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Supersonic

Supersonic

:For the video game character see Super Sonic. For the Oasis song, Supersonic (song). For the J J Fad hip-hop record, see Supersonic (album). Any speed over the speed of sound, which is approximately 343 m/s, 1,087 ft/s, 761 mph or 1,225 km/h in air at sea level, is said to be supersonic. Speeds greater than 5 times the speed of sound are sometimes referred to as hypersonic. Sounds are vibrations in an elastic medium. In gases sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas; whilst pressure has a much smaller effect. Since air temperature and composition varies significantly with altitude, mach numbers for aircraft are related to the speed of sound at sea level. In water at room temperature supersonic can be considered as any speed greater than 1,440 m/s or 4,724 ft/s. In solids, sound waves can be longitudinal or transverse and have even higher velocities. Supersonic fracture is crack motion faster than the speed of sound in a brittle material. This phenomenon was first discovered by scientists from the Max Planck Institute for Metals Research in Stuttgart (Markus J. Buehler and Huajian Gao) and IBM Almaden Research Center in San Jose, California (Farid F. Abraham).

Supersonic objects

Many modern fighter aircraft are supersonic. The Concorde and Tupolev Tu-144 were supersonic passenger aircraft. But, since Concorde's final retirement flight on November 26 2003, there are no supersonic passenger aircraft left in service. Most modern firearm munitions are supersonic, with rifle projectiles often travelling at speeds approaching Mach 3.

Breaking the sound barrier

In 1942 the United Kingdom's Ministry of Aviation began a top secret project with the Miles Aircraft to develop the world's first aircraft capable of breaking the sound barrier. The project resulted in the development of the prototype Miles M.52 aircraft, which was designed to reach 1000 mph (1600 km/h) at 36,000 feet (11 km) in 1 minute 30 seconds. The aircraft's design was revolutionary introducing many innovations which are still used on today's supersonic aircraft. The single most important development was the all-moving tailplane which allowed control to be maintained at supersonic speeds; this was the brainchild of Dennis Bancroft and his team at Miles Research. The project was cancelled by the Director of Scientific Research, Sir Ben Lockspeiser, before any manned fights were conducted. Subsequently, on government orders, all design data and research regarding the Miles M.52 was sent to BELL aircraft in the USA. There was an agreement for data exchange in both directions, but allegedly, after receiving the British data, the American government blocked the deal. Later experimentation on the Miles M.52 design proved that the aircraft would indeed have broken the sound barrier, with an unmanned 3/10 scale replica of the M.52 achieving Mach 1.5 in October 1948. Chuck Yeager was the first man to break the sound barrier in level flight on October 14 1947, flying the experimental Bell X-1 at Mach 1 at an altitude of 45,000 feet (13.7 km). Hans Guido Mutke claimed to have broken the sound barrier before Yeager, on April 9 1945 in a Messerschmitt Me 262. However, this claim is widely disputed. A team led by Richard Noble and driver Andy Green became the first to break the sound barrier in a land vehicle, called the Thrust SuperSonicCar, on October 15 1997, almost exactly 50 years after Yeager's flight.

Supersonic aerodynamics

Supersonic aerodynamics are simpler than subsonic because the airsheets at different points along the plane often can't affect each other. Supersonic jets and rocket vehicles require several times greater thrust to push through the extra drag experienced within the transonic region (around Mach 0.85-1.5). Aerospace engineers can gently guide air around the fuselage of the aircraft without producing new shock waves but any change in cross sectional area further down the vehicle leads to shock waves along the body. Designers use the Whitcomb area rule and minimize sudden changes in size. Whitcomb area rule Whitcomb area rule Whitcomb area rule Whitcomb area rule It should be kept in mind, however, that the aerodynamic principles behind a supersonic aircraft are often more complex than described above due to the fact that such an aircraft must be efficient and stable at both supersonic, transonic and subsonic flight. At high speeds aerodynamic heating can occur, so an aircraft must be designed to operate and function under very high temperatures. For example, the SR-71 Blackbird jet could fly continuously at Mach 3.1 while some parts were above 600F.

External links

- [http://www.mathpages.com/home/kmath109/kmath109.htm The Speed of Sound]
- [http://online.cctt.org/physicslab/content/phy1/lessonnotes/Sound/lessonsound.asp Sound]
- [http://www.makeitlouder.com/Decibel%20Level%20Chart.txt Supersonic sound pressure levels] Category:Sound Category:Aerospace engineering Category:Aerodynamics

Oasis (band)

Oasis are a British rock band that originally formed in Manchester. They were one of the most prominent bands in the Britpop movement that emerged in Great Britain as a reaction to Grunge and House music in the mid-1990s. The band is led by lead guitarist/songwriter/vocalist Noel Gallagher and his younger brother, vocalist/songwriter Liam Gallagher, who are the only remaining original band-members. Musically, they cite bands such as The Beatles, Slade, The Stone Roses, The Kinks and T.Rex as influences. They rose to prominence during 1994 when, in addition to the success of their classic debut album Definitely Maybe, the Gallagher brothers featured regularly in tabloid newspaper stories, with frequent reports of heavy drinking, drug taking and boisterous behaviour. At the height of their fame, their third album, Be Here Now, released on Tuesday, August 26, 1997, reached #1 in the UK charts and also became the fastest selling album in chart history, with almost half a million copies sold on the first day alone. Oasis have outlasted many of their Britpop contemporaries. Blur, Suede, Pulp and other less successful groups have split up, or record only infrequently, while Oasis maintain a regular schedule of releases and touring. Their latest album, Don't Believe The Truth was a UK #1, and tickets for their concerts continue to sell out quickly.

History

Early years and breakthrough (1991-1994)

Pulp, Guigsy, Tony McCaroll and Bonehead]] Oasis, named after a club that The Beatles once played in, evolved from an earlier band, The Rain, who took their name from a 1966 Beatles' B-side. The Rain comprised of Paul "Guigsy" McGuigan (bass guitar), Paul "Bonehead" Arthurs (guitar), Tony McCaroll (drums) and Chris Hutton (vocals). When Guigsy invited school friend Liam Gallagher to join the group, Gallagher accepted, and quickly pushed for the band's name to be changed to Oasis. Oasis first played live in August of 1991, at the Boardwalk club in Manchester. Noel Gallagher, who had recently returned from touring America as a roadie for the Inspiral Carpets, came to watch his younger brother play. A few months later he was invited to join the band. Although he had been critical of them, he agreed, with the provision that he would become the band's sole songwriter and leader, and that they would commit to an earnest pursuit of commercial success. After gaining a loyal and vocal following on the local Manchester gig circuit, Oasis signed to Creation Records in late 1993. Following a limited white label release of their song "Columbia", the commercial singles "Supersonic" and "Shakermaker" were released in the spring of 1994. Both gained national radio airplay and were Top 40 hits in the United Kingdom. In August 1994, their polished and melodic single "Live Forever," made the UK Top 10, and brought the band a measure of fame. Also around this time the band were involved in a high-profile incident on a ferry off the coast of the Netherlands. Liam Gallagher and McGuigan were arrested for fighting, whilst Arthurs and McCarroll were detained for alleged shoplifting. All four were subsequently refused entry to the Netherlands, and this incident became the first of many tabloid stories on the band. The publicity helped their debut album, Definitely Maybe (named after a song of the Kinks from their album State of Confusion), enter the charts at #1 in September 1994, and it became the fastest selling debut album in UK chart history. More hit singles quickly followed. The October 1994 single "Cigarettes & Alcohol" reached #7 in the UK charts amidst controversy that its central riff directly plagiarised T.Rex's 1972 release "Get it On". The EP "Whatever" was released in December 1994, peaking at #3 in the UK charts and foreshadowing the band's move toward a mellower sound on the following album. That song, too, was the subject of accusations of plagiarism, and Neil Innes, formerly of the Bonzo Dog Doodah Band, successfully sued on the basis that a substantial part of the melody was taken from his song How Sweet to be an Idiot. Tensions between the Gallgher brothers on their first U.S.A. tour, coupled with a distain for Americans, caused Noel to temporarily quit the band after a disasterous gig in L.A. and fly to San Francisco without telling anyone. When Oasis' manager tracked him down, they decided to take a trip to Las Vegas so as to calm Noel down. Legend has it that he met a woman on her honeymoon here (who thought he resembled George Harrison), and that after a long conversation, shre pursuaded him to rejoin Oasis. The song "Talk Tonight" (one of the b-sides to "Some Might Say") is thought to be written for this woman.

