This BBC podcast is supported by ads outside the UK. and a valuable community. ASR does it. So, now you can listen to your podcast. BBCNL, the place for the best British misdaad series. Just on your Netherlands TV. there's some fundamental chemistry that could make the difference between glory and defeat on the snow. More on that soon. And technology journalist and broadcaster Gareth Mitchell has been scouring the science journals for us and is here. Welcome, Gareth. Hello, Vic. Very nice to be here. So I'm going to be talking about what is apparently the world's smallest computer. Spoiler alert, it's ridiculously small. And good news for emergency vehicle drivers in Finland. Excellent. I look forward to that. Stick around. But to start with, we are sticking with chemistry today because you will almost certainly have heard the term forever chemicals. The UK government has just announced plans to tackle these particularly persistent compounds collectively known as PFAS or per or polyfluoroalkyl substances. There are thousands of them and they're in lots of things that we use and wear every day. And their chemistry means that they stick around and accumulate in the environment, in drinking water and even in our bodies. In its first ever forever chemical plan, the UK government has said it will increase PFAS testing and seek alternatives so that these substances can be phased out. And of course, this has all made us wonder about the science. What exactly do we know about PFAS and where these substances are coming from? So joining me now is Stephanie Metzger, Policy Advisor at the Royal Society of Chemistry. Hello, Stephanie. Welcome to Inside Science. Hi. What do we mean when we talk about this group of chemicals? What are they? Absolutely. This is a really important thing to know because PFAS, as you say, are a group of chemicals. Depending on the definition and the list you look at, it could be anywhere from 10,000, 15,000 or even more different kinds of substances. But the thing that they all share is a carbon-fluorine bond, which is an extremely strong bond that means that they're very durable. They don't break down easily. And that's what gives them all these useful properties. Heat resistance, slipperiness, waterproofing, oil-proofing, stain-resistant properties. This carbon-fluorine bond is what makes them all very durable and useful. Right. So what makes them useful also makes them problematic because they're so difficult to break down. You're right. So when we use them, if they get out into the environment, for example, they can stick around for a long time. Again, there's variations across the group. Some break down more quickly than others. But often they, even the ones that do break down more quickly, break down into often smaller versions of PFAS. And they often find their sort of smallest, most stable form. And that persists in the environment for a long time. And what do we know about where they've come from? It sounds like a lot of different sources because they have so many different uses. Yeah. So they are used in industry as an ingredient, as part of a process. And so they can come out of industrial facilities. Some PFAS can get into the environment via wastewater treatment plants or landfills where they may have accumulated, especially in the case of old landfills. Historically, our landfills weren't as well contained. They weren't well lined. And so they can leach out into the ground. And so just briefly, because we're going to come on to this in a bit more detail, but what is the UK government's PFAS plan? What are they proposing? The PFAS plan has a pretty comprehensive overview, actually, of the different issues with PFAS. Basically, it's trying to look at where PFAS comes from, how it moves around in the world, in the environment and supply chains. And then ultimately, are we exposed to it and what can we do about that? And you mentioned there, Stephanie, we're learning more about the sources of PFAS in our environment all the time. So just yesterday, we had some new evidence published about a huge increase in the release of one particular forever chemical called TFA. Lucy Hart at Lancaster University led that study. Basically, wherever we look for TFA, we find it. But the reason we were interested in the CFC replacements is actually from evidence from ice cores in the Arctic. These are ice cores that aren't influenced by any other sources other than atmospheric deposition. and the trend of increasing TFA seen in these ice cores since around the 1970s matched the increasing use of CFC replacements. CFCs caused the hole in the ozone layer, so these were replaced with HCFCs, which still caused some ozone depletion but less than CFCs. Then they were followed by HFCs, which protected the ozone layer but are potent greenhouse gases. Now, these are being phased out and we're on to HFOs, which aren't greenhouse gases, but they produce this forever chemical TFA at a much quicker rate. So we found that over the study period, which was 2000 to 2022, TFA production from CFC replacement chemicals had increased three and a half fold over the study period. From these sources alone, we could explain almost all of the TFA deposited in the ice cores. We've been through this series of substitutions where we substitute a gas before we look into its impacts. I think this is something that's important to look into with HFOs before their use becomes too widespread. A lot of acronyms in there, but that seems to kind of sum up the replacement of one chemical with another. So what do you make of this research, Stephanie? So this is something we call regrettable substitution, which is