The 2nd millennium was the thousand-year period that commenced on January 1, 1001 and ended on December 31, 2000, encompasses the High Middle Ages, the Renaissance, the Early Modern Age, the age of Colonialism, industrialization, the rise of nation states, and culminates in the 20th century with the impact of science, widespread education, and universal health care and vaccinations in many nations. The centuries of expanding large-scale warfare with high-tech weaponry (of the World Wars and nuclear bombs) are offset by growing peace movements from the United Nations, the Peace Corps, religious campaigns warning against violence, plus doctors and health workers crossing borders to treat injuries and disease and the return of the Olympics as contest without combat.

Scientists prevail in explaining intellectual freedom; humans take their first steps on the Moon during the 20th century; and new technology is developed by governments, industry, and academia across the world, with education shared by many international conferences and journals. The development of movable type, radio, television, and the internet spread information worldwide, within minutes, in audio, video, and print-image format to educate, entertain, and alert billions of people by the end of the 20th century.

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".

Dark horse is a term used to describe a little-known person or thing that emerges to prominence, especially in a competition of some sort or a contestant that seems unlikely to succeed.

The term began as horse racing parlance. A dark horse is a race horse that is not known to gamblers and thus is difficult to place betting odds on.

The earliest-known use of the phrase is in Benjamin Disraeli's novel The Young Duke (1831). Disraeli's protagonist, the Duke of St. James, attends a horse race with a surprise finish: "A dark horse which had never been thought of, and which the careless St. James had never even observed in the list, rushed past the grandstand in sweeping triumph."

The term has been used politically in such countries as Peru, Philippines and United States.

Politically, the term reached America in the nineteenth century when it was first applied to James K. Polk, a relatively unknown Tennessee Democrat who won the Democratic Party's 1844 presidential nomination over a host of better-known candidates. Polk won the nomination on the ninth ballot, and went on to win the presidential election.