Discovery

What do you get if you smash two hydrogen nuclei together? Helium and lots of energy – it's nuclear fusion!Nuclear fusion is the power source of the sun and the stars. Physicists and engineers here on earth are trying to build reactors than can harness fusion power to provide limitless clean energy. But it’s tricky.Rutherford and Fry are joined by Dr Melanie Windridge, plasma physicist and CEO of Fusion Energy Insights, who explains why the fourth state of matter – plasma – helps get fusion going, and why a Russian doughnut was a key breakthrough on the path to fusion power.Dr Sharon Ann Holgate, author of Nuclear Fusion: The Race to Build a Mini Sun on Earth, helps our sleuths distinguish the more familiar nuclear fission (famous for powerful bombs) from the cleaner and much less radioactive nuclear fusion.And plasma physicist Dr Arthur Turrell, describes the astonishing amount of investment and innovation going on to try and get fusion power working at a commercial scale.

Sneezes, wheezes, runny noses and red eyes - this episode is all about allergies.An allergic reaction is when your immune system reacts to something harmless – like peanuts or pollen – as if it was a parasitic invader. It’s a case of biological mistaken identity.Professor Judith Holloway from the University of Southampton guides our sleuths through the complex immune pathways that make allergies happen and tells the scary story of when she went into anaphylactic shock from a rogue chocolate bar.Professor Adam Fox, a paediatric allergist at Evelina Children’s Hospital, helps the Drs distinguish intolerances or sensitivities – substantial swelling from a bee sting, for example - from genuine allergies. Hannah’s orange juice ‘allergy’ is exposed as a probable fraud!Hannah and Adam explore why allergies are on the increase, and Professor Rick Maizels from the University of Glasgow shares his surprising research using parasitic worms to develop anti-allergy drugs!Contributors: Professor Judith Holloway, Professor

Pi is the ratio between a circle’s diameter and its circumference. Sounds dull – but pi turns out to have astonishing properties and crop up in places you would never expect. For a start, it goes on forever and never repeats, meaning it probably contains your name, date of birth, and the complete works of Shakespeare written in its digits.Maths comedian Matt Parker stuns Adam with his ‘pie-endulum’ experiment, in which a chicken and mushroom pie is dangled 2.45m to form a pendulum which takes *exactly* 3.14 seconds per swing.Mathematician Dr Vicky Neale explains how we can be sure that the number pi continues forever and never repeats - despite the fact we can never write down all its digits to check! She also makes the case that aliens would probably measure angles using pi because it’s a fundamental constant of the universe.Nasa mission director Dr Marc Rayman drops in to explain how pi is used to navigate spacecraft around the solar system. And philosopher of physics Dr Eleanor Knox serves up some philoso-

Why are some smells so nasty and others so pleasant? Rutherford and Fry inhale the science of scent in this stinker of an episode.Our sleuths kick off with a guided tour of the airborne molecules and chemical receptors that power the sense of smell. Armed with a stack of pungent mini-flasks, professor Matthew Cobb from the University of Manchester shows Hannah and Adam just how sensitive olfaction can be, and how our experience of some odours depends on our individual genetic make-up.Dr Ann-Sophie Barwich from Indiana University reveals how most everyday smells are complex combinations of hundreds of odorants, and how the poo-scented molecule of indole turns up in some extremely surprising places.With the help of a flavoured jellybean and some nose clips, Hannah experiences how smell is crucial to flavour, adding complexity and detail to the crude dimensions of taste.Speaking of food, listener Brychan Davies is curious about garlic and asparagus: why do they make us whiff? Professor Barry Smith from the Centr

How do winds start and why do they stop? asks Georgina from the Isle of Wight. What's more, listener Chris Elshaw is suprised we get strong winds at all: why doesn't air just move smoothly between areas of high and low pressure? Why do we get sudden gusts and violent storms?To tackle this breezy mystery, our curious duo don their anoraks and get windy with some weather experts.Dr Simon Clark, a science Youtuber and author of Firmament, convinces Adam that air flow is really about the physics of fluids, which can all be captured by some nifty maths. The idea of pressure turns out to be key, so Hannah makes her own barometer out of a jar, a balloon and some chopsticks, and explains why a bag of crisps will expand as you walk up a mountain.Professor Liz Bentley, Chief Executive of the Royal Meteorological Scoiety, reveals how the dynamics of a simple sea breeze – where air over land is heated more than air over water – illustrates the basic forces driving wind of all kinds.Then everyone gets involved to help Ada

