Concrete is the most widely used substance on earth after water. It’s quite literally the foundation of the modern world, and no wonder - it’s strong, cheap, and mouldable into nearly any shape. But these benefits come at a cost: concrete production is responsible for around 8% of global CO2 emissions - that’s around three times more than the aviation industry. Concrete might not look pretty, but given its carbon footprint, should we be more careful about how we use it? And rather than throwing waste into landfill, could we recycle it instead? That’s what Crowdscience listener Catherine wants to know. To investigate, Marnie Chesterton and Anand Jagatia learn more about what makes concrete such a brilliant and versatile material. It’s down to the chemistry of how cement dries – which, it turns out, is anything but boring. They find out how the stuff is made, and why that produces so much carbon. And they hear about some ingenious projects to repurpose demolition waste – including creating underwater habitats for marine life, and using 3D printers to turn crushed concrete into street furniture. With Prof John Provis, Prof Becky Lunn, Chris LaPorta, Sheryl Lee, Dr Edward Randviir and David Lacy Presented by Marnie Chesterton and Anand Jagatia. Produced by Anand Jagatia for BBC World Service [Image: Discarded Concrete, Credit: Getty Images]
Mais episódios de "CrowdScience"
Does dark matter still matter?
30:24Scientists have been searching for dark matter for decades, and think there’s six times more of it in the universe than the stuff we can actually see, like stars and planets. But they still don’t know what it is. So how can we be sure dark matter really exists? And why does it matter, anyway? Back in 2018, armed with a boiler suit, hard hat and ear defenders, Marnie Chesterton travelled over a kilometre underground into a hot and sweaty mine to see how scientists are valiantly trying to catch some elusive particles – in the hope of settling things once and for all. Several years on we return to the problem, tackling a few more CrowdScience listeners’ questions about dark matter, and hearing whether we’re any closer to uncovering its mysteries. We’re joined in our quest by Dr Chanda Prescod-Weinstein, physicist and author of The Disordered Cosmos: A Journey into Dark Matter, Spacetime, and Dreams Deferred. With Professor Malcolm Fairbairn, Dr Chanda Prescod-Weinstein, Dr Chamkaur Ghag and Professor Katherine Freese. Presented by Marnie Chesterton Produced by Graihagh Jackson and Cathy Edwards
Are big-heads smarter?
28:26We live in a world where bigger is often seen as better - and the size of someone's brain is no exception. But a listener in Nairobi wants to know, does size really matter when it comes to grey matter? CrowdScience presenter Marnie Chesterton is on a mission to find out if the physical attributes of our head and brain can tell us anything about what's going on inside. We certainly thought so in the past. In the 1800s, phrenology – determining someone’s characteristics by their skull shape – was very fashionable and curator Malcolm MacCallum gives us a tour of the extensive phrenological collection of death masks and skulls in Edinburgh’s anatomy museum. It's a 'science' that's now been completely debunked. Yet there’s no escaping the fact that over our evolutionary history, human brain size has increased dramatically alongside our cognitive capabilities. But is it the whole story? Rick Potts, Director of the Human Origins Program at the Smithsonian tells of the point in time when human brains expanded the most; a time when the climate was changing, resources were unreliable and the intelligence to be adaptable might mean the difference between life and death. Adaptability is also key to Professor Wendy Johnson’s definition of intelligence, although she points out that IQ test, flawed as they are, are still the best predictor we have for intelligence… and that, yes, there is a weak correlation between having a larger head, and doing better at IQ tests. Why is that? We don’t know, says Dr Stuart Ritchie from KCL. According to him, neuroscientists are only in the foothills of understanding how a physical difference in the brain might underpin a person’s psychology. But researching this could offer valuable insights into how our amazing brains work. [Image: Brain being measured. Credit: Getty Images]
Why do we get bored?
30:27“I’m bored!” We can all relate to the uncomfortable - and at times unbearable - feeling of boredom. But what is it? Why does it happen? And could this frustrating, thumb-twiddling experience actually serve some evolutionary purpose? CrowdScience listener Brian started wondering this over a particularly uninspiring bowl of washing up, and it’s ended with Marnie Chesterton going on a blessedly un-boring tour through the science and psychology of tedium. She finds out why some people are more affected than others, why boredom is the key to discovery and innovation, and how we can all start improving our lives by embracing those mind-numbing moments. Featuring: Prof James Danckert (University of Waterloo, Canada), Dr Elizabeth Weybright (Washington State University), Dr Christian Chan (Hong Kong University) and Annie Runkel (University of Dundee). Presented by Marnie Chesterton Produced by Samara Linton Image: Young Asian girl feeling lonely and bored at home. Screen addiction withdrawal symptoms (Credit: Oscar Wong, Getty Images)
How do you like your eggs in the morning?
