Great Ormond Street Hospital is the last chance for children in the UK whose lungs are failing because of cystic fibrosis and other conditions. In a few very severe cases each year, their only hope of survival is to undergo a radical and risky step - a double lung transplant.

Great Ormond Street is Britain's leading hospital for treating children with serious diseases of the brain - from tumours to epilepsy to rare neurovascular conditions. To save lives, doctors have no option but to undertake treatments which carry grave risks - children may be left with a mental impairment or may not even survive.

Climate activist Greta Thunberg takes a year off school to explore the science of global warming and challenge world leaders, calling for action on climate change.

What's really going on inside your stomach? In this documentary, Michael Mosley offers up his own guts to find out. Spending the day as an exhibit at the Science Museum in London, he swallows a tiny camera and uses the latest in imaging technology to get a unique view of his innards digesting his food. He discovers pools of concentrated acid and metres of writhing tubing which is home to its own ecosystem.

The heart is the most symbolic organ of the human body. Throughout history it has been seen as the site of our emotions, the very centre of our being. But modern medicine has come to see the heart as just a pump; a brilliant pump, but nothing more. And we see ourselves as ruled by our heads and not our hearts.

Immerse yourself in the lives of extraordinary characters that stand a few inches tall. From chipmunks to mice, be entertained and spellbound by the creatures that call the Hidden Kingdoms home.

This is the story of two young animals forced to grow up fast. In Africa's savannah, a baby elephant shrew learns how speed is the secret to survival amongst the largest animals on Earth; and in America, a young grasshopper mouse confronts the Wild West's deadliest creatures to stake a claim of his own.

This is the story of two tiny animals coming of age.

Child psychologist Laverne Antrobus delves into the Horizon archive to find out how science has shaped our approach to parenting and education over the last fifty years.

This episode looks at the issues that will change the way we live our lives in the future. Rather than relying on the minds of science fiction writers, mathematician Hannah Fry delves into the data we have today to provide an evidence-based vision of tomorrow. With the help of the BBC's science experts - and a few surprise guests - Hannah investigates the questions the British public want answered about the future.

Changes to the bacteria that live inside all of us are responsible for increasing the number of people with allergies, suggests new research.

We are in the grip of an allergy epidemic. 50 years ago one in 30 were affected, but in Britain today it is closer to one in three. Why this should be is one of modern medicine's greatest puzzles.

It's the process that powers the Sun, and scientists know that if they could just make nuclear fusion happen here on Earth they could solve all the world's energy problems. Billions of dollars have been spent on trying to make it happen, but now an American scientist claims to have created nuclear fusion simply by bombarding a flask of liquid with sound waves. Many scientists refuse to believe his claims, so Horizon has assembled a team to replicate the experiment. This film reveals the team's findings

Michael Mosley puts himself through a battery of health tests available to people who feel perfectly well. From an expensive heart scan to a new national screening procedure to detect the earliest signs of bowel cancer, Mosley sets out to discover which if any of the tests are worth doing.

The search for extra-terrestrial life has been going for 50 years - but there's been a recent breakthrough. Astronomers have discovered a new planet called Gliese 581 c. It is the most Earth-like planet ever found. It orbits a star and may have habitats capable of supporting life. NASA hopes to find 50 more Earth-like planets by the end of the decade, all of which increases the chance that alien life has begun elsewhere.

Dr Alice Roberts asks one of the great questions about our species: are we still evolving? Alice follows a trail of clues from ancient human bones, to studies of remarkable people living in the most inhospitable parts of the planet, to the frontiers of genetic research to discover if we are still evolving - and where we might be heading.

What makes us good or evil? It's a simple but deeply unsettling question. One that scientists are now starting to answer.

Touch, sight, smell, hearing and taste - our senses link us to the outside world. Dr Kevin Fong looks back through 40 years of Horizon archives to find out what science has taught us about our tools of perception - why babies use touch more than any other sense, why our eyes are so easily tricked.

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.

In this third Horizon special, Dr Chris Van Tulleken is joined by his brother Xand and Dr Guddi Singh to take us through the latest developments and answer current concerns.

Forget the Big Bang. The real moment of creation was the moment of first light, the moment the first stars were born. Horizon tells the scientific version of the story of Genesis.

Horizon investigates a new era of Alzheimer's research, which is bringing hope to millions of sufferers across the world.

Scientists genuinely don't know what most of our universe is made of. The atoms we're made from only make up four per cent. The rest is dark matter and dark energy (for 'dark', read 'don't know'). The Large Hadron Collider at CERN has been upgraded. When it's switched on in March 2015, its collisions will have twice the energy they did before. The hope is that scientists will discover the identity of dark matter in the debris.

Scientists genuinely don't know what most of our universe is made of. The atoms we're made from only make up four per cent. The rest is dark matter and dark energy (for 'dark', read 'don't know'). The Large Hadron Collider at CERN has been upgraded. When it's switched on in March 2015, its collisions will have twice the energy they did before. The hope is that scientists will discover the identity of dark matter in the debris.

The film follows Rosemary, Phil and Ray as they undergo remarkable new treatments - from a billion pound genetically targeted drug designed to fight a type of skin cancer, to advanced robotic surgery.

Exploring the murky and fast-paced world of the hackers out to steal money and identities and wreak havoc with people's online lives, and the scientists who are joining forces to help defeat them.

The hunt for life within the long-dead bones of dinosaurs may sound like the stuff of Hollywood fantasy - but one woman has found traces of life within the fossilised bones of a T Rex.

Horizon reveals the science behind our perception of colour, a highly subjective illusion.

Earthquakes are among the most devastating natural disasters on the planet. In the last hundred years they have claimed the lives of over one million people. Earthquakes are destructive mainly because of their unpredictable nature. It is impossible to say accurately when a quake will strike but a new theory developed by Professor Geoffrey King could help save lives by preparing cities long in advance for an earthquake