When a person with severe anorexia nervosa refuses food, the very treatment they need to survive, is that refusal carefully considered and rational, as it can appear to those around them? Or is it really the illness that’s causing them to say ‘no’?

This is one of the thorny ethical dilemmas that Jacinta Tan has wrestled with over the course of her career. She is deeply curious about the mind, and has spent hundreds of hours sitting with people with anorexia nervosa, not persuading them to eat, rather listening to them talk about what’s going on in their minds and how the illness influences their decisions.

These rich internal worlds, that she has revealed, shape her work as a Child and Adolescent Psychiatrist at Oxford Health NHS Foundation Trust, where she treats people with eating disorders. The views of those with the conditon and their families have been central to the recent government reviews of the Eating Disorder Services that she led in Scotland and Wales.

These conditions can be hugely challenging to treat. Jacinta Tan tells Jim Al-Khalili how it's the art of medicine, as much as the science, that helps people recover.

PRODUCER: Beth Eastwood

Pete Smith is very down to earth. Not least because he’s interested in soil and the vital role it plays in helping us to feed the world, mitigate climate change and maintain a rich diversity of species on planet earth. He was born in a pub and failed the 11+ exam (designed to identify bright children just like him) but he became a distinguished professor nonetheless.

Chi Onwurah tells Jim Al-Khalili why she wanted to become a telecoms engineer and why engineering is a caring profession.

As a black, working class woman from a council estate in Newcastle, she was in a minority of one studying engineering at university in London and encountered terrible racism and sexism. She went on to build digital networks all over the world, the networks that make today's instant multimedia communications possible. And Chi built the first mobile phone network in Nigeria, when the country was without a reliable electricity supply. Today she is Shadow Minister for Science, Research and Innovation.

When Chi decided to go into politics, her engineering colleagues were not impressed. Why would anyone leave their noble profession to enter a chaotic, disreputable and dubiously useful non-profession, they asked. But, Chi believes, parliament desperately needs more scientists and engineers, not only to help us solve science-based problems but also to create technical jobs and build a strong economy.

Ailie's first engineering challenge was working out how to get the solids to settle in a mixture of raw sewage at a treatment plant in Stuttgart. Years later, she worked on the Boston Big Dig and realised that large-scale construction projects were her thing. A seven lane highway was rerouted underground and a bridge built using blocks of expanded polystyrene to support the on off ramps. When Bostonians complained about the vibrations from all the drilling, their beds were put on springs. She returned home to the UK to run the transformation of St Pancras Station in London, creating an international terminal for Eurostar while preserving the historic features of the original building. Preventing 690 cast iron pillars that supported the platform from 'breaking like carrots' was a particular challenge, as was keeping the Midlands mainline running. Next she took on Crossrail and was in charge of the challenging central London section, with a budget of £7.5 billion. Aware that diverse teams tend to be more successful she recruited a top team of engineers in which 30% were women.

Ailie talks to Jim about how she rose from doing experiments with sewage to become one of the most successful engineers in the UK.

Producer: Anna Buckley

Ben Garrod is an obsessive bone collector and wild animal behaviourist. He was destined for a career in medicine but a chance encounter with primatologist Jane Goodall reignited his life long passion for conservation and led to him managing and researching the habituation of wild chimpanzees in Africa. It was a chance to record primate behaviour that had never been seen before and examine how resilient chimps can be to anthropogenic change. Further extraordinary insights into the speed of evolution through the clues in the bones of island monkeys was to follow.

He is a professor of Evolutionary Biology and Science Engagement at the University of East Anglia and the presenter of several landmark TV series on animal bones and extinction, such as The Secrets of Bones and most recently, Attenborough and the Mammoth Graveyard. Ben shares his passion for the contrasting insights into conservation and extinction, the value they play, and describes his own extraordinary journey from exploring animal remains washed up on Norfolk beaches to years spend tracking chimps in Uganda to eminent science communicator and public figure.

