CrowdScience

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 are also fascinated in how string becomes jumbled up and one man has even won an IgNobel award for his work in this field. Doug E Smith discovered that if you put a piece of string in a box then spin it around, its length, thickness and how long you shake the box for, all determine whether it will tie itself up. Not only that, the more the string becomes twisted, the more likely it is to cross over itself and become impossible to untangle.

While tangles might be annoying in hair or cables, they’re also a fundamental part of human life. Our DNA is constantly folding itself to fit inside tiny spaces – there are two metres of the stuff inside every cell, where it’s packed down tightly, before it must untangle and duplicate for those cells to divide. It does this with the help of specific enzymes, and when the process goes wrong it leads to cell death. But scientists are also studying molecular tangles that might benefit us humans, and creating nano-sized knots that can be turned into nets or meshes with incredible properties.

Producer: Ilan Goodman

Presenter: Marnie Chesterton

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 how our whole system – body and brain – works better when we’re walking, compared to standing still. We’re probably set up this way because of our evolutionary history: hunting and gathering needed us to be ‘cognitively engaged endurance athletes’.

We stop for a break.. but is it true that we shouldn’t sit down to rest during a walk? Our listener Sarah is a keen hillwalker but likes to take the weight off her feet every now and again. Her hillwalking friends disapprove, saying she should rest on her feet. Is this a myth CrowdScience can bust?

And finally a question from listener Matteo: is walking or running better for your health? Numerous studies show significant benefits to both forms of exercise, but in the end, the best kind of exercise is the one you’re motivated to do.

With Caroline Williams, Dr François-Xavier Li, Professor Dick Greene and Professor Duck-Chul Lee.

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 core activity for many people stuck in their homes, one listener wants us to find out if eating food whilst watching the TV affects our perception of taste. We then journey to the skies and ask if it is true that food tastes blander on aeroplanes, what does that mean for astronauts’ mealtimes? Back on earth, Marnie explores whether humans are the only animals that season their food.

Tuck in your napkins and prepare to feast on a smorgasbord of scientific snacks.

Presented by Marnie Chesterton and Produced by Melanie Brown and Hannah Fisher for the BBC World Service.

Guests:

Professor Charles Spence

Dr Kristine Beaulieu

Mr. Takashi Funahashi

Ruben Meerman

Chef Jozef Youseff

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 listener Annabel, who wonders why things other people love to sniff, she finds disgusting. Anand Jagatia investigates the science of smell, gets up close to the world’s smelliest plant and finds out if smell training can help those with long-term issues after Covid.

Contributors

Ellie Byondin, supervisor of the Princess of Wales Conservatory at London’s Kew Gardens

Thomas Hummel, University of Dresden

Carl Philpott, from the UK’s Norwich Medical School

Sissel Tolaas, artist and smell historian based in Berlin

Noam Sobel, Weizmann institute of science

Presented by Anand Jagatia and Produced by Marijke Peters for the BBC World Service

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 does the answer have any implications for the future of Earth? Could the atmosphere eventually run out?

Contributors:

Anuradha TK, former project director at ISRO

Matt Genge, geologist at Imperial College London

Jon Larsen, researcher at the University of Oslo

Anjali Tripathi, astrophysicist

Ethan Seigel, journalist and astrophysicist

Presented by Marnie Chesterton.

Produced by Caroline Steel for the BBC World Service.

[Image: Earth on scales. Credit: Getty Images]

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 because it can contribute to diabetes, heart disease and obesity. But that’s tricky when you consider it’s now in everything from salad dressings, to savoury sauces.

Manufacturers have been promoting sugar alternatives for decades but recreating the unique taste and feel of it in the mouth are a challenge. Marnie Chesterton gets to try a brand new innovation – a so-called ‘rare’ sugar that has 70 percent of the sweetness but almost none of the calories. In nature, allulose is found in figs, but one producer has discovered a way to make it in the lab. Does it taste as good as it claims? Whilst switching to alternative sugars and sweeteners may reduce the calories, some researchers claim that tasting sweetness, wherever it comes from, can disrupt the body’s mechanism for regulating blood-sugar levels, increasing the risk for conditions like diabetes.