where you get rid of one hazardous chemical or material and you instead use a new one that ends up also having issues. Sometimes they may have the same issues. Sometimes they may have different issues, like the researcher there mentioned. So we need to take a broader look at how these changes, these substitutes may affect also sustainability how they may affect human health how they may affect the environment and try to make a more informed choice so we don end up with this same problem cropping up every five or ten years when we discover the next thing Thank you Stephanie Metzger And as you said, this is just the start, so we will be following the story closely. Time now for our global science guru, Roland Pease, who's been scratching heads with astronomers puzzling over some of the most distant things ever seen. A select group of astronomers have been huddled in a workshop this week in Bern, Switzerland, to debate a newly understood kind of object detected by the James Webb Space Telescope at the edge of the universe, dating from within the first billion years after the Big Bang. Objects, which showed up in some of the first of the JWST's images. I mean, we all got these images from JWST, and then you just start looking at what is there, right? and then you start searching for things that you could not have seen before. And then you stumble upon this weird class of objects that we now call little red dots. Anna de Graaf is among those attending who, for the past year or so, has been pushing a particular interpretation of these intense but featureless points of red light, that they're black hole stars. More of that in a moment. Though more conventional explanations were tried first. We probably remember there was a big hype over people finding ultra-massive galaxies in the early universe that would break our cosmological model and be in tension with all sorts of models. And we now know that these are little red dots and that they are actually probably a completely different phenomenon. But yeah, that's part of the whole sort of origin story for where we are now. Ultra-massive galaxies could produce the right amount of light, but where would all the stars come from so soon after the Big Bang? Also, where had all the bluer parts of the spectrum gone? Quasars like we have in more nearby galaxies, supermassive black holes fed by in-spiralling gas and shredded stars were also an option, but faced similar objections. Aneta Graf has been running a programme called Rubies that breaks the light from these little red dots into different wavelengths in the hope that the spectral details would make up for the lack of spatial information. And she was right. Yeah, in the past year, I think the key discovery has been that we found some really extreme little red dots. So one of them is the cliff. And what is so extreme about these sources is that their spectral shape is very different from any other galaxy or black hole that we know of. So this is, again, the intensity of the different colors is unlikely. Yes, exactly. And what is peculiar about this, so why it's called the cliff, is because it has almost no blue light. And then all of a sudden it shoots up. And so it has a very sharp transition like Eclipse. Is that saying that some of the light has been absorbed? Yeah, so what it's saying is that this feature actually comes from, it's a feature of hydrogen. So hydrogen gas that's very dense can essentially absorb light up to a certain wavelength. So what, you're saying that it's a black hole and then there's... And then there must be some very, very dense hydrogen gas around it. Yeah. And what was unique about this source actually is because it was so extreme, We could actually, for the first time, rule out all these swaths of models that we had been considering before. For other little red dots, they're less extreme. I mean, hydrogen is the main gas which is produced at the beginning of the universe. Yes. I guess there would be a lot of hydrogen around in the early universe. And that presumably is part of your story. Right. Yeah. So, I mean, the fact that there is hydrogen gas is not surprising, maybe. But what is surprising is how dense it is, right? It's not quite at the density of an actual star like our sun, but it is not very far off either. And so it is much, much denser than any gas that we see, for instance, in the Milky Way and like star forming regions. And so it is very different in that sense. I mean, you've been calling them black hole stars, which I understand to be a bit of maybe a confusing term. Yeah, the reason for that is not entirely unjustified. so what happens we think is happening is that you have something in the center which is most likely an increasing black hole just because it's so luminous and this increasing black hole can be embedded in this atmosphere of very dense gas and similar to a star right which also has a source of energy in the center that energy is then absorbed by the gas around and then this gas begins to glow And that is sort of the star part of this picture. Of course, it is radically different from a star, because in a star, we think nuclear fusion is happening in the center. But the analogy is really in the sense that you have this glowing ball of gas around it that's actually powered by this black hole in the center. And when you say it's accreting, what you're saying is it's swallowing material onto its surface? It is swallowing material, exactly. And that material would presumably be the inside part of this hydrogen gas, but you may not know that. What it looks like is a major unknown, I should say. So the key thing is that this ball of gas