NOVA follows a team of volcano sleuths as they embark on a worldwide hunt for an elusive volcanic mega-eruption that plunged the medieval earth into a deep freeze. The mystery begins when archaeologists find a hastily dug mass grave of 4,000 men, women, and children in London. At first they assume it's a plague pit from the Black Death, but when they date the bones, they're a century too early. So what killed off these families? The chronicles of that time describe a run of wild weather that devastated crops and spread famine across Europe. NOVA's expert team looks for the signature of a volcanic eruption big enough to have blasted a huge cloud of ash and sulfuric acid into the atmosphere, which chilled the entire planet. From Greenland to Antarctica, the team finds telltale "fingerprints" in ice and soil layers until, finally, they narrow down the culprit to a smoldering crater on a remote Indonesian island. Nearly 750 years ago, this volcano's colossal explosion shot a million tons of rock and ash into the atmosphere. Across the globe, it turned summer into winter. What would happen if another such cataclysm struck again today?
Their beauty has captivated us for millennia. Their cost can be extraordinary–some are even considered priceless. Precious gems like diamonds, rubies, emeralds, opal, and jade are the ultimate treasures of the earth, and each one is made from a specific–and often torturous–recipe of chemistry, pressure, and heat. The secrets to their sparkle, color, and even strength lie deep inside the gems themselves, but could they also hold clues to one of the most enduring mysteries in the field of geology? From Tiffany’s workshop in New York to the sapphire mines of Sri Lanka, from North Carolina’s emerald fields to the jade-laden Forbidden City of China.
The enduring luster of gold, the conductivity of copper, the strength of steel—the special properties of metals have reshaped societies and defined eras; they have such an important role in human history that entire ages have been named after them. But what gives metals their astounding characteristics? From the perfect ring of a bronze bell to the awe-striking steel construction of Beijing’s “Bird’s Nest” stadium, how have humans perfected metalworking? And how have metals enabled our modern hi-tech world? Explore the science of metals with chemists and engineers as they literally test the mettle of metals and investigate how these remarkable materials have ushered humanity from the Stone Age to the stars.
Ice may be nothing more than frozen water but, as Iain explains, it holds extraordinary power. Descending 150m down a frozen waterfall, he sees a glacier in action from below and discovers why the huge Jacobshaven glacier is retreating, he shows how it shaped our past and may now threaten our future.