- 1 The Truth About Vitamins
Every year we spend 300 million on vitamin supplements, but do they actually do us any good? Some believe they offer the promise of preventing or even curing some of the world's biggest killers, such as heart disease and cancer. Others claim that taking large doses of some vitamins may in certain cases be harmful. So what are the facts?
Air Date: 2004-09-09
- 2 King Solomon's Tablet of Stone
2001. A clandestine meeting of leading Israeli archaeologists are shown a remarkable artefact. It's a stone tablet, apparently from 1,000BC. The writing on its face describes repairs to the temple of King Solomon. It is the first archaeological evidence ever found of this legendary building. The relic caused a sensation. But this was only just the start...
Air Date: 2004-09-16
- 3 What Really Killed the Dinosaurs?
Until recently most scientists thought they knew what killed off the dinosaurs. A 10km-wide meteorite had smashed into the Yucatan peninsula in Mexico, causing worldwide forest fires, tsunamis several kilometres high, and an 'impact winter' - in which dust blocked out the sun for months or years. It was thought that the dinosaurs were blasted, roasted and frozen to death, in that order. But now a small but vociferous group of scientists believes there is increasing evidence that this 'impact' theory could be wrong. That suggestion has generated one of the bitterest scientific rows of recent times.
Air Date: 2004-09-23
- 4 Making Millions the Easy Way
In the mid-1990s, a team of American science students took on the might of the Las Vegas casinos, and came home with millions of dollars. Hardworking engineering students during the week, they became high-rolling gamblers by the weekend and proved that, in one game at least, the house doesn't always win. The game was blackjack, and the students were from the world-renowned Massachusetts Institute of Technology (MIT). Their audacious winnings marked the climax of an arms race between casino and player that began 40 years earlier with maths professor Edward Thorp. He realised that the one feature of blackjack that made it different from other casino games also made it possible to beat.
Air Date: 2004-09-30
- 5 Saturn - Lord of the Rings
With its famous rings, Saturn is the most distant planet clearly visible to the naked eye. But how did the rings get there and when were they formed? To study the planet in detail, scientists needed to get closer. So on 15 October 1997, the Cassini-Huygens spacecraft was launched.
Air Date: 2004-10-07
- 6 The Hunt for the Supertwister
Following the storm chasers who risk their lives to discover how a strong wind is turned into a 500km/h killer tornado.
Air Date: 2004-10-14
- 7 Global Dimming
Horizon producer David Sington on why predictions about the Earth's climate will need to be re-examined.
Air Date: 2004-10-21
- 8 Dr Money and the Boy with No Penis
An experiment on nature versus nurture goes tragically wrong.
Air Date: 2004-10-28
- 9 Einstein's Unfinished Symphony (1)
As Albert Einstein lay on his deathbed, he asked only for his glasses, his writing implements and his latest equations. He knew he was dying, yet he continued his work. In those final hours of his life, while fading in and out of consciousness, he was working on what he hoped would be his greatest work of all. It was a project of monumental complexity. It was a project that he hoped would unlock the mind of God.
Air Date: 2004-11-04
- 10 Einstein's Equation of Life and Death (2)
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.
Air Date: 2004-11-11
- 11 Living with ADHD
Attention deficit hyperactivity disorder (ADHD) is one of the most feared and misunderstood of all medical conditions. Despite over 200 scientific papers being published on this neurological condition every year, it remains stigmatised and controversial. Some doctors don't even believe it exists. Yet it is estimated that as many as 3-5% of the childhood population, and over one million adults in the UK are affected by ADHD. These people are often described as stupid, lazy, disorganised, wild, out of control or woozy on drugs. But the reality is altogether more complex, and deeply moving.
Air Date: 2004-11-18
- 12 Neanderthal
In 1848 a strange skull was discovered on the military outpost of Gibraltar. It was undoubtedly human, but also had some of the heavy features of an ape... distinct brow ridges, and a forward projecting face. Just what was this ancient creature? And when had it lived? As more remains were discovered one thing became clear, this creature had once lived right across Europe. The remains were named Homo neanderthalensis (Neanderthal man) an ancient and primitive form of human.
