Discovery

The Dark Ages are often painted as an era of scholarly decline. The Western Roman Empire was on its way out, books were few and far between, and, if you believe the stereotype, mud-splattered peasants ran around in rags.However, it was far more intellectually vibrant than you might imagine. Out of this era emerged a set of ‘problems to sharpen the young,’ including the famous river crossing puzzle that’s still taught in maths today. The presumed author of these riddles is Alcuin of York – ‘the most learned man in the world.’ And it was this monk and his puzzles that laid the foundations for a branch of mathematics called combinatorics – the thinking behind today’s computer coding and cryptography. Philip Ball speaks to historian Mary Garrison from the University of York to learn of Alcuin's character and how he encouraged his students to learn for the sake of learning, as opposed to salvation. And University College London mathematician Hannah Fry shows Philip just how much of a role combinatorics plays in to

All countries are supposed to measure and report their greenhouse gas emissions but BBC environment correspondent, Matt McGrath, reveals there are gaping holes in national inventories. He uncovers serious failings in countries’ accounts of warming gases with many not reporting at all. There are disturbing signs that some banned warming chemicals, which are supposed to have been phased out completely, are once again on the rise. And evidence that worthless carbon credits are still being traded. Meanwhile scientists are growing increasingly frustrated by the refusal of countries to gather and share accurate data in the face of this planetary emergency(Photo: The Jungfraujoch Air Monitoring Station in Switzerland. Credit: Jungfraujoch)

Every three seconds someone is diagnosed with dementia, and two thirds of the cases are Alzheimer’s Disease. As the global population ages, this is becoming an epidemic, and with no cures currently available for the collection of neurodegenerative conditions that include Alzheimer’s, Parkinson’s and Motor Neurone Disease the public and personal cost is escalating. Sue Broom reports on new efforts to find ways to stop the progress of these diseases for the first time, and to bring treatment for neurodegenerative conditions in line with those of cancer and heart disease.Picture: Human head, Credit: Science Photo LibraryPresenter: Sue Broom

Two deadly cases today sent in by listeners to curiouscases@bbc.co.ukThe Dark Star "What's inside a black hole and could we fly a spaceship inside?" asks Jorge Luis Alvarez from Mexico City.Astrophysicist Sheila Rowan explains how we know invisible black holes actually exist. Plus cosmologist Andrew Pontzen is on hand to help cook one up.But which of our intrepid doctors will volunteer to fly into the heart of a black hole?Kate Bush’s Sonic Weapon "It started while listening to the excellent Experiment IV by Kate Bush. The premise of the song is of a band who secretly work for the military to create a 'sound that could kill someone'. Is it scientifically possible to do this?" asks Paul Goodfield.Hannah consults acoustic engineer Trevor Cox to ask if sonic weapons could kill. And Adam delves into subsonic frequencies with parapsychologist Chris French to investigate their spooky effects.Plus the team investigates the Curious Case of the Embassy in Cuba – could a sonic weapon really be responsible for the wide-

The Polar Opposite No one knows why the Earth's magnetic North and South poles swap. But polar reversals have happened hundreds of times over the history of the Earth. John Turk emailed curiouscases@bbc.co.uk to ask, “when is the next pole swap due and what will happen to us?” Featuring Prof Lucie Green from Mullard Space Science Laboratory and Dr Phil Livermore from the University of Leeds. Plus, astronaut Terry Virts, author of The View from Above, describes his experiences of a strange magnetic glitch in the earth's magnetic field, known as The Bermuda Triangle of Space.The World That Turns "Why does the Earth spin?" asks Joe Wills from Accra in Ghana. Hannah quizzes cosmologist Andrew Pontzen about the birth of the Solar System. BBC weatherman John Hammond describes the curious things that would happen if the Earth spun the opposite way. Send your questions to: curiouscases@bbc.co.ukPicture: The Earth reflecting light from the sun whilst aboard the International Space Station, Credit: Alexander Gerst /

The Astronomical Balloon "How far up can a helium balloon go? Could it go out to space?" asks Juliet Gok, aged 9. This calls for an experiment! Dr Keri Nicholl helps Adam launch a party balloon and track its ascent. But their test doesn't quite go to plan. Meanwhile, Hannah discovers where space begins by asking Public Astronomer Dr Marek Kukula, from the Royal Observatory Greenwich. Send your Curious Cases to the team: curiouscases@bbc.co.ukThe Forgetful Child "Why don't we remember the first few years of our lives?" asks David Foulger from Cheltenham. The team investigate the phenomenon of 'infant amnesia' with Catherine Loveday from the University of Westminster. 40% of us claim to remember being under two years old and 18% recall being babies. But can we really trust these early memories? Martin Conway from City University thinks not.Picture: A baby contemplates the sole of its foot, circa 1950, Credit: H. Armstrong Roberts/Retrofile/Hulton Archive/Getty ImagesProducer: Michelle Martin.