is similar to the sun, right? We cannot look inside the sun. We only see the outer layer. And so it's very hard to tell what's actually going on on the inside. So we think that somehow there must be the gas accreting onto the black hole in the center. And so some people suggest that this strange configuration allows for extremely rapid black hole growth. That this could be a phase of essentially very, very rapid black hole growth, which is important in the overall stories of how, you know, supermassive black holes form in the first place. Well, which is where I was going to take this conversation. I mean, do you have any idea of the mass of the black hole that's causing all this roaring energy? We did a poll this week and let's say there's no concept. Well, yeah, it varies a lot. And so I think most people feel comfortable by saying it's roughly a million solar masses. So that's pretty big. That's quite a lot of it. It's certainly large, right? And so these objects are very, very luminous. And so they're a billion times, 10 billion times more luminous than the sun. And so there's a lot of luminosity in the systems. And so it has to be something relatively massive. But like I said, so all we see is the outside. And we might understand what the mass is of the overall thing, but we don't know what actually is in the inside. And so, yeah, the most extreme suggestions in the room were you could either have just a thousand solar masses in there, or there are people claiming a hundred million solar masses. And so that is quite a range. And given that you're at this workshop with, I don't know how many other people talking about this, I presume amongst astronomers, this is pretty exciting. And I don't know, what's been the most interesting aspect of the debate you've had this week? Well, the most exciting aspect is that we build a 10 billion dollar space telescope, and you hope to find something that you've never seen before. And the fact that we found a new phenomenon that we truly do not understand is just incredibly exciting. So that is the main excitement. It's actually like figuring out this puzzle. And we might have heated arguments, you know, on the details, but it's actually the fun of it. I think it's the start of essentially a new field. And I think we do realise that we had, you know, over dinner last night, had some discussions that it is a very special phase to be in. It's almost a shame if we figure out what it is, because it's actually part of the thrill is like the unknown. Anna de Graaf, a clay fellow at the Harvard Center for Astrophysics, about to take up a post at the Max Planck Institute in Germany with some... I know you want to listen to your podcast so I keep it short Because if you think it important to make a duroze choices can ASR maybe help Well, I think, how then? Well, for example, when you're doing a lot of things that are you love to do. Will you know more about the insurance where a duroze schade is possible? Go to asr.nl slash duurzamekeuzes. This does ASR for you and a duroze. ASR does it. So, we can now listen to your podcast. on bbc.com or wherever you get your podcasts. Think phenomenal in the cosmos to keep her busy. You heard it here first. Thanks, Roland Pease. A reminder, you're listening to Inside Science from the BBC World Service. The 2026 Winter Olympic Games are upon us, hosted in Milan, Cortina, Italy. When it comes to world-class mountainous sports, there's some important chemistry involved in the art of sliding on snow. Between snow and ski there's a layer of wax specifically developed for each sport and even for each type and temperature of snow. For competitors at this level the right wax can mean the difference between a medal and an early exit. In a moment we'll hear directly from the head coach of Team GB but first for some insight into the fundamental science of ski wax I spoke to Jostain Vinouet, manager of the British cross-country team and wax expert. What's actually in that substance that's speeding things up, that's reducing that friction between ski and snow? We can say that the most important is always the ski itself can be as decisive as 75 to 80 percent of the glide we're doing them and then we are able to manipulate the last 20 percent. A typical glide product now, it looks almost like a candle in substance when you hold it but then you melt it on the snow and some of them are made so hard that they are crushed into small pieces that have to be applied on the ski with a wax iron on high temperature. But what's in them, there are different types of things. There are like hydrocarbons and it's used in silicone. We have, for instance, Vaseline. Teflon can be used. And then you use different types of waxes like Harpix and other polymers to adjust the quality of it, how hard you want to have it and what temperature point you want to melt it on the ski. Because some products we have to melt on, like say 140 degrees with an iron but others are up to 200 degrees. Talk me through then you have an unwaxed ski and that sort of hits the snow and there's a certain amount of friction between that surface and that snow. What's the wax then doing? How is it changing that contact that means that that skier can ski faster? When you ski on the snow the snow melts under the ski. It will be creating a kind of a film of water between the snow and the ski and we want to have a product who can get rid of the water as easy as possible that is different from cold conditions to wet conditions in cold conditions you want to make like a dry surface as possible and very smooth and use hard products what many some teams do but especially like the biggest