Beyoncé performs "Single Ladies (Put a Ring on It)" live in Central Park as part of the Good Morning America 2011 Summer Concert Series.

When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable "trophic cascade" occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains the process.

From their sixteenth album "Emergency," released in 1984, here is American band Kool and the Gang with their hit "Fresh."

Watch the official video for Justin Bieber's 2010 hit song "Baby," in collaboration with Ludacris. This video has both been YouTube's most watched, and most disliked video of all time. Enjoy.

Andrew McCarthy goes on a wild goose chase looking for a gravity hill in Ireland, and in the process shows us the charm of the Irish countryside.

Orcas are at the top of the food chain, but it is unprecedented that they would go after a great white shark. From the boat, whale watchers and experts alike are shocked by what they see.

"Girls Just Want to Have Fun" is a song written by and first recorded by American musician Robert Hazard. However, it is much better known as a single by American singer Cyndi Lauper.

Actors Neil Patrick Harris and Cobie Smulders sit down with Entertainment Weekly to talk about the relationship between their characters Barney and Robin on the show How I Met Your Mother.

Coldplay perform "Viva la Vida" at the BBC Radio Theater. Although the title of the song is taken from a painting by Mexican artist Frida Kahlo, the lyrics contain many historical and biblical references. The song won "Song of the year" at the Grammy awards.

In this episode of SciShow Kids, Jessi talks about how solar eclipses occur, and why they can only be seen from certain locations.

Seattle artist Matt Sellars shows off the Clovis Point, a skateboard of his own design. Check out a few scenes from its construction and test drive!

David and Ben Crystal explain why Shakespeare verses read with Original Pronunciation convey very different emotions and open up another level of understanding.

David Gilmour of the legendary British rock band Pink Floyd performs "Wish You Were Here" live and unplugged.

Scottish DJ Calvin Harris pulled a number of collaborators onto the stage for his performance at the BBC Music Awards. John Newman sings "Blame," which is followed directly by "Outside" featuring Ellie Goulding.

Theresa May gives her first speech as Britain's new prime minister, outlining her priorities for the UK with a focus on domestic issues.