Naked Scientists Special Editions Podcast

To better understand how personal exposure to air pollution can impact an individual's health, Katie Haylor met up with Cambridge University chemist Lia Chatzidiakou for a walk around central Cambridge. And to find out how air pollution can be monitored across a whole city, Katie climbed up to the roof of Cambridge University's chemistry department with Cambridge University chemist Lekan Popoola.... Like this podcast? Please help us by supporting the Naked Scientists

Researchers have gained new insights into how bacteria move in complex environments. Bacteria move using a system called "swim-and-tumble": they swim in a straight line for a bit, then tumble in a circle, which gives them a chance to correct their course. They can't see where they're going - they can't see at all - but they can sense and follow gradients of increasing concentration of food, like following a delicious smell into the kitchen. This type of movement is called chemotaxis, and it's been well studied in bacteria moving in a clear area. But in the real world, such as inside the human... Like this podcast? Please help us by supporting the Naked Scientists

Geologists from the University of California, Berkeley, found something unexpected in sand samples from Japan. Rather than natural particles, from rocks or plants, these tiny blobs of glass seem to have been formed in an atomic blast, and they might mean that the destroyed buildings of Hiroshima have been hiding in plain sight ever since. Ruby Osborn spoke to Mario Wannier about his research, which has been published in the journal Anthropocene. Like this podcast? Please help us by supporting the Naked Scientists

Harassment in online communities is not a new phenomenon, but it is a growing one, with 40-46% of people reportedly having experienced it. Communities like reddit, one of the world's largest discussion forums, often have moderation teams responsible applying self-imposed rules which govern acceptable behaviour. These rules are not always well presented, or well adhered to. Researchers from Princeton University have collaborated with the moderation team at the reddit science discussion community "r/science", to determine how the clear presentation of the expected standards, or social norms... Like this podcast? Please help us by supporting the Naked Scientists

Everyone's heard of T-Rexes, the twenty-foot-tall monsters that roamed the Earth back in the Late Cretaceous Period. But you may not have heard of their miniature cousin. It's a six foot tall dinosaur called Suskityrannus hazelae, and it gives us a clue about when and how T-Rexes got as big as they did. Sterling Nesbitt is the paleontologist who found the second and most complete fossil of this new dinosaur, but it took him twenty years to put this paper together. Phil Sansom asked him how. Like this podcast? Please help us by supporting the Naked Scientists

Caster Semenya, a South African athlete with unusually high testosterone for a woman, has lost her appeal against new regulations from the International Association of Athletics Federations. The regulations set an upper limit on how much testosterone a female athlete is allowed to have compete in middle distance running, and require any woman over this limit to artificially lower her testosterone if she wants to continue competing. Ruby Osborn discussed the story. Like this podcast? Please help us by supporting the Naked Scientists

Our society uses - and then throws away - a vast amount of plastic, which then accumulates in the environment. To combat this, in recent years, new types of plastic bags have become available, labelled as "compostable" or "biodegradable."Both of these terms indicate the bag can break down and so avoid pollution, although biodegradable bags take longer than compostable bags. There's also a third type, oxo-biodegradable, which have an additive that should make them decompose a bit faster than standard biodegradable bags.So when you see a plastic bag labelled "biodegradable," how long do you... Like this podcast? Please help us by supporting the Naked Scientists

Before Britain was a nation of shopkeepers we were a nation of farmers; before that, the population were a bunch of hunter gatherers. But farming didn't catch on here until 1000 years after it had in Europe. Why was always a mystery, but now DNA technology is shedding new light on how this could have happened. Ben McAllister has been looking into the story... Like this podcast? Please help us by supporting the Naked Scientists

Human babies grow inside their mothers for 40 weeks enclosed in a watery bag that expands as they do. And as the clock ticks during pregnancy, various processes kick in to thin the membrane material that surrounds the baby so that the bag ruptures at the right time to promote labour. But in some cases this happens far too early and can trigger a pre-term birth, and now scientists at Queen Mary University of London have discovered why. And if we know how it works, we might be in a position to discover how to stop it, as Tina Chowdhury explains... Like this podcast? Please help us by supporting the Naked Scientists

Batteries are in almost everything we use. Our phones, computers, energy storage, even in transport. Typically, to see how well a battery performs, scientists have to charge and discharge them over and over until, ultimately, the battery stops working. This can take years of development and testing, plus it's an expensive process. Now researchers from MIT and Stanford University in America have turned to AI to help. Izzie Clarke spoke to William Chueh who explained how AI has stepped in Like this podcast? Please help us by supporting the Naked Scientists

