The Science Hour

Pledges to reduce greenhouse gas emissions are largely unachievable says a major audit of commitments to the Paris Climate Accord. Air pollution in Delhi is so bad, breathing the toxic particles has been likened to smoking. Can a scientific assessment of the multiple causes help provide a way forward? We examine a new way of making new plastic – from old plastic. And why sending some stem cells to the international space station might help astronauts travel further. We’re all familiar with the sensation of sleepiness – heavy eye-lid, that warm, fuzzy feeling. But, one listener wants to know, what’s actually going on in our body and brain when tiredness takes over? We investigate how our psycho-motor skills are affected by fatigue in a driving simulator. And we ask how does sleepiness change with age? Why, when tired, do adults crave a nap but children become ever more excitable? And what the hell’s going on with teenagers? We have some answers. (Image: Tourists wearing masks to protect themselves from smog in New Delhi, India. Credit: Sushil Kumar/Hindustan Times via Getty Images)

The Santa Ana in the south, and the Diablo in the north, are winds that are fuelling the terrible fires raging in California this week. They’re also blamed for bringing down power lines that sometimes start the fires. Roland Pease talks to Janice Coen of the National Center for Atmospheric Research NCAR who has been developing a highly detailed model to forecast how wind, mountains, and flames interact during a wildfire. The glaring gaps in human genetics are in Africa – much overlooked because the companies and universities sequencing DNA are mostly based in Europe, the US and other advanced economies. A ten-year attempt to fill in some of those gaps came to fruition this week, with the release of a study covering thousands of individuals from rural Uganda. Deepti Gurdasani, of Queen Mary University London, explains the data reveal both new medical stories, and the scale of past migration within Africa. There are also gaps in the climate record from Africa. Knowing past climates could help massively in understanding the prospects for climate change in coming years on the continent. Journalist Linda Nordling has just published an article in Nature that shows that the records exist – old weather data collected since the 19th Century. It’s just they’re scattered, unexamined, in vaults and collections across Africa. Most of us take the ability to speak fluently for granted but for listener Breeda it has been a lifelong struggle. She has asked us to investigate whether there is a cure for stuttering and if not, what is the best way to live with it is. Breeda is not alone as stammering is a neurological condition that affects 70 million people worldwide. (Image: A firefighter sets a back fire along a hillside during firefighting operations to battle the Kincade Fire in Healdsburg, California. Credit: Philip Pacheco/ /AFP via Getty Images)

A quantum computer has performed a calculation considered impossible for conventional computers, but how meaningful is the result? As our guest reveals, this quantum state can be hugely significant and garbage – at the same time. Also we look at a new method of gene editing, which avoids cutting up DNA, get to grips with where the worlds worms live and watch elements being created in distant solar collisions. Listeners Michael and Ricky have been walking a tributary of the River Thames in London, UK. They’ve noticed that there are loads of fish, which have only returned in recent years thanks to clean water initiatives. But what about salmon, they wonder? Could they one day return too? If they popped some salmon eggs in the river, would they return to spawn later on in their lives? We head to Norway to find out whether it’s possible. There, we follow the life cycle of salmon, from birth to death and travels to the salmon’s spawning grounds, before following their path out to sea and beyond. We explore the science behind ‘natal homing’ - returning to the place of your birth in order to reproduce. It isn’t just confined to salmon. But how does it work? (Photo: A quantum circuit from Google's Sycamore computer. Credit: Google)

A variety of malarial parasites have existed amongst the great apes for millennia, we look at how one of them jumped species and why humans became its preferred host. And from Antarctica we hear about a potential new treatment for malaria found in a deep sea sponge. We also look at why improved monitoring is changing our perceptions of earthquakes and follow the story of an endangered Polynesian snail. What exactly is the relationship between mathematics and reality? That’s the impossibly difficult question we have been set this week by our listener Sergio in Peru. It’s one that’s been pondered by humans for millennia: the Greek philosopher Pythagoras believed “All is number”. Is maths a human construct to help us make sense of reality - a tool, a model, a language? Does maths create its own reality? Or is it reality itself? (Photo: A young gorilla. Credit: Hermes Images/AGF/Universal Images Group via Getty Images)

Nobel prizes this week went to a range of discoveries that you might be familiar with, in fact you might be using one of them right now – the lithium ion battery. The scientists credited with its Invention got the chemistry prize. And the tantalising prospect of life on other planets plays into the physics prize win. We see what salamanders have to offer in the treatment of arthritis. Human life expectancy has been increasing for decades. In many developed countries, we can now expect to live into our 80s, and it isn’t uncommon to live to 90 or even 100 years old. But eventually our bodies fail, old age is undoubtedly a clear indicator of approaching death. This fact annoyed 79 year old listener Bill, who emailed in to set us the task of seeking out the secrets to a longer, healthier life. Bill has a personal target to live to 200 years old, so can he do it?