Horizon Season 46 Episodes

Episode 1

Why Are Thin People Not Fat?

The world is affected by an obesity epidemic, but why is it that not everyone is succumbing? Medical science has been obsessed with this subject and is coming up with some unexpected answers. As it turns out, it is not all about exercise and diet. At the centre of this programme is a controversial overeating experiment that aims to identify exactly what it is about some people that makes it hard for them to bulk up.

Episode 2

Cannabis: The Evil Weed?

Cannabis is the world's favourite drug, but also one of the least understood. Can cannabis cause schizophrenia? Is it addictive? Can it lead you on to harder drugs? Or is it simply a herb, an undervalued medicine? Addiction specialist Dr John Marsden discovers that modern science is finally beginning to find answers to these questions. John traces the cannabis plants' birthplace in Kazakhstan; finds the origins of our sensitivity to cannabis in the simple sea squirt; and finds out just what it does to our brains. He meets people who have been changed by this drug in drastically different ways - from those whose lives have been shattered to those who lives have been revived.

Episode 3

Why Do We Dream?

Horizon uncovers the secret world of our dreams. In a series of cutting-edge experiments and personal stories, we go in search of the science behind this most enduring mystery and ask: where do dreams come from? Do they have meaning? And ultimately, why do we dream? What the film reveals is that much of what we thought we knew no longer stands true. Dreams are not simply wild imaginings but play a significant part in all our lives as they have an impact on our memories, the ability to learn, and our mental health. Most surprisingly, we find nightmares, too, are beneficial and may even explain the survival of our species.

Episode 4

Can We Make a Star on Earth?

Professor Brian Cox takes a global journey in search of the energy source of the future. Called nuclear fusion, it is the process that fuels the sun and every other star in the universe. Yet despite over five decades of effort, scientists have been unable to get even a single watt of fusion electricity onto the grid. Brian returns to Horizon to find out why. Granted extraordinary access to the biggest and most ambitious fusion experiments on the planet, Brian travels to the USA to see a high security fusion bomb testing facility in action and is given a tour of the world's most powerful laser. In South Korea, he clambers inside the reaction chamber of K-Star, the world's first super-cooled, super-conducting fusion reactor where the fate of future fusion research will be decided.

Episode 5

The Secret Life of Your Body Clock

Why are people more likely to have a heart attack at eight in the morning or crash their car on the motorway at two in the afternoon? The answer lies in our biological clock.

Episode 6

What's the Problem with Nudity?

Modern research, mainly in London and Turku (Finland), examines paleontological evidence and modern test-subjects on how the unique human sense of nudity roots in biological evolution. It proves nudity, except for patches on skull and genitals, was an advantage in hot Africa about 3 million years ago, and cloths evolved 500,000 years ago giving greater flexibility. Humans are conditioned to select 'healthy' mates from corresponding indicators, such as limited hairiness and features discernible under clothing.

Episode 7

How to Survive a Disaster

When disaster strikes who lives and who dies is not purely a matter of luck. In every disaster, from those people face once in a lifetime, to those they face every day, there are things that can be done to increase the chances of getting out alive. Horizon has gathered a team of leading experts to produce the ultimate guide to disaster survival. Through controversial experiments, computer simulations and analysis of hundreds of survivor testimonies from plane crashes to ferry disasters and even 9/11, they will reveal what happens in the mind in the moment of crisis and how the human brain can be programmed for survival.

Episode 8

Who Do You Want Your Child to Be?

58 mins

David Baddiel, father of two, sets out to answer one of the greatest questions a parent can ask: how best to educate your child. Taking in the latest scientific research, David uncovers some unconventional approaches: from the parent hot-hosing his child to record-breaking feats of maths, to a school that pays hard cash for good grades. David witnesses a ground-breaking experiment that suggests a child's destiny can be predicted at four, and hears the three little words that can ruin a child's chance of success for good. He also uncovers the neurological basis for why teenagers can be stroppy and explosive and has his own brain tinkered with to experience what it is like to struggle at school. Through it all, David's quest remains true: to maximise his child's potential for success and happiness.

Episode 9

Why Can't We Predict Earthquakes?

59 mins

Last century, earthquakes killed over one million, and it is predicted that this century might see ten times as many deaths. Yet when an earthquake strikes, it always takes people by surprise. So why hasn't science worked out how to predict when and where the next big quake is going to happen? This is the story of the men and women who chase earthquakes and try to understand this mysterious force of nature. Journeying to China's Sichuan Province, which still lies devastated by the earthquake that struck in May 2008, as well as the notorious San Andreas Fault in California, Horizon asks why science has so far fallen short of answering this fundamental question.

Episode 10

Alan and Marcus Go Forth and Multiply

Ever since he was at school, actor and comedian Alan Davies has hated maths. And like many people, he is not much good at it either. But Alan has always had a sneaking suspicion that he was missing out. So, with the help of top mathematician Professor Marcus du Sautoy, Alan is going to embark on a maths odyssey. Together they visit the fourth dimension, cross the universe and explore the concept of infinity. Along the way, Alan does battle with some of the toughest maths questions of our age. But did his abilities peak 25 years ago when he got his grade C O-Level? Or will Alan be able to master the most complex maths concept there is?

Episode 11

How Violent Are You?

What makes ordinary people commit extreme acts of violence? Michael Portillo investigates the dark side of human nature, and discovers what it is like to inflict pain.

Episode 12

Do I Drink Too Much?

Addiction expert John Marsden, who likes a drink, makes a professional and personal exploration of our relationship with alcohol, undergoing physical and neurological examinations.

Episode 13

The Secret You

Marcus du Sautoy goes in search of answers to one of science's greatest mysteries: how do we know who we are? He subjects himself to a series of experiments in order to find out.

Episode 14

Fix Me

Horizon follows the emotional journey of three young people with currently untreatable conditions to see if, within their lifetime, they can be cured.

Episode 15

Who's Afraid of a Big Black Hole?

Scientists now believe black holes could hold the key to answering the ultimate question: what was there before the big bang? However, researching them is next to impossible.

Episode 16

Why Do We Talk?

Talking is a phenomenon that is unique to humans, yet it remains a mystery. Horizon meets the people unlocking the secrets of speech and looks at the theories of linguistics.

Episode 17

How Long Is a Piece of String?

Alan Davies tries to answer the proverbial question: how long is a piece of string? But the task soon turns into a mind-bending voyage of discovery where nothing is as it seems.

Episode 18

How Many People Can Live on Planet Earth?

In a Horizon special, naturalist Sir David Attenborough investigates whether the world is heading for a population crisis. In his lengthy career, Sir David has watched the human population more than double from 2.5 billion in 1950 to nearly seven billion. He reflects on the profound effects of this rapid growth, both on humans and the environment. While much of the projected growth in human population is likely to come from the developing world, it is the lifestyle enjoyed by many in the West that has the most impact on the planet. Some experts claim that in the UK consumers use as much as two and a half times their fair share of Earth's resources. Sir David examines whether it is the duty of individuals to commit not only to smaller families, but to change the way they live for the sake of humanity and planet Earth.