and best teams do they they make their own products products you can't buy on the on the open market it is the competition outside of the tracks as well. Thank you to Jostine Fenway there. I also managed to talk to Pat Sharples, head coach for GB Snow Sports, just before he flew out to Italy. At the higher level, getting the waxing right, especially in the racing disciplines, is, you know, the real difference between winning or losing or even just being on that podium. It's absolutely key factor. And that's why we do employ some of the best wax technicians in the world to come and help us, support us to do this. And what does that mean then getting the waxing right? What are the differences for different disciplines, different conditions? There's so many different types of wax and the few key factors you're looking about when choosing to pick the selected waxes that you need is the different conditions, weather conditions, but mainly the temperature and snow conditions. There's lots of different types of snow. You know, you've got the wet sleety snow, you've got the very dry, cold, crystal snow. And then you've just got the rock solid ice. So when we're at a competition, our technicians are very much monitoring all of these different conditions. And then that will help them select which waxes that we'll use to put on the skis and snowboards. So can you give me an example? Like what would be the difference between a wax that you would use if you were doing a downhill on solid ice as opposed to if you had light fluffy snow and you were doing cross-country skiing? If it was solid ice and it was very, very cold conditions, you would use harder wax, but it takes a lot more time to actually get to go onto the base. As soon as you put it on the base, you're wanting it to soak in so the base absorbs that wax and it's going to last for that whole entire run. If it's more warmer, slushier conditions, this is where you'd get an ultra soft wax and it just glides so easily the other thing as well we know that even on certain length courses that the conditions can change from the top to where you're going to get at the bottom so our technicians sometimes put double layers up or even triple layers of different waxes in to kick in at certain stages and and of course we're seeing even the snow itself change the the conditions are changing with winter sports with climate change they're becoming more unpredictable but we're also seeing the use of more artificial snow what's the difference there and how do you adapt to that when it comes to to wax um again with with the artificial snow now you find that it's much harder and the snow it's more hard pack than you know your sort of soft wetty sleety type of snow a lot of the racers prefer that you can get a better edge grip into that as well tends to be a colder snow which again would you sort of opt for those harder waxes however again what we're seeing like you mentioned as well with climate a lot of the snow especially on lower resorts now tends to be wetter warmer sort of temperatures with more sleetier snow and again the bigger factor we've sort of seen as well is a lot of people say you know it doesn't seem to snow as much now in the mountains and things as it used to because of climate It actually does. It's just that lower down, the ground isn't as hard-packed or as cold. So the snow tends to melt much quicker than say it would do in the past. What else are you seeing in terms of the impact on winter sports and on, you know, at the highest level where you work and climate change? I say in alpine skiing we noticed it more over the last couple of years because there been some of the legendary World Cup competitions that have been on lower slopes You know you can bring up all the fans people can go up there create that sort of big party atmosphere to support the athletes And we're seeing those lower resorts get affected by it more. Because as I mentioned, you know, the ground just doesn't seem to freeze as hard as it used to, so the snow will melt quicker. Now, it's an incredibly busy time for you, so I won't keep you too much longer, Pat. But can you just give us some tips about who, what to look out for during these games people to to look out for is one of our senior alpine athletes mr dave riding who won kitsbuel a few years back and this is going to famously announce that this is going to be his last games um he's going to be competing in the slalom we've got andrew musgrave competing in cost country and then in our freestyle disciplines there's so much talent here we've got the likes of mia brooks kirstie muir from park and pipe ski and snowboard as well as zoe atkin who's the current world halfpipe champion. So, yeah, there's so much talent right across the board with a lot of, like I said, senior and experienced athletes as well as some really new up-and-coming athletes. Fantastic. Thank you very much indeed. Have a brilliant Winter Olympics. Thanks so much. Thanks for having me. Thanks to Pat Sharples and Jostine Venue there from Team GB. And for fellow scientific nomenclature nerds, the science of friction and lubrication is known as tribology. Good luck to all of the tribes competing in Milan. We will be tuning in. And Gareth Mitchell has been sitting patiently waiting to bring us the highlights from the plethora of research published this week. Hello again, Gareth. What have you got for us? All righty. So we're going to start in Finland, where they are thinking through how to make things better for emergency vehicles. So they have to go very fast, obviously. They have to do so safely. What they're doing, ingeniously, is putting together