Britpop and the Blur rivalry (1995-1996)

During early sessions for their second album, original drummer Tony McCaroll was sacked. Noel Gallagher has since claimed that his departure was a result of him not being technically good enough to play on more complex songs. There were also reports of scuffles with the Gallaghers. He was replaced with quiet Londoner Alan "Whitey" White, whose brother Steve had drummed for Paul Weller and his band Style Council. McCaroll later attempted to [http://news.bbc.co.uk/1/hi/entertainment/showbiz/2525313.stm sue the Gallaghers] over his sacking, citing breach of contract, but lost the suit on a technicality. Style Council] Oasis soon had their first UK #1 with the first single from their second album, "Some Might Say" (the only track on the second album to feature McCaroll), in late April 1995. During this period, the British media seized upon a supposed rivalry between Oasis and fellow Britpop band Blur. Noel Gallagher played along, telling The Observer that he hoped Damon Albarn and Alex James of Blur would "catch AIDS and die." He subsequently [http://ireland.iol.ie/~kglennon/paper/bandi.htm apologised] for this in a formal letter to Melody Maker magazine. On Monday, August 14, 1995, Blur and Oasis released new singles on the same day, setting up a "Battle of the Bands" that dominated the week's music news. Perhaps in part because it was more cheaply priced (99p vs £1.99), Blur's "Country House" outsold Oasis' "Roll With It" 274,000 copies to 216,000 during the week. An alternative explanation given at the time was that there were problems associated with the barcode on the 'Roll With It' single case, which did not record all sales. Nonetheless, Oasis' second album, (What's the Story) Morning Glory? became the second largest selling album of all-time in the UK. Although a softer sound led to mixed reviews, the album went on to sell over 18 million copies worldwide and spawned two further hit singles, "Wonderwall" and "Don't Look Back In Anger", which reached numbers 2 and 1 respectively. The album's opening track "Hello", with its singalong chant, is a common feature of Oasis' live performances. It features a sample from Gary Glitter's 1973 Top 10 hit Hello, Hello, I'm Back Again. As their career reached its zenith, Oasis performed back-to-back concerts at Knebworth on the 10 and 11 August 1996. The band sold out both shows within minutes - 250,000 people over 2 nights, at the time a record-breaking number for an outdoor concert held in the UK. This record was later broken by Robbie Williams who played to 125,000 each night over a 3 day period. In September 1995, Guigsy briefly left the band on tour in the US, citing nervous exhaustion. He was replaced by Scott McLeod, formerly of The Ya-Yas, who featured on some of the tour dates as well as in the "Wonderwall" video before leaving abruptly. In order to complete the tour, Guigsy was successfully convinced to return to the band. "He looks a bit like the old one," Noel Gallagher joked when he reintroduced him to the press.

The recording and release of Be Here Now (1997-1998)

The Ya-Yas Oasis spent the end of 1996 and the first quarter of 1997 planning their third album. Be Here Now was released in August 1997, the band choosing to launch it on a Thursday rather than the traditional Monday. Preceded by the UK #1 single "D'You Know What I Mean", the album was perhaps their most anticipated effort, and as such became the subject of considerable media attention. Anticipation culminated with the screening of the documentary, "Right Here, Right Now" on BBC1 on the eve of the album's release. The attendant press attention and hype helped the album become the fastest-selling album in UK history (a record which still stands), selling 423,000 units on its day of release, and reached number 2 in the US album chart. Be Here Now ultimately outsold Definitely Maybe worldwide but could not match the sales of (What's the Story) Morning Glory. Although early media reviews were positive, once the hype had died down, the album was criticised for being bloated and derivative by fans and critics, and Noel Gallagher himself later disavowed the album. Most of the critics focused on the extensive length of several songs, the heavier sound, and over production. Melody Maker later gloated that Be Here Now had become the album most frequently sold to second-hand record shops, ending the era of Oasis as media darlings. When an argument between band members interrupted the band's American tour of the album, Oasis nearly self-destructed. After a Yellow Submarine-inspired video for their fourth UK #1, "All Around The World", the group kept a low profile throughout 1998, although a compilation of popular B-sides, The Masterplan, was released in autumn 1998. However, the band were still subject to much attention from the tabloid newspapers.

Changing styles (1999-2004)

The recording of the fourth album also saw founding member Arthurs leave the band. His departure was reported at the time as amicable, with Noel stating that Arthurs wanted to spend more time with his family. Arthurs' statement clarified his leaving so as "to concentrate on other things"[http://news.bbc.co.uk/1/hi/entertainment/415855.stm]. However, in a recent interview Noel has offered a contradicting version: that a series of violations of Noel's 'no drink or drugs' policy for the album's sessions resulted in a confrontation between the two. Finding the pressure of being in the band without his close friend too great, bass player "Guigsy" soon gave notice. White, however, elected to remain with the Gallaghers. Thus he, Liam and Noel had to re-record much of the album, with Noel playing all guitar and bass parts. Colin "Gem" Archer, formerly of Heavy Stereo, was brought in as guitarist while Andy Bell, formerly of Ride joined later on bass guitar. Bell had never played bass before and he was obliged to learn playing it as well as all Oasis songs of the back catalogue at the last minute before their starting tour. With the death of Creation Records, Oasis formed their own label, Big Brother, named after Noel, as a subsidiary label of the Sony Music Entertainment group. Oasis's fourth album, Standing on the Shoulder of Giants was released in February 2000 to good first-week sales. The album was greeted by lukewarm reviews, however, being seen as experimental, and a departure from their traditional sound, and as of 2005 it remains their lowest-selling album worldwide, although it did spawn another UK number 1 with "Go Let It Out". Go Let It Out The spring of 2000 saw the new line-up embark on a world tour, which again proved eventful. In Barcelona they were forced to cancel a gig at the last-minute because of a hand injury sustained by Alan White. As a result, the band spent the whole night drinking, and a fight broke out between the Gallagher brothers. Noel then jetted home immediately and announced he had quit overseas touring. The band replaced him with guitar technician Matt Deighton to complete the remaining tour dates. After two months of ongoing rumours about band's long-term future, Noel returned for the British leg of the tour, which culminated in a Wembley show. A live album of the show, called Familiar to Millions, was released in late 2000. Noel, White and Liam all ended marriages during this period. Liam, whose marriage to actress/singer Patsy Kensit had been well-known among tabloid readers, soon started a relationship with former All Saints' Nicole Appleton, who soon became pregnant with their son Gene. In mid-2001 the band returned to work on their next record. Oasis' fifth album, Heathen Chemistry, was released in July 2002. The record retained an experimental flavour, but also borrowed heavily from British rock music of the 1960s and 70s. Heathen Chemistry was also a much more balanced recording process for the band, with Liam, Andy and Gem all penning songs. This new working method, along with a less fighting and drug and alcohol abuse in the studio, ultimately gave the record a more relaxed feel compared to past efforts. Johnny Marr provided additional guitar as well as backup vocals on several songs, and while critics gave Heathen Chemistry lukewarm reviews, it was commercially successful. Then the band embarked on a world tour that was successful but flavoured with incidents. In late summer of 2002, whilst the band was on tour in the United States, Noel, Andy and touring keyboardist Jay Darlington were involved in a car accident. While none of the band members sustained any major injuries, some shows were cancelled as a result. Liam also suddenly bolted offstage for no apparent reason during a show in Fukuoka, Japan, leaving Noel to take over vocal duties. It was the second Fukuoka show in three years that Liam failed to complete; over the years Oasis have developed a reputation for cancelling concerts or ending them prematurely on a whim. In December 2002, whilst on the European leg of the tour, Liam and White, as well as three members of the band's entourage, were arrested in Munich after being involved in a drunken brawl at a local club. Liam was considerably inebriated and became involved in a scuffle with other drinkers. The scuffle saw Liam lose his two front teeth. He also jumped on the club's stage and kicked a police officer in the groin. As a result of the brawl, extremely drunk White had a brain scan in hospital afterwards and two of the band's security guards required serious medical attention. The altercations led to 12 shows being cancelled, the band incurring £170,000 in losses, and two years later Liam was fined £45,000, with part of the money going to the injured police officer. After the end of the tour, the band spent the rest of 2003 out of the spotlight. A major line-up change occurred, after the band was enjoying times of stability in their lines. After nine years in the band, "original" drummer and longtime performer Alan White left the band in early 2004, the announcement coming just a month into recording the follow-up to Heathen Chemistry. Although various rumours have circulated regarding the reasons for White's departure, his brother Steve White stated on his own website that Alan was just tired with being in Oasis and wanted some time off to be with his girlfriend. This became the first of many setbacks in the recording of Oasis' sixth studio album, resulting in the scrapping of the first sessions. After some time in the sessions, when Noel handled the sticks, the band decided to return to five-member line-up, so after some consideration trying Terry Kirkbride who played on one track on their next album, they settled on Zak Starkey - the son of the Beatles drummer Ringo Starr (Richard Starkey) - current The Who-drummer, who also was performing with Johnny Marr and the Healers. Marr is a close friend of Noel, so he recomendeded Zak. In June 2004, Oasis headlined the Glastonbury Festival for the second time in their career, and debuted two tracks - Gem's "A Bell Will Ring" and Liam's "The Meaning of Soul". The concert, although badly received, was their first major show, introducing their new drummer. In September 2004, the band released Definitely Maybe: The DVD in commemoration of the 10th anniversary of the release of their debut album. The DVD contains an enhanced audio version of the album, four hours of live footage, and interviews with band members and the production team.

