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.

The 1980s was a time when artists in both the UK and US were delivering powerful social commentary in their songs. Dylan Jones selects some of the finest alternative voices from this era. From The Cure on Top of the Pops at the beginning of the decade to The Stone Roses' debut TV performance in 1989, this episode takes a comprehensive look at the alternative music of an entire era. It also features powerful live performances from Billy Bragg, Tracy Chapman, Bronski Beat and The Selecter. In addition, there are archival gems from Pixies, The Smiths, Suzanne Vega, The Fall, REM and many more.

On the trail of tiger sharks in the Pacific, Will Smith explores the power of smell. Sharks have a sense of smell that's hundreds of times more potent and accurate than that of humans. An enormous part of their brain is dedicated to smelling, to finding their way through the vast expanse of the ocean.

Will Smith confronts his fear of nature on powerful white-water rapids in Iceland. "Over five expeditions, I've followed explorers into situations that were straight-up scary. It was worth it to discover the Earth's wonders. But your boy was tripping more than once. Because when I see wilderness, you know, nothing but nature, I get nervous because I don't understand it."

By August 1949 the USSR became the world's second superpower, thanks to its spies who had stolen America's atomic secrets. But by March 1953, Stalin is dead and KGB chief, Beria, is executed later the same year. Nikita Kruschev tries to reduce the power of the security service, splitting it into several sections...but it doesn't last and, soon, the KGB is back.
In the USSR, countless KGB operatives spied on opponents of the regime at home, guarded the state and party leadership, and abroad tried to find out as much as possible about the intentions of the NATO countries and, if possible, to sabotage them.

Hitler’s rise to power was a unique moment in history. Germany suffered a humiliating defeat in WWI; now it's crippled by massive war reparations. Hitler offers a scapegoat: the Jews. The Nazis are quick to institute anti-Semitic laws and stoke distrust of the Jews. Anyone deemed 'undesirable,' from political opponents, to the handicapped, gypsies and Jews are sent to camps. There they are either worked to death, starved or executed. But just how much did the rest of the world know of what was going on?