CrowdScience

The news has been full of references to ‘El Niño’, a global weather phenomenon that, this year, is forecast to be the biggest yet. CrowdScience listener Kennedy is a farmer in Kenya and this has got him worried. He wants to know exactly what El Niño is, why it causes such differing weather patterns all over the world and, most importantly, how it might affect his crops.
Always keen to help listeners answer global science questions with local impacts, CrowdScience is on the case. Presenter Anand Jagatia travels to meet oceanographer Ligin Joseph, from the University of Southampton in the UK. Equipped with a tank full of water, a sprinkling of turmeric, some purple dye and a hairdryer, Ligin recreates the Pacific Ocean in his living room. How does changing the hairdryer setting create a mini-El Niño in the tank, and why does that affect the weather everywhere else?
Peruvian biologist Rosa Vasquez Espinosa, from Amazon Research International, has already witnessed the effects of El Niño first hand. She tells Anand about the extreme rain and drought Peru has already seen, as well as describing how Peruvian fishermen first observed El Niño hundreds of years ago.
And what about CrowdScience listener Kennedy’s crops in Kenya? How can a phenomenon that originates in the South American Pacific have an impact on a country that faces the Indian Ocean, 13,000km away? Hannah Kimani from the Kenya Meteorological Department explains, and has some advice for Kennedy and farmers like him.
Presenter: Anand Jagatia
Producer: Eloise Stevens
Editor: Ben Motley
(Photo: Dark clouds with calm dark blue ocean view - stock photo CrowdScience overlay Credit:imagedepotpro via Getty Images)

In November 2016 the BBC World Service launched a brand new show in which listeners would send in their science questions, and a team of fearless presenters would find answers. Ten years on, CrowdScience is still going strong. 
We’ve answered over five hundred questions from our listeners, spoken with thousands of scientists and covered subjects from the mundane to the profound. Our audience’s insatiable curiosity has taken us to the bottom of the ocean, to the top of volcanoes and to the edge of a hurricane. We’ve been on adventures in audio that have been surprising, fascinating and breathtaking, all to find answers to questions sent in by CrowdScience listeners.
In true CrowdScience fashion, we wanted to celebrate our tenth anniversary with our listeners. We asked the audience for their CrowdScience stories, and to pick some of their favourite moments from the last decade. As a result we’re revisiting some incredible episodes, including butterflies that migrate thousands of kilometres, how to measure the weight of the internet and why cables get tangled. CrowdScience has brought you fascinating stories, intriguing experiments and thought-provoking moments, and we’ll be hearing from listeners who have found our programmes more valuable than we could have imagined.
Our tenth anniversary show also gives presenter Anand Jagatia time to chat with other CrowdScience presenters about what makes CrowdScience special, including some unforgettable experiences and moments from the show. With ten years of episodes to choose from, it hasn’t been an easy task. 
And with a seemingly inexhaustible supply of questions from curious listeners, we’re already looking forward to the next ten!
Presenter: Anand Jagatia
Producer: Christine Bennett
Editor: Ben Motley

CrowdScience listener Nyok, in South Sudan, is right-handed and has always felt very creative. He's also noticed that left-handed people seem to be more logical. He's wondering if this has anything to do with the idea that different sides of your brain can be dominant for different tasks.
We covered the basics on hand preference three years ago, in a CrowdScience episode called ‘Why aren’t we all ambidextrous?’, so presenter Caroline Steel delves into the archive to find out about the evolution of hand preferences. Psychologist Sebastian Ocklenburg from MSH Medical School in Hamburg, Germany, and neuropsychologist Marietta Papadou Pastou from the National and Kapodistrian University of Athens in Greece, explain why most people are right-handed and why we think cultural differences are also a factor.
In that show Caroline also spoke to neuropsychologist David Carey from the University of Bangor in Wales. He was so fascinated by Caroline’s answer to a test question that he invited her for a brain scan. Three years later – thanks to Nyok’s question - she’s finally taking him up on the offer!
Caroline is mixed handed, which means that she prefers her left hand for some tasks and her right hand for others. So what can an MRI scan tell us about which side of her own brain she’s using? Richard Binny, Director of the Bangor Imaging Institute, slides her into the machine before David talks her through the results.
But does which hand you prefer really predict whether you’re more creative, or more logical?
Presenter: Caroline Steel
Producer: Margaret Sessa-Hawkins with Sam Baker
Editor: Ben Motley
(Photo: Split Brain Illustration with Mathematical Equations and Neural Networks - stock photo Credit:bymuratdeniz via Getty Images)

CrowdScience listener Lauren from Belgium has near-complete hearing loss in one ear, because all the sensory hair cells in her inner ear have died. This got her thinking about how complicated the human ear is and whether there are other animals with simpler ears, in particular insects. Do they even have ears?
Presenter Caroline Steel hears Lauren’s call and sets off on a hunt for insect ears. She discovers that crickets have them just below their knees. In Fernando Montealegre-Zapata’s laboratory at the University of Lincoln in the UK, she serenades a cricket to test just how much of her voice it can hear.
But crickets aren’t the only ones with ears. Invertebrate neurobiologist Natasha Mhatre, from Western University in Canada, explains that you can find ears almost anywhere on an insect body – from between the legs of a praying mantis to the mouthparts of a moth.
So are there even simpler ears out there? Sensory biologist Joerg Albert from University College London in the UK tells Caroline how male mosquitoes use antennae to listen out for females. But they aren’t exactly simple. In fact, a mosquito probably has more sensory neurons around their antennae than you are using to hear right now.
And what about the insects that can’t hear? Scientist Jayne Yack from Carleton University in Canada unveils the hidden world of vibroscapes. Caterpillars on a leaf, for example, can sense the vibrations created by peers, predators, and even airborne sounds. Which makes Caroline wonder: when does vibration sensing actually become hearing?
Presenter: Caroline Steel
Producer: Florian Bohr
Editor: Ben Motley
(Photo: Insect singing and playing the guitar in flamenco concert - stock photo Credit: Fernando Trabanco Fotografía via Getty Images)

Some animals lay eggs, and their young hatch out of them. Other animals give birth to live young. But which strategy is best?
That’s the question that’s been bothering CrowdScience listener Sameer in Canada. Is giving birth to live young a good reproductive strategy? It takes a lot of time and effort, and it doesn’t result in that many offspring. Egg-laying, on the other hand, allows you to produce lots of young at one time to maximise the chance of survival, seems easier than giving birth, and you can lay eggs more often. So why have humans and most other mammals evolved to give birth to live young?
To find the answer, presenter Anand Jagatia travels way back into the past with Paul Barrat from London’s Natural History Museum in the UK to look at the evolutionary history and advantages of egg-laying. What have gravity and moisture got to do with the success of an egg?
Palaeontologist Kimi Chapelle from Stony Brook University in the US shows Anand the oldest eggs ever found, and we discover why even older eggs are missing from the fossil record.
We discover how the evolution from egg-laying to birth-giving is happening right in front of our eyes, with Camilla Whittington from the University of Sydney, Australia. And we might even have an answer to the age-old question about eggs - which came first?
You can see the oldest eggs ever found here: https://www.nhm.ac.uk/discover/news/2020/april/most-detailed-look-inside-worlds-oldest-dinosaur-eggs.html
(Photo: A chick hatching from egg on egg tray. Credit: David Malan/Getty Images)
Presenter: Anand Jagatia
Producer: Margaret Sessa-Hawkins
Editor: Ben Motley