9.6/1011 votesLoading...#1 - Valley of Life or Death
Season 37 Episode 15 - Aired 11/16/2000
At the heart of the AIDS epidemic in Africa, there is a deadly mystery that has puzzled scientists for years. There are groups of people who are four times less likely to get HIV than other people, sometimes living just yards away, across a single valley - people with apparently similar behaviour and lifestyle. Scientists realised that if they could understand why these people are so much less vulnerable to the HIV virus, it might lead to an answer that could save millions of lives. And after 15 years of detective work it turns out there may be a remarkably simple answer: the high risk areas for HIV coincide with tribes who are uncircumcised. In Africa, it seems a man is much more likely to get HIV if he is uncircumcised. In Kaoma, Western Zambia, a young boy is on his way to the sacred Mukondaa - the tribal circumcision ground. Around him the tribal elders are gathered, dressed in their ceremonial garb, and vivid masks. But the young boy himself is an outsider, not from this tribe, and none of his relatives or ancestors have ever been circumcised. In fact, his parents are only prepared to break the taboo of their own tribe because they believe that circumcision could save his life by protecting him from AIDS. At first sight this belief seems like the kind of superstition to which desperate people often turn in times of plague. But now there is scientific evidence that suggests these people could well be right. There have now been twenty seven statistical studies that show a big difference in HIV infection between circumcised and uncircumcised men. For example, among the uncircumcised people of Kisumu in Western Kenya, a man is three times as likely to get AIDS than his circumcised neighbours. Among truck drivers in Mombasa the difference is four-fold. Horizon travels across Africa, tracing the work of scientists who have unearthed the statistical data behind this correlation. At the same time microbiologists have been battling to understand the complex and insidious virus, and their work indicates that the foreskin may be a key entry point for HIV. The logical conclusion for these scientists is that if you remove the foreskin, you begin to protect the man. No-one believes that circumcision can protect completely - the evidence so far only indicates that it reduces the risk of infection by HIV, and then only during heterosexual sex. Unquestionably, condoms are still the best protection. But in the many countries where the use of condoms is minimal, it seems that circumcision might help to reduce the spread of AIDS. In the absence of a vaccine for AIDS, and the lack of condom use in the developing world, should governments think the unthinkable and encourage the circumcision of young boys in non-circumcising tribes as a public policy? Opposing this idea are the voices of tribal elders who are loath to change tribal traditions that have existed for generations, and a fierce Western anti-circumcision lobby which believes that circumcision is a form of mutilation and violates basic human rights.
Director: N/A
Writer: N/A
- 9.4/1013 votesLoading...
#2 - The Writing on the Wall
Season 11 Episode 6 - Aired 2/11/1974
In this episode, Horizon looks at connections between crime and poor housing design in the USA.
Director: N/A
Writer: N/A
- 9.0/107 votesLoading...
#3 - Cloning the First Human
Season 38 Episode 11 - Aired 10/25/2001
Doctors Panayiotis Zavos and Severino Antinori claim they are ready to embark on the greatest human experiment of our age. They say they will attempt to clone a human being before the year is out. Most people think the objections to this are ethical - human cloning would create many moral dilemmas. There is another question that few ever ask: is the science actually ready yet for cloning healthy humans? Horizon follows the latest research, which has led many scientists to believe that Zavos and Antinori's plans to clone the first human could end in tragedy. The programme also meets couples like Matthew and Desiree Racquer who think cloning offers them the only way to raise a child who is truly their own. For decades, cloning remained within the realms of science fiction. The idea that instead of combining a sperm and an egg, a new human could be made from a single cell taken from an adult, seemed completely absurd. But that all changed in February 1997, when the Roslin Institute introduced the world to Dolly the sheep - the first animal cloned from an adult. Ever since Dolly, scientists have been continuing to experiment with cloning animals. So far, they have succeeded in cloning sheep, cattle, pigs, goats and mice, fuelling the belief that humans could be next. But even Dolly's creator, Professor Ian Wilmut, is concerned that beneath the veneer of success lies a disturbing reality. Most cloning attempts on animals so far have resulted in failed implantation or abnormal foetuses. Of the animals born alive, some soon die of catastrophic organ failure. Others appear to be healthy for weeks or even months, then die suddenly, sometimes from bizarre new illnesses which do not occur in nature. Years of painstaking work are only now revealing some vital clues to what is going wrong. Horizon talks to the scientists who have uncovered new evidence, suggesting that the process of cloning itself causes subtle errors in the way genes function. These random errors may be like a time bomb inside every clone, causing some of the strange - often fatal - problems. There's no reason to think cloned human babies would fare any better. According to embryologist Dr Susan Avery, death might be the best outcome for many human clones. If they survived, they would suffer from catastrophic illnesses that modern medicine is powerless to prevent or cure. Dr Zavos claims that these problems are the result of the still unsophisticated methods being used by animal researchers. Using advanced in vitro fertilisation ('test tube baby') techniques, he claims that he will strive to make human cloning safer than natural reproduction. Now though, it seems that some IVF procedures themselves are being investigated for possible harmful effects on the long term health of children. Professor Gerald Schatten of the University of Pittsburgh reveals evidence of these risks, which could be magnified in cloning. Most reproductive specialists believe that the danger to any human born by cloning is enormous. But the would-be human cloners are determined to clone a human baby. If they proceed, they may be courting tragedy.