Resurgence (2005-)

In May 2005 the band resurfaced after three years and three scrapped recording sessions with their sixth album Don't Believe the Truth. It featured the previous album's democratic songwriting duties with Noel contributing five songs, Liam three, Andy two and Gem one. The album was leaked on the internet a month before its actual release and was well-received by fans and critics alike. As of December, this album had spawned 2 UK #1 singles with "Lyla" and "The Importance of Being Idle" topping the charts, while Let There Be Love entered at #2. They also entered the albums chart at #1. The sleeve of the new album is also more understated than earlier designs, subsequently emanating a different tone compared to the band's previous albums. Andy Bell has likened the album to Forever Changes by Love, Highway 61 Revisited by Bob Dylan and Revolver by The Beatles. The Beatles This album signalled the end of Oasis' current recording contract and Noel hinted that they won't renew their contract with Sony because of their pressure for putting Lyla as a first single. Following his comments whilst accepting the "Best Music DVD" award at the NME Awards in London in February 2005, speculation grew that they were seeking to work once again with former boss Alan McGee on a new label, albeit one with major backing. Noel has since claimed that this was not what his comments referred to. June 2005 saw the band embarking on a huge international tour. The North American Tour began with a sold out concert in Toronto (voted the best concert of the summer by the Toronto Star).Oasis showed their appreciation to the crowd by playing a solid 1.5 hour set. They continued the tour with two large gigs in the USA; at Madison Square Garden, where 16,000 seats were sold within the first hour; and at the Tweeter Center in Mansfield, Massachusetts where the band played to their largest audience of any tour in the United States, with 20,000 in attendance. There was also some crowd trouble at their acclaimed televised Manchester homecoming gig when a crowd barrier was broken, and the 60,000 fans were forced to wait 25 minutes while the problem was fixed. In July 2005 the band announced that they would finish the year with four gigs in Ireland, two at Belfast's Odyssey Arena and two at Dublin's Point Depot, concluding on Thursday December 22. In September 2005, Oasis contributed three new recordings to the soundtrack of the new UK movie, Goal! including a new song "Who Put The Weight Of The World On My Shoulders?" penned and sung by Noel Gallagher with Gem playing bass. The soundtrack was released on the bands own record label - Big Brother Records - and also contained a remixed version of "Morning Glory" as well as a re-recorded version of "Cast No Shadow" with Jeordie White (aka Twiggy Ramirez) contributing bass. At the 2005 Q Awards Oasis led the way with 5 nominations including best live act, best album, best video and best act in the world today, along with best track for "The Importance of Being Idle". From those awards Oasis won 2, for best album and the people's choice award.

Next album

In August 2005, only weeks before headlining the dual-venue V Festival, an interview with Noel [http://www.xfm.co.uk/Article.asp?id=110279] revealed that the band plan to release a second b-sides album in 2006, embracing material from the last three albums. It's unknown whether there will be a bitter lawsuit wrangling again for this b-side album, as drummer Alan White performed on the batch of these b-sides, but is out of the band as his forerunner McCaroll, who sued Oasis over rights of Definitely Maybe b-sides. As contradiction to his earlier statement that the band won't release new material before 2007, he said later in October in an interview, however, that Oasis are thinking about releasing a non-LP single (their first since 1994's "Whatever") called "The Boy With the Blues" which was written by Liam. The single is expected early 2006. It's possible yet unknown that the band release a new album next year, as Noel added they had plenty of other new material in hand, though he wasn't sure if it was destined for Oasis' next release.: "We've got about 11 pretty good songs for the next record that were left over from this one, but if we go into the studio I don't know if we're gonna go in there and say 'Right we're making an album'," he mused. "We're just going record the ones for this one that we didn't record in our own studio and see how it goes." "Stop the Clocks"
"Stop the Clocks" is a Noel Gallagher song written during the Heathen Chemistry sessions, whilst Liam was singing the vocals to "Stop Crying Your Heart Out". It is similar in style to the ballad "Champagne Supernova", although with minimal instrumentation, featuring only Noel and a guitar backing.

Discography

Studio albums Image:OasisDefinitelyMaybealbumcover.jpg|Definitely Maybe (30 August 1994) - #1 UK, #58 US, #1 IRL
Note:This album is the UK's fastest selling debut album Image:Oasis - (What's The Story) Morning Glory album cover.jpg|(What's the Story) Morning Glory? (2 October 1995) - #1 UK, #8 FRA, #4 US, #1 IRL, #7 ITA
Note: This album is the U.K's 2nd biggest selling album Image:Oasis Be Here Now album cover.jpg|Be Here Now (21 August 1997) #1 UK, #2 US, #1 FRA, #1 CAN, #1 AUS, #1 JPN, #2 GER, #1 IRL, #2 ITA
Note:This album is the UKs fastest selling album selling 695,761 in the first four days of its release and already #1 in 28 countries charts Image:StandingontheShoulderofGiantsOasisalbumcover.jpg|Standing on the Shoulder of Giants (28 February 2000) - #1 UK, #24 US, #6 FRA, #8 CAN, #12 AUS, #5 GER, #1 IRL, 1# ITA Image:HeathenChemistryOasisalbumcover.jpg|Heathen Chemistry (1 July 2002) - #1 UK, #23 US, #8 FRA, #5 CAN, #3 AUS, #4 GER, #1 IRL, #2 ITA Image:Oasis Don't Believe the Truth.jpg|Don't Believe the Truth (30 May 2005) - #1 UK, #12 US, #5 FRA, #3 CAN, #5 AUS, #1 JPN, #2 GER, #1 IRL, #1 ITA, #1 ARG Compilations Image:MasterplanOasisalbumcover.jpg|The Masterplan (B-sides compilation album) - (2 November 1998) - #2 UK, #51 US, #11 CAN, #1 IRL Singles From Definitely Maybe:
- "Supersonic" - (11 April 1994) #31 UK
- "Shakermaker" - (13 June 1994) #11 UK
- "Live Forever" - (8 August 1994, #10 UK, #39 US
- "Cigarettes & Alcohol" - (10 October 1994) #7 UK Non-album single:
- "Whatever" - (19 December 1994) #3 UK, #40 AUS From (What's the Story) Morning Glory?:
- "Some Might Say" - (24 April 1995) #1 UK
- "Roll With It" - (14 August 1995) #2 UK, #48 AUS
- "Wonderwall" - (30 October 1995) #2 UK, #8 US, #1 AUS
- "Don't Look Back in Anger" - (19 February 1996) #1 UK, #55 US, #19 AUS From Be Here Now:
- "D'You Know What I Mean" - (7 July 1997) #1 UK, #3 CAN, #1 AUS, #1 ITA
- "Stand By Me" - (22 September 1997) #2 UK, #48 AUS, #2 ITA
- "All Around The World" - (12 January 1998) #1 UK, #2 ITA From Standing on the Shoulder of Giants:
- "Go Let It Out" - (7 February 2000) #1 UK, #1 CAN, #23 AUS, #1 ITA
- "Who Feels Love?" - (17 April 2000) #4 UK, #7 CAN
- "Sunday Morning Call" - (3 July 2000) #4 UK, #8 CAN From Heathen Chemistry:
- "The Hindu Times" - (15 April 2002) #1 UK, #1 CAN, #22 AUS, #1 ITA
- "Stop Crying Your Heart Out" - (17 June 2002) #2 UK, #6 CAN, #48 AUS, #2 ITA
- "Little by Little" / "She is Love" - (23 September 2002) #2 UK, #2 CAN, #2 ITA
- "Songbird" - (3 February 2003) #3 UK, #2 CAN From Don't Believe the Truth:
- "Lyla" - (16 May 2005) #1 UK, #4 CAN, #23 AUS, #2 ITA
- "The Importance of Being Idle" - (22 August 2005) #1 UK, #1 ITA, #63 GER
- "Let There Be Love" - (28 November 2005) #2 UK, #14 IRE, #2 ITA, #4 WALES Exclusive International Singles From (What's the Story) Morning Glory?:
- "Champagne Supernova" - (US and AUS only, 17 June 1996 #26 AUS
- "Morning Glory" - (US and AUS only, 30 August 1996) #25 AUS From Be Here Now:
- "Don't Go Away" - (Japan only, 19 February 1998) From The Masterplan:
- "Acquiesce" - US Modern Rock Tracks #24 Live Releases and Videos
- Live By The Sea - (31 August 1995)
- ...There And Then - (14 October 1996)
- Familiar to Millions - (13 November 2000) - #5 UK, #182 US - 1.5 million
- Definitely Maybe - The DVD - (7 September 2004)

