There are almost a million people in the UK living with dementia, and Alzheimer’s is the most common form. But the disease actually starts long before any noticeable symptoms appear, and over the past decade, studies have shown that it is much more complex than previously thought. Julie Williams has been at the forefront of this effort, uncovering the genes that make us susceptible, and has transformed our understanding of this devastating disease. She has brought researchers together to create bigger datasets and more powerful studies. Her current work with scientists from other fields, like immunology and computational biology, is looking at the mechanisms underlying Alzheimer’s disease. Julie tells Jim about her early interest in science, her time as Chief Scientific Advisor to the Welsh government, and her belief in ‘team science’ – collaborating and sharing research findings across international borders and disciplines. Produced by Florian Bohr

Since 1900, our best estimates suggest that earthquakes have caused around 2.3 million deaths worldwide; we saw the devastating effects of one just recently, in Turkey and Syria. And as scientists have been at pains to point out over the years, there is no reliable short-term warning system. But thanks to the work of people like James Jackson, an Emeritus Professor of Active Tectonics at the University of Cambridge, we are finding new ways of understanding and withstanding seismic activity. James tells Jim Al-Khalili about his career travelling the world in search of quake sites and fault lines – trialling new technology and techniques in a quest to understand the processes that shake and shape our planet’s surface; and working out how this information can help vulnerable cities become more resilient to quakes in future... Produced by Lucy Taylor.

Marie Johnston is a pioneer in the field of health psychology: the discipline that seeks to understand how psychological, behavioural and cultural factors contribute to our physical and mental health. Today an emeritus professor in health psychology at the University of Aberdeen, her career exploring behavioural interventions has shown that even the subtlest shift in how we act can dramatically change our behaviour and lives for the better – whether that’s in an individual recovering from a stroke, or a nation coming to terms with pandemic safety measures, while her work setting up the UK’s first stress management clinic showed why mental health support needed to come out of psychiatric hospitals and into general practice. Marie tells Professor Jim Al-Khalili why she believes the right interventions can be a powerful tool in improving public health, and indeed our healthcare system; and how an accident at the hairdresser's many years ago helped her become more approachable... Produced by Lucy Taylor.

Professor Dame Julia King, Baroness Brown of Cambridge, is an engineer whose fascination with metals, and skill for handling both research projects and people, has taken her from academia to industry to the House of Lords. She tells Jim Al-Khalili how the dressmaking skills she learnt from her mother as a child helped her to understand the composite structures used in wind turbines later in life. And how she designed metal alloys that are resistant to both large and small cracks. As the author of the UK government's Review of Low Carbon Cars in 2007, Julia set out a route to decarbonising a major segment of the transport sector within 25 years, making an important contribution to the UK's plans to try and achieve Net Zero. But achieving Net Zero is not enough. With demand for electricity set to double or treble by 2050, there’s an urgent need to radically reform our national infrastructure and guarantee supply. Julia became a cross-bench member of the House of Lords in 2015. She’s now chair of its Science and Technology Committee, holding the government to account on its promise to make the UK a science superpower.

Jim Al-Khalili talks T cells, our immune response and Long Covid with Prof Danny Altmann. Danny Altmann joined ‘team T cells’ in his twenties and has been studying how these killer operate ever since. How do they know which cells to search and destroy? The T cell wing of our immune response is highly targeted and incredibly clever, on a par with the most sophisticated military intelligence operation and in recent decades there have been dramatic advances in our understanding of how it all works . Danny tells Jim how he came to study our immune response to all sorts of pathogens, from anthrax to zika, why he spends every morning from 5 to 6am in the bath reading 19th century classics and why he’s determined to try and understand Long Covid. Producer: Anna Buckley

Jim Al-Khalili talks to astrophysicist Haley Gomez about defying expectations and becoming a world expert on cosmic dust. For centuries, cosmic dust was a major source of irritation to optical astronomers because, like smog, it stopped them from seeing the stars. Now studies of these tiny particles are challenging some deeply held assumptions about the physics of the universe. Haley’s research has changed the textbook explanation of how cosmic dust is formed and helped to open our eyes to just how many galaxies there are in the universe. In 2018 she was awarded an MBE for services to physics and inspiring the next generation of physicists and astronomers from less privileged communities. A cause which is very close to her heart. Produced by Anna Buckley and recorded in the Pier Head Building in Cardiff as part of the Cardiff Science Festival.