Director: N/A
Writer: N/A
- 8.7/10147 votesLoading...
#4 - Gentlemen, Lift Your Skirts
Season 18 Episode 9 - Aired 3/9/1981
Horizon examines the design of Formula One racing cars with a particular reference to the aerodynamic 'skirt'.
Director: N/A
Writer: N/A
- 8.7/1091 votesLoading...
#5 - Do You Know What Time It Is?
Season 45 Episode 15 - Aired 12/2/2008
Particle physicist Professor 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.
Director: N/A
Writer: N/A
- 8.6/106 votesLoading...
#6 - Miracle In Orbit
Season 37 Episode 5 - Aired 2/3/2000
When and how did space and time begin? The birth of the Universe is one of the biggest mysteries in astronomy. It has perplexed the best scientific minds for centuries. Decades before space travel was possible, astronomers dreamed of putting a telescope into orbit to try and answer these fundamental questions. It wasn't until the 1970s, when space flight had become a reality, that NASA resolved to build just such a space telescope. They named it Hubble. This was one of the most ambitious missions ever conceived. The technical challenges were enormous and it took 12 years to design and build. Travelling at seventeen thousand miles an hour, the Hubble Telescope would take pictures of the furthest reaches of space, transmitting them 400 miles back to Earth. In April 1990 the Hubble Space Telescope was launched. But just weeks later, disaster struck - the $2 billion telescope had a fatal flaw in its main mirror. This was not just a disaster for NASA; it was a national scandal. Hubble had to be saved; scientists and engineers began to search desperately for a solution to the problem. Plans for an adventurous repair mission began to take shape but it was two years before work could be carried out. It took astronauts five gruelling space-walks to carefully replace the instruments and patch up the telescope. But nobody knew if Hubble would be able to deliver on any of its original promises. Finally, the miracle happened. An unexpected avalanche of data from Hubble confirmed that the telescope was fixed. At last it began to solve the most fundamental puzzles of the Universe. Hubble has given us breathtaking images of the birth of stars; it has found black holes swallowing matter at the centre of galaxies; and last year the Hubble Telescope resolved the most fundamental question in astronomy - the age of the Universe. At last, half a century of scientific endeavour was rewarded. Horizon marks the 10th anniversary of the launch of the Hubble Space Telescope by tracing the extraordinary tale of triumph, disaster and eventual success of this unique window into the Universe.
Director: N/A
Writer: N/A
- 8.6/1026 votesLoading...
#7 - Atlantis Reborn Again
Season 37 Episode 19 - Aired 12/14/2000
Horizon puts Graham Hancock's controversial theories about the past to the test, dissecting his evidence for a lost civilisation. Graham Hancock offers various pieces of evidence to support his theory. He claims that the mysterious lost civilisation left its mark in ancient monuments, which he calculates were built to mirror certain constellations of stars. His hugely popular ideas have attracted such a wide audience that they stand to replace the conventional view of the past, which is based on scientific evidence that the civilisations of the ancient world were developed independently, by different peoples, on different continents.
Director: N/A
Writer: N/A
- 8.5/109 votesLoading...
#8 - The Missing Link
Season 38 Episode 2 - Aired 2/1/2001
A trail from Greenland to Britain via Latvia offers new evidence into how evolution could have seen aquatic life form legs and walk.
