Hagia Sophia-Istanbul's Ancient Mystery
Season 42, Episode 16
Feb 25, 2015
Istanbul's magnificent Hagia Sophia has survived on one of the world's most active seismic faults, which has inflicted a dozen devastating earthquakes since Hagia Sophia was built in 537 AD. As Istanbul braces for the next big quake, a team of architects and engineers is investigating Hagia Sophia's seismic secrets. NOVA follows the team's discoveries as they examine the building's unique structure and other ingenious design strategies that have insured the dome's survival. The engineers build a massive eight-ton model of the building's core structure, place it on a motorized shake table and hit it with a series of simulated quakes.
Petra - Lost City of Stone
Season 42, Episode 15
Feb 18, 2015
More than 2,000 years ago, the thriving city of Petra rose up in the bone-dry desert of what is now Jordan. An oasis of culture and abundance, the city was built by wealthy merchants who carved spectacular temple-tombs into its cliffs, raised a monumental Great Temple and devised an ingenious system that channeled water to vineyards, bathhouses, fountains and pools. But following a catastrophic earthquake and a slump in its desert trade routes, Petra's unique culture faded and was lost to most of the world for nearly 1,000 years. Now, in a daring experiment, an archaeologist and sculptors team up to carve an iconic temple-tomb to find out how the ancient people of Petra built their city of stone.
Colosseum-Roman Death Trap
Season 42, Episode 14
Feb 11, 2015
The Colosseum is a monument to Roman imperial power and cruelty. Its graceful lines and harmonious proportions concealed a highly efficient design and advanced construction methods that made hundreds of arches out of 100,000 tons of stone. In its elliptical arena, tens of thousands of gladiators, slaves, prisoners and wild animals met their deaths. Ancient texts report lions and elephants emerging from beneath the floor, as if by magic, to ravage gladiators and people condemned to death. Then, just as quickly, the Colosseum could be flooded with so much water that ships could engage in sea battles. Could these legends be true? Now, with access to one of the world's most protected world heritage sites, archaeologists and engineers team up to re-create ancient Roman techniques to build a 25-foot lifting machine and trap-door system capable of releasing a wolf into the Colosseum's arena for the first time in 1,500 years.
Season 42, Episode 13
Jan 28, 2015
In Tampa, Florida, in February 2013, a giant hole opened up under the bedroom floor of Jeffrey Bush, swallowing the 36-year-old as he slept. His body was never found. Bush was a victim of a sinkhole—a growing worldwide hazard that lurks wherever limestone and other water-soluble rocks underpin the soil. When carbon dioxide in the air dissolves in rainwater, it forms a weak acid that attacks the soft rocks, riddling them with holes like Swiss cheese. Sinkholes can occur gradually when the surface subsides into bowl-shaped depressions or suddenly, when the ground gives way—often catastrophically. Sinkholes have swallowed highways, apartment buildings, horses, camels, even golfers, with monster-size holes cracking the earth from Siberia to Louisiana. With compelling eyewitness video of dramatic collapses, and following scientists as they explore the underlying forces behind these natural disasters, NOVA travels the globe to investigate what it's like to have your world vanish beneath your feet.