How a once-derided approach to statistics paved the way for AI. Jim Al-Khalili talks to pioneering mathematician, Professor Sir Adrian Smith. Accused early in his career of ‘trying to destroy the processes of science’, Adrian went on to prove that a branch of statistics (invented by the Reverend Thomas Bayes in 1764) could be used by computers to analyse vast sets of data and to learn from that data. His mathematical proofs showed that Bayesian statistics could be applied to all sorts of real world problems: from improving survival rates for kidney transplant patients to tracking Russian submarines. And paved the way for a dramatic explosion in machine learning and AI. Working as a civil servant (2008-2012) he helped to protect the science budget in 2010, transforming the landscape for scientific research in the UK. And he has been vocal, over many years, about the urgent need to make sure children in the UK leave school more mathematically able. In 2020, he became President of the UK's prestigious national science academy, The Royal Society. Producer: Anna Buckley

Clifford Johnson's career to date has spanned some seemingly very different industries - from exploring quantum mechanics around string theory and black holes, to consulting on some of Hollywood's biggest movies; but it makes sense once you understand his ambition of making science accessible to all. A Professor in the Department of Physics and Astronomy at the University of Southern California in Los Angeles, Clifford's worked in the United States for decades – but was born in the UK, then spent his formative years on the Caribbean island of Montserrat, before moving back to England to study. Here, he fell in love with quantum mechanics - before moving to the US, where he's broken new ground in finding ways to talk about quantum gravity and black holes. Clifford's other big passion is getting as many people as possible engaged with science, making it more exciting, entertaining and most importantly diverse - and it's this attitude that's led to regular work as a science consultant on various TV shows and films; and even a recent cameo in a major movie... Produced by Lucy Taylor.

A fur-stripped mouse carcase might not sound like the cosiest of homes – but that’s where the burying beetle makes its nest; and where Rebecca Kilner has focused much of her research. A Professor of Evolutionary Biology at the University of Cambridge, Rebecca’s work – initially with cuckoos, then more recently with the beetles – has shed invaluable light on the relationship between social behaviours and evolution. She tells Jim Al-Khalili how the beetles’ helpfully swift generational churn and mouse-based parenting has allowed her team to study evolution in action, demonstrating for the first time what was previously just evolutionary theory. Producer: Lucy Taylor

Motor Neuron Disease (MND) is a degenerative disease that relentlessly attacks the human nervous system, deteriorating muscle function to the point where patients can no longer move, talk, eat, or even breathe. To date there’s no cure, and until fairly recently there were only minimal treatments to ease the symptoms. Pam Shaw has dedicated her career to changing that. A Professor of Neurology at Sheffield University and Founding Director of the Sheffield Institute for Translational Neuroscience, she recently led clinical trials into a drug that delivered unprecedented results: showing that it could slow the progression of MND in certain patients, and even improve symptoms for some. It’s just one small step – but with a new tranche of research funding and a national institute to study the disease on the cards, Pamela believes this could be the start of real progress in understanding and treating Motor Neuron Disease. Producer: Lucy Taylor

Professor Chris Elliott is something of a ‘food detective’. A Professor of Food Safety and Microbiology at Queen's University Belfast and a founding director of its Institute for Global Food Security (IGFS), his work is all about developing scientific solutions to protect us from contaminated food, be it accidental or criminal. Following the 2013 horse meat scandal – when prepared foods purporting to be made from beef were found to contain undeclared horse-meat – Chris conducted the independent review of the UK food system that brought to light the growing threat of food crime. Since then, his name’s become synonymous with solving cases of food fraud; today he receives regular tip-offs on everything from oregano scams to dodgy potatoes. But as Chris tells Jim Al-Khalili, his team at the IGFS are pioneering new techniques to read the molecular fingerprint of foodstuffs, with technology that they hope will stop the fraudsters in their tracks… Producer: Lucy Taylor

What use to science is a pesky organism that feeds on rotting fruit? Professor Bambos Kyriacou has spent fifty years observing the behaviour of fruit flies. He keeps them in the lab and in his garden in their thousands, has recorded fruit fly courtship songs using a microphone loved by Jonny Carson (because it made his voice sound deeper) and invented equipment to keep track of their sleeping patterns. He tells Jim Al-Khalili how fruit flies sparked his interest in genetics and how experiments with insomniac fruit flies opened our eyes to the fundamental importance of body clocks.