Director: N/A
Writer: N/A
- 8.5/107 votesLoading...
#9 - Killer Algae
Season 38 Episode 3 - Aired 2/8/2001
A tropical seaweed that escaped from an aquarium is endangering sea life in the Mediterranean and has gone on to infect the California coast.
Director: N/A
Writer: N/A
- 8.4/1013 votesLoading...
#10 - The Food Allergy War
Season 22 Episode 12 - Aired 4/1/1985
Horizon investigates how food allergy has developed from the 1950's to the present.
Director: N/A
Writer: N/A
- 8.4/1013 votesLoading...
#11 - Project Poltergeist
Season 41 Episode 9 - Aired 3/18/2004
This is the story of two genuine scientific heroes. For forty years, John Bahcall and Ray Davis were engaged in a single extraordinary experiment - to find out why the Sun shines. In the end they would triumph. Davis would win the Nobel Prize and, thanks to their work, a whole new theory about how the universe is put together may have to be created. At the heart of this story is a tiny, utterly mysterious thing called a neutrino. Trillions of them pass through your body every second, touching nothing, leaving no trace. Yet neutrinos are one of a handful of fundamental particles in the universe, essential to every atom in existence and clues to what makes the Sun work. But their ghost-like quality made trapping and understanding them immensely difficult. What then followed was a bizarre series of experiments. They led from a vat containing 600 tons of cleaning fluid, to a vast cavern in a Japanese mountain, to a hole in the ground in Canada two kilometres deep. What they would reveal would stun the world of science. It seems that neutrinos may be our parents. They may be the reason why everything, including us, exists.
Director: N/A
Writer: N/A
- 8.4/1016 votesLoading...
#12 - King Solomon's Tablet of Stone
Season 41 Episode 12 - Aired 9/23/2004
No description available
Director: N/A
Writer: N/A
- 8.4/1019 votesLoading...
#13 - Nuclear Nightmares
Season 43 Episode 11 - Aired 7/13/2006
Horizon explores the topical scientific issues investigates, the truth behind our fear of radioactivity and asks whether our nuclear nightmares really are based on reality. From Hiroshima to Chernobyl scientists have been studying the impact of exposure to radiation for over 60 years and have always assumed that any level of radiation is bad. But now some scientists are questioning the power of radiation to cause cancer and finding evidence to suggest that it may have beneficial health effects.
Director: N/A
Writer: N/A
8.4/1034 votesLoading...#14 - Goodbye Cassini - Hello Saturn
Season 54 Episode 14 - Aired 9/18/2017
A billion miles from home, running low on fuel, and almost out of time. After 13 years traversing the Saturn system, the spacecraft Cassini is plunging to a fiery death, becoming part of the very planet it has been exploring. As it embarks on its final assignment - a one-way trip into the heart of Saturn - Horizon celebrates the incredible achievements and discoveries of a mission that has changed the way we see the solar system. Strange new worlds with gigantic ice geysers, hidden underground oceans that could harbour life and a brand new moon coalescing in Saturn's magnificent rings. As the world says goodbye to the great explorer Cassini, Horizon will be there for with a ringside seat for its final moments.
Director: N/A
Writer: N/A
- 8.3/1057 votesLoading...
#15 - IRAS - The Supercooled Eye
Season 22 Episode 14 - Aired 4/22/1985
This Horizon documentary examines the Infra-Red Astronomical Satellite (IRAS) which has detected evidence of planetary systems around distant stars.
Director: N/A
Writer: N/A
- 8.3/1032 votesLoading...
#16 - Malaria: Battle of the Merozoites
Season 29 Episode 5 - Aired 2/3/1992
In this episode, Horizon look at attempts to persuade major respected organizations to do controlled trials on a synthetic malaria vaccine.
Director: N/A
Writer: N/A
- 8.3/1023 votesLoading...
#17 - The Black Sun
Season 29 Episode 6 - Aired 2/17/1992
Horizon follows five teams of scientists on the island of Mauna Kea in Hawaii as they wait for a solar eclipse.
Director: N/A
Writer: N/A
- 8.3/1013 votesLoading...
#18 - Pill Poppers
Season 47 Episode 9 - Aired 1/20/2010
Over a person's lifetime they are likely to be prescribed more than 14,000 pills. Antibiotics, cholesterol lowering tablets, anti-depressants, painkillers, even tablets to extend youth and improve performance in bed. These drugs perform minor miracles day after day, but how much is really known about them? Drug discovery often owes as much to serendipity as to science, and that means much is learnt about how medicines work, or even what they do, when they're taken. By investigating some of the most popular pills people pop, Horizon asks, how much can they be trusted to do what they are supposed to?