Band Members Over the Years

1991-1995:
- Liam Gallagher - Lead Vocals
- Noel Gallagher - Lead Guitar/Lead Vocals/Backvocals
- Paul 'Bonehead' Arthurs - Rhythm Guitar
- Paul 'Guigsy' McGuigan - Bass Guitar
- Tony McCaroll - Drums. Replaced by Alan White in 1995 1995-1999:
- Liam Gallagher - Lead Vocals/Tamborine
- Noel Gallagher - Lead Guitar/Lead Vocals/Backvocals
- Paul 'Bonehead' Arthurs - Rhythm Guitar. Replaced by Gem Archer in 1999
- Paul 'Guigsy' McGuigan - Bass Guitar. Replaced by Andy Bell on Bass in 1999
- Alan White - Drums 1999-2003:
- Liam Gallagher - Lead Vocals
- Noel Gallagher - Lead Guitar/Lead Vocals/Backvocals
- Gem Archer - Rhythm Guitar/Backvocals
- Andy Bell - Bass Guitar
- Alan White - Drums. Replaced by Zak Starkey in 2004 2004-present:
- Liam Gallagher - Lead Vocals
- Noel Gallagher - Lead Guitar/Lead Vocals/Backvocals
- Gem Archer - Rhythm Guitar/Backvocals
- Andy Bell - Bass Guitar
- Zak Starkey - Drums Keyboards
- Mike Rowe (1995-2002) (recording)
- Jay Darlington (2000-present) (touring) TimeAxis = orientation:horizontal format:yyyy ImageSize = width:750 height:250 PlotArea = width:700 height:200 bottom:20 left:20 Colors = id:canvas value:rgb(0.97,0.97,0.97) id:grid1 value:rgb(0.86,0.86,0.86) id:grid2 value:gray(0.8) id:bars value:rgb(0.96,0.96,0.6) BackgroundColors = canvas:canvas Period = from:1991 till:2006 ScaleMajor = unit:year increment:1 start:1991 gridcolor:grid1 BarData= barset:Bandmembers PlotData= # set defaults width:25 fontsize:L textcolor:black align:left anchor:from shift:(10,-4) color:bars barset:Bandmembers from:1991 till:2006 text:"Liam Gallagher" from:1992 till:2006 text:"Noel Gallagher" from:1991 till:1999 text:"Paul Arthurs" from:1999 till:2006 text:"Gem Archer" from:1991 till:1999 text:"Paul McGuigan" from:1999 till:2006 text:"Andy Bell" from:1991 till:1995 text:"Tony McCaroll" from:1995 till:2004 text:"Alan White" from:2004 till:2006 text:"Zak Starkey" Through the years, several 'stand-in' musicians have played with Oasis at various times and for various reasons. Scott McLeod (Sept 95 - Oct 95), formerly of Manchester band "The Ya-Yas", stood in for Guigsy when he was suffering from exhaustion. Scott played a handful of American dates and also featured in the Wonderwall video. Matt Deighton (May 00 - July 00), part time guitarist with Paul Weller, was drafted in to replace Noel who quit midway through the 2000 world tour after a fight with Liam. All international dates were completed by Matt, with Noel returning to duties on all UK dates. Steve White (Summer 2001), long time session drummer, member of Paul Weller's band and most importantly brother of Alan White, stood in for a number of US dates after Alan was suffering from tendonitis.

Awards

1993 1994
- Q Award for "Best New Act". 1995
- Brit Award for "Best British Breakthrough Act"
- Ivor Novello Award for "Songwriters Of The Year" to be shared with Blur.
- NME 3 awards: "Best New Band", "Album Of The Year - Definitely Maybe" & "Single Of The Year - Live Forever".
- Q Award for "Best Live Act". 1996
- Brit Award 3 awards: "Best British Album - What's The Story (Morning Glory?)", "Best British Group" & "Best British Video - Wonderwall".
- NME 4 awards: "Best Band", "Best Live Band", "Best Album - What's The Story (Morning Glory?)", "Best Single - Wonderwall".
- Q Award for "Best Act In The World Today". 1997
- NME Brat Awards 2 for "Best Musical Event - Knebworth" & "Band Of The Year".
- Q Award for "Best Act In The World Today". 1998 1999 2000
- NME for "Hero Of The Year - Liam Gallagher".
- Q Award for "Best Live Act". 2001 2002 2003
- NME 3 awards for "Best UK Band", "Artist Of The Year" & "Best Haircut - Liam Gallagher". 2004 2005
- NME award for "Best Music DVD - Definitely Maybe"
- 2 Q Awards for "Best Album - Don't Believe the Truth" and "People's Choice Award"

Famous support acts

Over the years Oasis have always managed to bring well-known bands on as support acts for their live shows, the most memorable time was Knebworth. Here are some of the acts:

- Richard Ashcroft
- The Verve
- The Happy Mondays
- The Charlatans
- Ocean Colour Scene
- The Prodigy
- The Chemical Brothers
- The Bootleg Beatles
- Manic Street Preachers
- Doves
- Jet
- Travis
- The Black Crowes (on the tour they both co-headlined, they would switch support to headline each night)
- Kasabian
- The Coral
- The Zutons
- Razorlight
- Foo Fighters (Cardiff Millenium Stadium - Dec 10, 2005)
Plaudits
Oasis are regularly voted towards the top of many "Greatest of all time" polls, some of which include:
- Observer Music Monthly 100 Greatest British Albums poll, June 2004- #19 Definitely Maybe, #70 (What's The Story) Morning Glory?
- Channel 4 100 Greatest Albums of All Time, April 2005- #6 Definitely Maybe, #15 (What's The Story) Morning Glory?
- NME's 100 Best Albums of All Time, 2003- #13 Definitely Maybe, #37 (What's The Story) Morning Glory?
- Q Magazine's 100 Greatest Albums of All Time, 2003- #8 Definitely Maybe, #22 (What's The Story) Morning Glory?
- Q Magazine's 50 Greatest Bands List, 2004- #13 Oasis
- Virgin Radio's 100 Greatest British Artists, 2003- #3 Oasis
- Q Magazine's 100 Greatest Gigs, 2004- #3 Oasis- Knebworth 1996
- SPIN Magazine's Top 100 Albums 1985-2005- #28 Definitely Maybe
- Q Magazine's 50 Best British Albums Ever, July 2003- #1 Definitely Maybe
Trivia

- Of the 8 UK Number 1s in Oasis' history, none have spent longer than a week at the top of the chart summit.
- Out of the 8 UK Number 1s in Oasis' career history, only two do not feature Liam Gallagher on lead vocals. Don't Look Back in Anger (1996) and The Importance of Being Idle (2005) both feature Noel Gallagher on lead vocals.
- Oasis' current drummer, Zak Starkey, is the son of Beatles legend Ringo Starr
- In the 11 years since they entered the limelight, the band's lineup has undergone many changes. However, Noel claims that the crew are exactly the same.
- In 2005, when he turned 65, Ringo Starr said that Oasis were the one band of the last 20 years that he enjoyed listening to, and even more now, especially when his beloved son is drumming with them.
- Since August 8, 1994, every Oasis single has managed to hit the top 10, and since December 19, 1994 every Oasis single has managed to hit the top 4 in the official UK charts.
- Noel has claimed that all of Oasis's members are actually talented drummers, comparing Liam's "loud as fuck" playing to John Bonham, Bell to Reni of the Stone Roses and Archer to drummers of the late punk era. However, he feels that he is the best of them, and attributes the bands trouble with drummers, in part, to this.
- As well as a multi-instrumentalist & songwriter, Gem Archer is also a talented artist.
- Andy Bell claims to have written "Turn Up the Sun" - the opening track on 2005s Don't Believe the Truth - on his own, tripping, in the woods just outside Stockholm where he lives with his Swedish wife Ida.
- The cover artwork of Be Here Now includes the album's release date, as well as strong references to bands such as The Beatles and The Who.
- The distinctive Oasis logo was dropped from the covers of Standing on the Shoulder of Giants and Heathen Chemistry in favour of a flashier, more sci-fi logo. Don't Believe the Truth sports a return of the original logo.
- Hindu Times, the lead single from Heathen Chemistry, shares a riff with the Stereophonics song Same Size Feet.
See also

- The Music
- No Way Sis
- Primal Scream
- Blur
- Ian Brown
- Paul Weller
- The Chemical Brothers
- Best selling music artists - World's top selling music artists chart.
External links

