Discovery

Naomi Alderman tells the story of Hertha Marks Ayrton, the first woman to be admitted to the Institution of Electrical Engineers, who improved electric arc lights.Photo: Street lamps light up a road in Colombo, credit: Ishara S.KODIKARA/AFP/Getty Images

Testosterone has been claimed as one of the most important drivers of human life – through the agency of sex and aggression. In the 19th century, Charles-Eduoard Brown-Séquard injected himself with extracts from ground-up animal testicles, and made startling claims for its rejuvenating properties and its ability to enhance virility. But the amount of testosterone derived from the injection was actually so small that it could only have been a placebo effect. Today synthesised testosterone is increasingly prescribed for the so-called ‘male menopause’; it’s also regularly used for trans men as they transition, as well as for some women with low libido. In ‘How Much Testosterone Makes You a Man’, Naomi Alderman explores how testosterone had been used and abused in the past. She considers the credits and deficits of its story, and asks what it can tell us about identity and masculinity.Image: Stick men, BBC Copyright

Prior to 1543 it was generally believed that the earth lay static in the centre of the universe, while the Sun, moon, planets and stars revolved around it in various complex paths, some even looping back and forth, as described by the Egyptian astronomer Ptolemy over a millennium before. This Ptolemaic system sat comfortably reconciled with philosophy and biblical scripture, not to mention immediate experience and observations.In the 16th century astronomy and astrology were closely intertwined, as the art of predicting where the small dots of light on the night sky would appear had consequences if you were the sort of person who based your actions on horoscopes. But astronomers didn't have the right to start telling philosophers and theologians how the universe was actually constructed - what its mechanisms were - they merely observed the moving dots of light and used mathematics to predict where they would be the next night, week or month. This was an essential function for the Catholic church too - as the all-important date of Easter is based around a complicated lunar pattern.But also at that time in northern Europe, Martin Luther and others had begun a protestant revolution, fundamentally questioning the authority of the Pope and Vatican.It was an auspicious time for a fairly middle ranking Catholic cleric, Nicolaus Copernicus, working in a remote corner of northern Poland to drop a note around telling other astronomers that he'd worked out a new system that made for better astronomical calculations by making the moon travel round a spinning earth, and the earth and all the planets travel around the Sun. If that were the true shape of the universe, the bible could no longer be literally true.It took 30 years, but eventually a keen young Austrian mathematician convinced him to publish his book. So a German radical protestant published a book by a mild-mannered Polish Catholic cleric, a book that allegedly simplified the cosmos, rightfully placing the Sun at the centre of our local universe, kicking off the scientific revolution and leading to the European enlightenment.But as Phil Ball explains, the real story of 'De Revolutionibus Orbium Coelestium' - 'On the Revolutions of Heavenly Spheres' - is not quite as straight forward as all that.Image: © BBC

We humans are such a successful species. Homo sapiens have been around for only around 100 000 years and in that time we have utterly transformed the world around us. Our shelters allow us to live in all climates and from the poles to the tropics; our technology lets us communicate across the planet. We’ve created art and music and literature; and our agriculture has changed global biodiversity, shifting forever the way we feed ourselves. In other words, human culture dominates the earth. Gaia Vince finds out what has given us the cultural edge over other animals. This includes our closest relatives – the great apes – with whom we share over 95% of our genes. She meets researchers at Birmingham University comparing the abilities of chimps and human children, and has a go at making a prehistoric stone hand axe by flint knapping. Photo credit: William West/AFP/Getty Images

Whether it's gossiping over a drink, teaching our children, or politicians debating we use words to communicate with each other and share ideas. It’s what makes us human. But what if we can’t? Could it be possible to broadcast our thoughts directly from our brains without the need for speech? Gaia Vince meets the scientists who say they are getting close to being able to read minds. For the last decade neuroscientists have been using fMRI brain scanners and EEG to try to communicate with people who’d been diagnosed as being in a persistent vegetative state. They have woken up following a coma but although their eyes are open and they have spontaneous movements, they have no cognitive function and are not capable of higher level thought. Dr Damian Cruse, of Birmingham University, tells Gaia about the results of these experiments. People with other medical conditions that lead to a loss of speech, such as motor neurone disease, can already communicate with technology. We hear from Sarah Ezekiel, who has had MND since 2000 and whose life has been transformed by being able to talk artificially with eyegaze software on a computer. Neurologist Dr Kai Miller at Stanford University explains how he is using electrodes already implanted in the brains of people with severe epilepsy to determine what they are seeing. And Gaia explores the ethical problems that follow from technology that captures thoughts with cognitive scientist and philosopher Dr Adina Roskies of Dartmouth College in the US and Professor Geraint Rees, the editor of a recent collection of essays called "I know what you're thinking: brain imaging and mental privacy". She looks at the controversial privacy issues raised by the technology, such as could someone put thoughts into another's mind?Image: Fortune teller gazing into a crystal ball, © Creatas