The Astronomical Balloon "How far up can a helium balloon go? Could it go out to space?" asks Juliet Gok, aged 9. This calls for an experiment! Dr Keri Nicholl helps Adam launch a party balloon and track its ascent. But their test doesn't quite go to plan. Meanwhile, Hannah discovers where space begins by asking Public Astronomer Dr Marek Kukula, from the Royal Observatory Greenwich. Send your Curious Cases to the team: curiouscases@bbc.co.ukThe Forgetful Child "Why don't we remember the first few years of our lives?" asks David Foulger from Cheltenham. The team investigate the phenomenon of 'infant amnesia' with Catherine Loveday from the University of Westminster. 40% of us claim to remember being under two years old and 18% recall being babies. But can we really trust these early memories? Martin Conway from City University thinks not.Picture: Baby Foot, Credit H. Armstrong Roberts/Retrofile/Hulton Archive/Getty ImagesProducer: Michelle Martin.

“How on earth do cats find their way back to their previous home when they move house?" asks Vicky Cole from Nairobi in Kenya. Our enduring love for our feline friends began when Egyptian pharaohs began to welcome domesticated moggies into their homes. Pictured reclining in baskets at the feet of royalty, pet cats soon became fashionable throughout society in Egypt. Today they are the most popular pet in the world, and home is definitely where their hearts lie. "Whereas dogs are bonded to people, cats are bonded to place," explains zoologist Dr John Bradshaw. "It's very typical for them to try and find their way back to their old house when you move." But how do they do it? And if their navigational skills are so good, why do they get lost? Prof Matthew Cobb reveals the super-senses that cats possess, and how to spot when your pet is deploying them.Itchy and Scratchy "What is an itch and how does scratching stop it? Why does scratching some itches feel so good?!" asks Xander Tarver from West Sussex in England

Science sleuths Drs Rutherford & Fry take on everyday mysteries and solve them with the power of science. Two cases in this episode concerning the inner workings of our bodies, and not for the faint hearted! The Broken Stool "Science tells us that our body houses microbial organisms. Then how much our weight is really our weight? If I am overweight, is it because of my own body cells or excess microflora?" asks Ajay Mathur from Mumbai in India.Adam bravely sends off a personal sample to the 'Map My Gut' project at St Thomas' Hospital to have his microbes mapped. Prof Tim Spector reveals the shocking results - a diet of fried breakfasts and fizzy drinks has left his guts in disarray. But help is at hand to makeover his bacterial lodgers.Science writer Ed Yong, author of 'I Contain Multitudes', reveals how much our microbes weigh. We're just beginning to discover the vast array of vital functions they perform, from controlling our weight, immune system and perhaps even influencing our mood and behaviour.

Sydney Brenner was one of the 20th Century’s greatest biologists. Born 90 years ago in South Africa to impoverished immigrant parents, Dr Brenner became a leading figure in the biological revolution that followed the discovery of the structure of DNA by Crick and Watson, using data from Rosalind Franklin, in the 1950s. Brenner’s insights and inventive experiments laid foundation stones for new science of molecular biology and the genetic age in which we live today, from the Human Genome Project to gene editing. Sydney Brenner talks to biologist and historian Matthew Cobb of the University of Manchester about this thrilling period in biological science, and Dr Brenner’s 20 year-long collaboration with DNA pioneer Francis Crick: a friendship which generated some of their most creative research. Producer: Andrew Luck-BakerPicture: Sydney Brenner, Credit: Cold Spring Harbor Lab Archive

This is a big story about a little snail. Biologist Helen Scales relates an epic tale that spans the globe and involves calamity, tragedy, extinction and we hope, salvation. It stars the tiny tree-dwelling mollusc from French Polynesia, Partula, a snail that has captivated scientists for centuries. Like Charles Darwin studied finches on the Galapagos, Partula became an icon of evolution because, in the living laboratories of the Pacific islands, it had evolved into multiple species. But a calamity drove Partula to extinction, when a botched biological control, the predatory Rosy Wolf Snail, was introduced. It was supposed to eat another problem mollusc, but in a cruel twist, devoured tiny Partula instead. An international rescue mission was scrambled to save a species and from just one or two rescued individuals, populations of this snail species have been built up over thirty years in captive breeding programmes in zoos around the world. And now, in the nailbiting sequel, we track Partula’s journey home.Pict

For more than 200 years Britain ruled India, bringing many aspects of British culture to India - including European science developed during the enlightenment. However centuries earlier India had already pioneered work in astronomy, mathematics and engineering. How was India’s scientific progress affected by colonialism? Did British rule hold the country back, or did it drive it forward? Presented by Angela Saini.Picture: The Indian Space Research Organisation (ISRO) communication satellite GSAT-19, carried onboard the Geosynchronous Satellite Launch Vehicle (GSLV-mark III ), launches at Sriharikota on June 5, 2017, Credit: ARUN SANKAR/AFP/Getty Images