- [http://www.oasisinet.com/ Oasis Official website]
- [http://www.cigarettes-and-alcohol.com/phpBB2/index.php Cigarettes and Alcohol] - French forum who got the 'kète'
- [http://www.oasislive.it/ Oasis Live] - Good italian site, with updated news, forum, chat, newsletter and more
- [http://oasisobsessedfans.port5.com/ Oasis Obsessed Fans: One of the worlds' highest rated fan sites]
- [http://www.oasis-news.com/ Oasis News] Updated News, Reviews, Tour Info. Check it out!
- [http://www.oasisfans2005.com OasisFans2005.com] - Oasis on tour 2005
- [http://www.stopcryingyourheartout.com Stop Crying Your Heart Out] - Stop Crying Your Heart Out
- [http://dmoz.org/Arts/Music/Bands_and_Artists/O/Oasis/ Open Directory Project:Oasis ]
- [http://www.biff-lyrics.com/artists/oasis/songs.html Oasis Lyrics]
- [http://www.oasisinet.de/ www.oasisinet.de]
- [http://www.oasisnews.blogger.com.br Oasis News Brazil] - #1 Latin America Fan-Site
- [http://www.fotolog.net/oasis_photos Oasis Photos]
- [http://www.andrewkendall.com/pages/photogallery/pictureindex.php?id=742 Oasis Photos by Andrew Kendall]
- [http://www.frappr.com/oasislive/ The Worldwide Oasis fans map] http://www.live4ever.us/ Category:Oasis Category:British musical groups Category:Britpop musical groups Category:Rock music groups Category:Creation Records groups ja:オアシス (バンド)

J J Fad
J J Fad (Just Jammin' Fresh and Def) was a trio of female rappers known as M.C.J.B. (Juana Burns), Baby-D (Dania Birks) and Sassy C. (Michelle Franklin).
Discography

- 1988: Supersonic Produced by Dr. Dre, D.J. Yella. Executive Producer Eric "Eazy E" Wright. Ruthless Records/Atco/Atlantic
- 1991: Not Just A Fad
External links

- [http://www.atlanticrecords.com/jjfad/ Atlantic Records J.J. Fad site]
- [http://www.allmusic.com/cg/amg.dll All Music Guide biography]
- [http://www.globaldarkness.com/articles/jj_fad_bio.htm Globaldarkness]

Supersonic (album)

"Supersonic" is a 1988 hip-hop album by J J Fad released on Ruthless Records. The album was produced by Dr. Dre and D.J. Yella and Ruthless founder Eric "Eazy E" Wright served as executive producer. The album was distributed by Atco Records, a division of Atlantic Records.

Track listing

Pop side #Supersonic #Way Out #Blame It On The Muzick #In The Mix #Eenie Meenie Beats Hip-hop side #My Dope Intro #Let's Get Hyped #Now Really #Time Tah Get Stupid #Is It Love

Speed of sound

:This page is about the physical constant that describe the speed of sound waves in a medium. For Coldplay single of their album, X&Y, see Speed of Sound (single). The speed of sound c (from Latin celeritas, "velocity") varies depending on the medium through which the sound waves pass. It is usually quoted in describing properties of substances (e.g. see the article on sodium). More commonly the term refers to the speed of sound in air. The speed varies depending on atmospheric conditions; the most important factor is the temperature. The humidity has very little effect on the speed of sound, while the static sound pressure (air pressure) has none. Sound travels slower with an increased altitude (elevation if you are on solid earth), primarily as a result of temperature and humidity changes. An approximate speed (in metres per second) can be calculated from: :

c_ = (3315 + (06 \cdot \theta)) \ \mathrm\,

where

\theta\,

(theta) is the temperature in degrees Celsius. A more accurate expression is :

c = \sqrt

where
- R (287.05 J/(kg·K) for air) is the universal gas constant (In this case, the gas constant R, which normally has units of J/(mol·K), is divided by the molar mass of air, as is common practice in aerodynamics)
- κ (kappa) is the adiabatic index (1.402 for air), sometimes noted γ
- T is the absolute temperature in kelvins. In the standard atmosphere: T₀ is 273.15 K (= 0 °C = 32 °F), giving a value of 331.5 m/s (= 1087.6 ft/s = 1193 km/h = 741.5 mph = 643.9 knots).
T₂₀ is 293.15 K (= 20 °C = 68 °F), giving a value of 343.4 m/s (= 1126.6 ft/s = 1236 km/h = 768.2 mph = 667.1 knots).
T₂₅ is 298.15 K (= 25 °C = 77 °F), giving a value of 346.3 m/s (= 1136.2 ft/s = 1246 km/h = 774.7 mph = 672.7 knots). In fact, assuming an ideal gas, the speed of sound c depends on temperature only, not on the pressure. Air is almost an ideal gas. The temperature of the air varies with altitude, giving the following variations in the speed of sound using the standard atmosphere - actual conditions may vary. In a Non-Dispersive Medium – Sound speed is independent of frequency, therefore the speed of energy transport and sound propagation are the same. Air is a non-dispersive medium.
In a Dispersive Medium – Sound speed is a function of frequency. The spatial and temporal distribution of a propagating disturbance will continually change. Each frequency component propagates at each its own phase speed, while the energy of the disturbance propagates at the group velocity. Water is an example of a dispersive medium. In general, the speed of sound c is given by :

c = \sqrt

where :C is a coefficient of stiffness :

\rho

is the density Thus the speed of sound increases with the stiffness of the material, and decreases with the density. In a fluid the only non-zero stiffness is to volumetric deformation (a fluid does not sustain shear forces). Hence the speed of sound in a fluid is given by :

c = \sqrt

where :K is the adiabatic bulk modulus For a gas, K is approximately given by :

K=\kappa \cdot p

where :κ is the adiabatic index, sometimes called γ. :p is the pressure. Thus, for a gas the speed of sound can be calculated using: :

c = \sqrt

which using the ideal gas law is identical to:

c = \sqrt

(Newton famously considered the speed of sound before most of the development of thermodynamics and so incorrectly used isothermal calculations instead of adiabatic. His result was missing the factor of κ but was otherwise correct.) In a solid, there is a non-zero stiffness both for volumetric and shear deformations. Hence, in a solid it is possible to generate sound waves with different velocities dependent on the deformation mode. In a solid rod (with thickness much smaller than the wavelength) the speed of sound is given by: :

c = \sqrt

where :E is Young's modulus :

\rho

(rho) is density Thus in steel the speed of sound is approximately 5100 m/s.
In a solid with lateral dimensions much larger than the wavelength, the sound velocity is higher. It is found be replacing Young's modulus with the plane wave modulus, which can be expressed in terms of the Young's modulus and Poisson's ratio as: :

M = E \frac

For air, see density of air. The speed of sound in water is of interest to those mapping the ocean floor. In saltwater, sound travels at about 1500 m/s and in freshwater 1435 m/s. These speeds vary due to pressure, depth, temperature, salinity and other factors. For general equations of state, if classical mechanics is used, the speed of sound

c

is given by :

c^2=\frac

where differentiation is taken with respect to adiabatic change. If relativistic effects are important, the speed of sound

S

is given by: :

S^2=c^2 \left. \frac \right|_

(Note that

e= \rho (c^2+e^C) \,

is the relativisic internal energy density; see relativistic Euler equations). This formula differs from the classical case in that

\rho

has been replaced by

e/c^2 \,

Table - Speed of sound in air c, density of air ρ and acoustic impedance Z vs. temperature °C

Mach number is the ratio of the object's speed to the speed of sound in air (medium).

Sound in solids

In solids, the velocity of sound depends on density of the material, not its temperature. Solid materials, such as steel, conduct sound much faster than air.

External links

- [http://www.sengpielaudio.com/calculator-speedsound.htm Calculation: Speed of sound in air and the temperature]
- [http://www.sengpielaudio.com/SpeedOfSoundPressure.pdf The speed of sound, the temperature, and ... not the air pressure]
- [http://www.pdas.com/atmos.htm Properties Of The U.S. Standard Atmosphere 1976] Category:Chemical properties Category:Fluid dynamics Category:Acoustics Category:Units of velocity ko:음속 ja:音速

Metre per second

Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. The symbol is m/s, or equivalently, m s^-1.

Conversions

1 metre per second is equivalent to:
- 3.2808 feet per second
- 2.2369 miles per hour
- 3.6 km/h

Feet per second

Feet per second is a unit of speed; it expressses the number of feet traveled in one second. Abbreviations include ft/s, ft/sec, etc. Category:Units of velocity

Kilometre per hour

]] Kilometre per hour (American spelling: kilometer per hour) is a unit of both speed (scalar) and velocity (vector). The symbol is km/h or km·h⁻¹. It is often spoken and sometimes written as klicks or kays in slang usage. By definition, an object travelling at a speed of 1 km/h for an hour would move 1 kilometre.

