Author: BBC World Service

How should we tackle the biggest clean-up job in history? Listener Michelle from Ireland sends CrowdScience to investigate what to do with years’ worth of spent nuclear fuel. Most of the highly toxic waste is a by-product from nuclear power production and the stockpiles across the world continue to grow. “Could we blast it into the sun? Dilute it across the continent? Or should we bury it?” Michelle asks.

We travel deep into the Finnish bedrock to visit what could be its final resting place and speak to the scientists who are securing the facility many ice-ages into the future. The nastiest stuff in the waste soup needs to stay put for thousands of years before it becomes safe. No man-made structure has ever before lasted so long. The Finnish solution is not easy to replicate in other countries as communities oppose nuclear waste being permanently buried in their backyard.

Presenter Marnie Chesterton discovers that scientists have come up with solutions that could let us recycle the spent fuel more effectively, but it costs more than the industry is willing to spend. The clean-up job of the century comes down to dollars and not science.

Presenter: Marnie Chesterton Producer: Louisa Field

(Photo: a man in protective workwear in waste factory. Credit: Getty Images)

Mohammed is from India and he’s blind. He emailed CrowdScience because he wanted to know more about new technologies that could help him see again. Specifically, he was interested in artificial vision - what is it and what does it look like?

Bobbie Lakhera travels to Germany to find out. There, she meets a blind patient called Manuel. He’s about to have a major operation. A computer chip will be implanted into his eye and his surgeon, Florian Gekeler, believes that it will restore some of Manuel’s sight. But what happens if you have no eyes for a chip like this to be inserted into? Bobbie speaks to Dr Nader Pouratian about his brain prosthesis. Because the implant is attached directly to the visual cortex of the brain, it means you could have no eyes or no optic nerve and you could still see with this type of therapy. Whilst both these technologies are limited to black and white vision, Bobbie asks whether one day we may be able to develop systems that give those living with blindness 20/20 vision.

Presenter: Bobbie Lakhera Producer: Graihagh Jackson

(Photo: A female iris, bionic eye concept. Credit: Getty Images)

When it comes to speed, humans have got nothing on cheetahs - or greyhounds, kangaroos or zebras for that matter. It’s over long distances we really come into our own: when running for hours or even days, our body structure and excellent sweating skills make us able to outpace much faster mammals.

But what are the limits of human endurance? Can we run ever further and faster, and what’s the best diet to fuel such ambitions? This week’s questions come from two CrowdScience listeners in Japan who already know a fair bit about stamina, having run several marathons and long-distance triathlons between them. We head to Greece, legendary birthplace of the marathon, to witness an even more arduous challenge: hundreds of athletes following in the footsteps of the ancient Greek messenger Pheidippides, to run an astonishing 246km across the country. The ever-so-slightly less fit CrowdScience team do our best to keep up, and try to discover the secrets of these runners’ incredible endurance.

Presenter: Marnie Chesterton Producer: Cathy Edwards

(Photo: a runner in the Spartathlon ultramarathon, with kind permission from the International Spartathlon Association)

Would you willingly break a mirror, walk under a ladder or cut up an image of someone you love - or might you be worried about tempting fate – even if you don’t believe in supernatural forces? Anand Jagatia enters the world of magical thinking on behalf of CrowdScience listeners to explore why - even in this era of scientific rationalism – superstition, magic and belief in concepts like the evil eye and luck appear deeply entrenched in our cultures and psyche. Meeting historians and psychologists, Anand sets out to reveal the enduring lure of superstition and explore the biological factors that can influence us, like how our brains have evolved to look for connections and find patterns in seemingly random events. Is it possible that some people are ‘lucky’ and can we enhance our own ‘luck’? Experimental evidence is thin on the ground but finger’s crossed, CrowdScience can find some. Presenter: Anand Jagatia Producer: Melanie Brown

(Image: A handmade Voodoo Doll with pins. Getty Images)

As the US reaches the end of another hurricane season listener Kelly wants to know if it’s possible to prevent these devastating storms? She lives in Florida, the hurricane capital of the world, and has survived 100mph winds whipping through her home. But could science hold the solution to these extreme weather events?

Marnie Chesterton had the unique opportunity to fly into hurricane Florence with the weather scientists gathering data that helped forecasters predict its path, and reports from on board a plane near the eye of the storm. She hears from one researcher who wants to ‘whiten’ clouds to lower sea temperatures and reduce hurricane formation but learns others fear interventions like this could have unintended consequences elsewhere.

Presenter: Marnie Chesterton Producer: Marijke Peters

(Photo: Hurricane between Florida and Cuba. Credit to: NASA and Getty Images)

As the show that takes your questions and turns them into audio adventures reaches its 100th episode, Marnie Chesterton revisits a few of our most liked, talked-about, and inbox-filling programmes to find out how science is getting on with the answers. Marnie heads to a place where important queries have been tackled for hundreds of years - the University of Cambridge in the UK - to chase down some burning follow-ups on topics that have piqued your interest. She finds out what the future holds for the next generation of batteries as they're expected to power everything from smart phones to your car and even your house. Then she scrubs up to tackle your tough questions on the best ways to keep clean.

Finally, Marnie visits a memory laboratory at Cambridge University to discover whether the very process of asking questions might be one way to help us remember more.

(Photo: A woman from a group raises her hand to ask a question. Credit: Getty Images)

This violent and repetitive involuntary constriction of the chest muscles is highly infectious, and can result in convulsions, profuse tears and a reddening of the face. People are known to clutch their chests or roll around on the floor during the more intense bouts. Buy why? It seems a particularly odd thing to do and that’s why CrowdScientists, Erin from Australia, Geraldine from Switzerland, and Musweu from Zambia wanted to find out more about laughter. In pursuit of an understanding of what laughter is, and why we do it, Geoff Marsh attempts to distinguish the sounds of friends from strangers laughing together, and explores the earliest origins of this rib-rending behaviour. In the process he discovers that we’re not alone in laughing, and uncovers the importance of this ability for making and maintaining friendships.

Presenter: Geoff Marsh Producer: Rory Galloway

(Photo: Two young girls eating an ice-cream and Laughing. Credit: Getty Images)

E-cigarettes and vaping may only have been around for a decade or so but it's estimated more than 35 million people globally have taken it up. Marnie Chesterton heads to a vape show to discover why these gadgets are proving so popular, and hears from one expert who warns they could be damaging lung immune cells. She examines the research behind claims that e-cigarettes can help smokers quit, and finds conflicting evidence about how good they are at giving people the nicotine hit they crave. It's a research field that's in its infancy and with vaping technology constantly changing, it's little wonder some scientists say it's a struggle to keep up.

Presenter: Marnie Chesterton Presenter: Marijke Peters

(Photo: A woman smoking an e-cigarette. Credit: Getty Images)

Have you ever been out driving and noticed your mind… wandering? CrowdScience listener Sian Gardiner has. When travelling to visit her parents she has to cross a very large, very obvious bridge. But there are times when she finds herself on the other side with no memory of having gone over it. How is that even possible? Presenter Geoff Marsh buckles up to find out. He travels through the science of how driving becomes second nature, brakes sharply when he realises he’s not necessarily in conscious control at 70mph, and tries to refocus when he discovers why drivers don’t always see things that are staring them in the face. He also asks what’s happening when our mind drifts away from the road, and what can be done to help drivers pay more attention and reduce accidents.

Presenter: Geoff Marsh Producer: Anna Lacey Sound design: Peregrine Andrews

(Photo: A woman sits in her car, looking through window glass with rain drops. Credit: Getty Images)