Seasons & episodes

Horizon examines claims that measures to protect American and NATO troops against chemical and biological weapons may have backfired.

Horizon series on the emergence of the new sex drug Viagra for men.

Horizon explores the history of experimentation with chimpanzees, our closest living relatives.

Horizon tells the story of maverick scientist John Ostrom and his theory that birds are really just dinosaurs with feathers. Thirty years later, a revolution in palaeontology has proven him correct. Horizon looks at the compelling and recent evidence that shows how modern birds fine-tuned their unique design for flight. It also confirms that Velociraptor dinosaur is more closely related to the sparrow than it is to the crocodile.

Horizon investigates how science is fighting against the mosquito-spread disease Malaria.

Horizon follows the work of various scientists attempting to turn back the biological clock.

Horizon presents an investigation into how Thalidomide is being used to treat leprosy, AIDS, and cancer with encouraging results.

In this program, Horizon reveals how laughter and play are crucial to the development of the brain, and how some scientists are recommending play as an alternative to drugs in helping to treat hyperactive youngsters.

Horizon examines how observations of supernova in distant parts of the universe has provided evidence of the accelerating expansion of the universe. This new evidence suggests the existence of a new type energy in space which may have significant implications for the ultimate fate of the universe.

Horizon looks at the knowledge gained following the Spanish Flu Pandemic of 1918.

In this episode, Horizon reports from Africa on the effect that rising elephant numbers are having on humans and the natural environment.

Horizon presents a documentary looking at the United States heart specialist, Michael DeBakey, and his work and research into making miniature pumps which could help make permanent artificial hearts in the future.

In this Horizon documentary, we present Alfred Steinschneider's theory on cot death where gaps in breathing could be responsible for the death of many infants.

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.

Horizon presents this documentary by scientists who have calculated that the Earth will be hit by a small asteroid within 50 years. How will this effect our planet?

In this report, Horizon investigates the rare disease called Fibrodysplasia Ossificans Progressiva, which causes muscles and ligaments to turn into solid bone. This disease causes severe disfigurement and suffering, and often-time death. We look at the research by scientists trying to find out the causes of the disease and how to find a cure.

Dramatisation of biologist David Lack's struggle to reconcile scientific evidence for evolution with his belief in God.

Horizon presents a documentary about Multiple Personality Disorder (MPD) where in the 1980's, it suddenly became the talk of the town. Tens of thousands of Americans were diagnosed with an illness that was previously unheard of. A trigger for this sudden was the release of a film, "Sybil". Telling the dramatic story of a woman diagnosed with Multiple Personality Disorder, the film was shown across America making Sybil a household name.

Could giant volcanic 'chimneys' on the ocean floor unlock the secret of how life began on Earth?

Horizon reports on a February 1999 catastrophic avalanche at Galtür in Austria that claimed 31 lives. Over the next six months, Horizon followed a team of scientists as they pieced together the extraordinary chain of events that led to the disaster. The scientists' investigations into the extreme forces of nature responsible for the tragedy are making people re-evaluate their calculations about avalanches.

Horizon presents the extraordinary story of a beautiful mathematical formula that changed the world, the financial markets, and indeed capitalism itself. It could do the unthinkable - it took the risk out of playing the money-markets. To its inventors it brought the Nobel Prize for economics. To those who used it, it brought great wealth. But this glittering tale would end in tragedy.

The Aztecs are regarded as the most bloodthirsty of the Central American peoples, but they were also one of the most sophisticated. DrTony Spawforth discovers how, on arriving in Mexico, they created a new and brutal mythology from the relics of an earlier civilisation.

