Discovery

Zoologist and founder of the Sloth Appreciation Society, Lucy Cooke, unleashes her inner sloth to discover why being lazy could actually be the ultimate evolutionary strategy.The explorers of the New World described sloths as ‘the lowest form of existence’, but sloths are actually some of the most enduring of all tropical mammals. They make up one third of the mammalian biomass in rainforests and have survived some 64 million years - outliving far flashier animals like sabre tooth tigers. The secret to the sloth’s success is their slothful nature and their suite of energy-saving adaptations. In fact slothfulness is such a successful strategy, that there are examples all over the animal kingdom, including, surprisingly, worker ants. Recent studies in humans have shown the many health benefits of adopting a slower pace of life. Sleep itself is universal amongst the animal kingdom. All animals do it, but why remains a mystery. What is clear though, is that unleashing your inner couch potato is no bad thing, be y

Does knowing that someone is inflicting pain on you deliberately make the pain worse? Professor Irene Tracey meets survivors of torture and examines the dark side of pain.Producer: Geraldine Fitzgerald(Photo: A woman mourns during the funeral procession of Abdulrassul Hujairi. Credit: Joseph Eid/AFP)

What if your brain could naturally control pain? Professor Irene Tracey and her colleagues are trying to unlock the natural mechanisms in the brain that limit the amount of pain we feel.We hear about how children learning judo are taught special techniques and from ex-marine Chris Shirley who ran a marathon carrying a 45kg rucksack and could ignore the pain of the blisters and torn shoulder muscles. One study found that religious people feel less pain than agnostics by looking at a picture of the Virgin Mary. Neuroscientists and psychologists are beginning to understand how this is possible, how the brain can block out pain in the right circumstances, so is this something we could all benefit from? Picture: The statue of the Virgin Mary, Credit: Francisco Leong/AFP/Getty ImagesProducer Geraldine Fitzgerald

Scientists reveal why we feel pain and the consequences of life without pain. One way to understand the experience of pain is to look at unusual situations which give clues to our everyday agony.Phantom limb pain was described in ancient times but only after WWI did it gain acceptance in modern medicine. For those living with it, it can be a painful reminder of a lost limb. New studies are now unravelling why the brain generates this often unpleasant experience and how the messages can be used positively.Its only since the 1980s that doctors agreed that babies are able to feel pain but we still don’t know how the developing brain processes information and how premature babies can be protected from the many invasive tests they have to go through. New research aims to provide appropriate pain relief that could have long term consequences.Picture: Nerve cells, computer artwork, Credit: Science Photo Library

Mystery still surrounds the experience of pain. It is highly subjective but why do some people feel more pain than others and why does the brain appear to switch off under anaesthesia so we are unaware of the surgeon’s scalpel? Professor Irene Tracey uses brain scanners to ask if we can actually see pain in the brain. On air we hear for the first time the results of the latest research into diabetes and nerve pain. Promising new techniques means scientists are able to see regions in the brain which effectively turn up the pain in some people and not others.Anaesthetics prevent pain during surgery but how the brain disengages is only just beginning to be understood, which could in the future lead to personalised doses of anaesthetics leading to faster recovery times.Picture: Graphic of neurons firing in the of the neural network within the Brain, Credit: Science Photo Library

In Bristol in 1799, a young man started to experiment with newly discovered gases, looking for a cure for tuberculosis. Humphry Davy, aged 20, nearly killed himself inhaling carbon monoxide. Nitrous oxide was next. It was highly pleasurable, ‘particularly in the chest and extremities’ and he began to dance around his laboratory ‘like a madman’, before passing out. By day, he gave the gas to patients, carefully noting their reactions. In the evenings, he invited his friends over to have a laugh (with assistants on standby to revive them with oxygen, as needed). The Romantic poets, Robert Southey and Samuel Taylor Coleridge could barely contain their excitement. During one session, Davy noted that the gas numbed his toothache and suggested that it could perhaps be used during surgical operations. But it was another fifty years before nitrous oxide was used by doctors. Throughout the 20th century, it was widely used during dentistry and to numb the pain of childbirth. (Nitrous oxide is the gas in ‘gas and air’

Philip Ball reveals the dramatic tale of Lise Meitner, the humanitarian physicist of Jewish descent, who unlocked the science of the atom bomb after a terrifying escape from Hitler's Germany. One of the most brilliant nuclear scientists working in Germany her flight from terror cost Hitler’s regime dearly.In the early 20th Century it was barely possible for women to work in science at all and yet Einstein once called Meitner Germany’s own Marie Curie. It was Meitner’s insight that began the nuclear age and her story remains ever relevant, as the threat of nuclear conflict lies once again over the world.Philip Ball talks to historian Dr Patricia Fara about Lise Meitner and her research and to Patricia Lewis of the International Campaign to Abolish Nuclear Weapons or ICAN, based in Geneva, which this year was awarded the Nobel Peace prize for its work in trying to reverse nuclear proliferation, about Meitner’s legacy today.Picture: Lise Meitner, Credit: Central Press/Getty Images

Roland Pease tells the story of how fifty years ago geologists finally became convinced that the earth’s crust is made up of shifting plates. The idea of mobile continents, continental drift, had been talked about, for example because it looked like Africa and South America had once been joined, and were now separated by the Atlantic. But given the solidity of rocks and the vastness of continents, that idea made no sense. Until plate tectonics, as it became known, gave it a scientific basis and rebuilt it into a mechanism that explained earthquakes, mountain belts, chains of volcanic islands and many other geological phenomena. Roland Pease talks to many of the key researchers in the story, now in their 70s and 80s, and finds out how their work transformed our understanding of the earth. Picture: Tectonic plates of planet earth - map with names of major and minor plates, Credit: PeterHermesFurianPresenter: Roland Pease

Maria Merian was born in 1647. At the time of her birth, Shakespeare had been dead for 30 years; Galileo had only just stood trial for arguing that the Earth moved around the Sun. And yet, here in Germany, was a child who would become an important but oft-forgotten figure of science.Aged 13, she mapped out metamorphosis, catching caterpillars from her garden and painting them in exquisite detail. At that point, most believed that caterpillars spontaneously generated from cabbages and maggots materialised from rotten meat. She later voyaged to Suriname in South America to pursue pupae further, discovering not just new species but also the conditions needed for their survival. Some call her the first field ecologist; others admire her for her eloquent brushwork. However, her studies will help today’s biologists plot which insects lived where. These data are invaluable because this could help scientists predict what species will survive climate change. Naomi Alderman discusses the life and legacy of Maria Merian

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