For centuries, the precise workings of gravity have confounded the greatest scientific minds - from Newton to Faraday and Einstein - and the idea of controlling gravity has been seen as little more than a fanciful dream. Yet in the mid 1990s, UK defence manufacturer BAE Systems began a ground-breaking project code-named Greenglow. Nasa was simultaneously running its own Breakthrough Propulsion Physics Project". It was concerned with potential space applications of new physics, including concepts like 'faster-than-light travel' and 'warp drives'. Looking into the past and projecting into the future, Horizon explores science's long-standing obsession with the idea of gravity control. It looks at recent breakthroughs in the search for loopholes in conventional physics and examines how the groundwork carried out by Project Greenglow has helped change our understanding of the universe. Gravity control may sound like science fiction, but the research that began with Project Greenglow is very much ongoing, and the dream of flying cars and journeys to the stars no longer seems quite so distant.

Earth is the most colourful place we know of. But the colours we see are far more complex and fascinating than they appear. In this series, Dr Helen Czerski uncovers what colour is, how it works, and how it has written the story of our planet - from the colours that transformed a dull ball of rock into a vivid jewel to the colours that life has used to survive and thrive". But the story doesn't end there - there are also the colours that we can't see, the ones that lie beyond the rainbow. Each one has a fascinating story to tell. Early Earth was a canvas for the vast new palette of the colours of life, with the diversity of human skin tones telling the story of how humanity spread and ultimately conquered the planet. Dr Helen Czerski explores the true masters of colour - which are often the smallest and most elusive - travelling to the mountains of Tennessee to witness the colourful mating display of fireflies, and revealing the marine creatures that can change the colour of their skin in order to hide from the world.

Iain Stewart investigates a new and controversial energy rush for the natural gas found deep underground. Getting it out of the ground involves hydraulic fracturing - or fracking. We travel to America to find to find out what it is, why it is a potential game changer and what we can learn from the US experience". Sometimes, this is right under the places people live in. He meets some of the people who have become rich from fracking as well as the communities worried about the risks. Director Jeff Wilkinson

Annalisa Piras and former editor of The Economist Bill Emmott, which explores the crisis facing Europe. Through case studies of citizens in different countries, the film explores a range of factors that have led to the present crisis, economic and identity challenges across Europe. High-level experts analyse how and why things are going so wrong. The film includes fictional scenes, set in a post-EU future, which feature archaeologist Charles Granda (played by Angus Deayton) travelling on a flight through a menacing storm, explaining to a child passenger what the EU was. Sombre, thought-provoking and witty, the film frames Europe through the eyes of those who have most at stake - the Europeans themselves.

David Attenborough embarks on an extraordinary journey to unravel one of nature s most gripping stories the evolution of flying animals. The power of flight is one of the greatest miracles of nature. Over one hundred billion creatures soar through the air today - from nectar-drinking hummingbirds, to armoured airborne beetles; from bats hunting in the black of night, to bizarre winged lizards. The film travels back in time to unravel the astonishing 300-million-year story of how these animals first appeared, and then evolved into the huge variety of aeronauts that fill our skies today. Only now, using the latest scientific analysis, can he reveal the hidden mechanics behind their gravity-defying skills. Ground-breaking 3D cameras, high speed filming and stunning CGI bring the viewer closer than ever to this astounding aerial world.

Birds of paradise are one of David Attenborough's lifelong passions. He was the first to film many of their beautiful and often bizarre displays, and over his lifetime he has tracked them all over the jungles of New Guinea. In this very personal film, he uncovers the remarkable story of how these 'birds from paradise' have captivated explorers, naturalists, artists, film-makers and even royalty. He explores the myths surrounding their discovery 500 years ago, the latest extraordinary behaviour captured on camera and reveals the scientific truth behind their beauty": the evolution of their spectacular appearance has in fact been driven by sex. And in a final contemporary twist to this story of obsession and royalty, he travels to the desert of Qatar, to a state-of-the-art facility which houses the largest breeding group of these birds in the world - a sheikh's very own private collection. There he has his closest ever encounter with a greater bird of paradise and its dramatic display, reliving the experience that captivated him in the forests of New Guinea more than 50 years ago.