CrowdScience listener Marie, in Sweden, has always had difficulty with her sense of time. She often thinks that events that happened years ago took place recently or that a holiday coming up is happening sooner than it is. So she wants to know if time is a sense, like the sense of taste or touch, and if it’s something she can learn. Anand Jagatia talks to scientists who’ve studied time, memory and how our brains process and store the events in our lives to find an answer to Marie’s question. Along the way he discovers why time speeds up as we get older, how our bodies register time passing and how our brains put everything that happens to us in order. Featuring: Dr Marc Wittmann, Institute for Frontier Areas in Psychology and Mental Health in Freiburg, Germany Dr Maï-Carmen Requena-Komuro, former PhD researcher, Dementia Research Centre, University College London Professor György Buzsáki, Neuroscience Institute, New York University Professor Adrian Bejan, Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University Presenter: Anand Jagatia Producer: Jo Glanville Sound Design: Julian Wharton Production Co-ordinator: Jonathan Harris Image credit: Peter Cade/ Stone/ Getty Images

What are the actual chances of finding alien life? The idea of meeting an extra-terrestrial has ignited imaginations for hundreds of years, and it’s also inspired real science: the Search for Extra-Terrestrial Intelligence - or Seti - is an organisation that brings together researchers across the world in pursuit of distant life forms. This same dream is on the mind of listener Andrew in Yorkshire in the UK, who has been looking into the sheer size of the universe, and wants to know: how many stars are there in existence, how many planets, and how many planets that could harbour life? CrowdScience presenter Marnie Chesterton sets off on a space odyssey to answer these questions. She starts at Jodrell Bank Observatory in Cheshire, where University of Manchester astrophysicist Eamonn Kerins tells her the number of stars in the universe, and explains the Drake Equation - the mathematical formula that underpins SETI’s work. It’s a series of seven numbers that combine to give you the probability of making contact with an alien civilisation. The next step after stars is the number of planets; Michelle Kunimoto of MIT, who works on Nasa’s TESS mission, explains the transit technique for finding distant worlds. Supposedly anyone can learn to use this technique, so Michelle puts Marnie to a test of her planet-hunting prowess. Distant planets are a huge leap forward - but not all of them will be hospitable to life. Eamonn breaks down how scientists define a habitable planet, as well as how to determine habitability using telescope observations. Marnie speaks to Mary Angelie Alagao from the National Astronomical Research Institute of Thailand about a cutting-edge piece of optical kit designed to block out the light from stars so you can take direct images of the planets next to them. Finally, it’s time to put everything together and get some actual numbers for listener Andrew - as well ask how long it could take to find proof of alien life. (Photo credit: Mark Garlick/Science Photo Library/Getty Images)

Compared to the entirety of human existence, our history of flying in aeroplanes is very short indeed. So what does this fast form of travel do to bodies that have evolved for land-based living? That's what listener Sofia wants to know after working as a flight attendant for over a decade. What effect does working at 35,000 feet have on one's health? How disruptive to your circadian rhythms is hopping across ten time zones in less than 24 hours? What's happening in our stomachs if a crisp packet blows up to the point of popping as the cabin pressure changes? And why do we feel so darn dehydrated when we get off a plane? Host Caroline Steel not only talks to the experts about everything from swollen ankles to what we should eat and drink on planes, she also records her own journey from London to Australia. She does just about everything wrong along the way, but the experts sort her out with some top tips for her next long-haul flight on how to avoid blood clots and even, how to avoid jet lag all together! While in Australia, Caroline also visits a sleep lab where researchers can simulate jet lag to learn how to improve flight safety and the wellbeing of flight attendants and pilots. Join Caroline on her journey as CrowdScience takes to the skies to find out what frequent flyers need to know when it comes cosmic ionising radiation and what we can all do to make that next flight a little more pleasant. Produced by Sam Baker for the BBC World Service. Featuring: Tony Schiemer, Senior Aviation Medical Officer, Royal Australian Air Force Eileen McNeely, Executive Director, SHINE at Harvard T. H. Chan School of Public Health Tracey Sletten, Senior Lecturer, Turner Inst for Brain & Mental Health, Monash University (Photo: Getty Creative # 1432221653)

