Roses are red, violets are blue but according to the latest understanding these colours are really an illusion. One that you create yourself. Horizon reveals a surprising truth about how we all see the world. You may think a rose is red, the sky is blue and the grass is green, but it now seems that the colours you see may not always be the same as the colours I see. Your age, sex and even mood can affect how you experience colours. Scientists have unlocked the hidden power that colours can have over your life - how red can make you a winner, how blue makes time speed up. Watch an experiment where for people in a blue pod, a minute lasts 11 seconds shorter.

Discover the story behind the scenes of the band's fifth studio album Hotel California, one of the best-selling albums of all time. Henley said about this work: 'They are the same themes that run through all of our work: loss of innocence, the cost of naiveté, the perils of fame, of excess; exploration of the dark underbelly of the American dream, idealism realized and idealism thwarted, illusion versus reality, the difficulties of balancing loving relationships and work, trying to square the conflicting relationship between business and art; the corruption in politics, the fading away of the Sixties dream of peace, love and understanding.

Killing Kennedy begins in 1959, at major turning points for both the future president and his assassin. John F. Kennedy (played by Rob Lowe) is in Washington, D.C., preparing to announce his presidential candidacy, while Lee Harvey Oswald finds himself in the U.S. embassy in Moscow, renouncing his U.S. citizenship. These two events start both men-one a member of one of the United States' most wealthy and powerful families, the other a disillusioned former Marine and Marxist-on a cataclysmic track that would alter the course of history". Throughout the film, we see their highs and lows, culminating in not one but two shocking deaths that stunned the nation. Based on the best-selling book by Bill O'Reilly and Martin Dugard.

Horizon explores the strange and wonderful world of illusions – and reveals the tricks they play on our senses and why they fool us. We show how easy it is to trick your sense of taste by changing the colours of food and drink, explain how what you see can change what you hear, and see just how unreliable our sense of colour can be. But all this trickery has a serious purpose. It’s helping scientists to create a new understanding of how our senses work – not as individual senses, but connected together. It holds the intriguing possibility that one sense could be mapped into another.

In the last in the series Professor Jim Al-Khalili explores how studying the atom forced us to rethink the nature of reality itself. He discovers that there might be parallel universes in which different versions of us exist, finds out that empty space isn't empty at all, and investigates the differences in our perception of the world in the universe and the reality.

Particle physicist Prof. Brian Cox asks, 'What time is it?' It's a simple question and it sounds like it has a simple answer. But do we really know what it is that we're asking? Brian visits the ancient Mayan pyramids in Mexico where the Maya built temples to time. He finds out that a day is never 24 hours and meets Earth's very own Director of Time. He journeys to the beginning of time, and goes beyond within the realms of string theory, and explores the very limit of time. He discovers that we not only travel through time at the speed of light, but the experience we feel as the passing of time could be an illusion.