A shadow is an area where direct light from a light source cannot reach due to obstruction by an object. It occupies all of the space behind an opaque object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or reverse projection of the object blocking the light. The sun causes many objects to have shadows and at certain times of the day, when the sun is at certain heights, the lengths of shadows change.

An astronomical object casts human-visible shadows when its apparent magnitude is equal or lower than −4. Currently the only astronomical objects able to produce visible shadows on Earth are the sun, the moon and, in the right conditions, the planet Venus.

Shadow length when caused by the sun changes dramatically throughout the day. The length of a shadow cast on the ground is proportional to the cotangent of the sun's elevation angle—its angle θ relative to the horizon. Near sunrise and sunset, when θ = 0° and cot(θ) is infinite, shadows can be extremely long. If the sun passes directly overhead, then θ = 90°, cot(θ)=0, and shadows are cast directly underneath objects.

Jessica Ellen Cornish (born 27 March 1988), better known by her stage name Jessie J, is an English singer and songwriter. Born and raised in London, she studied at the BRIT School before signing with Gut Records and striking a songwriting deal with Sony/ATV Music Publishing where she wrote for artists such as Chris Brown and Miley Cyrus.

Signed with Universal, Jessie J came to prominence following the release of her debut single "Do It Like a Dude" which peaked at number two on the UK Singles Charts. After scoring her first number one in the United Kingdom, France, Ireland and New Zealand with the song "Price Tag", she released her debut album Who You Are (2011) which charted at number two in the UK. Other releases from the album include "Nobody's Perfect", "Who's Laughing Now" and "Who You Are" which charted within the top 20 in the UK but the release of fifth single "Domino" spawned international chart success, peaking at number 6 on the Billboard Hot 100 in the US, and becoming her second UK number one. Aside from her musical career, Jessie J is currently a coach and mentor on television show The Voice UK.

Jimmy Lee Lindsey Jr. (May 1, 1980 – January 13, 2010), better known by the stage name Jay Reatard, was an American musician from Memphis, Tennessee. Lindsey was signed to Matador Records. He released recordings as a solo artist and as a member of The Reatards and Lost Sounds.

Lindsey's recording career began at the age of 15, when a home-made demo tape he had sent in to Goner Records caught the ear of former-Oblivian and Goner Records’ owner, Eric Friedl. Lindsey's introduction to Friedl and his Oblivians bandmates had come that same year when the Oblivians had returned home to Memphis as an opening act for Rocket from the Crypt. Upon seeing the act live, Lindsey became enamored with their sloppy, lo-fi music and set forth creating his own brand of heavily distorted garage rock music. Friedl was impressed by Lindsey's demos and signed him to his label, later commenting, "I loved the racket so we did the record, and I've been a fan of everything he's done since. He's a pretty amazing kid."

Francis Albert "Frank" Sinatra,  /sɨˈnɑːtrə/, (December 12, 1915 – May 14, 1998) was an American singer and film actor.

Beginning his musical career in the swing era with Harry James and Tommy Dorsey, Sinatra became an unprecedentedly successful solo artist in the early to mid-1940s, after being signed to Columbia Records in 1943. Being the idol of the "bobby soxers", he released his first album, The Voice of Frank Sinatra in 1946. His professional career had stalled by the 1950s, but it was reborn in 1953 after he won the Academy Award for Best Supporting Actor for his performance in From Here to Eternity.

He signed with Capitol Records in 1953 and released several critically lauded albums (such as In the Wee Small Hours, Songs for Swingin' Lovers, Come Fly with Me, Only the Lonely and Nice 'n' Easy). Sinatra left Capitol to found his own record label, Reprise Records in 1961 (finding success with albums such as Ring-a-Ding-Ding!, Sinatra at the Sands and Francis Albert Sinatra & Antonio Carlos Jobim), toured internationally, was a founding member of the Rat Pack and fraternized with celebrities and statesmen, including John F. Kennedy. Sinatra turned 50 in 1965, recorded the retrospective September of My Years, starred in the Emmy-winning television special Frank Sinatra: A Man and His Music, and scored hits with "Strangers in the Night" and "My Way".

Samuel George "Sammy" Davis Jr. (December 8, 1925 – May 16, 1990) was an American entertainer and was also known for his impersonations of actors and other celebrities.

Primarily a dancer and singer, Davis started as a child vaudevillian who became known for his performances on Broadway and Las Vegas. He went on to become a world famous recording artist, television and film star. Davis was also a member of Frank Sinatra's "Rat Pack".

At the age of three Davis began his career in vaudeville with his father and "uncle" as the Will Mastin Trio, toured nationally, and after military service, returned to the trio. Davis became an overnight sensation following a nightclub performance at Ciro's after the 1951 Academy Awards. With the trio, he became a recording artist. In 1954, he lost his left eye in an automobile accident.

His film career began as a child in 1933. In 1960 he appeared in the first Rat Pack film, Ocean's 11. After a starring role on Broadway in 1956's Mr Wonderful, Davis returned to the stage in 1964's Golden Boy, and in 1966 had his own TV variety show, The Sammy Davis Jr. Show. Davis' career slowed in the late sixties, but he had a hit record with "The Candy Man", in 1972, and became a star in Las Vegas earning him the nickname Mister Show Business.