PBS' premier science series helps viewers of all ages explore the science behind the headlines. Along the way, NOVA programs demystify science and technology and highlight the people involved in scientific pursuits.
While this process of erosion takes millions of years, the fragile roof of a cavern near the surface can collapse in an eye blink, with little or no advance warning. Sinkholes can range from a few meters across to one in Egypt that measures 50 x 75 miles, and a Chinese hole nearly half a mile deep.
Gemstones like diamonds, rubies, opal and jade are the ultimate treasures. Delve into Earth's depths to discover how these precious stones are forged and what explains the unique allure of each captivating gemstone.
Gold, bronze, iron, steel... metals are pillars of our civilization, but what makes them so special? Discover their unique properties and explore how our mastery of metals has led us from the stone age to today's hi-tech world.
Four-lane highways may be a necessity to our modern society, but they can be a death traps for millions of animals that try to cross them. Around the world, wildlife need to roam for breeding, foraging, and to carry out their traditional migrations–but they are often blocked by ranches, farms, roads, and other human-made obstacles.