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The Worst Episodes of Horizon

Every episode of Horizon ranked from worst to best. Explore the Worst Episodes of Horizon!

Worst episode
S54E1 Clean Eating: The Dirty Truth
5.760 votes
Top season
Season 62
8.7avg
Binge time
48d 20h
1174 episodes

Episode Rankings

  1. #1 Worst Episode
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    Horizon Season 54 Episode 1 - Clean Eating: The Dirty Truth
    5.7/10(60 votes)
    S54:E1

    Imagine if the food you eat could 'clean' your body and make you feel well. Dr Giles Yeo investigates the latest diet craze and social media sensation - clean eating. In a television first, Giles cooks with Ella Mills, the Instagram entrepreneur behind Deliciously Ella, one of the most popular brands associated with clean eating, and examines how far her plant-based cooking is based on science. She tells him clean has lost its way: "Clean now implies dirty and that's negative. I haven't used it, but as far as I understood it when I first read the term, it meant natural, kind of unprocessed, and now it doesn't mean that at all. It means diet, it means fad". Giles sifts through the claims of the Hemsley sisters, who advocate not just gluten-free but grain-free cooking, and Natasha Corrett, who popularises alkaline eating through her Honestly Healthy brand. In America, Giles reveals the key alternative health figures whose food philosophies are influencing the new gurus of clean. He discovers that when it comes to their promises about food and our health, all is not always what it appears to be. Inside a Californian ranch where cancer patients have been treated with alkaline food, Giles sees for himself what can happen when pseudoscience is taken to a shocking extreme.

    Director:Unknown
    Writer:Unknown

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  2. Horizon Season 54 Episode 12 - What Makes a Psychopath?
    6.1/10(89 votes)
    S54:E12

    Psychopaths have long captured the public imagination. Painted as charismatic, violent predators lacking in all empathy, they provide intrigue and horror in equal measure. But what precisely is a psychopath? What is it that drives them to cause harm, even kill? And can they ever be cured? Presented by psychologist Professor Uta Frith, this is an in-depth exploration of the psychopathic mind including one of the most notorious of all, Moors murderer Ian Brady. Through an ongoing correspondence between the Horizon team and Brady, the film features some of the very last letters he wrote. The film also features a series of candid interviews with prison inmates who not only describe their crimes but why they think they committed them. Horizon explores not only how each individual's crimes were shaped by their own life experiences, but also gives an insight in to how these people think and behave. Working with the world's experts in the field, the film sheds light on the biological, psychological and environmental influences that shape a psychopath. And it looks to the future, with groundbreaking research that suggests a lifetime of incarceration is not the only option to manage violent and dangerous psychopaths.

    Director:Unknown
    Writer:Unknown

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  3. Horizon Season 55 Episode 7 - A Week Without Lying - The Honesty Experiment
    5.8/10(21 votes)
    S55:E7

    Deception is an integral part of human nature and it is estimated we all lie up to nine times a day. But what if we created a world in which we couldn't lie? In a radical experiment, pioneering scientists from across Europe have come together to make this happen. Brand new technology is allowing them to rig three British people to make it impossible for them to lie undetected. Then they will be challenged to live for a whole week without telling a single lie. It is a bold social experiment to discover the role of deception in our lives - to investigate the impact lying has on our mental state and the consequences of it for our relationships, and to ask whether the world would be a better or worse place if we couldn't lie.

    Director:Unknown
    Writer:Unknown

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  4. Horizon Season 53 Episode 15 - The Lost Tribes of Humanity
    5.9/10(22 votes)
    S53:E15

    Alice Roberts explores the latest discoveries in the study of human origins, revealing the transformation that has been brought about in this field by genetics.

    Director:Unknown
    Writer:Unknown

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  5. Horizon Season 20 Episode 4 - How Much Can You Drink?
    5.5/10(13 votes)
    S20:E4

    Horizon examines some of the effects that moderate amounts of alcohol can have on the body.

    Director:Unknown
    Writer:Unknown

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  6. Horizon Season 52 Episode 15 - OCD: A Monster In My Mind
    6.5/10(100 votes)
    S52:E15

    Most of us think that Obsessive Compulsive Disorder (OCD) is just over fussy tidying. But it's actually much more serious. Sophie has to check that she hasn't killed people, looking for dead bodies wherever she goes, Richard is terrified of touching the bin, and Nanda is about to have pioneering brain surgery to stop her worrying about components on her body - that her eyebrow might not be aligned or that she has bad breath. Professor Uta Frith meets the people living with OCD, looks at the therapy available and asks what neuroscience can offer by way of a cure.