In this moving film Horizon follows the Loughran family in their fight to save the life of their daughter Sheila who suffers from cystic fibrosis. They lost their youngest daughter Ann to the disease in 1974 at the age of 15, and now as the health of their third daughter Sheila deteriorates, they must face the prospect of losing a second child. The current shortage of donor organs means that Sheila's only hope of survival is a rare and controversial operation that requires her two surviving siblings to undergo an arduous and potentially fatal operation. An X-ray of Shelia's lungs Cystic fibrosis (CF) is the most common genetic disease in this country and it is incurable. The lungs of people with cystic fibrosis become covered with a sticky mucus making them extremely susceptible to bacterial infection. Over time these infections badly scar the lungs, until eventually they stop functioning. The defective CF gene is harmless when only a single copy of the gene is inherited. However, both the Loughran parents carry the gene, giving any child they may have a 25% chance of being born with cystic fibrosis. In fact two of their four children were born with the condition. Horizon joins the family at a time when Sheila's health has deteriorated to such an extent that she requires oxygen 24 hours a day and has only months to live. Although on the waiting list for a donor lung, with 50% of patients dying while waiting to receive a transplant, Sheila's chances are not good. The family has become aware of a controversial new operation, pioneered in the UK by Professor Sir Magdi Yacoub at Harefield Hospital. The technique, known as Living Donor Lung Transplantation, would involve removing Sheila's diseased lungs and, in an extraordinary three-way operation, replacing them with a lobe from one of the lungs of each her two siblings. There have been six of these groundbreaking operations carried out in this country. However, only three patients have lived longer than a month. There is a clear moral dilemma - with such a low success rate, is it ethical to put the lives of two healthy people at risk? Even if the operation is initially successful it may only give Sheila five more years to live, by which time her new lungs are likely to fail again. Damian Loughran Sheila's brother and sister, Damian and Josephine, feel compelled to do anything they can to save their dying sister. They undergo stringent tests before being certain that they are compatible donors and fit for surgery. They will have to face the risk of haemorrhaging and infection, both of which could potentially be fatal. After the operation both donors will be left with a 20-25% permanent loss of lung function. Despite these dangers, Damian and Josephine remain determined to proceed. As all three of their children are wheeled in for the 12-hour operation, Mary and Harry Loughran's emotion is apparent. A day later, Sheila is breathing with her new lungs, but it is not long before complications arise. She is unable to absorb food and develops an abscess on her lung. Sheila is kept under sedation and so is unaware of these complications. Sadly, three weeks after the operation, Sheila loses her fight for life.

On a barren desert in South America lies one of the greatest archaeological puzzles in the world. Etched in the surface of the desert pampa sand are hundreds of straight lines, geometric shapes and pictures of animals and birds - and their patterns are only clearly visible from the air. They were built by a people called the Nasca - but why and how they created these wonders of the world has defied explanation. On the pampa, south of the Nasca Lines, archaeologists have now uncovered the lost city of the line-builders, Cahuachi. It was built nearly two thousand years ago and was mysteriously abandoned 500 years later. New discoveries at Cahuachi are at last beginning to give us insight into the Nasca people and to unravel the mystery of the Nasca Lines. Distorted heads The Lines were first spotted when commercial airlines began flying across the Peruvian desert in the 1920's. Passengers reported seeing 'primitive landing strips' on the ground below. No one knew who had built them or indeed why. Since their discovery, the Nasca Lines have inspired fantastic explanations. SpiderPerhaps most famously, the Austrian writer Erich von Danikken claimed that they were evidence that the earth had been visited by extra-terrestrials. The lines, he said, were runways for their spacecraft. Scientific study began in the 1940s with the arrival of a German mathematician and astronomer called Maria Reiche. She lived at Nazca until her death in 1998 and was known as the Lady of the Lines. Reiche believed that the lines were a sophisticated astronomical calendar. However, in 1965, astronomer Gerald Hawkins came to Nazca and used computers to check Reiche's theory. Hawkins could find no correlation between the lines and the stars. Giuseppe Orefici Italian archaeologist Giuseppe Orefici has been excavating the immense Cahuachi site for the last 17 years. Every year he brings a team of specialists to South America for three, intensive months of excavation. Horizon joined Orefici and his team in the hot, windy months of 1998 and this is a fascinating record of their extraordinary finds. Woven clothCahuachi is emerging as a treasure trove of the Nasca culture. As Orefici and his team excavate, discoveries of paintings on preserved pottery, and the ancient technique of weaving that the Nasca people developed, have given an insight into how the lines may have been made, and what they might have been used for, more than 1500 years ago. MummyMost exciting is the discovery of human remains. Stunningly preserved in the dry soil of the Peruvian desert are the mummified bodies of the Nasca themselves. Orefici's colleagues Brian Harrison and Andrea Drusini carry out modern autopsies on these remarkable finds, and reveal the strange world and rituals of the Nasca people. CahuachiOriginally believed to have been a military stronghold, Cahuachi is now reckoned to be a place of ritual and ceremony, and Orefici's stunning new evidence confirms this idea. Cahuachi is now revealed to have been abandoned after a series of natural disasters destroyed the city. But before they left it, the Nasca people covered the city in the arid pampa sand where, until recently, it has remained a barely visible mound in the desert.