Air Date: 2004-11-25
- 13 An Experiment to Save the World
In March 2002, the scientific world was rocked by some astonishing news: a distinguished US government scientist claimed he had made nuclear fusion out of sound waves in his laboratory. Horizon investigates.
Air Date: 2004-12-02
- 14 Who's Afraid of Designer Babies?
Every parent wants their child to have the best in life. But would this extend to picking the best genes for them? To date, genetic technology has only been used to treat serious disease in children. But as ways are developed to manipulate our DNA, there are those who think that parents will inevitably want to choose their children's genes, and create 'designer babies'. A designer baby today Philippa Handyside's son Ruiaridh is a genetically selected baby. Some might call him a designer baby. But Philippa wasn't aiming to create a perfect child and there is nothing unusual about her child's genes. Genetic technology seemed the only way she could have a baby at all. Philippa had a problem with her DNA. It didn't affect her health, but it meant that most of her eggs didn't carry all the genes needed for a baby to grow healthily. The result was that each time she became pregnant, she miscarried. Doctors suggested that Philippa try a technique called pre-implantation genetic diagnosis (PGD). Using PGD scientists can screen embryos outside the womb, long before they develop into babies. They can select just those embryos that carry healthy genes. This ensures the baby is free from genetic abnormalities. Ruiaridh might have grown from a specially selected embryo, but he's not really a designer baby at all. The embryo was created from one of Philippa's eggs and her husband's sperm, just as in IVF. His genes have not been altered, or enhanced in any way. The doctors simply chose an embryo that didn't carry Philippa's genetic disorder. It would actually be very difficult to make a true designer baby using PGD. Today, it can only be used to look at one or two genes at a time. On the other hand, most character traits we might want to choose � anything from height to intelligence � are influenced by a whole range of genes. What's more, there is no way of altering the genes inside an embryo using PGD. If you don't carry the genes to be intelligent, sporty or good-looking, then there's no way any of your embryos will either. To have a real designer baby, we'd need to be able to choose any genes we wanted and insert them into our children. Inserting new genes In 1998 Dr French Anderson put forward a radical proposal. He thought he would soon be able to insert new genes into babies in the womb. The idea was to treat genetic diseases caused by a single damaged gene by inserting a new, healthy gene into a foetus's cells. French Anderson had already used this technique � called gene therapy � in children with faulty white blood cells, with some success. But the cells with healthy genes would eventually die, so the patients would have to have the procedure all over again. French Anderson wanted to try gene therapy in the womb because then he could get the healthy genes into special blood cells called stem cells. These cells grow all the blood cells in the body. If the healthy gene could be injected into the stem cells, then the patient's body would produce new white blood cells with healthy genes on its own. In short, they would be cured. But for all Anderson's plans, this technique has never been used on human babies in the womb. There turned out to be problems with gene therapy. In 1999 an 18-year-old died during a gene therapy trial, and there have been cases of children developing leukaemia after gene therapy treatment. For now, using it on babies in the womb is far too risky. A human clone: the ultimate designer baby There is however potentially another way to insert genes into an embryo long before birth � cloning. No scientific discovery has created as much hysteria as the cloning of Dolly the sheep. She was the first mammal cloned from the DNA of an adult cell. It was a process that brought human cloning one step closer. Shortly after Dolly, Polly was born. She wasn't just a clone. A human gene had been added early on in the cloning process. She was a true, genetically modified, "designer sheep". Since Polly, there has been a flurry of claims that humans have been, or soon will be, cloned. But no one has yet produced evidence that a human clone has been created. Most serious scientists won't even consider the idea of cloning a human. The procedure is not very effective. Less than 10 per cent of non-human cloning attempts are successful. And many of the pregnancies result in miscarriage or deformities. It is a procedure that is simply too dangerous to use to produce a human baby. But cloning technology is being used on human eggs. Scientists from Newcastle University and the Newcastle Fertility Centre are using cloning to create stem cells. The research has only just begun, but the ultimate aim is to create cloned stem cells from the DNA of a patient with a degenerative disease. These cells could then be turned into whatever types of cells are needed to treat their damaged organs. It could one day lead to cures for diabetes, Alzheimer's or heart disease. There will always be a risk that genetic technology will be hijacked to create designer children. But for now, the technical difficulties make it unlikely anyone will be able to create a true designer baby in the near future.