    Director:Unknown
    Writer:Unknown

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  8. Horizon Season 56 Episode 5 - The 250 Million Pound Cancer Cure
    6.1/10(22 votes)
    S56:E5

    Following the NHS as they start to implement proton beam therapy, an advanced but expensive cancer treatment, as well as following as the first children awaiting the lifesaving treatment.

    Director:Unknown
    Writer:Unknown

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  9. Horizon Season 57 Episode 5 - Hubble: The Wonders of Space Revealed
    5.9/10(14 votes)
    S57:E5

    To celebrate the 30th anniversary of its launch, this film tells the remarkable story of how Hubble revealed the awe and wonder of our universe and how a team of daring astronauts risked their lives to keep it working.

    Director:Unknown
    Writer:Unknown

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  10. Horizon Season 41 Episode 5 - The Dark Secret of Hendrik Schön
    5.8/10(12 votes)
    S41:E5

    Imagine a world where disease could be eradicated by an injection of tiny robots the size of molecules. That is the hope offered by nanotechnology - the science of microscopically small machines. But others fear nanotechnology could lead to a non-biological cancer - where swarms of tiny nanobots come together and literally devour human flesh. Sounds like science fiction? It certainly did until a brilliant young scientist called Hendrik Schön seemed to bring it a step closer. Schön's great breakthrough was to make a computer transistor out of a single organic molecule. It was an achievement of almost incalculable brilliance. Some speculated this technology could spell the end of the entire silicon chip industry. Crucially, Schön's transistor was organic. Suddenly, this seemed to be the first step towards true nanotechnology, where minute computers could grow as living cells. Scientists speculated about how these tiny machines could be used to target diseases with astonishing precision. Others wondered - could the military use them as a new weapon? Others, including Prince Charles, were terrified. If these machines can grow by themselves, how do we stop them from growing? What happened next would destroy reputations and shatter lives - because there was more to Hendrik Schön's discovery than anyone knew.

    Director:Unknown
    Writer:Unknown

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  11. Horizon Season 51 Episode 1 - Monitor Me
    6.7/10(126 votes)
    S51:E1

    Dr Kevin Fong explores a medical revolution that promises to help us live longer, healthier lives. Inspired by the boom in health-related apps and gadgets, it's all about novel ways we can monitor ourselves around the clock. How we exercise, how we sleep, even how we sit.

    Director:Unknown
    Writer:Unknown

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  12. Horizon Season 52 Episode 7 - Secrets of the Solar System
    6.5/10(36 votes)
    S52:E7

    New planets are now being discovered outside our solar system on a regular basis, and these strange new worlds are forcing scientists to rewrite the history of our own solar system. Far from a simple story of stable orbits, the creation of our solar system is a tale of hellfire, chaos and planetary pinball.

    Director:Unknown
    Writer:Unknown

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  13. Horizon Season 55 Episode 9 - Body Clock: What Makes Us Tick?
    6.4/10(27 votes)
    S55:E9

    We all have a biological clock ticking away inside us that governs our daily rhythms. This affects our health as much as our diet and whether we exercise. So what can we do to manage this internal clock better? To find out, evolutionary biologist Ella Al-Shamahi locks former commando Aldo Kane in an abandoned nuclear bunker with no way of telling the time - for ten days. Monitored around the clock by a team of scientists, he carries out a barrage of tests to uncover exactly what makes our body clock tick. Above ground, Ella meets two time-starved couples to test the latest thinking on how we can manage our body clocks better. In trying to improve their sleep, and their lives, she uncovers practical advice that we can all take on board. Studies on shift workers show that regularly disrupting our sleep makes us more at risk of diabetes, heart disease and even cancer. So getting to grips with our biological clock couldn't be more important.

    Director:Unknown
    Writer:Unknown

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  14. Horizon Season 46 Episode 2 - Cannabis: The Evil Weed?
    6.7/10(97 votes)
    S46:E2

    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.

    Director:Unknown
    Writer:Unknown

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  15. Horizon Season 55 Episode 6 - Stopping Male Suicide
    6.4/10(24 votes)
    S55:E6

    Suicide is the biggest killer of men under 50 in the UK - causing more deaths in this group than car accidents, and even more than cancer. This means that the most likely thing to kill Dr Xand Van Tulleken is himself. And he wants to know why. In this sensitive film, Xand finds out what we know about why people develop suicidal thoughts, and whether there is anything that we can do about it.