some technology that makes sure all the traffic signals that are along the route of the emergency vehicle, that the lights turn green at each of the intersections as the vehicles approach. Ah, how are they doing that? So what's going on is that this is FinTraffic, which runs traffic control and management in Finland. They've been telling me that the technology involves a number of different components, including transponders on the emergency vehicles. So they're only activated when the blue lights are on. But when you have a blue light situation, the transponder transmits the vehicle's location to the centralised traffic management system. And so from there, then, a whole load of very clever software then sequences the traffic lights to create what they call a green wave. You know, it's a very satisfying wave of green lights that just open up in front of the emergency vehicles. But, of course, the other thing that has to happen is making sure that the opposing vehicles stop and to stop in time. You know, you can't literally just have lights just turning red all of a sudden because it's going to cause chaos. So because they have this transponder system that can give the traffic management computers enough warning of the vehicle approaching, it means there's plenty of time to gradually turn the light red at the intersections so that opposing vehicles can stop safely to allow those emergency vehicles to power on through. Clever and seamless. In a very different ecosystem, I have been focusing quite a lot in the past couple of weeks on unexpected prey for predators. So last week I looked at a story about polar bears eating walruses and other things in an area where they were losing sea ice. This week there's just been some research published about pumas eating penguins in Patagonia for all of the peas in this story. I think this is absolutely fascinating. So this is an area of Patagonia which has been inhabited relatively recently in the last sort of 100 years or so by a population of megalanic penguins. And they've moved in there after being sort of on these offshore islands because there are no predators there or there were no predators there. Now a conservation mission to basically bring back and conserve the puma has changed that situation completely. So the pumas have come into these colonies and are killing the penguins. It's the first time that these two species have met. And apparently the pumas are doing quite a lot of damage. In this study published in the Journal for Nature Conservation, the researchers found that over a period of about four years, the pumas had killed 7,000 penguins. And of course, the penguins are fairly easy targets because they're ground nesting, they can't fly, they don't really have any defences against the puma. So it's this fascinating sort of accidental rewilding consequence, I suppose. Yeah. What is it about animals beginning with P, like possums in New Zealand? P animals, they're troublemakers, aren't they? They are indeed. But what else do you have for us finally today, Gareth? Well, this is fascinating. It's apparently the world's smallest programmable autonomous robots. And I must say, if I'd had a pound for every time that I hear the world's smallest on a press release. I was going to say, that needs fact-checking, doesn't it? So is it the world's smallest? Well, I haven't found anything smaller, put it that way. So in all seriousness, absolutely remarkable. This is researchers at the University of Pennsylvania and University of Michigan. And they've come up with robots that are 0.3 millimetres in length, 0.2 millimetres wide. So for context, it's about half the size of a grain of sugar. Wow. OK. And why? The idea is to come up with little robots that are able to move around in the human body. And that might be to deliver drugs, for instance, to tumour targets or other targets within the body. And even when I hear the word robot, I can't help thinking of something with arms and legs and looks a bit humanoid. This obviously is nothing like it. It's basically like a tiny little chip. You know, imagine like the chip or the circuit board in your phone. This is a tiny version of that. and on this little circuit board there's just enough room for some sensors that can pick up temperature for instance so they can direct the robot to maybe warmer or colder parts of the body and then like a processor that takes up most of the power on this little board but then fascinatingly, because I was thinking well how do they move because they can't have little flippers on them so on this little circuit board it creates tiny electromagnetic fields that interact with the solution in which the robot is in inverted commas swimming And it interacts with the fluid in such a way that the electromagnetic field causes like an equal and opposite physical, like mechanical reaction that basically allows the robot to move around and swim and get to where it needs to be in the body. Fascinating and clever. Gareth Mitchell, thank you so much for bringing us some technological solutions and do come back soon. I'd love to. Thank you. And that is all we have time for this week. I'll be back with you next week. See you soon. This is not the future we were promised. Like, how about that for a tagline for the show? From the BBC, this is The Interface, the show that explores how tech is rewiring your week and your world. This isn't about quarterly earnings or about tech reviews. It's about what technology is actually doing to your work and your politics, your everyday life. And all the bizarre ways people are using the internet. Listen on BBC.com or wherever you get your podcasts.
