David Murdock

Great Cathedral Mystery

David Murdock, Jonas Elmore

From PBS - 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.

Worlds Most Dangerous Drug

David Murdock

Methamphetamine is one of the hardest drugs to quit. Its abuse is ravaging rural communities and cities alike. NGC correspondent Lisa Ling goes inside this global epidemic to find out what makes meth so addictive and destructive.

Mystery Skeletons of the Sahara

David Murdock

Jonathan Davis, Dr. Paul Sereno

An investigation into prehistoric, fossilised human remains found in the Saharan Desert.