Operation Sigma Sigma
The Sigma is an experimental glider developed in Britain from 1966 by a team led by Nicholas Goodhart. After disappointing performance during flight testing the Sigma was passed on to a Canadian group which carried out modifications, making the Sigma more competitive.
Design and development
Designed to compete in the 1970 World Championships, the team aimed to develop a wing that would climb well through a high lift coefficient and a large wing area, but equally had the "maximum possible reduction of area for cruise at low lift coefficients". At the same time for the minimum possible drag they aimed for "extensive" laminar flow. To achieve this they employed flaps that would alter both wing area and wing camber. Based on analysis of the nature of thermals encountered in cross-country flying, they reasoned that by having a slow turning circle, their sailplane could stay close to the central (and strongest) part of the thermal and gain maximum benefit.
Its unusual feature is its ability to vary its wing area using Fowler flaps. It had been tried before by the Hannover Akaflieg in 1938 with their AFH-4, the South African Beatty-Johl BJ-2 Assegai and the SZD Zefir gliders.
Sigma (cosmology)
Sigma in cosmology was a property of galaxies used when trying to work out the mystery of galaxies and their supermassive black holes.
History
In the late 1990s the NUKER experts had made observations with a spectroscope of two galaxies, one of an active galaxy with an active galactic nucleus called NGC10-68 and a dormant galaxy next door to us named Andromeda.
The observations are shown. The light from the centre in Andromeda galaxy was distorted proving the existence of super-massive black holes.
Other observations proved most galaxies had a similar centre whether it be active or dormant.
They then realised that the black holes must have something to do with a galaxy's formation, so they turned to something they thought was useless: the speed of the stars around the edge of the galaxy. This was Sigma, the speed of the stars at the edge of the galaxy supposedly unaffected by the mass of the black hole at the centre.
Usage In Cosmology
The NUKER team calculated the sigma of several stars in different galaxies and the mass of the black hole at the (nucleus) centre. They expected no correlation what so ever. But when plotting their results on a Scatter diagram and drawing a line of best fit they ended up with a positive correlation. It appeared that the heavier the black hole at the centre was the faster the stars within the galaxy travelled.
Sigma (duo)
Sigma is an English drum and bass duo consisting of Cameron Edwards and Joe Lenzie. They met at Leeds University at drum and bass nights. Their 2010 collaboration with DJ Fresh, "Lassitude", peaked at number 98 on the UK Singles Chart. Their single "Nobody to Love" topped the UK Singles Chart, becoming their first UK number one. Follow-up single "Changing", featuring Paloma Faith, also got to number one.
Career
Formation
Lenzie and Edwards met in 2006 at Leeds University; Cameron was working in local record store Tribe Records and with Echo Location's Obi running local night Event Horizon, while Lenzie was DJing hip-hop and warming up Event Horizon for such acts as Rahzel and Grandmaster Flash. Once they had finished in Leeds, they relocated to London and became a three-piece with Edwards' school friend Ben Mauerhoff, being signed under DJ Fresh's Breakbeat Kaos. After a while, long distances took their toll – Edwards and Mauerhoff were based in Surrey, whereas Lenzie was based in Harpenden, Hertfordshire and they couldn't get three people into the Harpenden studio – and Mauerhoff left. In December 2008 they formed their own record label, Life Recordings (so called because, according to Lenzie, the industry demanded that it be their life). Its inaugural release was a VIP mix of their early Bingo Beats single "El Presidente".
Raise
Raise may refer to:
See also
Raise!
Raise! is the eleventh studio album by Earth, Wind & Fire, produced by the band's leader Maurice White for Kalimba Productions, and released in 1981 on CBS Records. Raise! has been certified platinum in the US by the RIAA for sales of over a million copies and gold in the UK and Canada by the British Phonographic Industry and Music Canada respectively.
Raise! was the bestselling R&B album of 1982. The album featured the #1 R&B and # 3 Pop hit "Let's Groove". The single "Wanna Be With You" won EWF a Grammy for Best R&B Vocal Performance By A Duo Or Group. Raise also marked the return to the band of rhythm guitarist Roland Bautista, last heard from on 1972's Last Days and Time.
Raise! would be the final EWF album to be released on ARC. The label would be discontinued by Columbia Records the following year.
Critical reception
Ken Tucker of Rolling Stone describes Raise! as a reflection of "street-gritty black pop" and that on "Let's Groove" and the fast, cutting "Lady Sun", the horn section screams like a car running a red light". Music critic Robert Christgau says that on the album, he felt "a show of strength was due".
Raise (Lake District)
Raise is a fell in the English Lake District. It stands on the main spine of the Helvellyn range in the Eastern Fells, between Thirlmere and Ullswater.
Topography
The Helvellyn range runs broadly north-south for about 7 miles (11 km), remaining above 2,000 ft (600 m) throughout its length. Raise is near the centre of this ridge, with Stybarrow Dodd to the north and White Side to the south. As with many of these fells, Raise displays smooth grassy slopes on the west and rougher ground to the east. Here however the contrast is much less marked than further south around Helvellyn and Nethermost Pike.
Unusually for such a high fell, the slopes of Raise do not have a toehold at valley level on either side. In the west the boundary streams of Sticks Gill (West) and Brund Gill meet just below White Side's Brown Crag. As Fisherplace Gill they descend a further thousand feet to the valley, and originally turned north to join St John's Beck. All of this changed as part of the Thirlmere reservoir scheme in 1894, when a water race was constructed to carry most of the water into the lake. To the east the fell is also squeezed out at height by its neighbours, failing to reach the shore of Ullswater. Raise has a short eastern ridge, Stang, descending between Sticks Gill (East) and Glenridding Beck, but these streams combine above the site of the old Greenside Mine to leave Sheffield Pike and Birkhouse Moor overlooking Glenridding.
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