    Director:Unknown
    Writer:Unknown

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  16. Horizon Season 43 Episode 19 - We are the Aliens
    6.3/10(18 votes)
    S43:E19

    Clouds of alien life forms are sweeping through outer space and infecting planets with life – it may not be as far-fetched as it sounds. The idea that life on Earth came from another planet has been around as a modern scientific theory since the 1960s when it was proposed by Fred Hoyle and Chandra Wickramasinghe. At the time they were ridiculed for their idea – known as panspermia. But now, with growing evidence, it's back in vogue and even being studied by NASA. Horizon meets the scientists on a mission to get to the bottom of the beginnings of life on Earth - from the team in Texas who are lovingly building a robotic submarine called DEPTHX to explore a moon of Jupiter, to Southern India where they are investigating a mysterious red rain which fell for two months in 2001. According to local scientist Godfrey Louis, the rain contains biological cells unlike any he had seen before – with no DNA and the ability to replicate at 300°C. Louis has come to the conclusion that the cells are extra-terrestrial in origin.

    Director:Unknown
    Writer:Unknown

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  17. Horizon Season 46 Episode 9 - Why Can't We Predict Earthquakes?
    6.3/10(18 votes)
    S46:E9

    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.

    Director:Unknown
    Writer:Unknown

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  18. Horizon Season 36 Episode 6 - New Star in Orbit
    5.8/10(9 votes)
    S36:E6

    In this report, Horizon explores the arguments for and against the building of the Space Station Freedom and will it ever justify it's huge cost.

    Director:Unknown
    Writer:Unknown

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  19. Horizon Season 41 Episode 3 - The Atkins Diet
    5.8/10(9 votes)
    S41:E3

    This is the truth about the world's most famous, most glamorous and most controversial diet. The Atkins diet says that eating fat can make you thin. It says you don't need to bother watching the calories. Rene Zellweger, Geri Halliwell and a host of other celebrities swear by it. But many scientists think it is scientific nonsense. Some even believe it is dangerous. Horizon cuts through the confusion and provide the answers. When Dr Atkins first launched his diet, he was accused of breaking one of the most fundamental laws of nature. Scientists said that if you eat more, you'll get fatter. They also said it could kill. Fat increases your cholesterol levels. You'd get a heart attack. The only problem was that people who followed the Atkins diet got thinner. Much of the rest of us got fatter. Then came studies showing that cholesterol levels can actually improve on the Atkins diet. So what was going on? Horizon's investigation seems to show that the diet may really work - but for a reason and in a way that no scientists or even Atkins himself had seriously considered.

    Director:Unknown
    Writer:Unknown

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  20. Horizon Season 46 Episode 12 - Do I Drink Too Much?
    6.5/10(24 votes)
    S46:E12

    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?

    Director:Unknown
    Writer:Unknown

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  21. Horizon Season 51 Episode 9 - Living with Autism
    6.6/10(27 votes)
    S51:E9

    When pioneering developmental psychologist Professor Uta Frith started her training back in the 1960s, she met a group of beautiful, bright-eyed young children who seemed completely detached from the rest of the world. It turned out they had just been given the then-new diagnosis of autism. Uta passionately wanted to know more about these children, and they inspired her to dedicate the rest of her career to studying the autistic mind. On the eve of National Autism Day, Horizon reveals how Uta's lifetime study of people with autism has transformed our understanding of this mysterious condition. In this film Uta shows how people with autism perceive and interact with the world and how, for them, another kind of reality exists. She meets people with autism who have extraordinary talents, and explains why they often fail to understand jokes. She also explores whether many of us could be just a little bit autistic.

    Director:Helen Sage
    Writer:Unknown

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  22. Horizon Season 46 Episode 6 - What's the Problem with Nudity?
    6.7/10(39 votes)
    S46:E6

    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.

    Director:Unknown
    Writer:Unknown

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  23. Horizon Season 53 Episode 2 - Project Greenglow - The Quest for Gravity Control
    6.7/10(36 votes)
    S53:E2

    Documentary exploring science's long-standing obsession with the idea of gravity control, including recent breakthroughs in the search for loopholes in conventional physics. The programme examines how the groundwork carried out by Project Greenglow in the mid-1990s by UK defence manufacturer BAE Systems (based on the work of Eugene Podkletnov[82]) has changed the understanding of the universe, making the dream of flying cars and journeys to the stars no longer quite so distant.

    Director:Nic Young
    Writer:Unknown

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  24. Horizon Season 39 Episode 15 - Stone Age Columbus
    6.1/10(10 votes)
    S39:E15

    Who were the first people in North America? From where did they come? How did they arrive? The prehistory of the Americas has been widely studied. Over 70 years a consensus became so established that dissenters felt uneasy challenging it. Yet in 2001, genetics, anthropology and a few shards of flint combined to overturn the accepted facts and to push back one of the greatest technological changes that the Americas have ever seen by over five millennia. The accepted version of the first Americans starts with a flint spearhead unearthed at Clovis, New Mexico, in 1933. Dated by the mammoth skeleton it lay beside to 11,500 years ago, it was distinctive because it had two faces, where flakes had been knapped away from a core flint. The find sparked a wave of similar reports, all dating from around the same period. There seemed to be nothing human before Clovis. Whoever those incomers were around 9,500BC, they appeared to have had a clean start. And the Clovis point was their icon - across 48 states.