Conversions

- 3.6 km/h ≡ 1 m·s⁻¹, the SI derived unit of speed, metre per second
- 1 km/h ≈ 0.27778 m/s
- 1 km/h ≈ 0.62137 mph ≈ 0.91134 feet per second

External links

- [http://www.ex.ac.uk/trol/scol/ccspeed.htm Conversion Calculator for Units of SPEED] Category:Units of velocity ja:キロメートル毎時

Hypersonic

:This article is about hypersonic speeds in aerodynamics. For hypersonic sound, see HyperSonic Sound. For the laptop brand, see Hypersonic (laptop). For the video game character, see Hyper Sonic. In aerodynamics, hypersonic speeds are speeds that are highly supersonic. In the 1970s the term generally came to refer to speeds of Mach 5 and above.

Hypersonic regime

Supersonic airflow is decidedly different than subsonic flow. Practically everything about the way an aircraft flies changes dramatically as an aircraft accelerates to supersonic speeds. Even with this strong demarcation, there is still some debate as to the definition of "supersonic". One definition is that the aircraft, as a whole, is travelling at Mach 1 or greater. More technical definitions state that you are only supersonic if the airflow over the entire aircraft is supersonic, which occurs around Mach 1.2 on typical designs. From Mach 0.8-1.2 is therefore considered transonic. Considering the problems with this simple definition, it should be no surprise that a definition of hypersonic would be even more difficult, considering that there is no physical change in airflow that makes it "hyper." Some phenomena, such as increasing temperature and the formation of a shock layer, begin to affect vehicle design at about Mach 3. Others, such as chemically reacting flow, don't begin to have a significant effect until about Mach 7 or more. Generally these effects become important "as a whole" around Mach 5. The hypersonic regime is often defined as speeds where ramjets do not produce net thrust. This is a nebulous definition in itself, as there exists a proposed change to allow them to operate in the hypersonic regime (the Scramjet).

External links

- [http://hapb-www.larc.nasa.gov/Public/Projects/national_hypersonics_plan.html NASA website for National Hypersonics Plan]
- [http://www.mech.uq.edu.au/hyper/ University of Queensland Centre for Hypersonics] Category:Spacecraft propulsion Category:Aerospace engineering

Molecular mass

The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). The molecular mass can be calculated as the sum of the atomic masses of all the atoms of any one molecule. The molecular mass can also be measured directly using mass spectrometry. In mass spectrometry, the molecular mass of a small molecule (< ~200 atoms of a given element) is exact, that is, the sum of the most common isotopes of each element. Of larger molecules, it is average, or calculated using the elemental mass number or the periodic table, since there is likely to be a statistical distribution of atoms representing the isotopes throughout the molecule. The molar mass of a substance is numerically equal to the molecular mass, but expressed in mass units per mole, usually as g/mol (grams per mole). : Example: : The atomic mass of hydrogen is 1.00784 u and that of oxygen is 15.9994 u; therefore, the molecular mass of water with formula H₂O is (2 × 1.00784 u) + 15.9994 u = 18.01508 u. Therefore, one mole of water weighs 18.01508 grams. However, the exact mass of hydrogen-1 (the most common isotope) is 1.00783, and the exact mass of oxygen-16 (the most common isotope) is 15.9949, so the mass of the most common single molecule of water is 18.0105 u. Molecular mass or molar mass are used in stoichiometry calculations. Since molecules are created by chemical reactions, not nuclear reactions, a molecule's molecular mass exactly equals the sum of the atomic masses of its constituent atoms. The gram-molecular weight is the molecular weight of a chemical compound expressed in grams. Thus the molecular weight of calcium carbonate is 100 therefore the gram-molecular weight is 100 g. The Gram Molecular Weight is frequently used, particularly for calculating the concentration of solutions. Thus a molar solution will contain the gram molecular weight of a chemical dissolved to produce one litre of solution.

Molecular mass in polymer Chemistry

In polymer chemistry, due to the varying chain lengths between the polymer macromolecules, various types of molecular mass are used to quantify the molar mass distribution.

External links

- [http://www.vias.org/simulations/simusoft_molform.html Learning by Simulations] Calculation of Molecular Formulas from Molecular Masses Category:Mass Category:Chemical properties ja:分子量

Pressure

:For the psychological or political context, see Peer pressure. Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. Mathematically: :

p = F/A\,

where p is the pressure, F is the normal force, and A is the area. Pressure is transmitted to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point. It is a fundamental parameter in thermodynamics and it is conjugate to volume. A closely related quantity is the stress tensor σ which relates the vector force F to the vector area A via :

\mathbf=\mathbf

This tensor may be divided up into a scalar part (pressure) and a traceless tensor part shear. The shear tensor gives the force in directions parallel to the surface, usually due to viscous or frictional forces. The stress tensor is sometimes called the pressure tensor, but in the following, the term "pressure" will refer only to the scalar pressure. shear

Example

As an example of varying pressures, a finger can be pressed against a wall without making any lasting impression; however, the same finger pushing a thumbtack can easily damage the wall. Although the force applied to the surface is the same, the thumbtack applies more pressure because the point concentrates that force into a smaller area. Pressure is transmitted to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point. Unlike stress, pressure is defined as a scalar quantity. The gradient of pressure is force density. In the human body, baroreceptors monitor blood pressure.

Relative or gauge pressure

For gases, pressure is sometimes measured, not as an absolute pressure, but relative to atmospheric pressure; such measurements are sometimes called gauge pressure. An example of this is the air pressure in a car tire, which might be said to be "220 kPa," but is actually 220 kPa above atmospheric pressure. Since atmospheric pressure at sea level is about 100 kPa, the absolute pressure in the tire is therefore about 320 kPa. In technical work, this is written "a gauge pressure of 220 kPa." Where space is limited, such as on gauges, name plates, graph labels, and table headings, the use of a modifier in parentheses, such as "kPa (gauge)" or "kPa (absolute)," is permitted. In non-SI technical work, a gauge pressure is sometimes written as "32 psig," though the other methods explained above that avoid attaching characters to the unit of pressure are preferred [http://physics.nist.gov/Pubs/SP811/sec07.html#7.4 ¹].

Scalar nature of pressure

In static gas, the gas as a whole does not appear to move, the individual molecules of the gas, which we cannot see, are in constant random motion. Because we are dealing with an extremely large number of molecules and because the motion of the individual molecules is random in every direction, we do not detect any motion. If we enclose the gas within a container, we detect a pressure in the gas from the molecules colliding with the walls of our container. We can put the walls of our container anywhere inside the gas, and the force per unit area (the pressure) is the same. We can shrink the size of our "container" down to an infinitely small point, and the pressure has a single value at that point. Therefore, pressure is a scalar quantity, not a vector quantity. It has a magnitude but no direction associated with it. Pressure acts in all directions at a point inside a gas. At the surface of a gas, the pressure force acts perpendicular to the surface.

Hydrostatic pressure

Hydrostatic pressure is the pressure due to the weight of a fluid. :p = ρgh where ρ (rho) is density of the fluid, g is acceleration due to gravity, and h is height of the fluid above the point being measured. See also Pascal's law.

Stagnation pressure

Stagnation pressure is the pressure a fluid exerts when it is forced to stop moving. Consequently, although a fluid moving at higher speed will have a lower static pressure, it may have a higher stagnation pressure when forced to a standstill. Static pressure and stagnation pressure are related by the Mach number of the fluid. In addition, there can be differences in pressure due to differences in the elevation (height) of the fluid. See Bernoulli's equation. The pressure of a moving fluid can be measured using a Pitot probe, or one of its variations such as a Kiel probe or Cobra probe, connected to a manometer. Depending on where the inlet holes are located on the probe, it can measure static pressure or stagnation pressure.

