
David Murdock
2021Great 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.
Great Cathedral Mystery
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.
Worlds Most Dangerous Drug