DO WE HAVE YOUR ATTENTION?Good! But how does that work!?Our intrepid science sleuths explore why some things immediately catch your eye - or ear - while others slip by totally unnoticed. Even, on occasion, basketball bouncing gorillas.Professor Polly Dalton, a psychologist who leads The Attention Lab at Royal Holloway University, shares her surprising research into ‘inattentional blindness’ - when you get so absorbed in a task you can miss striking and unusual things going on right in front of you.Dr Gemma Briggs from the Open University reveals how this can have dangerous everyday consequences: you are four times more likely to have a crash if you talk on the phone while driving -even handsfree.Drs Rutherford and Fry also hear from stroke survivor Thomas Canning, who developed the tendency to ignore everything on the left side of space, despite his vision being totally intact. And Dr Tom Manly, from the University of Cambridge’s Cognition and Brain Sciences Unit, helps our sleuths unpack the neuroscience of

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 muli-media 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

Six and a half million dead. More than a hundred times that infected. The Covid-19 pandemic has wreaked havoc across the globe. But in the final months of the third year of this health crisis, some now claim it’s all over.Scientists with key roles in the global response join Claudia Hammond to consider the evidence behind the declarations that the pandemic has finished and they set out how, officially, this global health crisis will be brought to an end. They reject claims that the pandemic is over, but say the emergency phase of this global health crisis is coming to a close. But only if countries remain vigilant and maintain pandemic preparedness.If vaccines reach arms, if treatments are shared equally and if nations re-introduce public health measures like mask wearing and social distancing when the inevitable new waves (and potential new variants) emerge, the appalling loss of life we saw at the beginning of the pandemic, they tell Claudia, won’t be repeated. There are stark warnings too that the dramati

Literature student turned neuroscientist, Prof David Eagleman, tells Jim Al-Khalili about his research on human perception and the wristband he created that enables deaf people to hear through their skin. Everything we see, taste, smell, touch and hear is created by a set of electro-chemical impulses in the dark recesses of our brain. Our brains look for patterns in these signals and attach meaning to them. So in future perhaps we could learn to ‘feel’ fluctuations in the stock market, see in infra-red or echo-locate like bats? Each brain creates its own unique truth and David believes, there are no real limits to what we humans can perceive.

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 bio-tech 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 mid-life and why advising the White House is much harder than doing scientific research.

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 savin

In the third and final part of our series How Covid Changed Science, Devi Sridhar Professor of Global Health at Edinburgh University looks at the legacy and lessons of the pandemic for scientific research. Tackling the virus became a global issue, but many have pointed out the inequality of both resources and effort in the response. Going forward do we need to be directing research more towards improving health and disease surveillance in less wealthy parts of the world, would investing there help prevent future pandemics?

In the second of our series How Covid Changed Science, Devi Sridhar, Professor of Global Health at Edinburgh University looks at the scientific messaging. Just how do you explain to both politicians and the public that a growing global pandemic is likely to kill many people, and unprecedented measures such as a nationwide lockdown are needed to prevent even more deaths. What information should be imparted and how?Similarly how to address the clamour for information on the development of vaccines and other potential treatments when there often wasn’t clarity? And with the rise of misinformation how did individual scientists who became the subject of conspiracy theories cope with being targeted?In this programme we hear from scientists and politicians directly involved with the pandemic response. For some the experience of explaining their often highly technical research to the general public was a daunting experience. For others it became a mission to answer the publics concerns and fears.

