the energy of a discrete-time signal x(t) is defined as
Relationship to energy in physics
Energy in this context is not, strictly speaking, the same as the conventional notion of energy in physics and the other sciences. The two concepts are, however, closely related, and it is possible to convert from one to the other:
For example, if x(t) represents the potential (in volts) of an electrical signal propagating across a transmission line, then Z would represent the characteristic impedance (in ohms) of the transmission line. The units of measure for the signal energy would appear as volt2·seconds, which is not dimensionally correct for energy in the sense of the physical sciences. After dividing by Z, however, the dimensions of E would become volt2·seconds per ohm, which is equivalent to joules, the SI unit for energy as defined in the physical sciences.
On September 18, 2001, Collective Soul released their greatest hits compilation Seven Year Itch: Greatest Hits, 1994-2001 (stylized as 7even Year Itch). The compilation includes songs recorded from 1994 to 2001 and included two new tracks; "Next Homecoming" and "Energy". Seven Year Itch received decent reviews and was relatively successful It sold 225,000 copies in the first year after its release and reached number fifty on the Billboard 200; in Canada, it reached number nine on its albums chart and went platinum. All the songs in Seven Year Itch had charted in the US on the Billboard Hot 100, Mainstream Rock Tracks, or the Modern Rock Tracks chart, except for "Energy", which debuted in this compilation.
The compilation has sold over 500,000 copies. It saw a resurgence in sales after Collective Soul began putting out albums on their own independent label, El Music Group, beginning in 2004.
Seven Year Itch was the last album Collective Soul released through Atlantic Records and their last album to feature guitarist Ross Childress, who had been with the band since its 1993/1994 debut.
Right Now is the debut studio album by Scottish singer Leon Jackson, released on 20 October 2008, via Syco Music and Sony BMG. It was produced by Steve Mac. Jackson described the album as "a mixture in styles of modern jazz with singer-songwriter elements, and a lot of it is really soulful."Right Now received mixed reviews although the single, "Don't Call This Love", which was released as the album's second single in October 2008, entered the UK Singles Chart at number three and the Scottish Singles Charts at number one, where it remained on the top position for two weeks.
Right Now was a commercial success for Jackson, debuting within the top five in both the United Kingdom and Scotland. Right Now spent ten weeks within the UK Top 100 Album Charts, and twelve weeks within the Scottish 100 Album Charts. To date, the album has sold 135,892 copies in the UK, becoming Gold certified by the BPI.
Background and release
"The Album is a mixture in styles of modern jazz with singer-songwriter elements, and a lot of it is really soulful" - Leon Jackson speaking about Right Now