In the fifth episode Neil deGrasse Tyson explores questions that have baffled scientists for centuries. Can we know the universe? Are our brains capable of comprehending the cosmos in all of its complexity and splendor?. We don't yet know the answers because our brain remains almost as much of a mystery to that questions as the universe itself. An abandoned orphan's dream opened the way to understanding the architecture of thought.

Andrew Graham-Dixon reveals how the Medici family transformed Florence through sculpture, painting and architecture and created a world where masterpieces fetch millions today. Without the money and patronage of the Medici we might never have heard of artists such as Donatello, Michelangelo or Botticelli, and Graham-Dixon examines how a family of shadowy, corrupt businessmen, driven by greed and ambition, became the financial engine behind the Italian Renaissance.

Whether serving as Christian church, Islamic mosque, or secular museum, Hagia Sophia and its soaring dome have inspired reverence and awe. For 800 years, it was the largest enclosed building in the world—the Statue of Liberty can fit beneath its dome with room to spare. How has it survived its location on one of the world's most active seismic faults, which has inflicted a dozen devastating earthquakes since it was built in 537?" As Istanbul braces for the next big quake, a team of architects and engineers is urgently investigating Hagia Sophia's seismic secrets. Follow engineers as they build a massive 8-ton model of the building's core structure, place it on a motorized shake table, and hit it with a series of simulated quakes, pushing it collapse—a fate that the team is determined to avoid with the real building

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 whose camel caravans transported incense and spices from the Arabian Gulf. They carved spectacular temple-tombs into its soaring cliffs, raised a monumental Great Temple at its heart, 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 a thousand 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. Meanwhile, scientists using remote sensors and hydraulic flumes uncover the vast city and its sophisticated water system. The race is on to discover how these nomads created this oasis of culture in one of the harshest climates on Earth.

There is a tendency to deny German culture the equal reverence of Italy or Spain, and this enlightening new series provides a wonderful opportunity to explore a great, yet often neglected, artistic tradition whose influence has been just as profound. Andrew Graham-Dixon concludes his exploration of German art by investigating the dark and difficult times of the 20th century. Dominating the landscape is the figure of Adolf Hitler, failed artist, would-be architect and obsessed with the aesthetics of his 1,000-year Reich". In a series of extraordinary building projects and exhibitions, Hitler waged a propaganda war against every form of modern art as a prelude to unleashing total war on the whole of Europe. After the war the shadow of the Third Reich persisted, Germany remained divided and traumatised. How would artists deal with a past that everybody wanted to forget? Journeying through the work of Otto Dix and George Grosz and the age of the Bauhaus to the post-war painters Georg Baselitz, Hilla Becher and the conceptual artist Joseph Beuys is a long and strange journey, but the signs that art has a place at the heart of the new reunited Germany are clearly visible.

How should art depict the relationship between man and God? How can art best express eternal values? Can you and should you portray the face of Christ? For over 1,000 years these were some of the questions which taxed the minds of the greatest artists of the early West. In this three-part series, art historian Andrew Graham-Dixon sets out to unravel the mysteries of art from the pre-perspective era". In the first episode, Andrew traces the beginnings of Christian art in the declining Roman Empire, Egypt and medieval France, and reveals the ideas which lay behind the transition