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.

Japan's landscapes range from snowy mountains to subtropical warmth. They are full of wildlife - and animals' and people's lives often cross as they adapt to these extremes. The central island of Honshu is home to over 100 million people, and its biggest city, Tokyo, is one of the largest urban metropolises on earth. But it has a wild heart - most of Honshu is mountainous. This wilderness is home to an astonishing range of wildlife - black bears, monkeys, exquisite fireflies and even cow demons. But all across this island, from the mountains to the edge of the sea, people and nature are drawn together in the most unexpected ways.

The human brain is the most complex object we’ve discovered in the universe, and every day much of its neural circuitry is taken up with the tens of thousands of decisions we need to make. ‘How do I decide?’ is a journey through the unseen world of decisions, and how they get made. Decisión-making is what allows us to navigate a course through life. Discover how important emotions are in making decissions and, as we learn more about our own brains, we can break away from slavery to our impulses. Neuroscience shows that you're made up of multiple competing drives and by understanding how choices battle it out in the brain, we can learn how to make better decisions.

‘Who Is in Control?’ explores the great deception that greets us each morning when we awake: it feels as though we are in conscious control of our lives but the truth is that we are not. Instead almost every action, every decision, every belief that we hold is driven by parts of the brain that we have no access to.

The Arctic and Antarctic experience the most extreme seasons on Earth. Time-lapse cameras watch a colony of emperor penguins, transforming them into a single organism. The film reveals new science about the dynamics of emperor penguin behaviour. In the north, unique aerial images show a polar bear swimming more than 100km. Diving for up to two minutes at a time. The exhausted polar bear later attacks a herd of walrus in a true clash of the Titans.

The hunt for aliens is on! After a distinguished career in cosmology Professor Martin Rees, the astronomer royal, has taken up the search for extra-terrestrials. Looking for aliens is no longer science fiction - it is a question that's engaging some of the greatest minds in science." As our knowledge of the universe has increased, we're getting closer to answers. Many scientists now think we live in galaxy with a billion Earth-like planets, many of which may be teeming with life. But what kind of life? Has anything evolved into beings we could communicate with? This film gets inside the minds of the scientists considering one of the most exciting and profound questions we can ask - are we alone in the universe? Professor Rees thinks we may have our idea of what an alien is like all wrong. If he's right, it's not organic extra-terrestrials we should look for, it's machines.