- published: 24 Nov 2009
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Cold refers to the condition or subjective perception of having low temperature. A cold body is often described as the opposite of hot, or as having less heat, although the latter use of "heat" would be incorrect in the context of physics, as heat refers to the transfer of energy between bodies, which do not "have" heat themselves.
A lower bound to temperature is the absolute zero, defined as 0 K on the Kelvin scale, an absolute thermodynamic temperature scale. This corresponds to −273.15 °C on the Celsius scale, −459.67 °F on the Fahrenheit scale, and 0 °R on the Rankine scale.
Since temperature relates to the thermal energy held by an object or a sample of matter, which is the kinetic energy of the random motion of the particle constituents of matter, an object will have less thermal energy when it is colder and more when it is hotter. If it were possible to cool a system to absolute zero, all motion of the particles in a sample of matter would cease and they would be at complete rest in this classical sense. The object would be described as having zero thermal energy. Microscopically in the description of quantum mechanics, however, matter still has zero-point energy even at absolute zero, because of the uncertainty principle.
Demetria Devonne "Demi" Lovato (born August 20, 1992) is an American singer-songwriter, musician, and actress. Her earliest roles included Angela on Barney & Friends, before she became better known for her starring roles in the Camp Rock movies, as Sonny Munroe in the Disney sitcom Sonny with a Chance, and as the star of the 2009 movie Princess Protection Program. She is also involved in philanthropic activities through charity work and various social and environmental causes.
As a solo musical artist, Lovato released her debut album Don't Forget on September 23, 2008. The album debuted at number two on the Billboard 200 selling 89,000 copies in the first week. It has since shipped over 500,000 copies, earning a gold certification in the United States. Lovato released her second album, Here We Go Again, on July 21, 2009. The album debuted at number one on the Billboard 200, selling 108,000 copies in the first week. Her third studio album, Unbroken, was released on September 20, 2011 and peaked at number four on the Billboard 200. She is working on her fourth studio album.
Katheryn Elizabeth Hudson (born October 25, 1984), known by her stage name Katy Perry, is an American singer, songwriter and actress. Perry grew up with gospel music, and during her first year of high school she pursued a music career as Katy Hudson, releasing her first studio album called Katy Hudson which failed to chart. She recorded a solo album later, which was never released. After signing with Capitol Music Group in 2007, her fourth record label in seven years, she adopted the stage name Katy Perry.
She first gained recognition with the release of her first mainstream album, One of the Boys in 2008, which spawned three Billboard Hot 100 top-ten songs—"I Kissed A Girl", "Hot n Cold" and "Waking Up In Vegas". Perry supported the album with her Hello Katy Tour. In 2010, her third studio album, Teenage Dream (2010), which topped the Billboard 200 chart, and spawned five number one singles—"California Gurls", "Teenage Dream", "Firework", "E.T." and "Last Friday Night (T.G.I.F.)"—Teenage Dream was the only album (after Michael Jackson's Bad)—to do so, and the first female in history to achieve this milestone. She embarked on the California Dreams Tour, which grossed nearly $60 million worldwide. Perry re-released the album under the name of Teenage Dream: The Complete Confection on March 26, 2012, and the re-release has already spawned the number-one single "Part of Me".