Producer Adrian Washbourne

Steve Brusatte analyses the pace of evolutionary change and tries to answer big questions. Why did the dinosaurs die out and the mammals survive? How did dinosaurs evolve into birds? If you met a Velociraptor today you’d probably mistake it for a large flightless bird, says Steve. His intense interest in T. rex, Triceratops and all the other dinosaur species developed when he was a teenager and continues to this day. More recently, however, he’s focussed on the long history of mammals.

Steve talks to Jim Al-Khalili about his life and work, including the recent discovery of an incredibly well-preserved Pterosaur on the Isle of Skye, a place he likes to call Scotland’s Jurassic Park.

Sir Shankar Balasubramanian is responsible for a revolution in medicine. The method he invented for reading, at speed, the unique genetic code that makes each one of us who we are, is ten million times faster than the technology that was used in the human genome project at the turn of the century. What’s more, it can be done much more cheaply than before and on a desktop machine. And it’s transforming healthcare, by helping us to understand the genetic basis of many diseases (particularly cancers) and to develop new diagnostic tests, medicines and personalised treatments.

Image ©University of Cambridge

Early in her career, Julia wanted to know if it was possible to get someone to believe they committed a crime (when they hadn’t)? In a bold experiment she showed how students created false memories of criminal events in their teenage years, describing in rich detail how they had assaulted people, when no such events had taken place. What does this mean for a criminal justice system that relies heavily on memory-based evidence? Does it make it more difficult for the victims of crimes to have their voices heard? Victims of sex crimes, in particular. Or can the findings of false memory research be used to prevent miscarriages of justice? Julia talks to Jim Al-Khalili about growing up with her dad’s delusional beliefs and paranoid thoughts and how a profound appreciation that everyone’s reality is different pulled her to the field of false memory research.

Microbiologist Sharon Peacock has led one of the genuine science success stories of the pandemic. Professor Peacock is the founding director of COG-UK, the COVID-19 Genomics UK consortium. COG-UK is the network of 600 scientists and labs around the country which has acted as our surveillance system for the appearance and spread of new and dangerous variants of concern.

Thanks to Professor Peacock and her colleagues, the UK was way ahead of other countries in establishing a national network of SARS-CoV-2 sequencing and genomic analysis although she was the target of criticism when COG-UK was being set up in the spring of 2020. However, as she tells Jim Al-Khalili, it paid off. For example, it was the sequencing of virus samples by the consortium that last December identified the fast-spreading Alpha or so-called Kent variant. This was the variant responsible for the terrible second wave of deaths and hospitalisations last winter. It was a combination of the overwhelmed hospitals, rocketing infection rates and the discovery of Alpha that persuaded the government to tighten the rules for that Christmas and institute the lockdown in January.

Before the pandemic, Sharon Peacock was a pioneer and advocate for the application of pathogen genome sequencing in the National Health Service to tackle the growing menace of antibiotic resistance. She is a consultant in microbiology and Professor of Public Health and Microbiology at the University of Cambridge. This is not a list of titles and achievements which Sharon could have possibly imagined when she left school at 16, to work full time in her local corner shop.

Producer: Andrew Luck-Baker

The huge popularity of meerkats is in no small part down to Professor Tim Clutton-Brock, zoologist and evolutionary biologist of the University of Cambridge.

‘Meerkat Manor’ and many natural history TV documentaries that have followed the lives of these small appealing mongooses were filmed at the field research centre in South Africa which Tim set up three decades ago.

Colleagues describe Tim Clutton-Brock as one of the giants in the field of animal behaviour and societies, seeking to explain them from an evolutionary and ecological perspective.

He is renowned for his ambitious, long-term studies of populations of animals in the wild. His research follows hundreds of individuals to see how the animals develop and fare over their entire lifetimes and what factors determine their longevity and their success at producing offspring.

Professor Clutton-Brock talks to Jim Al-Khalili about his five decades of research; including why sons cost mothers more than daughters, getting close to fighting stags at night, and how to tame a meerkat so she’ll let you ultrasound her belly.

Producer: Andrew Luck-Baker