Quantum tunnelling

Quantum tunnelling or tunneling (see spelling differences) refers to the quantum mechanical phenomenon where a particle tunnels through a barrier that it classically could not surmount. This plays an essential role in several physical phenomena, such as the nuclear fusion that occurs in main sequence stars like the Sun. It has important applications to modern devices such as the tunnel diode,quantum computing, and the scanning tunnelling microscope. The effect was predicted in the early 20th century and its acceptance as a general physical phenomenon came mid-century.

Tunnelling is often explained using the Heisenberg uncertainty principle and the wave–particle duality of matter. Pure quantum mechanical concepts are central to the phenomenon, so quantum tunnelling is one of the novel implications of quantum mechanics.

History

Quantum tunnelling was developed from the study of radioactivity, which was discovered in 1896 by Henri Becquerel. Radioactivity was examined further by Marie Curie and Pierre Curie, for which they earned the Nobel Prize in Physics in 1903.Ernest Rutherford and Egon Schweidler studied its nature, which was later verified empirically by Friedrich Kohlrausch. The idea of the half-life and the impossibility of predicting decay was created from their work.

Tunnel 57

Tunnel 57 was a tunnel under the Berlin Wall, that in October of 1964 was the location of a mass escape by 57 East Berlin citizens. Student and future astronaut Reinhard Furrer was among the West German escape helpers who assisted the East Berliners in escaping. During the escape, East German border guards came upon the scene. A West German escape helper, Christian Zobel, opened fire, the bullet piercing the lung of young East German guard Egon Schultz, who was then also fatally wounded by friendly fire from another guard. A memorial plaque on the site today commemorates both the successful escape, and Schultz's death as a victim of the Berlin Wall.

References

Coordinates: 52°32′10.62″N 13°23′33.79″E / 52.5362833°N 13.3927194°E / 52.5362833; 13.3927194

Smile

A smile is a facial expression formed primarily by flexing the muscles at the sides of the mouth. Some smiles include a contraction of the muscles at the corner of the eyes, an action known as a "Duchenne smile". Smiles performed without the eye contraction can be perceived as "fake".

Among humans, smiling is an expression denoting pleasure, sociability, happiness, or amusement. It is distinct from a similar but usually involuntary expression of anxiety known as a grimace. Although cross-cultural studies have shown that smiling is a means of communication throughout the world, there are large differences between different cultures, with some using smiles to convey confusion or embarrassment.

Historical background

Primatologist Signe Preuschoft traces the smile back over 30 million years of evolution to a "fear grin" stemming from monkeys and apes who often used barely clenched teeth to portray to predators that they were harmless. The smile may have evolved differently among species and especially among humans. Apart from Biology as an academic discipline that interprets the smile, those who study kinesics and psychology such as Freitas-Magalhaes view the smile as an affect display that can communicate feelings such as love, happiness, pride, contempt, and embarrassment.

Smile! (novel)

Smile! is a children's book by Geraldine McCaughrean. In 2004 it won the Nestlé Smarties Book Prize Bronze Award.

References

The Remo Four

The Remo Four were a 1950s-1960s rock band from Liverpool, England. They were contemporaries of The Beatles, and later had the same manager, Brian Epstein. Its members were Colin Manley (born Colin William Manley, 16 April 1942, in Old Swan, Liverpool, Lancashire died 9 April 1999) (lead guitar/vocals), Phil Rogers (rhythm guitar/bass guitar/vocals) (born Philip Rogers, March 1942, in Liverpool), Don Andrew (born Donald Andrew, in 1942, in Liverpool) (bass guitar/vocals), and Roy Dyke (drums) (born 13 February 1945, in Liverpool). Andrew and Manley were in the same class at school (Liverpool Institute for Boys) as Paul McCartney.

Career

Manley and Andrew formed the Remo Quartet in 1958, with singer/guitarist Keith Stokes (born in 1942) and drummer Harry Prytherch (born in 1942). They progressed from playing local parties and contests to regular hall appearances, and turned professional, changing their name to the Remo Four in summer 1959. They played a mix of vocal harmony material (à la The Everly Brothers), and instrumental numbers in the manner of The Shadows, The Ventures, and Chet Atkins.