Air Date: 2004-12-09
- 15 The Lost Civilisation of Peru
Two thousand years ago a mysterious and little known civilization ruled the northern coast of Peru. Its people were called the Moche. They built huge and bizarre pyramids that still dominate the surrounding countryside; some well over a hundred feet tall. Many are so heavily eroded they look like natural hills; only close up can you see they are made up of millions of mud bricks. Several of the pyramids, known as 'huacas', meaning sacred site in the local Indian dialect, contain rich collections of murals depicting both secular and sacred scenes from the Moche world. Others house the elaborate tombs of Moche leaders. Out in the desert, archaeologists have also found the 2,000-year-old remains of an extensive system of mud brick aqueducts which enabled the Moche to tame their desert environment. Many are still in use today. Indeed there are signs that the Moche irrigated a larger area of land than farmers in Peru do now. But who were the Moche? How did they create such an apparently successful civilisation in the middle of the desert, what kind of a society was it, and why did it disappear? For decades it was one of the greatest archaeological riddles in South America. But now at last, scientists are beginning to come up with answers. As archaeologists have excavated at Moche sites they've unearthed some of the most fabulous pottery and jewellery ever to emerge from an ancient civilization. The Moche were pioneers of metal working techniques like gilding and early forms of soldering. These skills enabled them to create extraordinarily intricate artefacts; ear studs and necklaces, nose rings and helmets, many heavily inlaid with gold and precious stones. But it was the pottery that gave the archaeologists their first real insight into Moche life. The Moche left no written record but they did leave a fabulous account of their life and times in paintings on pots and vessels. Many show everyday events and objects such as people, fish, birds and other animals. Others show scenes from what, at first sight, look like a series of battles. But as the archaeologists studied them more closely they realised they weren't ordinary battles; all the soldiers were dressed alike, the same images were repeated time and again. When the battle was won, the vanquished were ritually sacrificed; their throats cut, the blood drained into a cup and the cup drunk by a God-like deity. It was, the archaeologists slowly realised, a story not of war but ritual combat followed by human sacrifice. But what did it mean. Was it a real or mythological scene; and, above all, was it a clue to the Moche's life and times? The first break through came when a Canadian archaeologist called Dr Steve Bourget, of the University of Texas in Austin, discovered a collection of bones at one of the most important Moche huacas. Examining them he realised he wasn't looking at an ordinary burial site. The bodies had been systematically dismembered and marks on neck vertebrae indicated they had had their throats cut. Here was physical proof that the images of combat and sacrifice on the pots were depicting not a mythological scene but a real one. Many of the skeletons were deeply encased in mud which meant the burials had to have taken place in the rain. Yet in this part of Peru it almost never rains. Bourget realised there had to be a deliberate connection between the rain and the sacrifices. It lead him to a new insight into the Moche world. The Moche, like most desert societies, had practiced a form of ritual designed to celebrate or encourage rain. The sacrifices were about making an unpredictable world more predictable. A harsh environment had moulded a harsh civilisation with an elaborate set of rituals designed to ensure its survival. These discoveries answered one question � what was the iconography all about � but still left a central riddle. What had gone wrong; why had Moche society finally collapsed? The next clue was to come from hundreds of miles away in the Andes mountains. Here climate researcher Dr Lonnie Thompson, of Ohio State University, was gathering evidence of the region's climatic history using ice cores drilled in glaciers. Almost immediately Thompson and his team noticed something intriguing. The historic records showed that over the last one hundred years, every time the ice cores showed drought in the mountains, it corresponded to a particular kind of wet weather on the coast, a weather system known as an El Nino. In other words drought in the mountains meant an El Nino on the coast. If Thompson could trace back the climate record in the mountains he'd also get a picture of what happened on the coast. The result was fascinating. The climate record suggested that at around 560 to 650 AD � the time the Moche were thought to have collapsed � there had been a 30-year drought in the mountains, followed by 30 years or so of heavy rain and snow. If the weather on the coast was the opposite, then it suggested a 30-year El Nino - what climatologists