Corals are sessile animals, meaning they are immobile and anchored to one spot for the entirety of their lives. Stony coral, leathery coral, and sea fan coral are featured in this segment, along with the beautiful fish that inhabit coral reefs.

The earth's bodies of water are the focus of this film about evolution. As the narrator points out, the vast depths of the earth's oceans remain barely explored.

The BBC looks at a new and innovative renewable energy invention, Kite Power Solutions. It is estimated that 30 kites could provide electricity for 75,000 homes.

We visit Bryce Canyon, where valuable fossils have helped understand the geological history of the planet. The sandstone spires of the canyon are breathtaking.

The Colorado Plateau and the Grand Canyon are just a few of the amazing geographical features of the Southwestern United States.

We learn more about how water interacts with the minerals in the rocks, and visit Monument Valley, a popular spot for filming westerns and commercials.

Geysers represent a very popular tourist attraction in Yellowstone Park. How do they work and where do they come from? And what is sandstone? The video answers these questions.

In Yellowstone Park, visitors can see many indigenous animals in their natural habitat and wonder at the park's natural hot springs.

While it took Destin eight months to learn how to ride a backwards bike, his young son learned how in two weeks. The son's reward was a trip to Australia, where he got to meet Canadian astronaut Chris Hadfield.

Who knows when we'll discover whether we are alone in the universe or not? Whatever the answer, the quest for more knowledge will never cease, nor grow dull.

Destin Sandlin, an Alabama engineer and YouTube star, shows us how very difficult it is to learn to ride a backwards bike. You think it's going to be a piece of cake, but it's not!

Judging by the 26 billion views on over 2 million YouTube videos of them, one thing is certain: cats are very entertaining. But their strange feline behaviors, both amusing and baffling, leave many of us asking: Why do cats do that? Tony Buffington explains the evolutionary history behind some of your cat’s strangest behaviors.

Physicists, philosophers, and UFO enthusiasts all have ideas on how many universes there may be or if there is extraterrestrial life. Chris Anderson summarizes the theories and expects that in the coming years physicists will arrive at more answers.

In the first of a new TED-Ed series designed to catalyze curiosity, TED Curator Chris Anderson shares his boyhood obsession with quirky questions that seem to have no answers.

Douglas Adams was a writer and author best known for The Hitchhiker’s Guide to the Galaxy. Sadly, he died of a massive heart attack in 2001 at the young age of 49. Each year, fans of his work celebrate the 25th of May (or “Towel Day”) as a tribute to the author.