We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.

We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.


United Kingdom




We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.




Am I a psychopath?

One CrowdScience listener finds herself unconcerned about much of the world’s problems, it leaves her wondering: am I a psychopath? Inspired by a previous episode on empathy, this listener asked is it true that psychopaths don’t empathise and what are the character traits of psychopathy? Marnie Chesterton talks with a diagnosed pro-social psychopath to find out. She also pays a visit to the Netherlands Institute for Neuroscience and gets into an MRI scanner to discover what is happening in...


Why do my cables keep getting tangled?

Anyone who has ever taken the Christmas lights out of the cupboard, only to discover they’re hopelessly tangled, will sympathise with this week’s listener Eric. He has a 45m garden hose that always seems to snarl up and snag when he waters his garden, and he wonders what he’s doing wrong? Marnie starts by discovering the important difference between tangles and knots, as she scales a cliff with an experienced climber who explains the way you tie rope is a matter of life and death. Physicists...


Why is standing more tiring than walking?

Standing takes less energy than walking, so why does it feel more tiring? At least, it does for CrowdScience listener Nina. She can march for hours without getting tired, but her legs and feet get achy after just a short time standing still. It’s one of three walking-themed questions CrowdScience is tackling this week. Taking inspiration from our active listeners, Marnie Chesterton walks up a hill with Caroline Williams, author of a new book about why humans are designed to move. We find out...


Why do I feel hungry?

Food. For all of us it is a basic necessity and for those lucky enough, it is something we spend a lot of time planning and enjoying. CrowdScience listeners certainly have a lot of food related questions; in this buffet of an episode Marnie Chesterton opens the fridge door to pick the tastiest. Starting with the seemingly simple question of what makes us feel hungry, and ending in outer-space, Marnie investigates flavour, nutrition and digestion. After a year when watching TV has become a...


What happened to my sense of smell?

It took a while before it was officially recognised as a major symptom of Covid-19, but loss of smell has affected up to 60 percent of people who have had the virus. And for a significant portion, smell continues to be an issue for weeks or months after their recovery. So what’s going on and how can you get your sense of smell back? We tend to think of our sense of smell as something universal – if it smells bad to me, it probably does to you but that is not the case for CrowdScience...


Does my equator look big in this?

Scales don’t come planet-sized, so answering a question from David in Ghana may require some ingenuity, after all, calculating the weight of the Earth is a huge task. Using a set of weighing scales and a 400 year-old equation, Marnie Chesterton attempts to find out just how much the Earth weighs and is it getting heavier or lighter over time? But how would a planet gain or lose mass? Which tips the scales: meteorites falling from space or gases constantly escaping from our atmosphere? And...


Why do I have such a sweet tooth?

They say life is sweet. Well that’s certainly the case for CrowdScience listener Trevor in Poland who wonders why he can’t stop reaching for the cookie jar. He grew up drinking fruit juice with added sugar but wonders whether his genes could be as important as his environment when it comes to his sweet tooth, especially since his wife seem to be satisfied with mainly savoury snacks. The World Health Organisation says added sugar should constitute a maximum of 5% of our daily energy intake...


What is the point of menstruation?

It's a topic that's taboo in many cultures, yet it's also something nearly every woman experiences – on average upwards of 400 times throughout her life: menstruation. Responding to a flood of questions from our CrowdScience listeners, Marnie Chesterton seeks to unpack how periods affect women physically, mentally and societally. Why did humans evolve to have periods when fewer than two percent of mammals share our experience of menstrual cycles? Is it really a good use of our limited energy...


Is my neighbour’s noise harming my health?

As millions more of us move to live in densely populated cities, we almost inevitably face living in closer proximity to our neighbours. Neighbour noise can certainly be a source of annoyance – but could it even be damaging to our health? Increasing evidence suggests that unwanted noise can cause sleep deprivation, distraction and annoyance, as presenter Anand Jagatia finds out. He discovers that noise annoyance has a small but significant impact on our wider health – including our...


How old are the elements?

You are a star. Literally. You are a carbon-based life form and those atoms of carbon in the molecules that make up your cells were formed by a nuclear fusion reaction at the heart of long dead stars. That goes for the oxygen in your lungs too. And the red blood cells that carry that oxygen to your tissues? They contain haemoglobin, and nestled at the heart of each molecule is an element (iron) formed by a supernova - the fiery explosion at the death of a star. Your body is a walking,...


