CrowdScience

Biometrics are being used everywhere to recognise us. On this edition of CrowdScience we try out the tech that tells us apart. We find out just how unique our irises are and meet a man who can pick people out from a crowd of thousands just by analysing the way they walk. Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk Presenter: Anand Jagatia Producer: Marij...

Our planet is getting rather cosy. In just over 200 years, the global population has grown from 1 billion to almost 7.5 billion – and the best estimates suggest it’s going to keep on increasing. But just how far can it go? When will we reach ‘peak human’? That’s what CrowdScience listeners Alan Donaldson and Francoise Brindle want to know: what’s the latest estimate for how many people the Earth c...

Mining asteroids, moons or even other planets has remained firmly within the realm of science fiction. But as certain elements become increasingly scarce on Earth, private companies and even nation states are looking to make extra-terrestrial mining a reality. Presenter Marnie Chesterton heads to an Earth-based mine in Scotland to see just how tricky space mining could be, and what possibilities i...

For most people the idea of chewing on a caterpillar or tucking into a tarantula is pretty unpalatable. Yet according to the United Nations, some two billion people around the world consume insects regularly. This prompted World Service listener Saman from Pakistan to ask the BBC CrowdScience team “are insects a serious food source?” To tackle this question, we head to Burkina Faso in West Africa...

Why do we have so many accents - even when we’re speaking the same language? What's happening in our brains and mouths to make us sound so different from each other? This week’s question from listener Amanda takes CrowdScience to Glasgow in Scotland: home to one of the most studied - and distinctive - accents of English. Along the way we visit a voice coach to try and learn a Texan accent, use ult...

Do your joints ache when it's raining? Are you blighted with headaches when the wind picks up? If the answer’s yes then you're definitely not alone. People have been linking their heath to the weather since the time of the Ancient Greeks - but is the effect real? CrowdScience heads for the hills and gets closer to the clouds to have a go at answering this 2,500 year old question. People who believ...

Can we really live on Mars? Or exist in a virtual world? And why does movie science sometimes have us shouting at the screen? Our panel of scientists and sci-fi experts reveal all in this special edition of CrowdScience recorded live at the South by Southwest Conference & Festivals in Austin, Texas, USA. To tackle all of our listeners’ questions about science in film, presenter Marnie Chestert...

The human race is getting fatter. But is it our fault? There are a whole host of factors influencing our weight - how many of them can we control? CrowdScience discovers how factors like our environment and our genes can tip the scales in the wrong direction. We visit an apartment complex originally designed for Olympic athletes, to see if people can get fitter just by living there. And from a bra...

Trees take in carbon dioxide but they also convert some of the toxic gases in our air. How much help can trees give us in fighting air pollution and could where we plant them make an even bigger difference? Crowdscience reports from the side of some busy roads on how canopy coverage may be part of the answer. At a lab in Louisiana one scientist is putting oak leaves through their paces to find out...

Our listener Joseph’s question might sound more sci-fi than science show. But as Marnie Chesterton discovers, robots have already entered the realm of medicine and are likely to become more important in the future. A visit to the operating theatre at the University College Hospital in London together with surgeon Caroline Moore reveals that robots take the scalpels out of surgery by letting surgeo...

A few weeks ago, CrowdScience asked if it pays to be nice. We found that the answer is yes – if you’re a human. But if being social is so great, why aren’t all animals doing it? That’s what our US listener Tony wants to know. After listening to ‘Does it Pay to be Nice?’ he rightly pointed out that cats lead mostly solitary lives - but don’t seem any worse off for it. So why have they taken this pa...

Death is one of life’s few certainties – or is it? To answer listener Pratibha’s question from New Delhi, India, presenter Marnie Chesterton asks medical and scientific experts if there is any evidence that humans could somehow come back into existence after their demise. We start at the end, by asking just what death is – and it turns out to be perhaps surprisingly complicated, especially if cold...

Earth’s surface may be 70 percent water but many places are struggling to access it. We look at a range of water supply options including delivering it by tanker. In Malta we meet a man trying to solve its water problems, with a clever contraption to recycle sewage. Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk Presenter: Marnie Chesterton Produders: Cathy...

