More than 2,000 years ago, the thriving city of Petra rose up in the bone-dry desert of what is now Jordan. An oasis of culture and abundance, the city was built by wealthy merchants whose camel caravans transported incense and spices from the Arabian Gulf. They carved spectacular temple-tombs into its soaring cliffs, raised a monumental Great Temple at its heart, and devised an ingenious system that channeled water to vineyards, bathhouses, fountains, and pools. But following a catastrophic earthquake and a slump in its desert trade routes, Petra's unique culture faded and was lost to most of the world for nearly a thousand years. Now, in a daring experiment, an archaeologist and sculptors team up to carve an iconic temple-tomb to find out how the ancient people of Petra built their city of stone. Meanwhile, scientists using remote sensors and hydraulic flumes uncover the vast city and its sophisticated water system. The race is on to discover how these nomads created this oasis of culture in one of the harshest climates on Earth.

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.

Upending the conventional wisdom of why we gain weight and how to lose it, Fed Up unearths a dirty secret of the American food industry—far more of us get sick from what we eat than anyone has previously realized. Filmmaker Stephanie Soechtig and TV journalist Katie Couric lead us through this potent exposé that uncovers why—despite media attention, the public’s fascination with appearance, and government policies to combat childhood obesity—generations of American children will now live shorter lives than their parents did.

The use of embryonic stem cells has ignited fierce debate across the spiritual and political spectrum. But what if we could create manmade stem cells - or find super cells in adults that could forever replace embryonic cells and remove the controversy? Today, we are on the brink of a new era - an age where we may be able to cure our bodies of any illness. Stephen Hawking has spent his life exploring the mysteries of the cosmos, now there is another universe that fascinates him - the one hidden inside our bodies - our own personal galaxies of cells." Hawking takes us on a fascinating journey exploring what these wondrous and baffling mechanisms are capable of. He is joined by the scientists who are on the front lines of discovery in this field including Dr. Doris Taylor who is customizing a donor's heart with the recipient's stem cells - her goal is to revolutionize heart transplants, Dr. Paul Lu and Dr. Mark Tuszynski may have created a breakthrough that could cure paralysis, and Dr. Vincent Giampapa who believes that stem cells can be used to stem the tide of aging and create a fountain of youth.

The extraordinary wildlife, culture and history of this immense, fascinating ocean and its myriad islands are revealed in stunning detail. With its coral reefs, turquoise lagoons and dramatic oceanic atolls, the South Pacific is the archetypal paradise. It is still relatively healthy and teeming with fish, but it is a fragile paradise. International fishing fleets are taking a serious toll on the sharks, albatross and tuna, and there are other insidious threats to these bountiful seas. We look at what is being done to preserve the ocean and its wildlife.

American paleontologist Pete Larson and his team discovered the largest and most complete Tyrannosaurus rex ever found (nicknamed 'Sue') while digging in the badlands of South Dakota. However the skeleton was seized from Larson by the federal government, followed by a ten-year-long battle with the FBI, the National Park Service, the Bureau of Indian Affairs, and Maurice Williams, on whose property the bones were discovered. Pete Larson also spent 18 months in prison." After the film aired, The Society of Vertebrate Paleontology, a society of professional academic paleontologists, issued a statement of full support for legally protecting fossils on public land and criticized Dinosaur 13 for implying that government regulations impede paleontological science