40:30Should you wash your eggs? Well believe it or not, there is quite an international debate about this question from CrowdScience listener Susan. In Canada, where Susan grew up, commercially sold eggs are washed before they reach stores, whereas in the UK where she is now living they are not. So what is best to avoid contamination? It’s one of a number of egg-themed questions that CrowdScience tries to crack in this episode. One of our presenters, Marnie Chesterton, heads over to Susan’s home in London to cook some eggs and explore other egg cooking questions from our listeners, such as what is the science behind frying an egg without it sticking to the pan and why are some boiled eggs harder to shell than others? Meanwhile this episode’s other presenter, Anand Jagatia, explores questions about eggs after they have hatched. He investigates a case of curious chicken behaviour sent in by listener Laurie, as well as working out how a cuckoo knows it’s a cuckoo when it’s been raised in another bird’s nest. Presented by Marnie Chesterton and Anand Jagatia Produced by Jonathan Blackwell for BBC World Service Featuring: Dr. Vincent Guyonnet, Dr. Valérie Lechevalier, Dr. Siobhan Abeyesinghe and Dr. Ros Gloag (Photo credit: Getty Images)
CrowdScience Christmas bonanza
31:43Raindrops on roses and whiskers on kittens – CrowdScience has covered a lot this year. And what better way to see out 2021 than to look back at a few of our (and your!) favourite things? Great questions are right at the top of the team’s list – especially with the way that for every one we answer, five more appear in our inbox! So for a festive treat, Marnie asks the crew to answer three of them. What's the sun's role in our sense of direction? Why are we so uncomfortable with other people’s sadness? And why does listening to the radio make us sleepy? (Or is it just too much eggnog…?) From our favourite listener advice on how to keep your Christmas lights untangled to why cold swimming could activate your Vagus nerve, tune in for new questions and more CrowdScience favourites to light up your holiday season! Presented by Marnie Chesterton and many members the CrowdScience Team – Melanie Brown, Marijke Peters, Caroline Steel, Hannah Fisher, Samara Linton and Anand Jagatia. Produced by Sam Baker for BBC World Service. Featuring: • Haneul Jang, post-doctoral researcher, the Max Planck Institute for Evolutionary Anthropology • Juliet Rosenfeld, psychotherapist and author of The State of Disbelief: A Story of Death, Love and Forgetting • Mathias Basner, professor of psychiatry, University of Pennsylvania
How can I keep fruit & veg fresh for longer?
33:13As many of us gear up for the annual Christmas feast, some of you may be wondering how to eat everything before it goes off. It’s a great question, as the UN puts global food waste at a whopping 1.3 billion tonnes a year – that’s one third of all edible produce being thrown in the bin. So this week the team investigates listener Peter’s query about what makes some fruit and vegetables rot faster than others. Preserving food used to be about ensuring nomadic populations could keep moving without going hungry, but these days some things seem to have an almost indefinite shelf-life. Is it about better packaging or can clever chemistry help products stay better for longer? A Master Food Preserver explains how heat and cold help keep microbes at bay, and how fermentation encourages the growth of healthy bacteria which crowd out the ones that make us ill. Presenter Datshiane Navanayagam learns how to make a sauerkraut that could keep for weeks, and investigates the gases that food giants use to keep fruit and veg field-fresh. But as the industry searches for new techniques to stretch shelf-life even further could preservatives in food be affecting our microbiome? Research shows sulphites may be killing off ‘friendly’ gut bacteria linked to preventing conditions including cancer and Crohn’s disease. Produced by Marijke Peters for BBC World Service. Featuring: Christina Ward, Master Food Preserver Dr Heidy den Besten, Food Microbiologist, Wageningen University Ian Shuttlewood, Tilbury Cold Store Professor Sally Irwin, University of Hawaii
What's the best way to make a decision?
