The towering Himalayas were among the last places on Earth that humanity settled. Scaling sheer cliff sides, a team of daring scientists hunts for clues to how ancient people found their way into this forbidding landscape and adapted to survive the high altitude. They discover rock-cut tombs filled with human bones and enigmatic artifacts, including gold masks and Chinese silk dating back thousands of years, and piece together evidence of strange rituals and beliefs designed to ward off the restless spirits of the dead.

Scientists and engineers work to control a nuclear renaissance five years after the disaster at the Fukushima Daiichi Nuclear Power Plant.

David Pogue investigates how batteries work and what the future may hold for technical innovation.

Shipbuilders in Italy work around the clock to build the Seven Seas Explorer, the world's largest and most luxurious cruise ship.

The art of origami reshapes the world, affecting drug development and future NASA space missions.

Investigators study wreckage of train accidents; safety experts test crash prevention designs.

Archaeologists discover a tunnel near Vilnius, Lithuania, which served as an escape route for Jews fleeing the Nazis during World War II.

Engineers build a dome to contain the crumbling remains of the Chernobyl nuclear reactor.

Design secrets that made chariots a war machine for hundreds of years; how they were used and how they helped unify China.

The water crisis in Flint, Mich., brings awareness to the vulnerabilities of water systems across the U.S.

The history of eclipse science and research into the solar corona.

The Cassini space probe attempts to dive between the innermost ring and top of Saturn's atmosphere.

A re-engineering of Greenwich armor to get a sense of what it was like to be a knight and how the armor was manufactured in medieval times.

Archaeological digs reveal new clues as to who built Stonehenge and why.

The architectural design of Beijing's ancient complex of palaces and temples enabled it to survive centuries of earthquake shocks.

The hunt for a volcanic mega-eruption that plunged medieval Earth into a deep freeze includes geologic evidence from Greenland to Antarctica.

Researching the Great Hurricane of 1780, which blasted its way across the Caribbean, why it was so dangerous and the potential for more mega-storms in the future.

Efforts to uncover the geologic footprints of colossal megafloods in Iceland and on the seabed of the English Channel.

Why some animals have extreme armaments, including claws, horns, fangs and stings.

Scientists test avian aptitude with brainteasers that reveal acute intelligence.

Scientists discover new clues as to the catastrophe that ended the reign of the dinosaurs on Earth.