Who could forget the beginning of 2020, when a ‘mysterious viral pneumonia’ emerged in the Chinese city of Wuhan. Soon, other countries were affected and deaths around the world began to climb. Perhaps most alarmingly of all, there were no proven treatments to help prevent those deaths. As the World Health Organisation declared the Covid-19 outbreak a pandemic, and the UK and the rest of the world braced itself for what was to come, doctor and drug-trial designer Martin Landray had his mind on a solution, devising the protocol, or blueprint, for the world’s largest drug trial for Covid-19. As Professor of Medicine and Epidemiology at Oxford University, Martin was perfectly positioned to jump, delivering what became known as the RECOVERY Trial. The trial was tasked to deliver clarity amid the predicted chaos of the pandemic and galvanised every acute NHS hospital in the UK. Within its first one hundred days, it had yielded three major discoveries and it has transformed Covid-19 treatment worldwide, already saving over a million lives. Sir Martin Landray was recently knighted for this work and RECOVERY’s legacy lives on, not just for Covid. Martin plans to revolutionise drug trials for other diseases too. PRODUCER: Beth Eastwood

Vlatko Vedral describes himself as a quantum information practitioner, who believes that our universe is made up of quantum bits of information. It is information, he tells Professor Jim Al-Khalili, rather than energy or matter, the traditional building blocks of classical Newtonian physics, that can help us to understand the nature of reality. Vlatko is Professor of Quantum Information Science at the University of Oxford and the Principal Investigator at the Centre for Quantum Technologies at the National University of Singapore and he talks to Jim in front of an audience at the Cheltenham Science Festival. At high school in Belgrade, in what was then Yugoslavia, young Vlatko was bowled over by the idea that you could take the micro-laws of quantum mechanics, and apply them to the complex systems of the macro world. This drive to see the big picture, was fuelled when, as an undergraduate at Imperial College, London, he saw three words – “Information is physical” – the title of a paper by the IBM physicist, Rolf Landauer. It was a light-bulb moment for Vlatko, who realised that the kind of information processing that the universe is capable of, depends on the underlying laws of physics. This revelation led to Vlatko’s incarnation as a self-confessed “physics fundamentalist” who unashamedly crowns physics the Queen and other disciplines, her servants. It is physics alone, he tells Jim, which can answer the fundamental questions of the universe and discover the ultimate reality. His PhD in 1997 at Imperial College, London, applied quantum mechanics, including super-positioning and entanglement (which Einstein famously called “spooky action at a distance”), to Claude Shannon’s Information theory, making Vlatko one of the pioneers in the field of quantum information. As new quantum computers come on stream, he tells Jim, quantum information practitioners, like him, will have the capacity to simulate complex systems in the macroscopic domain. Producer: Fiona Hill

Ant-loving professor, Adam Hart, shares his passion for leaf cutting ants with Jim Al Khalili. Why do they put leaves in piles for other ants to pick up? Talking at the Hay Festival, Adam describes the experiments he designed to test the intelligence of the hive mind. When does a waggle dance become a tremble dance? And how do the honey bees know when this moment should be? We like the phrase ‘as busy as a bee’. In fact, bees spend a lot of time doing nothing at all, a sensible strategy from the point of view of natural selection. And where does Adam stand on insect burgers? Producer: Anna Buckley

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. Tackling climate change in isolation is a mistake, he says. We need to consider all the challenges facing humanity and identify strategies that deliver benefits on all fronts: food security, bio-diversity and human development goals. He tells Jim Al-Khalili about his life and work and the urgent need for our degraded peat bogs to be restored. Peat bogs that have been drained (for grazing or to plant trees) add to our carbon emissions. Healthy peat bogs, however, are carbon sinks. Producer: Anna Buckley