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BBC World Service


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


CrowdScience

It seems bizarre to seek out experiences that are uncomfortable or downright painful. Yet examples abound: it’s common to eat painfully hot chillies, drink bitter coffee, or ‘feel the burn' when exercising - and enjoy it.
 
CrowdScience listener Sandy is baffled by this seemingly counterintuitive phenomenon, and has asked us to investigate. Presenter Anand Jagatia turns guinea pig as he tests a variety of unpleasant sensations, and unpicks the reasons we’re sometimes attracted to them. 
 
He meets chilli-eating champion Shahina Waseem, who puts Anand’s own attraction to spicy food to the test. Food scientist John Hayes explains how our taste receptors work and why our genes affect the appeal of bitter food. Neuroscientist Soo Ahn Lee describes her research looking at what happens in participants’ brains when they eat chocolate and capsaicin, the chemical that makes chillies hot.
 
As for the ‘pleasurable pain’ we sometimes experience when exercising, sports doctor Robin Chatterjee reveals the secrets of the ‘runner’s high’, while neuroscientist Siri Leknes explains why the feeling that something’s good for us can make discomfort pleasurable.
 
Presenter: Anand Jagatia
Producer: Jo Glanville
Editor: Cathy Edwards
Production co-ordinator: Ishmael Soriano
Sound engineer: Sue Maillot

(Image: Young man have bath in ice covered lake in nature and looking up, Czech Republic Credit: CharlieChesvick via Getty Images)

Why does pain sometimes feel good?

The Moon has always sparked human curiosity. It governs the tides and biological rhythms. It’s inspired myths and stories. It’s inspired us to reach out and explore it. And it's certainly inspired CrowdScience listeners, who have sent us a host of questions about it. And in a special lunar-themed episode we’ve brought together a panel of astronomers and planetary scientists to help answer them. 

What would life be like if there was no Moon? Would there even be life? Or what if we had two moons? Are the Moon and Earth equally battered by meteors? What would happen if an asteroid collided with the Moon? And could the Moon ever escape Earth’s gravity? 

Anand Jagatia is joined by Prof Sara Russell, Head of the Planetary Materials Group at the Natural History Museum in London; Prof Neil Comins from the University of Maine, author of the book What if the Moon didn’t Exist?; and Prof Katarina Miljkovic from Curtin University in Perth, Australia. 

Presenter: Anand Jagatia 
Producer: Jeremy Grange 
Editor: Cathy Edwards 
Production Co-ordinator: Ishmael Soriano 
Studio Manager: Andrew Garratt

(Photo: Landscape with the rising of the full moon during the golden hour Credit: Jose A. Bernat Bacete via Getty Images)

Will the Earth ever lose its Moon?

Did you know that flies fly in rectangles, fish hide by lighting themselves up and the moon is lifting the ground underneath your feet? Anand Jagatia quizzes members of the CrowdScience team on the moments from the past year that had them scratching their heads in amazement. 

We hear Dr Erica McAlister’s attempts to calculate how many flies have ever existed, and about flies’ mating choreography, courtesy of Prof Jochen Zeil. We learn how to tell a mosquito’s sex thanks to Eggrey Aisha Kambewa and Dr Steve Gowelo. 

Astronomer Dr Darren Baskill describes tides not of water but of land; Dr Edie Widder paints a vivid picture of a camouflaged creature of the deep; and we explore starfishes’ five-fold symmetry with Dr Imran Rahman. 

Khimlal Gautam, Mountaineer and Chief Survey Officer for the Government of Nepal, tells us of the near-death experience he had when checking the height of Mount Everest. 

And finally, axolotl expert Dr Elly Tanaka is astonished at the dedication of CrowdScience presenter Alex Lathbridge to the subject of her research. 

Presenter: Anand Jagatia 
Producer: Ben Motley 
Editor: Cathy Edwards 
Production Co-ordinator: Ishmael Soriano 
Studio Managers: Donald MacDonald and Giles Aspen

(Photo: Lost in formulas Credit: Cimmerian via Getty Images)

I didn’t know that!

When listener Diana fell on a run on her birthday, her first instinct was not to check her bruised hand, but instead to get up as quickly as possible and act as if nothing had happened. She felt embarrassed. Meanwhile, her son Marley loves to watch fail videos that, mostly, show people falling over. So why does falling – something that can cause serious injury – elicit both embarrassment and laughter? 

In the name of CrowdScience, presenter Caroline Steel trips, stumbles and falls. She spends a morning with clown Sean Kempton who teaches her slapstick skills, including how to do it safely. 

