CrowdScience

CrowdScience listener Matt wants to know why he's warm blooded. He started thinking about this when he was watching some ants during the recent heatwave in Europe and wondered why their blood didn't boil. What are the pros and cons of being warm-blooded like us or cold-blooded reptiles like lizards? Caroline Steel meets evolutionary biologist Dr Manuel Leal from the University of Missouri in the US, who explains the differences between ectotherms (cold-blooded animals) and endotherms (warm-blooded animals). She discovers that the terms cold blooded and warm blooded are actually misleading, because reptiles can reach a high body temperature and some might even become warmer than us. She talks to Simon Hodder, Professor of Environmental Ergonomics at Loughborough University in the UK, who describes how our bodies regulate heat, how we cool down when we get too warm and how that's all controlled by our brains. Caroline also gets to meet some hedgehogs in the wild with Julia Nowack, an ecophysiologist from Liverpool John Moores University, who researches thermoregulation and is monitoring hedgehogs when they hibernate. Changing body temperature is one of the ways that some endotherms survive the winter when it's colder and there's less food around. So who has the advantage? The warm-blooded endotherms who can heat their own bodies or the cold-blooded ectotherms who rely on the sun? Reptiles can get away with eating very occasionally while mammals and birds have to keep fuelling their energy with food to keep the heat going. That means we can live in most climates and have a better chance of escaping predators, but is it really best? Presenter: Caroline Steel Producer: Jo Glanville Editor: Ben Motley (Photo: European hedgehog (Erinaceus europaeus) adult animal in a snow covered garden in winter, England, United Kingdom - stock photo Credit: imageBROKER/Kevin Sawford via Getty Images)

Tuberculosis kills more than a million people every year. It’s the world’s leading cause of death from a single infectious agent. This is despite the fact that we've had a cure for TB since the 1940s and a vaccine that’s over 100 years old. So why is TB still causing so many people to die? That’s what CrowdScience listener John in Tanzania wants to know, and presenter Marnie Chesterton is on the case. Over in Paris, she’s joined by Dr Claas Kirchhelle, historian of science, medicine and technology at French National Institute of Health and Medical Research (INSERM) to look into the history and efficacy of the vaccine, known as BCG. As Dr Maximiliano Gutierrez, Associate Research Director at the Francis Crick Institute adds, the BCG is both effective and ineffective, protecting children well against severe TB, but offering inconsistent and often poor protection in adults. He also explains that antibiotics are a trickier treatment than we might expect. Over in Kenya’s Kibera slums, Janet tells us her about her experience of the drugs first hand. Dr Dany Beste, Senior Lecturer In Microbial Metabolism, University of Surrey, has been described as a dietician of mycobacterium tuberculosis. She explains the limitations of our knowledge of this bacterium, and why it is proving such a tricky customer. And since a better vaccine is the main hope for reducing the TB burden, Professor Angelique Luabeya Kany Kany, Chief Research Officer at University of Cape Town, shares her hopes for the first new alternative vaccine in 100 years: m72. Large phase 3 clinical trials are currently underway, and, if successful, could prevent millions of cases, and deaths a year. Presenter: Marnie ChestertonProducer: Marnie ChestertonEditor: Ben Motley (Photo: Doctor with vial of the doses vaccine for BCG Bacillus Calmette Guerin against tuberculosis disease. Medicine and health care concept - stock photo - Credit: angelp via Getty Images)

We’re delving into the CrowdScience archive to give you another chance to hear an award-winning show from 2025. CrowdScience listener Dorit has a problem. She wants the tiles in her new bathroom to be arranged randomly but, no matter what she does, it still looks like they form some kind of pattern. This has got Dorit thinking about randomness – what is it, how do you create it, why do we find it so hard to recognise, and is anything really random at all? And if nothing is truly random, does it mean that everything is theoretically predictable? Tiling your bathroom is a much more existential problem than you might have thought. Never afraid of a question, whether big (is everything pre-determined?) or small (how do I tile my bathroom?), CrowdScience is on the case. Anand Jagatia heads to Switzerland to meet Hugo Duminil-Copin, a mathematician at the University of Geneva who specialises in probability theory. On the top floor of an old bank, Hugo has Anand flipping an imaginary coin in a random order. Hugo explains that randomness is something that cannot be predicted by any means – so why is it so easy for Hugo to guess what Anand’s next move is? Meanwhile, at the National Institutes of Mental Health in Maryland USA, Susan Wardle is a cognitive neuroscientist who researches how the human brain processes visual information. Can neuroscience help Dorit with her tiling problem, and is there a reason why the human brain likes to put random objects into some kind of order? Geneva is also the birthplace of the first Quantum Random Number Generator for smartphones, and CrowdScience has persuaded some of the University of Geneva’s finest quantum physicists to hook a photon detector up to a synthesiser. Thanks to Tiff Brydges and Nicolas Brunner, we can actually hear quantum particles behaving randomly. But is quantum randomness truly random, or just a pattern that we can’t see? And could quantum physics help Dorit tile her bathroom? Presenter: Anand Jagatia Producer: Ben Motley Editor: Cathy Edwards(Photo: Many wooden dice - stock photo- Credit: akiyoko via Getty Images)