It sounds like a simple question – what is the time? But look closer and you realise time is a slippery concept that scientists still do not fully understand. Even though we now have atomic clocks that can keep time to one second in 15 billion years, this astonishing level of accuracy may not be enough. The complexity of computer-controlled systems, such as high-frequency financial trading or self...

From Chihuahuas to Great Danes, Mexican Hairless to Afghan Hounds, dogs are the most diverse mammal on the planet. There are currently over 500 recognised breeds worldwide with almost every conceivable combination of size, shape, coat, colour and behaviour. But why are there so many different kinds of dog? That's what listener Simon St-Onge in Quebec, Canada wants to know – and CrowdScience has ta...

Modern Martian hunting involves looking for the tiniest evidence of life. But when presenter Marnie Chesterton found out that a scientist she was meant to be chatting to about cleanliness had previously worked for NASA, the topic of space bugs turned out to be too intriguing to ignore, especially when a CrowdScience listener asked us a question on a similar theme. Could Earth's microbes hitch a ri...

To be healthy you need to be clean – or so we’ve thought throughout human history. The dazzling array of antibacterial products that exploded onto the scene in the 20th century took things to the next level, with their promises of eliminating 99.9% of germs. But could an obsession with cleanliness actually be bad for us? There’s a whole world of microbes out there: some make us sick, but others ar...

Is there a killer asteroid with Earth’s name on it? The dinosaurs ruled for many millions of years before coming to their violent end. Will humanity prevail or are we doomed to succumb like the dinosaurs? It’s a question that will keep you up at night. No wonder our listeners Zarin and Pablo wanted to know more. To find out, Anand Jaggtia heads to Denmark to see first-hand the evidence for a giant...

Why can't we use energy from the waves of the sea to create all the electricity that we need? Listener Michael in Kingston, Jamaica wants to know. Living on a Caribbean island means he’s never far from the might of the ocean – so could it power his house? Presenter Greg Foot heads to one of the world’s leading wave energy test locations, the coast of Cornwall in the UK, to find out. There, he witn...

Most of us want to be nice. But is it all it's cracked up to be? It's a question that's been nagging at listener Tony in Illinois, USA, for over 25 years. While studying at university, the lecturer asked him whether competing or co-operating was the best strategy for success – essentially, does it pay to work together or should we sharpen our elbows and look after number one? Nastaran Tavakoli-Far...

How would a fourth dimensional being appear to humans? "It would look just weird" is one way to answer the question 'How would a fourth dimensional being appear to humans?' But it's more complicated than that - theoretical cosmologist Andrew Pontzen describes how objects are viewed from one dimension to another, and how it might affect parking spaces. Also on the programme: our panel of experts di...

What effect does air travel have on the climate? That is the question listener Neil sent CrowdScience from New Zealand. If you have ever looked up at the sky and seen the wispy white streaks that airplanes leave behind, then you are looking at one of the major environmental impacts of air transport – contrails. To find out more, Anand Jagatia goes on a journey through the rugged, lava-ridden Icela...

Where did the first viruses come from? They have the potential to wipe out life on Earth. But could life on Earth itself have evolved from the first viruses? Like the chicken and the egg, there are fierce arguments about which came first and rival scientists get quite cross about it all. We take a dip into the primordial soup of creation and try to answer listener Ian's excellent question. Along t...

How much electric energy storage would it take to run the average home for 24 hours? Also: When will it be economical to locally store several days of electric energy for our home? Listener Gus in Texas, USA, wants to know – especially because he’s one of many people around the world who sometimes face lengthy power cuts. Presenter Marnie Chesterton takes Gus’s question to energy experts. She head...

What do scientists think is outside our universe? Asks Rebecca Standridge from San Francisco in the US. It’s a question which goes right to the limits of human understanding. We look for the answer using balloons, bubbles and the world’s oldest radio telescope. If you have a question about science that you'd like us to investigate email crowdscience@bbc.co.uk . Photo: Lovell telescope Jodrell Bank