call a mega El Nino � starting at around 560 AD, which was followed by a mega drought lasting another 30 years. Such a huge series of climatic extremes would have been enough to kill off an civilization � even a modern one. Here, at last, was a plausible theory for the disappearance of the Moche. But could it be proved? Archaeologists set out to look for evidence. And it wasn't hard to find. All the huacas are heavily eroded by rain - but scientists couldn't tell if this was recent damage or from the time of the Moche. But then Steve Bourget found evidence of enormous rain damage at a Moche site called Huancaco which he could date. Here new building work had been interrupted and torn apart by torrential rain, and artefacts found in the damaged area dated to almost exactly the period Thompson had predicted there would have been a mega El Nino. Thompson's theory seemed to be stacking up. Then archaeologists began to find evidence of Thompson's mega drought. They found huge sand dunes which appeared to have drifted in and engulfed a number of Moche settlements around 600 to 650 AD. The story all fitted together. The evidence suggested the Moche had been hit by a doubly whammy: a huge climate disaster had simply wiped them out. For several years this became the accepted version of events; the riddle of the Moche had been solved. There was only one problem. In the late 1990s American archaeologist Dr Tom Dillehay revisted some of the more obscure Moche sites and found that the dates didn't match with the climate catastrophe explanation. Many of these settlements were later than 650 AD. Clearly the weather hadn't been the cause of their demise. He also found something else. Many of the new settlements were quite unlike previous Moche settlements. Instead of huge huacas, the Moche had started building fortresses. They had been at war. But who with? Searching the site for clues, Dillehays's team were unable to find any non-Moche military artefacts. It could only mean one thing. The Moche had being fighting amongst themselves. Dillehay now put together a new theory. The Moche had struggled through the climatic disasters but had been fatally weakened. The leadership - which at least in part claimed authority on the basis of being able to determine the weather � had lost its authority and control over its people. Moche villages and and/or clan groups turned on each other in a battle for scare resources like food and land. The Moche replaced ritual battles and human sacrifices with civil war. Gradually they fought themselves into the grave. Yet even that's not the whole story. Today, along the coast of Peru it's impossible to escape the legacy of this lost civilization. Their art lives on in the work of local craftsmen. And if you travel to the highlands, the Moche tradition of ritualised combat is preserved in the Tinku ceremonies where highland villages conduct ceremonial battles against each other in the hope of ensuring a good harvest. Today, after 1,500 years, the Moche, and their legacy are beginning to take their place in world history. The story of the Moche is an epic account of society that thought it could control the world and what happened to it when it found it couldn't. It's a story of human achievement and natural disaster, human sacrifice and war.
Air Date: 2004-12-16
- 16 The Next Megaquake
On Boxing Day 2004 the world was shocked by one of the worst natural disasters of all time. The cause of so much devastation was the most powerful kind of earthquake on the planet - a megathrust. Megathrust earthquakes only occur on a particular kind of fault. Scientists have now discovered that just such a fault could cause a huge megathrust earthquake and tsunami right off the coast of North America. The subduction zones: The surface of the earth is divided into giant plates of rock - and most earthquakes occur at faults where two of the plates meet. Where the plates are colliding one of the plates usually gets pushed down under the other - this is subduction. Not surprisingly, the process of subduction can be very violent. The two plates can get stuck together and the result is that the area where subduction is occurring (the subduction zone) gets compressed. Eventually the strain on the fault becomes too much. The plates suddenly slip past each other. The result is a megathrust earthquake. Subduction zones are mainly found in South East Asia (like the subduction zone that caused the Indian Ocean Tsunami) and around the Pacific Rim. It has long been known that a subduction zone runs along the Pacific northwest coast, from northern California all the way to Vancouver Island in Canada. It's called the Cascadia Subduction Zone, and is linked to the Cascade Range of volcanoes that includes Mt St Helens. Quiet in Cascadia: No one, however, thought that this area was at significant risk from earthquakes, largely because there was no historical record of large earthquakes there. The first suggestion of a problem came when plans were drawn up to build a number of nuclear