string theory

Any of a number of theories in particle physics that treat elementary particles (see subatomic particle) as infinitesimal one-dimensional “stringlike” objects rather than dimensionless points in space-time. Different vibrations of the strings correspond to different particles. Introduced in the early 1970s in attempts to describe the strong force, string theories became popular in the 1980s when it was shown that they might provide a fully self-consistent quantum field theory that could describe gravitation as well as the weak, strong, and electromagnetic forces. The development of a unified quantum field theory is a major goal in theoretical particle physics, but inclusion of gravity usually leads to difficult problems with infinite quantities in the calculations. The most self-consistent string theories propose 11 dimensions; 4 correspond to the 3 ordinary spatial dimensions and time, while the rest are curled up and not perceptible.

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Ensemble consisting of two violins, viola, and cello, or a work written for such an ensemble. Since circa 1775 such works have been perhaps the predominant genre of chamber music. It was principally developed (if not quite invented) by Joseph Haydn, who wrote some 70 quartets between 1757 and 1803. Wolfgang Amadeus Mozart, Ludwig van Beethoven, Franz Schubert, Béla Bartók, and Dmitry Shostakovich are the preeminent subsequent quartet composers. Works called string quartets have traditionally observed the four-movement design of the sonata and symphony. Like most chamber music genres, quartet music was traditionally intended primarily for the private enjoyment of amateur musicians rather than for public performance.

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Any musical instrument that produces sound by the vibrations of strings. The strings may be of gut, metal, fibre, or plastic, and may be plucked, bowed, or struck. The orchestral stringed instruments include the violin, viola, cello, double bass, and harp. Keyboard stringed instruments include the clavichord, harpsichord, piano, and virginal. Seealso Aeolian harp; balalaika; dulcimer; guitar; kithara; koto; lute; lyre; mandolin; pipa; sitar; aynūd; ukulele; viol; zither.

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Lowest-pitched of the modern stringed instruments. It varies in size, up to 80 inches (200 cm) tall. Its shape also varies; its shoulders usually slope more than those of the violin, reflecting its status as a hybrid of the viol and violin families (the name comes from the double-bass viol). It emerged from these families in the late Renaissance, and it has always been less standardized in form than its cousins in the violin family. It normally has four strings; the orchestral instrument often has a lower fifth string (more often, an extension is added to the fourth string), and the jazz instrument has a higher fifth string. Its range is an octave below that of the cello. It is normally bowed in orchestral music and plucked in jazz. In rock bands and some jazz bands, the electric bass is used instead.

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Generally, string is a thin, flexible piece of rope or twine which is used to tie, bind, or hang other objects. String can be made from a variety of fibres.

Examples of string use include:

• String figures, designs formed by weaving string around one's fingers
• A bow string, an essential part of a bow.
• In musical instruments such as below.

String may also refer to:

In science, computers or mathematics:

• String (computer science), a sequence of symbols or digits in computer programming
• String literal, the notation for representing a string value within the text of a computer program
• String searching algorithm
• strings (Unix), a Unix program for finding character strings in binary files
• String theory, a popular grand unified theory
• String (physics), one of the main objects of study in string theory
• Cosmic String, a hypothetical 1-dimensional (spatially) topological defect in various fields.

In music:

• String instrument, a musical instrument that produces sound through vibrating strings
• Strings (music), flexible material that provides vibrations in string instruments
• String section, the violins, violas, cellos and double basses of an orchestra, often abbreviated as "strings"
• Strings (Pakistani pop band), a pop band from Pakistan
• String (Thai pop), a genre of Thai pop music

In sport:

• Strings (tennis), the part of a tennis racquet which make contact with the ball

Other meanings:

• G-string, a minimal type of underclothing that covers the genitals without covering the buttocks
• Strings (2004 film), a movie directed by Anders Rønnow Klarlund
• Strings (1991 film), a Canadian Genie Award-winning and Oscar-nominated animated short
• A character controlled by Marik in the Yu-Gi-Oh! series
• String bridge, the passage into the Gardens of Allah in Islam
• "String" is a Monty Python sketch about a marketing campaign for string, appearing initially on their Contractual Obligation Album