35:48Life is full of choices, from the mundane (like what to wear today) to the critical (how should we deal with the pandemic?). So how can we make the best decisions? That’s what listener David wants to know. To investigate, Caroline Steel learns how being smarter doesn’t necessarily make you a good decision maker. She speaks to researchers about the importance of ‘gut feelings’ – and how certain people with no intuition whatsoever can struggle to make choices. She also learns why it’s easier to give advice to other people than to follow it yourself, and how we can work together to make the best decisions in a group. Presenter: Caroline Steel Producer: Anand Jagatia Contributors: Wändy Bruin de Bruin - Professor of Public Policy, Psychology and Behavioural Science, University of Southern California, USA David Robson, science journalist and author Valerie van Mulukom, Assistant Professor, Coventry University, UK Liz Steel Igor Grossmann, Associate Professor of psychology, University of Waterloo, Canada Anita Williams Woolley associate professor of organisational behaviour and theory, Carnegie Mellon University, USA
What makes stuff sticky?
32:40What makes things sticky? Listener Mitch from the USA began wondering while he was taking down some very sticky wallpaper. Our world would quite literally fall apart without adhesives. They are almost everywhere – in our buildings, in our cars and in our smartphones. But how do they hold things together? To find out, presenter Marnie Chesterton visits a luthier, Anette Fajardo, who uses animal glues every day in her job making violins. These glues have been used since the ancient Egyptians –but adhesives are much older than that. Marnie speaks to archaeologist Dr Geeske Langejans from Delft University of Technology about prehistoric glues made from birch bark, dated to 200,000 years ago. She goes to see a chemist, Prof Steven Abbott, who helps her understand why anything actually sticks to anything else. And she speaks to physicist Dr Ivan Vera-Marun at the University of Manchester, about the nanotechnologists using adhesion at tiny scales to make materials of the future. Presented by Marnie Chesterton. Produced by Anand Jagatia for BBC World Service This episode was originally broadcast on 2nd October 2020
Which is better: Optimism or pessimism?
32:22In most cultures, the soundtrack to our lives is one of optimism. We are told to aim for the stars, dream big and believe that tomorrow will definitely be a better day. But why do so many people subscribe to the cult of 'glass half full' when life’s hardships should make any reasonable person a bit more wary? Listener Hannah from Germany - a self-described pessimist - is intrigued as to whether the optimistic way of life is really the best way to be. Taking on the challenge is Marnie Chesterton, who finds out why 80% of the population have an optimism bias and how the ability to hope and take risks may have helped the human species get where it is today. She also meets a man who pushes the optimistic outlook to its very limits - Base jumping world champion, Espen Fadnes. Listener Hannah on the other hand looks into the psychology of pessimism to find out if there are any advantages to her less rose-tinted view on life - and whether the culture we grow up in shapes how realistically we see the world. Producer: Caroline Steel Presentet: Marnie Chesterton Contributors: Espen Fadnes – Freefall professional Tali Sharot – Professor of neuroscience, UCL Julie Norem - Professor of psychology, Wellesley College Jeanne Tsai - Professor of psychology, Stanford (Image: Two arrows, one with a sad smiley and the other with happy smiley, pointing in opposite directions. Credit: Getty Images)
Would my cat survive in the wild?
30:39Cats started hanging out with humans thousands of years ago, and nowadays these fluffy, lovable pets are found in many of our homes. But there is no doubt lots of them still have keen hunting instincts - witness all the birds and small mammals they kill each year. CrowdScience listener Rachel started wondering whether her cat Eva could fend for herself while watching her uncoordinated swipes at a toy on a string, and seeing her fall off the sofa. Even though Eva was once a stray, she now lives entirely indoors, and it is hard to imagine her holding her own back on the mean streets. But could this pampered pet recover her survival instincts? Or would she go hungry, or fall foul of other cats or predators? Cat behaviour expert Roger Tabor is on hand with answers. His pioneering ‘cat-navs’ shine a light on what cats get up to inside and outside the home; we meet one of his subjects, a tiny cat with a fierce personality. Roger explains how a cat’s survival toolkit depends on their sex, breed, and above all their early life. Environment matters, too, so in Japan, where Rachel and her pet cat live, we visit a cat shelter to learn about the day-to-day challenges stray cats face. And just how ‘domestic’ are our cats, anyway? How different are they from their wildcat cousins, and how did they come to be our companions in the first place? It turns out beguiling humans might be even more of a survival trick than hunting. Presenter: Melanie Brown Producer: Cathy Edwards Contributors: Roger Tabor – Chartered Biologist and Cat Behaviourist Jamie Baker – Head Keeper, Battersea Park Children’s Zoo Dr Eva-Maria Geigl – Research Director, CNRS (French National Centre for Scientific Research) Susan Roberts and Cheryl Nodhturft-Mori – Japan Cat Network (Image: Cat in Lion costume. Credit: Getty Images)