Anatomy and the Vh1 reality series Tough Love.

Her single ''Shine'' was the lead track for the movie Nanny Diaries, is currently used in the Hibernian Aviva commercial in the Republic of Ireland and in the Norwich Union (soon to be Aviva) commercial in the United Kingdom. Withfirst-week sales in the United States.The CD's first-week chart position is 27 on the Billboard Top 200 Albums. Diana Ross is rumored to have recorded a duet with Izibor for the European edition of her upcoming album.

Her song "Mmm..." is featured in ''Step Up 2: The Streets'', ''Why Did I Get Married?'' and ''Seven Pounds'' starring Will Smith.

Her song "Carousel" is featured on the P.S. I Love You soundtrack.

Her song "Shine" is featured in an episode of Ghost Whisperer called 'Cursed' which aired 1 May 2009

Her song "Shine" is featured on the Special K advert

Her music was used in ''Second Chances'' an episode of MTV's The Hills.

Her song "If Tonight is my Last" was used as ''America's Best Dance Crew'' Season 4 elimination song.

A video of her performing her song "Mmm..." was featured in an episode of Bones called 'The Parts in the Sum of the Whole' as murder victim Gemma Arrington

Her song 'Mmm...' is featured in an episode of ''Private Practice'' called 'A Death In The Family' which aired 1 October 2009.

Laura debuts in One Tree Hill during the 8th Season (2010). Her song "Can't be Love", which she created specifically for the show, debuted during the 6th episode on October 20, 2010.

Musical style

Izibor cites James Brown, Aretha Franklin and Carole King as her inspirations. She described Phil Lynott as her idol, while naming Roberta Flack, Nina Simone, Candi Staton and Thin Lizzy her "musical heroes".

Izibor music has been compared to recording artists Aretha Franklin, Corinne Bailey Rae and Alicia Keys; her writing is compared to that of Carole King and Joan Armatrading. Nicole Frehsée of ''Rolling Stone'' magazine described Izibor's debut album, ''Let the Truth Be Told'', as "a sunny, chick-flick-worthy take on vintage soul". Noted UK R&B; writer Pete Lewis of 'Blues & Soul' described the album as "Anchored firmly in classic R&B; and effectively combining a reverence for the traditions of vintage, warm piano-driven soul with a fresh twist of modern sensibility". While Pete Daniel Smith of ''Sunday Mercury'' described the album as a "dazzling R&B; debut", noting a "a remarkable soul vocal that'll send shivers down your spine".

Discography

Studio albums

{|class="wikitable" !width="20" rowspan="2"|Year !width="250" rowspan="2"|Album !colspan="4"|Peak chart positions !width="200" rowspan="2"|Certifications(sales thresholds) |- !width="30"|IRE !width="30"|FRA !width="30"|NLD !width="30"|U.S. |- |2009 |''Let the Truth Be Told''

First studio album

Released: 8 May 2009

Label: Atlantic

|align="center"|2 |align="center"|60 |align="center"|64 |align="center"|27 | |}

Singles

2008: "From My Heart to Yours" #26 US R&B; #7 US Urban AC

2009: "Shine" - Released on 27 February 2009 as a digital download on the iTunes Store. #2 JP

2009: "Don't Stay" - Released on 11 May 2009 2009: "If Tonight is My Last"

Soundtrack songs

2008: "Carousel" (from P.S. I Love You)

2008: "Mmm..." (from Step Up 2: The Streets)

2008: "Shine" (from The Nanny Diaries)

2010: "Can't be love" (from One Tree Hill)

2010: "What More Can They Do" (from For Colored Girls)

2010: "WTF" (from Nothing)

Collaboration songs

2010: "Baby Baby" (from Miho Fukuhara in her album Music Is My Life)

Awards and nominations

!Source |- |align="center"|2004 |RTÉ 2fm Song Contest 2004 |Best Newcomer | |align="center"| |- |align="center"|2006 |Meteor Ireland Music Awards 2006 |Emerging Artist | |align="center"| |- |align="center" rowspan="2"|2009 |MOBO Awards |Best UK Newcomer | |align="center"| |- |Soul Train Music Awards |Centric Award - Soul Approved/Underground | |align="center"| |-

References

External links

Official website

Category:1987 births Category:Atlantic Records artists Category:Irish female singers Category:Irish people of Nigerian descent Category:Irish pianists Category:Irish pop singers Category:Neo soul singers Category:Irish record producers Category:Irish singer-songwriters Category:Music from Dublin (city) Category:Living people

de:Laura Izibor fr:Laura Izibor it:Laura Izibor