The dome that crowns Florence's great cathedral of Santa Maria del Fiore, the Duomo, is a masterpiece of Renaissance ingenuity and an enduring source of mystery. Still the largest masonry dome on earth, it is taller than the Statue of Liberty and weighs as much as an average cruise ship. Historians and engineers have long debated how its architect, Filippo Brunelleschi, kept the dome perfectly aligned and symmetrical as the sides rose and converged toward the center." More than four million bricks could collapse at any moment -- and we still don't understand how Brunelleschi prevented it. To test the latest theories, a team of U.S. bricklayers will help build an experimental "mini-Duomo" using period tools and techniques.

This documentary looks at the remarkable genius of Orson Welles on his centenary - the enigma of his career as a Hollywood star, a Hollywood director (for some a Hollywood failure), and a crucially important independent filmmaker. Orson Welles's life was magical: a musical prodigy at age 10, a director of Shakespeare at 14, a painter at 16, a star of stage and radio at 20, romances with some of the most beautiful women in the world, including Rita Hayworth. His work was similarly extraordinary, most notably Citizen Kane, (considered by many to be the most important movie ever made), created by Welles when he was only 25. In the years following Citizen Kane, Welles's career continued to change as he made film after film (some never finished, many dismissed) and acted in other projects often to earn money in order to keep making his own films. Magician features scenes from almost every existing Welles film, from Hearts of Age, (which he made in a day when he was only 18 years old) to rarely-seen clips from his final unfinished works like The Other Side of the Dream, The Deep, and Don Quixote, as well as his television and commercial work.

'Deliver Us from Drought' - Over the past years, Texas has experienced the worst drought in its recorded history. 97% of the scientific community agrees that human activity has contributed to extreme weather patterns around the world. But many Texans--legislators, community leaders and citizens--don't attribute their drought to humans, and have taken few if any initiatives to limit the state's CO2 emissions, currently the highest in the country. "The Resource Curse" - As humanity's appetite for energy grows exponentially, the extraction industry scrambles to the most remote regions on Earth. In the undeveloped Melanesian country of Papua New Guinea, America's Exxon Mobil has staked its claim to a $19 billion liquid natural-gas project. While some see Exxon's mammoth presence as the catalyst that will usher the underdeveloped country into the 21st Century, others predict the initiative could plunge its people into civil war.

Researchers discover film footage from World War II that turns out to be a lost documentary shot by Alfred Hitchcock and Sidney Bernstein in 1945 about German concentration camps liberated by allied troops. When Allied forces liberated the Nazi concentration camps in 1944-45, their terrible discoveries were recorded by army and newsreel cameramen, revealing for the first time the full horror of what had happened. Making use of British, Soviet and American footage, the Ministry of Information’s Sidney Bernstein (later founder of Granada Television) aimed to create a documentary that would provide lasting, undeniable evidence of the Nazis’ unspeakable crimes. He commissioned a wealth of British talent, including editor Stewart McAllister, writer and future cabinet minister Richard Crossman – and, as treatment advisor, his friend Alfred Hitchcock. Yet, despite initial support from the British and US Governments, the film was shelved, and only now, 70 years on, has it been restored and completed by Imperial War Museums. This eloquent, lucid documentary by André Singer (executive producer of the award-winning The Act of Killing) tells the extraordinary story of the filming of the camps and the fate of Bernstein’s project, using original archive footage and eyewitness testimonies.

Let's go behind the scenes at NASA to discover how it is preparing for its most ambitious and daring mission: to land men - and possibly women - on the surface of Mars. It's over 40 years since Neil Armstrong made the first human footprint on the moon. But getting to the red planet would involve a journey of at least three years. Meet the scientists and engineers who are designing new rockets, new space suits and finding ways to help astronauts survive the perils of this long voyage. And it turns out that having the 'right stuff' for a mission to mars might not be quite what you expect.

One man's journey to discover the bitter truth about sugar. Damon Gameau embarks on a unique experiment to document the effects of a high sugar diet on a healthy body, consuming only foods that are commonly perceived as 'healthy'. Through this entertaining and informative journey, Damon highlights some of the issues that plague the sugar industry, and where sugar lurks on supermarket shelves. This will change the way you think about healthy food.