Leon Barron monitors pollution in our rivers, keeping tabs on chemicals that could be harmful to the environment and to our health. He’s also gathered intelligence on the behaviour of millions of Londoners by studying the water we flush down the loo. His analysis of sewage revealed, for example, just how much cocaine is consumed in London every day. And he’s helped the Metropolitan Police to crack crimes in other ways too, inventing new chemistry tools that can be used by forensic scientists to uncover clues. At school he had no idea he wanted to be an analytical chemist but a short work experience placement at the fertiliser factory convinced him that this kind of detective work was fun. Producer: Anna Buckley

Tim Lamont is a young scientist making waves. Arriving on the Great Barrier Reef after a mass bleaching event, Tim saw his research plans disappear and was personally devastated by the destruction. But from that event he discovered a novel way to restore coral reefs. Playing the sounds of a healthy coral reef entices fish in to recolonise the wrecked reefs. Tim's emotional journey forced him to realise that environmental scientists can no longer just observe. They need to find new prisms with which to view the world and to intervene to save or protect the natural environment.

Daphne Koller was a precociously clever child. She completed her first degree – a double major in mathematics and computer science – when she was just 17 and went on to become a distinguished Professor at Stanford University in California. But before long she’d given up this comfortable academic position to create the biggest online education platform in the world. In 2018, she founded the drug discovery company Insitro hoping to create a space where data scientists and molecular biologists could work together as equals. Daphne tells Jim Al-Khalili how a single question from her supervisor nudged her to use her considerable mathematical ability to do something useful and why she believes the time is right for artificial intelligence to discover new medicines. Producer: Anna Buckley

Emily Holmes is a distinguished Professor of Clinical Psychology at Uppsala University and a neuroscientist who struggled to learn to read and write as a child. She tells Jim Al-Khalili about her work as a mental health scientist and her life-long love of art and explains why the images we see in our mind’s eye have more of an impact on our emotions than their verbal counterpart. And describes how this fundamental insight led her to develop a simple and cost-effective treatment for the fleeting flashbacks that haunt people with post traumatic stress disorder: briefly recalling the traumatic event and playing the computer game Tetris. Producer: Anna Buckley

Think Sahara Desert, think intense heat and drought. We see the Sahara as an unrelenting, frazzling, white place. But geo-archaeologist Dr Judith Bunbury says in the not so distant past, the region looked more like a safari park. In the more recent New Kingdom of Ancient Egypt, from around 3.5 thousand years ago (the time of some of Egypt’s most famous kings like Ahmose I, Thutmose III, Akhenaten, Tutankhamun and queens like Hatshepsut) evidence from core samples shows evidence of rainfall, huge lakes, springs, trees, birds, hares and even gazelle, very different from today. By combining geology with archaeology, Dr Bunbury, from the department of Earth Sciences at the University of Cambridge and Senior Tutor at St Edmund’s College, tells Jim Al-Khalili that evidence of how people adapted to their ever-changing landscape is buried in the mud, dust and sedimentary samples beneath these ancient sites, waiting to be discovered. With an augur (like a large apple corer), Judith and her team take core samples (every ten metre sample in Egypt reveals approximately 10,000 years of the past) and then read the historical story backwards. A model of the topography, the environment, the climate and the adapting human settlements can then be built up to enrich the historical record. The core samples contain chipped stones which can be linked directly to the famous monuments and statues in the Valley of the Kings. There are splinters of amethyst from precious stone workshops, tell-tale rubbish dumped in surrounding water as well as pottery fragments which can be reliably time-stamped to the fashion-conscious consumers in the reign of individual Pharaohs. The geo-archaeological research by Judith and her team, has helped to demonstrate that the building of the temples at Karnak near Luxor, added to by each of the Pharaohs, was completely dependent on the mighty Nile, a river which, over millennia, has wriggled and writhed, creating new land on one bank as it consumes land on another. Buildings and monuments were adapted and extended as the river constantly changed course. And Judith hopes the detailed, long-range climate records and models we already have, can be enriched with this more detailed history of people, their settlements and their activities within a changing landscape and this will contribute to our ability to tackle climate change. Producer: Fiona Hill

Nobel Prize-winning chemist Frances Arnold left home at 15 and went to school ‘only when she felt like it’. She disagreed with her parents about the Vietnam War and drove big yellow taxis in Pittsburgh to pay the rent. Decades later, after several changes of direction (from aerospace engineer to biotech pioneer), she invented a radical new approach to engineering enzymes. Rather than try to design industrial enzymes from scratch (which she considered to be an impossible task), Frances decided to let Nature do the work. ‘I breed enzymes like other people breed cats and dogs’ she says. While some colleagues accused her of intellectual laziness, industry jumped on her ideas and used them in the manufacture of everything from laundry detergents to pharmaceuticals. She talks to Jim Al-Khalili about her journey from taxi driver to Nobel Prize, personal tragedy in midlife and why advising the White House is much harder than doing scientific research. Producer: Anna Buckley

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