    Director:Unknown
    Writer:Unknown

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  25. Horizon Season 39 Episode 8 - The Fall of the World Trade Center
    6.3/10(13 votes)
    S39:E8

    The World Trade Center was built on revolutionary design principles. It turned conventional architectural and structural techniques on their head. Built from a thin web of steel, its design was efficient, cost-effective and would inspire a new wave in modern building techniques. The result was two towers that were both lightweight and strong. When they were completed they were the tallest in the world. They were also milestones of architecture for another reason. The two towers were the first skyscrapers explicitly designed to withstand being hit by a jet plane. Although they had considered an aircraft impact, the designers of the World Trade towers had not anticipated the effect of an aeroplane's fuel load. British-born survivor Paul Neal tells how he smelt jet fuel rushing through the lift shafts close to his desk. "I recognised it because I'm a private pilot. I recall smelling it and instantly dismissed it as being illogical because it didn't have any place in the World Trade Center." Survivor, Bill Forney, recalls the instant that the 767 aircraft hit the North Tower one floor above where he was sitting. "The building started shaking. It lurched back and forth. It was the first time that I had truly thought that I might die. After a terrifying six to ten movements back and forth it was over and it was done." The World Trade Center had ultra-lightweight floors, and used the latest fireproof 'drywall' to protect the stairwells and lift shafts. Much of this internal structure seems to have been vaporized when the planes crashed, exposing the underlying steel to the intense heat of multiple fires. Brian Clark was one of the only four survivors from both towers to escape from above where the planes hit. He describess clambering over the shattered walls to break through a smoke-filled stairwell to get out. "Drywall had been blown off and was lying up against the stair railing." he says, "We had to shovel it aside." Another survivor, window cleaner Jan Demczur, found the drywall so soft that he was able to dig through it with a squeegee to break out of a lift he was trapped in. The two towers responded differently to the initial impacts, because there were crucial differences between the collisions. The South Tower, struck second, was hit lower, and the damaged zone of the tower then had to support a much greater weight of building above it . Rather than being hit head-on, the South Tower was hit at an angle. The plane wreckage scraped along the inside of the east wall and piled up in the northeast corner. Here, the fire burned intensely. At the South Tower's inner core, one escape stair was left intact - the one furthest from the plane's path. Even then, only four people, one of them Brian Clark, managed to get down it. At the northeast corner and along the east wall, the connections between the floors and the outer wall began to break as the floors sagged in the heat. The floors were an essential part of the structure, bracing both the outer walls and the inner core. Already weakened by the impact and now unbraced, the outer wall columns of the South Tower could not support the weight above them. At 9.59am Eastern Time, they snapped. The entire top third of the tower then lurched to the north and east; the floors inside the rest of the tower piled down onto those below. The downward wave of destruction - a progressive collapse - was then unstoppable. Meanwhile, the North Tower, which had been hit first, was still standing. The core of the Tower had been hit head-on, and the core had been left mostly undamaged by the impact. However, the direct hit cut off all the escape routes without exception. Meanwhile, the fire inside the North Tower was spread around the core. Again, connections between floors and columns started to fail in the heat, but here in the North Tower, it was the connections at the core that gave way first. Without the floors to brace it, the core could not stand alone. 29 minutes after the first collapse, the core in the North Tower collapsed vertically, pulling the rest of the tower down with it. The implications of the Twin Towers collapse are disturbing. Whether anything can be done to make modern lightweight skyscrapers more robust in the aftermath of 11 September is a vital question that must now be answered.

    Director:Unknown
    Writer:Unknown

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  26. Horizon Season 48 Episode 6 - Asteroids - The Good, the Bad and the Ugly
    6.3/10(13 votes)
    S48:E6

    Famed for their ability to inflict Armageddon from outer space, asteroids are now revealing the secrets of how they are responsible for both life and death on our planet.

    Director:Unknown
    Writer:Unknown

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Worst Episodes Summary

"Clean Eating: The Dirty Truth" is the worst rated episode of Horizon. It scored 5.7/10 from 60 votes. Written and directed by Unknown, it aired on January 19, 2017. This episode scored 0.4 points lower than the second lowest rated, "What Makes a Psychopath?".

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