Presented by Marnie Chesterton and produced by Marijke Peters for the BBC World Service

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 reserves? What can the little Egyptian spiny mouse teach us about PMS symptoms? We hear why periods may reduce the number of faulty embryos that implant and how more menstrual cycles may even increase our chances of developing certain types of cancer.

Finally, as the number of periods a woman has over the course of her life has more than quadrupled since the pre-industrial era, Marnie asks: Do we really still need to have them?

Contributors:

Dr Nadia Bellofiore, Hudson Institute of Medical Research at Monash University

Dr Deena Emera, Buck Institute

Lameck Kiula, Jambo for Development

Sally King, Menstrual Matters & King's College London

Dr Diana Mansour, New Croft Centre & Newcastle University

Presented by Marnie Chesterton

Produced by Sam Baker and Melanie Brown for the BBC World Service

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 cardiovascular system – but that annoyance is not necessarily down to sound alone. Factors such as perception of the neighbourhood and relationships with our neighbours also play a part.

CrowdScience has examined living with unwanted noises before, and we revisit our trip to the acoustics lab at the University of Salford in Manchester, UK. Here, we meet the researchers and engineers investigating the best ways to make our homes more pleasant for our ears whilst still maintaining the ‘buzz’ of city life.

Contributors:

Contributors:

Professor Charlotte Clark, St George’s University of London

Professor Trevor Cox, University of Salford Manchester

Professor Bill Davies, University of Salford Manchester

Dr Mags Adams, University of Central Lancashire (formerly University of Salford Manchester, at time of recording)

Produced by Jen Whyntie and presented by Anand Jagatia for the BBC World Service.

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, thinking museum of some of the most violent events in the universe.

This, as CrowdScience host Marnie Chesterton discovers, isn’t as special as it sounds. All of the stuff on the earth - the elements that make clouds and mountains and mobile phones – they all have an origin story. CrowdScience tells that story, starting with the big bang and ending with physicists, creating new elements in the lab. Find out the age of the elements and the distance they have travelled to make their current home on earth.

Interviewees:

Dr Dorota Grabowska, Professor Andrea Sella, Dr Chris Pearson, Dr Jacklyn Gates

(Photo: Neutron star. Credit: Getty Images)

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 to know.

Crowdscience dives into this topic, and uncovers the that many crops are poisonous, and why so few plants are eaten globally. Host Anand Jagatia finds that even the modern scientific processes of crop breeding are very slow. But science can now engineer plants at the genetic level by adding, silencing or removing specific genes. This ‘genetic modification’ is hugely controversial but can be highly effective.

Anand finds a man who has spent decades making cotton seeds edible by removing the poisons they naturally produce in their seeds. This GM crop could help fend-off starvation. But sometimes introducing poisons can be as important as removing them, as we find in the genetically modified ‘BT eggplants’ in Bangladesh. The new gene makes the vegetable toxic to a major insect pest, so they are much easier to grow.

But GM crops are not the perfect solution. They have problems of gene escape, can increase the use of environmentally damaging herbicide, and can be open to monopolisation. In some countries, particularly in Europe, GM crops are hugely controversial. Anand finds out whether these concerns stand up to science and looks at the counterpoint in developing countries in Africa, South Asia and elsewhere, where local farmers like Patience Koku in Nigeria have little time for some of the concerns around GM, particularly as they see poor harvests, poverty and starvation as the more pressing problems.

Contributors:

Professor Sandra Knapp, The Natural History Museum in London

Professor Julie King, Nottingham University

Professor Keerti Rathore, Texas A&M University

Dr Yousuf Akhond, Bangladesh Agricultural Research Institute

Professor Matthew Cobb, University of Manchester

Patience Koku, Nigerian Farmer and member of the Global Farmer’s Network

Alliance for Science

Produced by Rory Galloway and presented by Anand Jagatia for the BBC World Service.

Image: Farmer with Fruits. Credit: Arif Hossain, Farming Future Bangladesh.