power stations near the coast of Washington state. Tom Heaton, a geophysicist and engineer from the California Institute of Technology, was brought in to examine the proposal from a geohazards perspective. Heaton pointed out the possibility that the Cascadia Subduction Zone might be capable of producing a megathrust earthquake. The lack of historical record might be explained if the last such earthquake had occurred before Europeans arrived in the region during the 18th century. Heaton pointed to the existence of Native American legends that might be describing a megathrust earthquake that had happened before written records began. In the end, the nuclear power station project ran out of money and the reactors were never completed. Heaton's concerns were still just theoretical - there was no scientific evidence that such earthquakes had actually occurred. When Brian Atwater, a specialist in marshes and estuaries, heard about Heaton's theory he decided to take a look himself. He started investigating in the very areas where the Native legends had been recorded. He found evidence that some time in the past there had been a sudden change in land level. The coast had dropped down, drowning forests under layers of mud. Other geologists soon found similar evidence all along the Pacific northwest coast. The simplest explanation was that there had been a huge megathrust earthquake in the past. This evidence, however, still wasn't enough to convince. The orphan tsunami: The most intriguing piece of evidence came from Japan. As the Indonesian earthquake has shown, megathrust earthquakes can create tsunamis capable of crossing entire oceans. If there had been a giant earthquake in Cascadia it should have sent a tsunami across to Japan. So Japanese geologist Kenji Satake looked in old Japanese texts for any record of such a tsunami. What he was looking for was an orphan tsunami, a wave the comes out of nowhere, with no local earthquake recorded. Satake and his colleagues found several such records from January 1700. The final proof came when scientists in America were able to date the land level change there by looking at the tree rings of drowned red cedar trees. They found that entire forests had been killed in the winter of 1699/1700, matching the Japanese records perfectly. This evidence enabled scientists to put together a picture of the last Cascadia megathrust earthquake. It occurred around 9pm on 26 January 1700, and would have had a devastating effect on over 600 miles of coast. It's little wonder that the Native people of the region passed on legends of that event that survive to this day. A deadly warning: Before the 1700 event was discovered, the people of the Pacific north-west would have had little awareness of the threat of earthquakes and even less of tsunamis. Now that is starting to change. Tsunami evacuation signs are being installed along the coast. The region's building codes are now some of the strictest in the world. All new buildings are designed to withstand a powerful earthquake. However, building to survive a megathrust earthquake is a major challenge. These earthquakes tend to last several minutes - much longer than other quakes - and there is little knowledge about how modern buildings will react to such shaking. As the events of Boxing Day 2004 showed, the tsunami unleashed by the sudden movement of the sea floor can be even more devastating than the earthquake. Unlike the Indian Ocean, the Pacific has a warning system that should give the other nations of the Pacific Rim many hours of warning. On the Pacific northwest coast, however, a tsunami from Cascadia will arrive in some places in under half an hour. In such regions the key to saving lives is education. People there have to know that if they feel an earthquake they should move inland and to high ground. This knowledge could save many lives. The terrible events of 26 December are a warning to the world that we should be better prepared for these huge geological catastrophes. This message has particular significance for the people of the Pacific northwest. One day that region will be hit by a megathrust that will probably be very similar to the Indonesian earthquake. At least, thanks to the work of many scientists, they have been forewarned.
Air Date: 2004-12-30
- 17 Malaria: Defeating the Curse
This is the story of an epic battle between science and nature. It's a battle to destroy a disease that is one of the biggest killers on the planet: malaria.
Air Date: 2005-01-06
- 18 Does the MMR Jab Cause Autism?
No public health issue of recent years has attracted such heated debate as the question of whether the MMR vaccine can cause autism. The MMR jab combines three childhood vaccines, against measles, mumps and rubella, into one injection, which is first given to children at around 12-18 months.
Air Date: 2005-01-13
- 19 Could Fish Make My Child Smart?
Scientists once got sacked for suggesting oily fish was good for you. Now all and sundry are hailing it as a panacea.
Air Date: 2005-10-06