How do we hear a sound and immediately know where it’s coming from? That’s the question that CrowdScience listener Chiletso asked himself one day as he heard his son bounce a ball and instantly knew its direction. In this ear-opening episode, presenter Anand Jagatia sets out to discover what makes left, right, up and down, sound so different. First, Anand gets blindfolded, so that Alan Archer-Boyd, former auditory scientist and lead engineer at BBC R&D, can put his sound localisation skills to the test. It turns out that having two ears and pinnae, those flappy bits of cartilage on the side of your head, help a lot. Professor Eric Knudsen shares how the barn owl’s asymmetrical ears allow it to hunt mice, even in complete darkness. And Anand uncovers how far he can push his own spatial hearing. Blind activist and researcher Thomas Tajo teaches him how to echolocate like a bat, and Dr Lore Thaler explains what is going on in the brain of experienced echolocators. If you can, listen on headphones! Presented by Anand Jagatia Produced by Florian Bohr for the BBC World Service Image: Boy with hands at his ears Credit: Silke Woweries/Getty Images

Sweating, nausea, chest pain and shortness of breath sound like the physical symptoms of a heart attack. For about 4% of the world’s population, they are also symptoms of an underdiagnosed condition that can leave sufferers curled in a ball and screaming on the floor. A CrowdScience listener wants to know why humans have panic attacks. Host Marnie Chesterton brings on board an expert co-presenter, novelist Tim Clare, to talk us through the hows and whys. Tim suffered from crippling panic attacks for over a decade. He decided enough was enough and has combed through the scientific literature, using himself as a guinea pig, to see what helped. Anxiety can be a useful sensation, helping you to detect and avoid dangers before they happen. But when that morphs into debilitatingly unpleasant symptoms, or an internal monologue saying “that’ll go badly, best to not leave the house,” something has gone wrong. Together, Tim and Marnie explore what’s going on in the brains of those whose threat circuit is faulty. Dr Oliva Remes, a mental health researcher at the University of Cambridge explains how common panic attacks are, and how they often present. Dr Bonnie Furzer at the University of Western Australia explains how exercise can help. Tim takes a dip to demonstrate how cold water, and the cold shock response can help. Dr Rebecca Taugher at the University of Iowa explains how scientists induce a panic attack in the lab, how she has been a guinea pig and why patient SM, without an amygdala, the brain’s so-called ‘fear-centre,’ could still be given a panic attack in the lab, just by inhaling extra amounts of carbon dioxide. Professor Alexander Shackman from the University of Maryland points out that the science will come so much further when researchers look at a genuine cross-section of the population, rather than focussing on those in educational establishments (easier to study) who often don’t experience panic attacks. PHOTO CREDIT: Woman hyperventilating into paperbag Credit: Peter Dazeley/Getty Images

When imagining a robot, a hard-edged, boxy, humanoid figure may spring to mind. But that is about to change. CrowdScience presenter Alex Lathbridge is on a mission to meet the robots that bend the rules of conventionality. Inspired by how creatures like us have evolved to move, some roboticists are looking to nature to design the next generation of machines. And that means making them softer. But just how soft can a robot really be? Join Alex as he goes on a wild adventure to answer this question from listener Sarah. He begins his quest at the ‘Hello, Robot’ Exhibition at the Vitra Design Museum in Weil am Rhein, Germany to define what a robot actually is. Amelie Klein, the exhibition curator, states anything can be a robot as long as three specific criteria are met (including a cute cuddly baby seal). With this in mind, Alex meets Professor Andrew Conn from the Bristol Robotics Lab who demonstrates how soft materials like rubber are perfect contenders for machine design as they are tough to break and - importantly for our listener’s question - bendy. Alex is then thrown into a world of robots that completely change his idea of what machines are. He is shown how conventionally ‘hard’ machines are being modified with touches of softness to totally upgrade what they can do, including flexible ‘muscles’ for robot skeletons and silicon-joined human-like hands at the Soft Robotics Lab run by Professor Robert Katzschmann at ETH Zurich. He is then introduced to robots that are completely soft. Based on natural structures like elephant trunks and slithering snakes, these designs give robots completely new functions, such as the ability to delicately pick fruit and assist with search and rescue operations after earthquakes. Finally, Alex is presented with the idea that, in the future, a robot could be made of materials that are so soft, no trace of machine would remain after its use... Presenter: Alex Lathbridge Producer: Julia Ravey (Image: RoBoa in action on a rooftop in Zurich. Credit: Julia Ravey)