Psychologist Rowland Miller explains why falling can be embarrassing and shares his theory of why humans have developed this emotion in the first place. Then it’s time for Caroline to try out Diana’s predicament herself. If a BBC presenter falls in a park, will she feel embarrassed? 
 
From embarrassment to laughter, psychologist Janet Gibson lists the ingredients of a funny fall, and humour expert Caleb Warren explains how they can get funnier with distance. Then Caroline tries, semi-successfully, to make members of the public laugh. Will clown Sean do a better job? 

Presenter: Caroline Steel 
Producer: Florian Bohr 
Editor: Cathy Edwards 
Production coordinators: Ishmael Soriano
Sound engineers: Bob Nettles, Tim Heffer and Giles Aspen

Why am I embarrassed when I fall?

While watching a feisty cockatoo chase after a hawk, CrowdScience listener Alison saw the hawk catch a thermal and rise effortlessly into the sky. The cockatoo gave chase, but the hawk climbed higher and higher until it became just a tiny speck, barely visible to the naked eye. 

And that got Alison thinking: just how high can birds go? Are there altitude limits for our feathered friends? Could a cockatoo, a sparrow, or even a duck reach such dizzying heights if they really put their wings to it? 

Presenter Alex Lathbridge sets out to investigate. Biologist Catherine Ivy reveals that life above the clouds isn’t easy. At high altitudes, the air is thinner, oxygen is scarce, and wings don’t generate as much lift. But some bird species have evolved incredible adaptations to overcome these challenges. 

Among them: bar-headed geese, renowned for their daring flights over the world’s tallest mountains. Physiologist Lucy Hawkes delves into how these geese defy the odds with their remarkable physiology, revealing the surprising discoveries she made while putting some of them on a treadmill. 

From super-powered hearts to clever lungs, we uncover the secrets behind nature’s impressive aviators. 

Presenter: Alex Lathbridge 
Producers: Ilan Goodman and Jeremy Grange 
Editor: Cathy Edwards 
Production co-ordinator: Ishmael Soriano 
Technical producer: Sarah Hockley

(Image: OIE A TETE BARREE (Anser indicus) EN VOL Credit: Jean-Patrick DEYA / Contributor via Getty Images)

How high can birds fly?

Smartwatches are increasingly popular and many of us use these wearable devices to monitor our performance and improve our fitness. But how reliable is the data they collect, and can they actually make us healthier? 

CrowdScience listener Caitlin from Malawi is a big fan of her smartwatch. Her husband Fayaz, however, is much more sceptical of its accuracy, and has asked us to investigate. We meet up with them both at the gym, where Caitlin and presenter Caroline Steel put their fitness trackers – and themselves – to the test. 

We visit public health researchers Dr Cailbhe Doherty and Rory Lambe, who investigate the accuracy of wearable consumer devices, at University College Dublin. Caroline again pushes herself to the limit to see how her smartwatch results measure up to those from gold standard laboratory equipment. 

But is it crucial for smartwatches to be accurate? If they get us off the couch, is that what makes the difference to our health? Health behaviour expert Dr Ty Ferguson from the University of South Australia has studied this very question. And finally, how does quantifying our every move affect the way we think about ourselves and how we live? Professor Deborah Lupton from UNSW Sydney, shares some insights. 

Presenter: Caroline Steel 
Producers: Jo Glanville and Sophie Ormiston 
Editor: Cathy Edwards 
Technical producer: Sarah Hockley 
Production co-ordinator: Ishmael Soriano

Is my smartwatch good for my health?

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 
Production co-ordinator: Ishmael Soriano 
Technical producer: Jackie Margerum

Is anything truly random?

Vermillion red, vibrant orange, golden yellows, even violet – we're enchanted by the colours that make up a stunning sunset or sunrise. CrowdScience listener Paulina, a lighting designer from Chile, often uses the sunsets she sees from her balcony as inspiration for her designs. And during the day and night, the sky can be all sorts of shades of blue. But Paulina wonders why, in the colour palette of the sky, she never sees any green. 

CrowdScience gazes skywards to investigate. Presenter Caroline Steel travels to the Arctic Circle to meet atmospheric physicist Katie Herlingshaw. Katie explains why we usually see the sky as blue, and what makes it transform into fiery reds and oranges at sunrise and sunset. We also peer into the science of perception, as neuroscientist Bevil Conway tells us what’s going on in our eyes (and brains) to make the colours we see in the sky. 

But there are some rare occasions when the sky can appear to be green, such as in a rainbow or a green flash at sunset. And then there is the spellbinding green glow of the aurora - the Northern and Southern Lights. We visit the northernmost aurora observatory in the world to try to understand this phenomenon. Are green skies more common than we think? 