More than 200 million women and girls alive today have undergone female genital mutilation, or cutting. It is where parts or all of a girl's genitals are damaged or removed. There are no medical benefits to FGM, and people who undergo the practice can face problems in later pregnancies, infections and even death due to blood loss. FGM is recognised internationally as a violation of the human rights of girls and women. The head of the UNFPA recently described it as child abuse. The BBC's Global Health correspondent Tulip Mazumdar has travelled to East and West Africa to investigate efforts to end the practice and ask why this extremely harmful tradition, is proving so difficult to stamp out. (Picture: Women in Narekuni © Krisztina Satori)

Depression or psychotic illness is experienced by hundreds of thousands, perhaps millions, of people in the UK. James Gallagher talks to the psychiatrists investigating this new understanding of mental illness and to people who may benefit from treatments aimed at the immune systems rather than their brain cells.“I believe this is one of the strongest discoveries in psychiatry in the last twenty years”, says Professor Carmine Pariante of his and other research on the immune system and depression. "It allows us to understand depression no longer as just a disorder of the mind and not even a disorder of the brain, but a disorder of the whole body. It shifts conceptually what we understand about depression."James also talks to New York journalist Susannah Cahalan. She began to experience paranoid delusions and florid hallucinations when her immune system made damaging antibodies against part of the molecular circuitry in her brain. Treatment to eliminate the antibodies prevented her committal to psychiatric hospital. Psychiatrist professor Belinda Lennox at the University of Oxford says she has evidence that a significant proportion of people presenting for the first time with psychotic symptoms are victims of a similar autoimmune problem. (Photo: Brain Cells © Science Photo Library)

How do you move a city? Lesley Riddoch travels to Arctic Sweden to find out. Kiruna is gradually sliding into Europe's biggest iron ore mine. The city has to be rebuilt two miles away. That requires an extraordinary blend of planning, architecture, technology and stoicism. If anyone can do it then it's the Swedes.

Meet Huang Ming, the Chinese inventor who describes himself as, 'the number one crazy solar guy in the world'. One of the prize exhibits of his museum in northern China is a vintage solar panel. It is a water heater, installed by President Jimmy Carter on the roof of the West Wing of the White House. Back in 1979 the installation was meant to symbolise a new solar-powered future for America. Instead, oil prices fell and Ronald Reagan removed the White House panels. Thirty-seven years on and it is China, not the US that is embracing the idea of a solar-powered economy. Huang Ming, an engineer, prominent political figure and businessman is leading the way with his foundation of Solar Valley. In 800 acres of land south of Beijing he employs 3000 people in solar research, development and manufacture. Peter Hadfield visits Solar Valley to see the fruits of the sun, from a solar-powered yurt to the world's biggest solar-powered building. He asks if Huang Ming can persuade his nation to turn its back on coal and oil and angle its face toward the sun.

Ascension Island is a tiny scrap of British territory, marooned in the tropical mid-Atlantic roughly halfway between Brazil and Africa. It is the tip of a giant undersea volcano – rugged, remote and, up until around 150 years ago, almost completely devoid of vegetation.Peter Gibbs visits to learn how 19th Century botanist Joseph Hooker, encouraged by Charles Darwin, planted a forest on the island’s summit to trap moisture brought by the trade winds, introducing a panoply of flora from around the world - ginger, guava, bamboo, ficus and dozens more.But is Ascension’s cloud forest all it appears? He talks to conservationists struggling to cope with invasive species running riot, hears about the rescue of Ascension’s tiny endemic ferns, encounters nesting turtles on the beaches and ventures among the chattering ‘wideawakes’ on the sweltering lava plains by the coast.(Photo: Ascension Island. Credit: Matthew Teller)