The Intergovernmental Panel on Climate Change (or IPCC) has recently issued a series of so-called "energy transition pathways". These are essentially routes that we as a society need to follow, in order to prevent global warming from exceeding the limit at which society cannot continue to function. All of these pathways rely on a technology known as "carbon capture", which would capture carbon dioxide from fossil fuel energy plants to prevent it from impacting the atmosphere. As a result, there has been a massive investment of money and resources in this technology. But, some new research from... Like this podcast? Please help us by supporting the Naked Scientists

The multinational team behind the Event Horizon Telescope (EHT), which spans the Earth by linking dishes in 8 different countries, have revealed the first images of the supermassive black hole - that has a mass 6 billion times that of our Sun - sitting at the centre of galaxy Messier 87, fifty-five million light years from Earth. For the first time we can see what a black hole - or rather the space around a black hole - looks like. Speaking with Chris Smith to discuss how this was done and what it means, and to answer questions from the Naked Scientists audience, is Cambridge University... Like this podcast? Please help us by supporting the Naked Scientists

Astronomers have used a new camera called the HiPERCAM to analyse a type of small, dim star that has proved elusive to standard cameras. The camera has allowed them to make detailed measurements of this cool subdwarf star 1500 light years away, and it's the first time they've been able to confirm the predicted model of this type of star. Ruby Osborn spoke to Dr Steven Parsons from the University of Sheffield about what makes this star so interesting, and how the HiPERCAM has helped them to study it. Like this podcast? Please help us by supporting the Naked Scientists

The Large Hadron Collider (LHC) is widely regarded as one of humanity's greatest scientific achievements. The 17 km long accelerator smashes particles together at high speeds, and looks at the products to search for new physics. So far we've learned a tonne about the smallest things in nature, such as quarks - which are tiny particles that make up the atoms that compose people, planets, stars, and everything else we can see. A few years ago, physicists discovered strange new particles known as pentaquarks. We knew they were made up of five quarks bound together, but their properties and... Like this podcast? Please help us by supporting the Naked Scientists

Catalytic converters are in car exhausts and convert toxic carbon monoxide into much less harmful carbon dioxide, as well as removing other pollutants. On a petrol car, they are the metal box you see just before the exhaust. Unfortunately, current catalytic converters don't work effectively at lower temperatures, usually only starting to work well when heated to about 200°C, once the vehicle has been running for a few minutes. This is what's known as the cold start problem and why the US Department of Energy have set a target to remove 90% of harmful emissions from exhausts below 150°C. A... Like this podcast? Please help us by supporting the Naked Scientists

Ever wondered how to get the best wifi reception in your house, given all those floors and walls which can interrupt the signal? Where to position the router and signal boosters, then where people should use their devices to get the best reception? There are so many combinations, making it labour-intensive to move things around and try all the different positions! But complex scenarios like this can be modelled by mathematical equations. Not the six minus what equals four type of equation, really complex ones. Additionally, metamaterials are materials that have a structure that take their... Like this podcast? Please help us by supporting the Naked Scientists

Having an injection is an experience common to us all, and whether you are unfussed by them or they make you feel faint, the actual needle used is the same for everyone and highly standardised. But given different parts of the body are more difficult to inject than others, this is not ideal. Scientists at Harvard Medical School realised this problem and have set about creating a more adaptive solution that could lead to big changes in healthcare. Jack Tavener spoke to Jeff Karp, who co-authored the study, about the challenges his team faced... Like this podcast? Please help us by supporting the Naked Scientists

US scientists have engineered into yeast the genes needed to make the key chemicals in cannabis. To find out why and what's involved, Chris Smith looked at the paper with York University's Ian Graham, who wasn't involved in the project but has expertise in this area. We last spoke with him in 2015 when he uncovered the genes needed to perform a similar feat so yeast could make morphine. Like this podcast? Please help us by supporting the Naked Scientists

The agriculture sector is responsible for about 25% of global warming according to the Intergovernmental Panel on Climate Change, so rearing livestock for meat is a significant problem. When ruminant animals such as cows and sheep digest food they burp large amounts of methane, a greenhouse gas that causes climate change. And growing the crops they are fed adds even more greenhouse gases to the atmosphere. It is now possible to cultivate edible meat in a lab, rather than rearing livestock. And because of this, the new technique is often promoted as more environmentally friendly than having... Like this podcast? Please help us by supporting the Naked Scientists

Antibiotic resistance is a growing problem that kills hundreds of thousands of people each year, from what should be preventable diseases. Up to date, scientists have been trying to figure out the reasons in each individual case, until now A group from McMaster University in Canada has published a paper which shows for the first time the two common physical characteristics of bacterial resistance to antibiotics. Mariana Campos has been talking to Maikel Rheinstadter, who explained what they did and how this could help in the development of new and improved medications. Like this podcast? Please help us by supporting the Naked Scientists