Until 2020 developing a new drug took at least 15 years. Scientists by and large competed with each other, were somewhat secretive about their research and only shared their data once publication was secured. And the public and the press had no interest in the various early phases of clinical trials. An incremental scientific step possibly on the road to somewhere was simply not newsworthy. Face masks were the preserves of hypochondriacs in the Far East, with no scientific evidence base for their use.Now the findings of research are published as soon as they are ready. Often they are being openly discussed in social media before they have been peer reviewed. The speed of research, collaboration between science and industry, and public perception of science are areas that have undergone incredible and likely permanent change. Devi Sridhar, Professor of Global Health at Edinburgh University hears from scientists in a variety of fields, whose working lives and practices have been affected, in some cases revoluti

If you look up into the night sky, there are around 7,000 active satellites orbiting the Earth. They’re part of our daily life – essential for things like the internet, the GPS in our cars and giving us weather reports. Seven thousand might not sound a lot in the infinite expanses of space. But the reality is that most satellites are found in a small slice of the solar system - called Lower Earth Orbit - and countries and satellite companies are planning to launch hundreds of thousands more in the next decade. So things are about to get crowded. In this week’s Discovery, Jane Chambers speaks to scientists, astronomers from the ALMA Observatory in Chile, space environmentalists and satellite companies like SpaceX about the benefits of this explosion in mega satellite constellations, as well as the unintended consequences to those who value a clear and unhindered view of the stars.Picture: Radio Telescopes at ALMA Observatory in the north of Chile, Credit: Jane Chambers

Giles Yeo learns how to make a Thai green curry with Meera Sodha. This is a recipe without meat or prawns but with tofu and lots of vegetables. If we need to eat less meat and dairy to help prevent global warming- what difference will altering our diets make to our health. For a long time now people have been urged to cut down on red meat and processed foods but if you have been eating them all your life it takes an effort to develop new habits. Plant based products that can replace for example dairy milks, cheeses, sausages, burgers and meat based dishes such as lasagne can be helpful in making this transition but are they healthier?

In Plant Based Promises, Giles Yeo a foodie and academic at Cambridge University, asks how sustainable are commercial plant based products? This is a fast growing sector with a potential value of $162 billion by 2030. Giles travels to the Netherlands Food Valley to look at companies developing plant based alternatives and to find out what role they have to play in changing diets. And Giles designs his own plant based Yeo Deli range online but discovers that new markets are already causing shortages of alternative proteins, so what will the future look like?In 2019 the Eat Lancet Commission set up specific targets for a healthy diet and sustainable food production. The aim was to keep global warming to within 1.5 degrees and to be able to feed the world’s 10 billion people by 2050. The Commission’s recommendations are best visualised as a plate of food, half fruits, vegetables and nuts and the other half whole grains, beans, legumes and pulses, plant oils and modest amounts of meat and dairy. Is there room on

In Plant Based Promises, foodie, researcher and broadcaster Giles Yeo looks at the science behind plant based diets and the increasing number of plant based products appearing in supermarkets and restaurants. The market for plant based products could be worth $162 billion in the next ten years and Giles asks how sustainable and healthy the products are and the role they play in decreasing the world's carbon footprint.Globally food production accounts for about 30% of greenhouse gases. In the UK we eat over six times the amount of meat and more than twice the amount of dairy products recommended to prevent the global temperature increasing more than 1.5 degrees C, after which extreme weather events become more severe. But eating less meat and dairy means new protein sources from plants are needed and how easy or practical is it for people to change their diets? Veganuary, where people pledge to go vegan for the month of January show that people are willing to change what they eat for a variety of reasons inclu

The smaller the thing you look at, the bigger the microscope you need to use. That’s why the circular Large Hadron Collider at CERN, where they discovered the Higgs boson is 27 kilometres long, and its detectors tens of metres across. But to dig deeper still into the secrets of the Universe, they’re already talking about another machine 4 times bigger, to be built by the middle of the century. Roland Pease asks if it’s worth it.Image: CMS Beampipe removal LS2 2019 (Credit: Maximilien Brice/CERN)

Episode 2: Lost in the DarkPhysics is getting a good understanding of atoms, but embarrassingly they’re only a minor part of the Universe. Far more of it is made of something heavy and dark, so-called dark matter. The scientists who discovered the Higgs boson ten years ago thought they’d also create dark matter in the underground atom smasher at CERN. But they haven’t seen it yet. Roland Pease joins them as they redouble their efforts at the upgraded Large Hadron Collider, and travels to Boulby Underground Laboratory inside Britain's deepest mine, where subterranean telescopes hope to see dark matter streaming through the Galaxy.Image: CMS Beampipe removal LS2 2019 (Credit: Maximilien Brice/CERN)