We go behind the scenes of a new exhibition on India at London’s Science Museum. What can historical objects tell us about India’s rich, and often hidden scientific past? We look at the influential mathematics, metallurgy and civil engineering of ancient India.The exhibition also contain artefacts from India’s time under the British Empire. We ask how the many years of colonial rule shaped the more recent scientific development of India. Science journalist Angela Saini presents.Image: Bakhshali manuscript, Credit: Bodleian Library

Can Africa’s Great Green Wall beat back the Sahara desert and reverse the degrading landscape? The ambitious 9 miles wide and 5000 miles long line of vegetation will stretch all the way from Dakar in the west to Djibouti in the east. Thomas Fessy is in Senegal where the wall has already begun to evolve into a series of forests and garden communities. He meets the planners, planters, ecologists and local villagers to hear how its early progress is reversing years of poor land use, turning nomads back to farmers, empowering women and creating healthy ecosystems for rain fed agriculture. But can it meet its ambition to stabilize an unstable region, reverse the growing trend of migration, fight the effects of climate change and ensure this big African dream doesn’t die in the sand?Picture: The Great Green Wall, credit: BBC Producer Adrian Washbourne

Can we Control the Dark Side of the Internet?The Internet is the world's most widely used communications tool. It’s a fast and efficient way of delivering information. However it is also quite dumb, neutral, treating equally all the data it passes around the world. From data that forms scientific research papers, the wealth of social media to keep us all connected with friends and relatives, entertainment or material we would rather not see- from political propaganda to horrific violence, the Internet makes no distinction. Is it time to change that? And can we? In this programme Aleks Krotoski looks at whether it’s possible to use technological fixes to regulate the internet or whether a more political approach is needed to governance of this vital but flawed communications medium.Picture: Human Hand Using Application on Mobile Phone, Credit: Onfokus

With the coming of the World Wide Web in the 1990s internet access opened up to everybody, it was no longer the preserve of academics and computer hobbyists. Already prior to the Web, the burgeoning internet user groups and chat rooms had tested what was acceptable behaviour online, but access was still limited. Aleks Krotoski asks whether the Web through enabling much wider use of the internet is the villain of the piece in facilitating not just entertainment and commerce, but all aspects of the darker side, from malicious computer hacking attacks, worms and viruses, to new channels for criminality, online extortion and identity theft.(Photo: Internet sign. Credit: code6d)

Just how did the Internet become the most powerful communications medium on the planet, and why does it seem to be an uncontrollable medium for good and bad? With no cross border regulation the internet can act as an incredible force for connecting people and supporting human rights and yet at the same time convey the most offensive material imaginable. It has become the most useful research tool on earth but also the most effective way of delivering threats to the security of governments, the health service and on a personal level our own identities.In this series Aleks Krotoski unravels the complexity of the internet, meeting the people who really invented it, looking behind the myths and cultural constructs to explain what it actually is and how it came to exist outside of conventional regulation. We’ll ask whether the nature of the net itself really is cause for concern - and if so what can be done to reign in the negatives of the internet without restricting the positives? In this first episode we go b

Silicon is literally everywhere in both the natural and built environment, from the dominance of silicate rocks in the earth crust, to ubiquitous sand in building materials and as the basis for glass. We've also harnessed silicon's properties as a semiconductor to build the modern electronics industry - without silicon personal computers and smartphones would simply not exist.Silicon is also found widely across the universe. It is formed in stars, particularly when they explode. And the similarities between how silicon and carbon form chemical bonds has led many to wonder whether there could be silicon based life elsewhere - perhaps in some far flung part of the galaxy where carbon is not as abundant as here on earth. As well as discussing the potential for silicon based life on other planets, Birkbeck University astrobiologist Dr Louisa Preston considers the varied uses of silicon here on earth, from its dominance in our built environment to its driving role in artificial intelligence and its ability to harn

For the first time in almost 100 years the USA is experiencing a full solar eclipse from coast to coast on August 21st 2017.Main image: Totality during the solar eclipse at Palm Cove on November 14, 2012 in Palm Cove, Australia. Credit: Ian Hitchcock / Getty Images

Carbon is widely considered to be the key element in forming life. It's at the centre of DNA, and the molecules upon which all living things rely.Monica Grady, Professor of Planetary Science at the Open University, explores the nature of carbon, from its formation in distant stars to its uses and abuses here on earth. She looks at why it forms the scaffold upon which living organisms are built, and how the mechanisms involved have helped inform the development of new carbon based technology, and products - from telephones to tennis rackets.One form of carbon is graphene which offers great promise in improving solar cells and batteries, and introducing a whole new range of cheaper more flexible electronics.Carbon is also the key component of greenhouse gases, carbon dioxide and methane. To counter some of the effects of man-made climate change, Scientists are now developing novel ways to speed up this mechanism - using waste materials created from mining and industry.Monica Grady also looks to space, and the s