Speed of light

The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its precise value is 7008299792458000000♠299792458 metres per second (approximately 7008300000000000000♠3.00×10⁸ m/s), since the length of the metre is defined from this constant and the international standard for time. According to special relativity, c is the maximum speed at which all matter and information in the universe can travel. It is the speed at which all massless particles and changes of the associated fields (including electromagnetic radiation such as light and gravitational waves) travel in vacuum. Such particles and waves travel at c regardless of the motion of the source or the inertial reference frame of the observer. In the theory of relativity, c interrelates space and time, and also appears in the famous equation of mass–energy equivalence E = mc².

The speed at which light propagates through transparent materials, such as glass or air, is less than c; similarly, the speed of radio waves in wire cables is slower than c. The ratio between c and the speed v at which light travels in a material is called the refractive index n of the material (n = c / v). For example, for visible light the refractive index of glass is typically around 1.5, meaning that light in glass travels at c / 1.5 ≈ 7008200000000000000♠200000 km/s; the refractive index of air for visible light is about 1.0003, so the speed of light in air is about 7008299700000000000♠299700 km/s (about 7004900000000000000♠90 km/s slower than c).

Iron Maiden

Iron Maiden are an English heavy metal band formed in Leyton, east London, in 1975 by bassist and primary songwriter Steve Harris. The band's discography has grown to thirty-eight albums, including sixteen studio albums, eleven live albums, four EPs, and seven compilations.

Pioneers of the New Wave of British Heavy Metal, Iron Maiden achieved initial success during the early 1980s. After several line-up changes, the band went on to release a series of UK and US platinum and gold albums, including 1982's The Number of the Beast, 1983's Piece of Mind, 1984's Powerslave, 1985's live release Live After Death, 1986's Somewhere in Time and 1988's Seventh Son of a Seventh Son. Since the return of lead vocalist Bruce Dickinson and guitarist Adrian Smith in 1999, the band have undergone a resurgence in popularity, with their 2010 studio offering, The Final Frontier, peaking at No. 1 in 28 different countries and receiving widespread critical acclaim. Their sixteenth studio album, The Book of Souls, was released on 4 September 2015.

Doctor Who

Doctor Who is a British science-fiction television programme produced by the BBC from 1963 to the present day. The programme depicts the adventures of the Doctor, a Time Lord—a space and time-travelling humanoid alien. He explores the universe in his TARDIS, a sentient time-travelling space ship. Its exterior appears as a blue British police box, which was a common sight in Britain in 1963 when the series first aired. Accompanied by companions, the Doctor combats a variety of foes, while working to save civilisations and help people in need.

The show is a significant part of British popular culture, and elsewhere it has become a cult television favourite. The show has influenced generations of British television professionals, many of whom grew up watching the series. The programme originally ran from 1963 to 1989. There was an unsuccessful attempt to revive regular production in 1996 with a backdoor pilot, in the form of a television film. The programme was relaunched in 2005 by Russell T Davies, who was showrunner and head writer for the first five years of its revival, produced in-house by BBC Wales in Cardiff. The first series of the 21st century featured Christopher Eccleston in the title role and was produced by the BBC. Series two and three had some development money contributed by the Canadian Broadcasting Corporation (CBC), which was credited as a co-producer.Doctor Who also spawned spin-offs in multiple media, including Torchwood (2006–2011) and The Sarah Jane Adventures (2007–2011), both created by Russell T Davies; K-9 (2009–2010); and a single pilot episode of K-9 and Company (1981). There also have been many spoofs and cultural references to the character in other media.

Speed Art Museum

The Speed Art Museum, originally known as the J.B. Speed Memorial Museum, now colloquially referred to as the Speed by locals, is the oldest, largest, and foremost museum of art in Kentucky. It is located in Louisville, Kentucky on Third Street next to the University of Louisville Belknap campus.

The museum offers visitors a variety of "art experiences" outside of its collection and international exhibitions, including the Speed Concert Series, the Art Sparks Interactive Family Gallery, and the popular late-night event, Art After Dark.

The Speed houses ancient, classical, and modern art from around the world. The focus of the collection is Western art, from antiquity to the present day. Holdings of paintings from the Netherlands, French and Italian works, and contemporary art are particularly strong, with sculpture prominent throughout.

With a $50 million expansion and renovation project planned through 2016, The Speed Art Museum is currently closed for construction. The new 62,500-square-foot North Building will double the overall square footage and nearly triple the gallery space from the existing wing. The expansion will create a space for larger special exhibitions, new contemporary art galleries, a family education welcome center, 150-seat theater, indoor/outdoor café, museum shop, and a multifunctional pavilion for performances, lectures and entertaining. Additionally, the new Elizabeth P. and Frederick K. Cressman Art Park and public Piazza will be created for the display of sculpture. During the closure, the Museum has opened Local Speed, a satellite space in Louisville's East Market District (NuLu) for rotating exhibitions, programs and events. Local Speed is located at 822 East Market Street. The museum plans to reopen on March 12, 2015.

Special relativity

In physics, special relativity (SR, also known as the special theory of relativity or STR) is the generally accepted and experimentally well confirmed physical theory regarding the relationship between space and time. In Einstein's original pedagogical treatment, it is based on two postulates:

It was originally proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies". The inconsistency of Newtonian mechanics with Maxwell’s equations of electromagnetism and the lack of experimental confirmation for a hypothesized luminiferous aether led to the development of special relativity, which corrects mechanics to handle situations involving motions nearing the speed of light. As of today, special relativity is the most accurate model of motion at any speed. Even so, the Newtonian mechanics model is still useful (due to its simplicity and high accuracy) as an approximation at small velocities relative to the speed of light.