Presenter: Caroline Steel 
Producer: Hannah Fisher 
Editor: Cathy Edwards 
Production Co-ordinator: Ishmael Soriano 
Studio Manager: Sarah Hockley

(Photo: View of sunset in Santiago, Chile. Photo montage courtesy of Paulina Villalobos)

Why isn't the sky green?

It’s citrus season in the northern hemisphere, and fruit trees are bursting with oranges and lemons. But CrowdScience listener Jonathan wants to know what happened to the tangerines he ate as a child in the 1960s? He remembers a fruit that was juicy, sweet and full of pips, found each Christmas at the bottom of his stocking. Tangerines today, he thinks, just don't compare. 

Crowdscience tries to track down this elusive fruit. Presenter Anand Jagatia traces the tangerine's origins back to Ancient China, as botanist David Mabberley explains that the name ‘tangerine’ comes from a fruit that made its way from Asia, to Africa and the Moroccan port of Tangier, before arriving in the US in the early 1800s. Professor Tracy Kahn from UC Riverside tells us about the hybridisation process that goes into breeding modern tangerines, but says that while the season for these fruits has been dramatically extended, there’s a cost in terms of diversity and flavour. 

Who better to help us track down this missing mandarin than a fruit detective? Well, that’s one of pomologist David Karp’s other job titles, and he reveals exactly which cultivar we might be looking for: the Dancy. So where can we find one? Over on Friend’s Ranches in Ojai, California, Emily Ayala shows us two trees planted by her late grandfather, and explains that nothing grown since really matches its unique flavour.

So what will listener Jonathan think when we send him a box? 

Presenter: Anand Jagatia 
Producer: Marijke Peters 
Editor: Cathy Edwards 
Production Co-ordinator: Ishmael Soriano 
Studio Manager: Jackie Margerum

(Image: Citrus oranges grow on tree, Hong Kong Credit: CHUNYIP WONG via Getty Images)

Whatever happened to tangerines?

The wetness of water seems blindingly obvious - but dive into the science and things aren’t so clear. 

CrowdScience listeners Rachel and Callum were washing their hands one day and it got them thinking about wetness. Why does water feel the way it does? And what makes a liquid wet? 

To find out, presenter Anand Jagatia takes a closer look at the behaviour of liquids with materials scientist Mark Miodownik, and finds out why they might not be as wet as we think. 

We learn what’s really behind the sensation of feeling something wet on your skin, with the help of physiologist Davide Filingeri and PhD student Jade Ward. 

And we turn to a philosopher, Vanessa Seifert, and a chemist, Tim Neudecker, to puzzle out exactly how many water molecules you need before the property of wetness emerges. 

Presenter: Anand Jagatia 
Producer: Anand Jagatia 
Editor: Cathy Edwards 
Production Co-ordinator: Ishmael Soriano 
Studio Manager: Bob Nettles and Andrew Garratt

(Image: A photo of a droplet falling into a body of water Credit: Flaviu Cernea / 500pxvia Getty Images)

Is water wet?

Humans have an outsized impact on the planet: we’ve wreaked havoc on countless ecosystems and one study estimates only 3% of land on Earth remains untouched by our influence. CrowdScience listener Teri has witnessed the harmful effects of development on natural habitats near her home, and wonders whether we can ever function as part of a healthy ecosystem. 

We look for answers in Teri’s home state, California. Humans have lived here for over 10,000 years and its first inhabitants formed a connection to their landscape unlike the exploitative approach of many later settlers. Today, the beliefs and traditions of the Karuk Tribe of northern California still emphasise a symbiotic relationship with nature, seeing plants and animals as their relations. 

Over the past couple of centuries much of the Karuk’s land has been degraded by mining, the timber industry and the outlawing of traditional burning practices. Tribal members show us how they’re working to try to restore ecological balance.

As for the rest of humanity: can we rein in our destructive relationship to nature; or even have a beneficial effect on our local ecosystems?

Contributors: 

Kathy McCovey - Karuk Tribe member and cultural practitioner 
Dr Steward Pickett - Ecologist, Cary Institute of Ecosystem Studies 
Bill Tripp - Karuk Tribe member and Director of Natural Resources and Environmental Policy, Karuk Tribe Department of Natural Resources 
Dr Frank Kanawha Lake - US Forest Service Research Ecologist and Tribal Liaison 
Will Harling - Co-lead, Western Klamath Restoration Partnership 

Presenter: Caroline Steel 
Producer: Cathy Edwards 
Editor: Richard Collings 
Production Co-ordinator: Jonathan Harris 
Studio Manager: Giles Aspen & Steve Greenwood 

(Image: Huckleberries and tanoak acorns gathered near a burn site. Credit: Stormy Staats)

Can humans be part of healthy ecosystems?

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