When ancient Greece fell into decline, mathematical progress stagnated as Europe entered the Dark Ages, but in the East mathematics reached new heights. In the second episode, Du Sautoy explores how maths helped build imperial China and discovers how the symbol for the number zero was invented in India. He also looks at the Middle Eastern invention of algebra and how mathematicians such as Fibonacci spread Eastern knowledge to the West.

From east to west, via mountains, volcanoes, deserts, lakes and Arctic ice, this breathtaking series uses stunning cinematography to chart the dazzling natural wonders of this vast country. Accounting for around 10 per cent of the world’s dry land, Siberia is famous as a brutally cold place. Yet it is home to a diverse range of habitats and animal life – including musk deer, camels, gazelles and the extraordinary Siberian salamander, which can spend years encased in -40°C ice and still survive.

Welcome to an extreme landscape of rock, ice and snow. We tour the mightiest mountain ranges, starting with the birth of a mountain at one of the lowest places on Earth and ending at the summit of Everest. Find out how some of the most secretive animals rise to the challenge of mountain life. Share one of Earth's rarest phenomena, a lava lake that has been erupting for over 100 years. The same forces built the Simian Mountains where we find troops of gelada baboons nearly a thousand strong. In the Rockies, grizzlies build winter dens inside avalanche-prone slopes and climb the peaks to devour abundant summer moths. In another world first, the programme brings us astounding images of a snow leopard hunting on the Pakistan peaks.

Trailblazing scientists are making ground-breaking discoveries in the rapidly evolving world of genetic engineering. Technologies like CRISPR are making it possible to quickly and cheaply change the DNA of all living things, including humans. Today, genes can be edited almost as easily as words on a computer screen. This new ability to alter our DNA holds the promise of curing disease , saving threatened species, solving the problem of world hunger and maybe even obtaining human perfection. But will the promise be fulfilled and at what cost?
The ability to gain control of our DNA is ground-breaking and revolutionary but there are varying opinions among scientists as to how the technology should be used responsibly. This documentary follows the science as it progresses at a breakneck speed.

The centre of our galaxy is home to an invisible monster of unimaginable power – a supermassive black hole named Sagittarius A star, with four million times the mass of the Sun. Recent astronomical breakthroughs have confirmed not only that black holes like Sagittarius A star exist, but that these bizarre invisible objects may be the ultimate galactic protagonists.
Stunning CGI takes us back to witness the fiery origins of our galaxy’s black hole 13.6 billion years ago, when the early universe was home to colossal blue stars, and when they ran out of fuel, they collapsed under their own enormous mass, crushing down into an object so small and so dense it punched a hole in the fabric of the universe. Over billions of years, Sagittarius A star feasted on nearby gas, stars, and through cataclysmic mergers with other black holes. A breakthrough discovery by Nasa’s Fermi gamma-ray telescope has shown that our black hole had the power to sculpt the entire galaxy, creating vast bubbles of gas above and below our galaxy and even protecting stars systems as ours.
In a mind-bending conclusion, Brian Cox reveals how our modern understanding of black holes is challenging our concepts of reality to the breaking point. In trying to understand the fate of objects that fall into Sagittarius A star, scientists have come to a stunning conclusion: space and time, concepts so foundational to how we experience the world around us, are not as fundamental as we once thought.

Andrew Marr sets off on an epic journey through 70,000 years of human history. Using dramatic reconstructions, documentary filming around the world and cutting-edge computer graphics, he reveals the decisive moments that shaped the world we live in today, telling stories we thought we knew and others we were never told." Starting with our earliest beginnings in Africa, Marr traces the story of our nomadic ancestors as they spread out around the world and settled down to become the first farmers and townspeople. He uncovers extraordinary hand-prints left in European caves nearly 30,000 years ago and shows how human ingenuity led to inventions which are still with us today. He also discovers how the first civilisations were driven to extremes to try to overcome the forces of nature, adapting and surviving against the odds, and reveals how everyday life in ancient Egypt had more in common with today's soap operas than might be imagined.