CrowdScience listener Eric, in New Zealand, has noticed his wisteria growing towards a neighbouring tree. He thinks that it actually knows where it’s going. But how can a plant have a sense of direction? Plants don’t have the advantage of brains or eyes, but that doesn’t seem to stop them from being clever enough to find out from their environment where to move and how to get there – all while being rooted to the spot. Marnie Chesterton visits the Natural History Museum and Kew Gardens in London, home to the largest collection of living plants in the world, to discover how plants make their manoeuvres, and talks to botanists and plant biologists for the latest findings on the mysterious life of climbing plants. Featuring: Dr Mariane Sousa-Baena, School of Integrative Plant Sciences, Cornell University Dr Ilia Leitch, Senior Research Leader, Kew Gardens Tom Freeth, Head of Plant Records, Kew Gardens Dr Silvia Guerra, Neuroscience of Movement Laboratory, Padua University Professor Christian Fankhauser, Centre for Integrative Genomics, Lausanne University Dr Sandra Knapp, Merit Researcher, Natural History Museum

If, like this week’s Crowdscience listener Lili, you’re an avid gymgoer, you may well have wondered where your fat disappears to when you exercise? Well, the short answer is that we convert it to energy that powers a whole range of physical processes, from breathing to walking as well as lying down and doing nothing. But the science behind energy expenditure is a little more complicated than that. Presenter Anand Jagatia pops on an exercise bike to have his metabolism measured, and learns that he may be relying on an entirely different source of fuel as he works up a sweat. But is all that hard work worth the effort it involves? Recent research suggests there's a limit to the number of calories us humans can burn, and that doing physical activity isn’t a sure-fire way to keep trim. Even hunter-gatherers who walk 13,000 steps a day have the same metabolic rate as the average American. So if working out isn't the best way to lose weight, how about harnessing our own fat to tackle the complications of obesity? It used to be thought brown fat was exclusive to babies (and bears) but we now know adults have some of it too, and it seems to play a vital role in combatting a range of chronic diseases including hypertension and diabetes. Presenter: Anand Jagatia Producer: Marijke Peters

Yoga benefits our health in many ways, say the yogis, but which claims are backed up by science? Can yoga actually alleviate depression, fix lower-back pain or even reduce cardiovascular disease? Presenter Marnie Chesterton gets into her Lotus (position) and finds out first-hand at a class. Whilst in warrior one, she discusses the potential physical and mental health benefits of this ancient art of stretching, balance and movement with her class teacher. Returning from mat to studio, Marnie puts some of those claims to experts around the globe. She investigates the evidence to find out whether health boosting properties are the key to yoga's enduring popularity. Pannalists: Rajvi Mehta Prof. Holger Cramer Dr Richard Davidson Presented by Marnie Chesterton Produced by Richard Walker

Why does the thought of giving a talk to an audience fill so many of us with sheer terror? Marnie Chesterton investigates for listener Nhial, who has seen his fellow students in Morocco become panic stricken at the prospect and wants to know the reason for our anxiety. According to one study, 77 per cent of us share that fear. Marnie finds out about the relationship between stress, our brains and our voices from research associate Dr Maria Dietrich at the University Hospital, Bonn University. She talks to Nhial’s tutor, Professor Taoufik Jaafari, at Hassan II University of Casablanca about the challenges facing his students. And she visits the National Theatre in London to get some expert training from Jeannette Nelson, head of voice, who works with some of the world’s leading actors. Could there be an evolutionary explanation for the purpose of public speaking? Is it something we actually need to be good at? Marnie asks evolutionary psychologist Professor Robin Dunbar at Oxford University and gets some surprising answers. She meets psychologist Dr Preethi Premkumar at London South Bank University, who has developed virtual reality therapy with colleagues at Nottingham Trent University, and tries out the treatment herself. Presenter: Marnie Chesterton Producer: Jo Glanville