There's been some bad news for the Great Barrier Reef, with experts declaring another mass bleaching—the fifth in just eight years. We find out what coral bleaching is and how it's impacting Australia's World Heritage-listed wonder.

Robby Naish dominated men’s windsurfing for two decades, becoming the biggest name in the sport. Now, his competition days behind him, with age and injury finally starting to catch up and turbulence in his family life, Robby is forced to take stock. He sets his sights on a new objective: riding the longest wave! This trailer was made for the movie that documents his challenge.

An American abroad: Joe Evans takes us on a tour of his apartment in Chiba, Japan. Look through his eyes as he encounters cultural differences in the mundane objects of daily life.

Rosetta revisits the exciting scientific discoveries she has made during her time at Comet 67P/Churyumov-Gerasimenko, including the successful search to find Philae. Now it's time to start preparing to descend to the comet for the end of her extraordinary mission.

Timothy Russell Strayer and Michael Barsinsky, two members of the "Occupy" movement, talk about the main points of the occupation with respect to the Guantánamo Bay problem and the ways in which society can be changed in a progressive way.

Barry Knight points to the banking sector as responsible for the current decline of American society with respect to social and political developments in the US.

Brothers Dudley and Chris had the honor of being part of the first ever Jamaican bobsled team, competing at the nineteen eighty-eight Winter Olympics. We hear the true story of how this unlikely team came into existence, and how Chris went from being a spectator to an Olympic competitor with less than a week’s training.

Decades later, the events of the nineteen eighty-eight Winter Olympics seem harder and harder to believe, even to the men at the heart of the original Jamaican Bobsled team. But it really did happen, and the proof is in the strong sporting and commercial legacy they leave for the next generations.

Let's find out more about an American activity aimed at school kids: the spelling bee. What is it and how does it work?

Sigrid talks about "The Elementary Spelling Book" by Noah Webster, which was the basis for the American English dictionary and a big part of the development of spelling bees in the United States.

Sigrid explains how a spelling bee normally proceeds. There are fixed rules and there are options.

In recent years, we've seen an increase in the intensity of tropical storms and hurricanes due to global warming. But how and why do hurricanes form? Sigrid provides a basic explanation of this phenomenon.

We continue to explore the phenomenon of hurricanes. Why are they so dangerous? And do they serve any purpose?

Columbus Day has always been a controversial holiday in the United States. In this video, Sigrid goes back in time to get some historical background, which sheds a new light on its significance.

Most Americans don't realize how Columbus Day came to be a national holiday, but it actually doesn't have that much to do with Christopher Columbus, and we might even recognize a connection to present-day events. To recall something Mark Twain once supposedly said, "History doesn't repeat itself, but it often rhymes."