Director: N/A
Writer: N/A
8.3/1026 votesLoading...#19 - The Truth About Personality
Season 50 Episode 16 - Aired 7/10/2013
Michael Mosley explores the latest science about how our personalities are created - and whether they can be changed. Despite appearances, Mosley is a pessimist who constantly frets about the future. He wants to worry less and become more of an optimist. He tries out two techniques to change this aspect of his personality - with surprising results. And he travels to the frontiers of genetics and neuroscience to find out about the forces that shape all our personalities.
Director: Helen Nixon
Writer: N/A
- 8.2/1014 votesLoading...
#20 - The Beersheva Experiment
Season 15 Episode 20 - Aired 11/3/1978
Horizon explores an experimental medical school in Israel where students are trained primarily to care for people.
Director: N/A
Writer: N/A
- 8.2/1034 votesLoading...
#21 - Conjoined Twins
Season 37 Episode 11 - Aired 10/19/2000
Conjoined twins are among the rarest of human beings. There are probably fewer than a dozen adult pairs living in the world today. Only a few hundred pairs of conjoined twins are born in the whole world each year - they appear about once in every 100,000 births - but more than half of them are stillborn, and one in three live for only a few days. Of those who survive, a very small number will be selected for separation surgery. But as there are few hospitals with the skills and experience to perform this kind of surgery, separation is still a very unusual event. The harrowing decisions which surgeons have to make when faced with conjoined twins have been highlighted by the recent case in Manchester, England. Separating conjoined twins is not only technically challenging; it can involves life and death decisions about whether one twin should be sacrificed in the hope of saving the other. But "sacrifice surgery" has a poor record of success, and the Manchester case is the latest round in an international debate about the value of separation operations. The confidence of the surgeons, who believe that separation is essential, is challenged by medical historian, Dr Alice Dreger of Michigan State University. She argues that twins themselves might take a different view - if they were ever given a chance to express it. Horizon interviews two pairs of adult conjoined twins - Lori and Reba Schappell in Pennsylvania and Masha and Dasha Krivoshlyapova in Moscow. Lori and Reba are joined at the head; Masha and Dasha are joined in their lower body. They say that they prefer their conjoined lives, despite the problems and challenges, rather than face the risks of separation surgery. Lori and Reba live independent lives in their own apartment in Pennsylvania; Lori enjoys working with computers and Reba is developing a career as a country singer. Masha and Dasha had a difficult childhood; they were subjected to medical experimentation when they were very young and hidden away from the public. Since the end of the communist era they have been able to tell their story. Their autobiography is being written by a British journalist, Juliet Butler. Horizon also follows surgeons at the Red Cross Children's Hospital in Cape Town, Africa as they plan to separate eight month old twins, Stella and Esther Alphonce. The baby girls are joined at the hip, and the surgeons have little doubt that they can and should be separated, even though the operation carries risks of disability for the twins. Historically conjoined twins who were not, or could not be separated have lived successful lives, even if this involved putting themselves on public display. The original Siamese twins, Chang and Eng Bunker, were joined by a narrow strip of flesh and could easily be separated today. Like Millie and Christine McCoy, who also lived in the USA in the middle of the last century, they earned fame and fortune touring the world. But life for conjoined twins has never been easy, Millie and Christine were kidnapped and sold several times in their childhood. The British conjoined twin sisters, Violet and Daisy Hilton, provoked a scandal in the USA when one of them tried to get married. They did eventually marry, but they were never separated. The tragedy for conjoined twins who spend their lives together is that they inevitably die together too. When one twin dies, the heart of the other twin keeps pumping until he or she is drained of blood. Is this another reason why twins should be separated when they are young? There are no simple answers, because every pair of twins is unique.
Director: N/A
Writer: Robert Eagle
- 8.2/1028 votesLoading...
