Episode
Horizon: How Long is a Piece of String?
Overview
Alan Davies attempts to answer the proverbial question: how long is a piece of string? But what appears to be a simple task soon turns into a mind-bending voyage of discovery where nothing is as it seems. An encounter with leading mathematician Marcus du Sautoy reveals that Alan's short length of string may in fact be infinitely long. When Alan attempts to measure his string at the atomic scale, events take an even stranger turn. Not only do objects appear in many places at once, but reality itself seems to be an illusion. Ultimately, Alan finds that measuring his piece of string could - in theory at least - create a black hole, bringing about the end of the world.
Details
- Series
- Horizon
- Season
- Season 46
- Episode
- Episode 17
- Air date
- 2009-12-22
- Runtime
- 60 min
Episode context
How Long is a Piece of String? is Episode 17 in 2009 of Horizon. It aired on 2009-12-22. The runtime is 60 min.
Previous / Next
Episode 16: Why Do We Talk?
Talking is something that is unique to humans, yet it still remains a mystery. Horizon meets the scientists beginning to unlock the secrets of speech - including a father who is filming every second of his son's first three years in order to discover how we learn to talk, the autistic savant who can speak more than 20 languages, and the first scientist to identify a gene that makes speech possible. Horizon also hears from the godfather of linguistics, Noam Chomsky, the first to suggest that our ability to talk is innate. A unique experiment shows how a new alien language can emerge in just one afternoon, in a bid to understand where language comes from and why it is the way it is.
Episode 18: How Many People Can Live on Planet Earth?
Naturalist Sir David Attenborough investigates whether the world faces a population crisis and if it is the duty of individuals to change the way they live.
More episodes from this season
Episode 15: Who's Afraid of a Big Black Hole?
Black holes are one of the most destructive forces in the universe, capable of tearing a planet apart and swallowing an entire star. Yet scientists now believe they could hold the key to answering the ultimate question - what was there before the Big Bang? The trouble is that researching them is next to impossible. Black holes are by definition invisible and there's no scientific theory able to explain them. Despite these obvious obstacles, Horizon meets the astronomers attempting to image a black hole for the very first time and the theoretical physicists getting ever closer to unlocking their mysteries. It's a story that takes us into the heart of a black hole and to the very edge of what we think we know about the universe.
Episode 14: Fix Me
Episode 13: The Secret You
With the help of a hammer-wielding scientist, Jennifer Aniston and a general anaesthetic, Professor Marcus du Sautoy goes in search of answers to one of science's greatest mysteries: how do we know who we are? While the thoughts that make us feel as though we know ourselves are easy to experience, they are notoriously difficult to explain. So, in order to find out where they come from, Marcus subjects himself to a series of probing experiments. He learns at what age our self-awareness emerges and whether other species share this trait. Next, he has his mind scrambled by a cutting-edge experiment in anaesthesia. Having survived that ordeal, Marcus is given an out-of-body experience in a bid to locate his true self. And in Hollywood, he learns how celebrities are helping scientists understand the microscopic activities of our brain. Finally, he takes part in a mind-reading experiment that both helps explain and radically alters his understanding of who he is.
Episode 12: Do I Drink Too Much?
Do I Drink Too Much? Alcohol is by far the most widely used drug - and a dangerous one at that. So why are so many of us drinking over the recommended limits? Why does alcohol have such a powerful grip on us? How much of our relationship with this drug is written in our genes? What are the real dangers of our children drinking too young? Addiction expert John Marsden, who likes a drink, makes a professional and personal exploration of our relationship with alcohol. He undergoes physical and neurological examinations to determine its impact, and finds out why some people will find it much harder than others to resist alcohol. Even at the age of 14 there may be a way of determining which healthy children will turn into addicts. John experiments with a designer drug being developed that hopes to replicate all the benefits of alcohol without the dangers. Could this drug replace alcohol in the future?
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 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 9: Why Can't We Predict Earthquakes?
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 8: Who Do You Want Your Child to Be?
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 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 6: What's the Problem with Nudity?
What is wrong with nudity? Why are people embarrassed about their bodies? How and why did they get the way they are?
Horizon takes a group of volunteers and subjects them to a series of psychological and physical tests to challenge attitudes to the naked human form. The questions raised strike at the heart of human physical and social evolution.
Human beings are the only creatures that can be 'naked' - but why, how and when did people lose their fur? That question takes Horizon around the world to meet scientists from Africa to Florida, and they are finding answers in unexpected places: the chest hair of Finnish students, the genetic history of lice, and the sweat of an unusual monkey.
It turns out that something everyone takes for granted may hold the key to the success of the entire human species.