Could we turn poisonous plants into edible crops?

There are over 400,000 species of plant on earth, they’re on every continent including Antarctica. But humans only regularly eat about 200 species globally, with the vast majority of our nutrition coming from just three species. Many of the fruits, leaves and tubers that other plants grow are packed full of toxins that are poisonous to us, and would make us very ill if we ate them. But could we take out the poisons and create new, edible crops? That’s what CrowdScience listener Marija wants...


Why is learning stuff harder as you get older?

Have you taken classes to learn a new sport or musical instrument or a language? It’s hard work! Why is it that as children we effortlessly absorb new skills and we don’t as adults? That’s what 50-something listener Gary Grief wondered about playing guitar. Do you need to play more frequently as an adult to attain the same level of expertise? Does the 10,000-hours theory still apply? Presenter and budding tabla-player Anand Jagatia embarks on a musical journey to discover what neuroscience...


Why are seeds such different sizes?

When eating a blackberry one day, CrowdScience listener Charles got a tiny seed stuck in his teeth. That got him wondering: why are seeds the size they are? Why does a blackberry have dozens of tiny pips, while a peach has one huge stone right in the middle? Plant seeds have been around for hundreds of millions of years, so they’ve had plenty of time to shapeshift into wildly different forms: from dust-like orchid seeds to giant coconuts. This evolution has been a long and intricate dance...


What can we learn from wastewater?

Most of us don’t like to dwell on our toilet habits, but this week Crowdscience has gone down the drain to discover what wastewater can tell us about our health. It’s been more than a year since scientists across the globe started to track the spread of Covid-19, with help from home test results and hospital data. Marnie Chesterton investigates the latest tool in their arsenal: sewage. Listener Kevin has heard how human waste can be monitored to check for virus levels, and wants to know if...


Why does grief leave me feeling this way?

Grief is universal. It is something almost all of us will go through at some point. And it is something that the people we love will experience when we die. Grief can be all consuming, it can make everyday tasks like getting out of bed, feel impossible. Which makes listener Oliver from Australia wonder - what is the point? It doesn’t bring what we lost, back. Why have we evolved to be so affected by loss? Be it the death of a loved one, the end of a relationship or the loss of a job. Does it...


Why do we gossip?

Gossip often has negative connotations, but does it get a bad rap? Might it serve a useful function and should we think of gossiping as an advanced social skill rather than a personality defect? CrowdScience listener Jayogi thinks it might be useful, and has asked CrowdScience to dig into the reasons why we find it so hard to resist salacious stories. Presenter Datshiane Navanayagam meets a scientist who views gossip as a key evolutionary adaption - as humans started to live in bigger...


If a tree falls in a forest… does it make a sound?

If a tree falls in a forest, and no-one is there to hear it, does it make a sound? This is an age-old debate that listener Richard and his family have been arguing about for years. Can CrowdScience settle it once and for all? Caroline Steel speaks to experts in hearing, biology, philosophy, physics and sound design, which takes her to some unexpected places. Professor Stefan Bleek is an expert in psychoacoustics who says that sounds only exist in our heads. Dr Eleanor Knox and Dr Bryan...


Do animals use medicine?

Animals experience all the colds, stomach pains, headaches, parasites, and general illnesses that humans do. But unlike us, animals can’t just grab a painkiller off the shelf at the supermarket to cure it. They don’t have a pharmacy to browse… or at least, not the sort that we’d recognise. Listener Andrew Chen got in touch to ask whether animals use any kind of medicine themselves. After all, our own drugs largely come from the plants and minerals found in wild habitats. So perhaps animals...


Can space exploration be environmentally friendly?

The space industry, with its fuel-burning rockets, requirements for mined metals and inevitable production of space junk, is not currently renowned for its environmental credentials. Can space exploration ever be truly environmentally friendly? Presenter Marnie Chesterton answers a selection of listeners’ questions on the topic of space environmentalism. She starts by examining the carbon footprint of spaceship manufacturing here on Earth, and asking whether reusable rocket ships such as...


How does my mind talk to my body?

This week CrowdScience investigates the information superhighway connecting mind with body. The Vagus nerve is part of our parasympathetic nervous system, delivering information from all our major organs to the brain stem, and stimulating it can help us switch off our fight or flight response and calm us down. But listener Mags wants to know what science says about its impact on our general wellbeing? Marnie Chesterton learns some deep breathing techniques and discovers how the length of our...