Units

The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N·m^-2 or kg·m^-1·s^-2). This special name for the unit was added in 1971; before that, pressure in SI was expressed in units such as N/m². Non-SI measures (still in use in some parts of the world) include the pound-force per square inch (psi) and the bar. The cgs unit of pressure is the barye (ba). It is equal to 1 dyn·cm^-2. Pressure is still sometimes expressed in kgf/cm² or grams-force/cm² (sometimes as kg/cm² and g/cm² without properly identifying the force units). But using the names kilogram, gram, kilogram-force, or gram-force (or their symbols) as a unit of force is expressly forbidden in SI; the unit of force in SI is the newton (N). The technical atmosphere (symbol: at) is 1 kgf/cm². Some meteorologists prefer the hectopascal (hPa) for atmospheric air pressure, which is equivalent to the older unit millibar (mbar). Similar pressures are given in kilopascals (kPa) in practically all other fields, where the hecto prefix is hardly ever used. In Canadian weather reports, the normal unit is kPa. The obsolete unit inch of mercury (inHg) is still sometimes used in the United States. Blood pressure is still measured in millimetres of mercury in most of the world, and lung pressures in centimeters of water are still common. These obsolete manometric units of pressure are based on the pressure exerted by the weight of some "standard" fluid under some "standard" gravity. They are effectively attempts to define a unit for expressing the readings of a manometer. When millimetres or inches of mercury are used today, they have precise definitions that can be expressed in terms of SI units. The water-based units depend on the density of water, a measured, rather than defined, quantity. The standard atmosphere (atm) is an established constant. It is approximately equal to typical air pressure at earth mean sea level and is defined as follows. :standard atmosphere = 101325 Pa = 101.325 kPa = 1013.25 hPa. A rule of thumb commonly used by scuba divers is that one atmosphere is approximately equal to the pressure exerted by ten metres of water. Non-SI units presently or formerly in use include the following.
- atmosphere.
- manometric units:
- centimetre, inch, and millimetre of mercury (Torr).
- millimetre, centimetre, metre, inch, and foot of water.
- imperial units:
- kip, ton-force (short), ton-force (long), pound-force, ounce-force, and poundal per square inch.
- pound-force, ton-force (short), and ton-force (long) per square foot.
- non-SI metric units:
- bar, millibar.
- kilogram-force, or kilopond, per square centimetre (technical atmosphere).
- gram-force and tonne-force (metric ton-force) per square centimetre.
- barye (dyne per square centimetre).
- kilogram-force and tonne-force per square metre.
- sthene per square metre (pieze).

External links

- [http://calc.skyrocket.de/en/ Online unit converter] - conversion of many different units.
- [http://avc.comm.nsdlib.org/cgi-bin/wiki_grade_interface.pl?An_Exercise_In_Air_Pressure An exercise in air pressure]
- [http://www.grc.nasa.gov/WWW/K-12/airplane/pressure.html Pressure being a scalar quantity] Category:Diving Category:Meteorology Category:Physical quantity Category:Thermodynamics ko:압력 ms:Tekanan ja:圧力

Mach number

Mach number (Ma) (pronounced "mack" in British English and "mock" in American English) is defined as a ratio of speed to the speed of sound in the medium in case. The Mach number is commonly used both with objects travelling at high speed in a fluid, and with high-speed fluid flows inside channels such as nozzles, diffusers or wind tunnels. As it is defined as a ratio of two speeds, it is a dimensionless number. At standard sea level conditions, Mach 1 is 1,225 km/h (761.2 MPH) in the atmosphere. Since the speed of sound increases as the temperature increases, the actual speed of an object travelling at Mach 1 will depend on the fluid temperature around it. It can be shown that the Mach number is also the ratio of inertial forces (also referred to aerodynamic forces) to elastic forces. The Mach number is named after Austrian physicist and philosopher Ernst Mach.

High-speed flow around objects

High speed flight can be classified in five categories:
- Subsonic: Ma < 1
- Sonic: Ma = 1
- Transsonic: 1 < Ma < 1.2
- Supersonic: 1.2 < Ma < 5
- Hypersonic: Ma > 5 (For comparison: the required speed for low Earth orbit is ca. 7.5 km/s = Ma 22.06 in air at sea level) At transsonic speeds, the flow field around the object includes both sub- and supersonic parts. The transsonic regime begins when first zones of Ma>1 flow appear around the object. In case of an airfoil (such as an aircraft's wing), this typically happens above the wing. Supersonic flow can decelerate back to subsonic only in a normal shock; this typically happens before the trailing edge. (Fig.1a) As the velocity increases, the zone of Ma>1 flow increases towards both leading and trailing edges. As Ma=1 is reached and passed, the normal shock reaches the trailing edge and becomes a weak oblique shock: the flow decelerates over the shock, but remains supersonic. A normal shock is created ahead of the object, and the only subsonic zone in the flow field is a small area around the object's leading edge. (Fig.1b) Fig. 1. Mach number in transsonic airflow around an airfoil; Ma<1 (a) and Ma>1 (b). When an aircraft exceeds Mach 1 (i.e. the sound barrier) a large pressure difference is created just in front of the aircraft. This abrupt pressure difference, called a shock wave, spreads backward and outward from the aircraft in a cone shape (a so-called Mach cone). It is this shock wave that causes the sonic boom heard as fast moving aircraft travels overhead. A person inside the aircraft will not hear this. The higher the speed, the more narrow the cone; at just over Ma=1 it is hardly a cone at all, but closer to a slighly concave plane. At fully supersonic velocity the shock wave starts to take its cone shape, and flow is either completely supersonic, or (in case of a blunt object), only a very small subsonic flow area remains between the object's nose and the shock wave it creates ahead of itself. (In the case of a sharp object, there is no air between the nose and the shock wave: the shock wave starts from the nose.) As the Mach number increases, so does the strength of the shock wave and the Mach cone becomes increasingly narrow. As the fluid flow crosses the shock wave, its speed is reduced and temperature, pressure, and density increase. The stronger the shock, the greater the changes. At high enough Mach numbers the temperature increases so much over the shock that ionization and dissociation of gas molecules behind the shock wave begin. Such flows are called hypersonic. It is clear that any object travelling at hypersonic velocities will likewise be exposed to the same extreme temperatures as the gas behind the nose shock wave, and hence choice of heat-resistant materials becomes important.

High-speed flow in a channel

As a flow in a channel crosses Ma=1 becomes supersonic, one significant change takes place. Common sense would lead one to expect that contracting the flow channel would increase the flow speed and at subsonic speeds this holds true. However, once the flow becomes supersonic, the relationship of flow area and speed is reversed: expanding the channel actually increases the speed. The obvious result is that in order to accelerate a flow to supersonic, one needs a convergent-divergent nozzle, where the converging section accelerates the flow to Ma=1, and the diverging section continues the acceleration to supersonic. Such nozzles are called De Laval nozzles. Category:Fluid dynamics Category:Dimensionless numbers ja:マッハ数

External links

- [http://www-rcf.usc.edu/~alexeenk/GDT/index.html Gas Dynamics Toolbox] Calculate Mach number and normal shock wave parameters for mixtures of perfect and imperfect gases.

Room temperature

Room temperature, in laboratory reports, is taken to be roughly 21–23 degrees Celsius (72 degrees Fahrenheit), or 294–296 kelvins. In describing an experiment, when researchers specify its temperature no more precisely than as "room temperature," this implies they have assumed that temperature differences of a few degrees do not matter to the phenomenon or question they were investigating. Typically researchers do not closely watch or control the temperature of a "room temperature" experiment. The phenomena that researchers have chosen to study at room temperature may occur in nature in the range of 21–23 °C ("ATP consumption in resting cockroaches"), or they may not ("biochemistry of warm-blooded animals"). Researchers choose to study a process outside its natural temperature range when they expect that the answer to their specific question ("What is the product of this enzymatic reaction?") will be the same at room temperature as it would have been had they conducted their experiment at a more naturalistic temperature. Experimentalists have an advantage in anticipating aspects of a room-temperature experiment, because the temperature is close to 25 °C (77 °F, 298 K), at which many of the material properties and physical constants in standards tables have been measured (more at standard state). By consulting such tables, a researcher may anticipate, for example, how fast a chemical reaction is likely to proceed. Ultimately, a scientist conducts experiments at room temperature because it is convenient. The convenience may be only modest, as in cases where researchers might have performed a more realistic experiment simply by placing some material in an oven or refrigerator. Or it may be more like a necessity, as in cases where maintaining a firm control over the temperature of apparatus and the other elements involved would pose significant conceptual, technological or financial challenges. When researchers have chosen either not to measure or not to control the temperature of an experiment; when they perform their experiment outdoors, or in a room where they perceive that the temperature varies either in time or in the space around an experiment; or when they simply sense that the temperature is beyond the range of 21-23 °C, they are liable to report that they conducted it at ambient temperature. Whether they do so may depend on whether they believe the process or question they are investigating could be sensitive to the size of the deviations from room temperature they expect. Being a less precise specification than even "room temperature", "ambient temperature" is more certain to be accurate. Because scientists strive for accuracy in their reports, many use this specification exclusively just as a matter of course, even to describe experiments that they could justifiably characterize as having been conducted at room temperature. Arguably, no precision is lost in this practice: In disciplines where experimenters always work in laboratories, and where temperature differences of a few degrees make little difference with regard to the questions that scientists ask, the distinction between ambient and room temperature literally is not worth making. And, of course, the ambient temperature of a room is room temperature. Yet small temperature differences have large effects on many natural processes. Therefore scientists who do observe a distinction between the two specifications may be sticklers about which one to apply. For example, heat given off by electronics or motors may warm the area around an experiment relative to the rest of a room. Under such circumstances, and depending on the question under investigation, some scientists would consider it inaccurate to report that an experiment took place at room temperature. The concept of room temperature is disputed by well-known entertainment lawyer Maura Wogan, who claims it is only an undefined idea. She handles high-profile cases.