#22 - The Lost Pyramids of Caral
Season 39 Episode 4 - Aired 1/31/2002
The magnificent ancient city of pyramids at Caral in Peru hit the headlines in 2001. The site is a thousand years older than the earliest known civilisation in the Americas and, at 2,627 BC, is as old as the pyramids of Egypt. Many now believe it is the fabled missing link of archaeology - a 'mother city'. If so, then these extraordinary findings could finally answer one of the great questions of archaeology: why did humans become civilised? For over a century, archaeologists have been searching for what they call a mother city. Civilisation began in only six areas of the world: Egypt, Mesopotamia, India, China, Peru and Central America. In each of these regions people moved from small family units to build cities of thousands of people. They crossed the historic divide, one of the great moments in human history. Why? To find the answer archaeologists needed to find a mother city - the first stage of city-building. They couldn't find one anywhere. Everywhere this first stage seemed destroyed or built over. And so, instead, scientists developed a number of theories. Some said it was because of the development of trade, others that it was irrigation. Some even today believe it was all because of aliens. Gradually an uneasy consensus emerged. The key force common to all civilisations was warfare. The theory was that only the fear of war could motivate people to give up the simple life and form complex societies. To prove it, archaeologists still had to find a city from that very first stage of civilisation. If it showed signs of warfare, then the theory had to be true. When archaeologist Ruth Shady discovered her 5,000 year old city of pyramids in the Peruvian desert, all eyes were on the New World. Ruth's extraordinary city, known as Caral, is so much older than anything else in South America that it is a clear candidate to be the mother city. It also is in pristine condition. Nothing has been built on it at all. Instead laid out before the world is an elaborate complex of pyramids, temples, an amphitheatre and ordinary houses. Crucially, there is not the faintest trace of warfare at Caral; no battlements, no weapons, no mutilated bodies. Instead, Ruth's findings suggest it was a gentle society, built on commerce and pleasure. In one of the pyramids they uncovered beautiful flutes made from condor and pelican bones. They have also found evidence of a culture that took drugs and perhaps aphrodisiacs. Most stunning of all, they have found the remains of a baby, lovingly wrapped and buried with a precious necklace made of stone beads.
Director: N/A
Writer: N/A
- 8.2/1026 votesLoading...
#23 - Freak Wave
Season 39 Episode 14 - Aired 11/14/2002
The world's oceans claim on average one ship a week, often in mysterious circumstances. With little evidence to go on, investigators usually point at human error or poor maintenance but an alarming series of disappearances and near-sinkings, including world-class vessels with unblemished track records, has prompted the search for a more sinister cause and renewed belief in a maritime myth: the wall of water. Waves the height of an office block. Waves twice as large as any that ships are designed to ride over. These are not tsunamis or tidal waves, but huge breaking walls of water that come out of the blue. Suspicions these were fact not fiction were roused in 1978, by the cargo ship München. She was a state-of-the-art cargo ship. The December storms predicted when she set out to cross the Atlantic did not concern her German crew. The voyage was perfectly routine until at 3am on 12 December she sent out a garbled mayday message from the mid-Atlantic. Rescue attempts began immediately with over a hundred ships combing the ocean.
Director: N/A
Writer: N/A
- 8.2/1049 votesLoading...
#24 - Einstein's Equation of Life and Death
Season 42 Episode 3 - Aired 1/27/2005
The story of Einstein's most famous equation E=mc² – its role in the creation of the atom bomb and our understanding of the beginnings of the Universe. Horizon brings you the second part of a two-part series on Albert Einsten. In the summer of 1939 Albert Einstein was on holiday in a small resort town on the tip of Long Island. His peaceful summer, however, was about to be shattered by a visit from an old friend and colleague from his years in Berlin. The visitor was the physicist Leo Szilard. He had come to tell Einstein that he feared the Nazis could soon be in possession of a terrible new weapon and that something had to be done.
Director: N/A
Writer: N/A
- 8.2/1048 votesLoading...
#25 - Can We Make a Star on Earth?
Season 46 Episode 4 - Aired 2/17/2009
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.
Director: N/A
Writer: N/A
The Best Episodes of Horizon
Every episode of Horizon ranked from best to worst. Let's dive into the Best Episodes of Horizon!
Horizon tells amazing science stories, unravels mysteries and reveals worlds you've never seen before.
Genre:Documentary
Network:BBC Two
Best Episodes Summary
"Valley of Life or Death" is the best rated episode of "Horizon". It scored 9.6/10 based on 11 votes. Directed by N/A and written by N/A, it aired on 11/16/2000. This episode scored 0.2 points higher than the second highest rated, "The Writing on the Wall".