Supersonic fracture

Supersonic fractures are fractures faster than the speed of sound in a material. Category:Materials science

Markus J. Buehler

Markus J. Buehler, German material scientist working in the area of multi-scale modeling of deformation and fracture of materials.

External links

- [http://www.wag.caltech.edu/home/mbuehler/ Markus J. Buehler] website at Cal Tech.

Farid F. Abraham

Abraham earned his Bachelor of Science and Ph.D from the University of Arizona in 1959 and 1962, respectively. By pioneering new methods of using computer modelling in research, he has made seminal contributions to science in the fields of fracture mechanics, membrane dynamics and phase transformation behavior of matter. He has authored three textbooks and over 200 papers published in international journals, including three cover articles in Science.

Bibliography

- Abraham, Farid. F. et al. (2003) "How fast can cracks move? A research adventure in materials failure using millions of atoms and big computers". Advances In Physics. 52, 727
- Abraham, Farid F. et al. (2002) "Simulating materials failure by using up to one billion atoms and the world’s fastest computer". Proceedings of the National Academy of Science. 99, 5777.
- Abraham, Farid F. et al. (2000) "Dynamically spanning the length scales from the quantum to the continuum". International Journal of Modern Physics. C11 (6), 1135
- Abraham, Farid F. et al. (1998) "Spanning the length scales in dynamic simulation". Computers In Physics. 12, 538
- Abraham, Farid F. (1997) "[http://portal.acm.org/citation.cfm?id=615498&coll=GUIDE&dl=GUIDE&CFID=50325015&CFTOKEN=90477135 Portrait of a Crack: Rapid Fracture Mechanics Using Parallel Molecular Dynamics]. IEEE Computational Science & Engineering. 4, 2.
- Abraham, Farid F. and Karkar, M. (1991) "Folding and unbinding transitions in tethered membranes." Science 252, 419
- Abraham, Farid F., and Tiller, William A. (1972) An Introduction to Computer Simulation in Applied Science. New York: Plenum Press. ISBN 0306305798

External links

- [http://www-cms.llnl.gov/bios/abraham_f.html Lawrence Livermore biography]
- [http://www.avh.de/automat_db/pub_laudatio.show_laudatio?p_humboldt_id=1074663 Profile]

Concorde

The Aérospatiale-BAC Concorde supersonic transport (SST) was one of only two models of supersonic passenger airliners to have seen commercial service. Concorde had a cruise speed of Mach 2.02 and a maximum cruise altitude of 60,000 feet (18,288 metres) with a delta wing configuration and an evolution of the reheat-equipped engines originally developed for the Avro Vulcan strategic bomber. It was the first civil airliner to be equipped with an analogue fly-by-wire flight control system. Commercial flights, operated by British Airways and Air France, began on January 21 1976 and ended on October 24 2003, with the last "retirement" flight on November 26 that year. November 26

Origins

November 26.]] In the late 1950s the British, French, Americans and Soviets were all interested in developing supersonic transport. Britain's Bristol Aeroplane Company and France's Sud Aviation were both working on designs, called the Type 233 and Super-Caravelle respectively. Both were largely funded by their respective governments as a way of gaining some foothold in the aircraft market that was until then dominated by the United States. The designs were both ready to start into prototype construction in the early 1960s, but the cost was so great that the companies (and governments) decided to join forces. The development project was negotiated as an international treaty between Britain and France rather than a commercial agreement between companies. This included a clause, originally asked for by Britain, on penalties for cancellation (it turned out that Britain was the country that tried to get out). A draft treaty was signed on November 28 1962. By this time both companies had been merged into new ones, and the Concorde project was thus a part of the British Aircraft Corporation and Aerospatiale. The consortium secured orders for over 100 new airliners from the leading airlines of the time. Pan Am, BOAC and Air France were the launch customers with six Concordes each. Some of the airlines in the order book included: Japan Airlines, Lufthansa, American Airlines, United Airlines, Air Canada, Braniff, Iran Air, Qantas, CAAC, Middle East Airlines and TWA . The aircraft was initially referred to in Britain as "Concord". In 1967 the British Government announced that it would change the spelling to "Concorde" to match the French. This created an uproar but it died down after a government minister stated that the suffixed "e" represented "Excellence, England, Europe and Entente (Cordiale)". Concorde 001 took off for the first test flight from Toulouse on March 2 1969 and the first supersonic flight followed on October 1. As the flight programme of the first development aircraft progressed, 001 started off on a sales and demonstration tour beginning on September 4 1971. Concorde 002 followed suit in June 2 1972 with a sales tour of the Middle and Far East. Concorde 002 made the first visit to the United States in 1973, landing at the new Dallas/Fort Worth International Airport to commemorate its opening. These trips led to an influx of orders for over 70 aircraft. However, a combination of factors caused a sudden cascade of order cancellations, including the 1970s oil crisis, acute financial difficulties of the partner airlines, a spectacular crash of the competing Soviet Tupolev Tu-144, and environmental issues such as sonic boom noise and pollution. Air France and British Airways ended up as the only buyers. The aircraft and parts were later sold to them for the nominal price of one British pound apiece; however, the governments continued to take a cut of any profits made. The United States had cancelled its supersonic (SST) program in 1971. Two designs had originally been submitted; the Lockheed L-2000, looking like a scaled-up Concorde, lost out to the Boeing 2707, which had originally been intended to be faster, carry 300 passengers, and feature a swing-wing design. It was suggested in France and the United Kingdom that part of the American opposition to Concorde on grounds of noise pollution was in fact orchestrated or at least encouraged by the United States Government out of spite at not being able to propose a viable competitor. However, other countries, such as Malaysia, also ruled out Concorde supersonic overflights due to noise issues. Both European airlines operated demonstration and test flights to various destinations from 1974 onwards. The testing of Concorde set records which are still not surpassed; it undertook 5,335 flight hours in the prototype, preproduction, and first production aircrafts alone. A total of 2,000 test hours were supersonic. This equates to approximately four times as many as for similarly sized subsonic commercial aircraft.

Technological features

1974 Many features common in the early 21st century airliners were first used in Concorde. For speed optimization:
- double-delta (ogive) shaped wings
- afterburning Rolls-Royce/Snecma Olympus turbojets with supercruise capability
- thrust-by-wire engines, ancestor of today's FADEC controlled engines
- droop-nose section for good landing visibility For weight-saving and enhanced performance:
- Mach 2.04 'sweet spot' for optimum fuel consumption (supersonic drag minimum, whilst jet engines are more efficient at high speed)
- mostly aluminium construction for low weight and relatively conventional build
- full-regime autopilot and autothrottle allowing "hands off" control of the aircraft from climb out to landing
- fully electrically-controlled analog fly-by-wire flight controls systems
- multifunction flight control surfaces
- high-pressure hydraulic system of 28 MPa (4,000 lbf/in²) for lighter hydraulic systems components
- fully electrically controlled analog brake-by-wire system
- pitch trim by shifting fuel around the fuselage for centre-of-gravity control
- parts milled from single alloy billet reducing the part number count Experience in making Concorde later became the basis of the Airbus consortium, and many of these features are now standard equipment in Airbus airliners. Snecma Moteurs, for example, got its first entry into civil engines here. Experience with Concorde opened the way for it to establish the CFM International with GE producing the successful CFM International CFM56 series engines. Although Concorde was a technological marvel when introduced into service in the early 1970s, thirty years later its cockpit cluttered with analogue dials and switches looks very dated. With no competition in either type or airline service, there was no commercial pressure to upgrade Concorde with new avionics or passenger comforts, as occurred with other airliners of the same vintage. The primary partners, BAC (later to become BAE Systems) and Aerospatiale (later to become EADS), are the joint owners of Concorde's type certificate. Responsibility for the Type Certificate transferred to Airbus with formation of Airbus SAS.

Scheduled flights

Airbus Scheduled flights started on January 21, 1976 on the London-Bahrain and Paris-Rio routes. The U.S. Congress had just banned Concorde landings in the US, mainly due to citizen protest over sonic booms, preventing launch on the coveted transatlantic routes. When the US ban was lifted in February for over-water supersonic flight, New York quickly followed by banning Concorde locally. Left with little choice on the destination, AF and BA started transatlantic services to Washington, D.C. on May 24. Finally, in late 1977, the noise concerns of New York residents gave way to the advantages of Concorde traffic, and