Banging the science drum

This BBC podcast is supported by ads outside the UK. It's time to see what you can accomplish with Shopify by your side. Bingo. BBC NL. The place for the best British misdaad series. This week I spent one of the coldest, wettest and gloomiest days of the year so far sitting on a fallen tree in the middle of a woodland. And it was glorious. Although I should say that the tree trunk had been carved into a bench and the bench was inside a wood-fired sauna cabin, which kept us very, very toasty. Armed with a wheelbarrow full of logs, we stoked the roaring fire while taking in views of the forest outside. And for the next few hours, we fell into an almost addictive rhythm, cooking ourselves for as long as we could before jumping into an icy stream to cool off, and then repeating the cycle all over again. I'm Anand Jagatia. From the BBC World Service, this is Unexpected Elements. As always on Unexpected Elements, I'm joined by panellists from all over the world. And first up today is science journalist Sandy Ong in Singapore. Hi, Sandy. Hello, hello, Anand. Ni hao. And in Bengaluru, India, is science and technology journalist Ed Gent. Welcome, Ed. Hi, Anand. Namaskara. Namaskara. Now, Unexpected Elements is the show that takes a slightly offbeat approach to what's in the news right now. Each week we scour the headlines for stories that give us a window into some fascinating science. And then we play Connect the Dots to link them all together, probably in a way you didn't expect. And here's what inspired us this time. Japan's Prime Minister, Sanai Takeichi, and the South Korean President, Lee Jae-myung, have put on a surprising display of unity by playing the drums together. Ms. Takeuchi thought this was a great idea. You can see them putting on these two matching shiny blue jackets. This was a surprising display of friendship between the two allies whose partnership often runs into snares. This is something that the people from both countries are very happy to see. Yes, this is the story that a diplomatic meeting between the president of South Korea and the prime minister of Japan went viral this week after the two leaders ended proceedings by performing a drum duet, banging out the rhythms to various K-pop hits. And what I love about the clip, if you watch it, is that the Japanese PM, Sanai Takeichi, apparently used to be a drummer in a heavy metal band and obviously knows what she's doing, looks very cool, while her South Korean counterpart has clearly just picked up a pair of drumsticks for the first time and is something of a novice. But you have to hand it to him for trying. and as he posted later on X, even if our timing was slightly different, our intention to find the same rhythm was shared. Some words for us all there. And rhythm is our theme for Unexpected Elements this week. That drumming session got me thinking about the drummer of the bird world, woodpeckers. Woodpeckers are headbangers in the literal sense of the word. Why exactly do they do this? Why do they peck wood? That's a great question, because at first glance, woodpeckers look like they're just slamming their heads against a tree trunk, right? But actually, they do this for a number of reasons. To look for yummy insects to eat, to create cavities for nesting, or just to communicate with each other. Now, woodpeckers can pet wood up to 20 times each second, which means that their heads are moving at around 20 kilometres an hour. They are huge numbers, and I'm imagining they generate lots of force in these collisions. does that repeated impact do them any damage? It turns out their brains are perfectly fine from all that pecking. So how exactly do woodpeckers avoid getting a concussion? That is a question that scientists have been trying to answer for decades. One popular idea is that woodpeckers have a spongy bone between their brains and their beaks. And this acts like an airbag to absorb shock and cushion the brain from hard knocks. This theory actually inspired the design of things like football helmets and shockproof electronics. That's really interesting. So even though we don't actually know if they're using this sort of spongy shock absorber to protect themselves, we've still used that idea in our own technology. Yes, exactly. So for instance, there's an American football helmet with a special tight-fitting collar that appears to help prevent concussions in players, and that was inspired by the woodpecker theory. But like you said, it's just a theory. And one biologist, Sam van Wassenburg from the University of Antwerp in Belgium, wasn't convinced by this explanation. So in 2022, he decided to study woodpeckers in a way that's never been done before, using high-speed video. So Sam teamed up with a bunch of different biologists and they went to four different zoos in Europe where they filmed six woodpeckers. So this was two birds each from three different species. And in total, they collected 109 high-speed videos. That's a great idea for an experiment. And I would love to see those slow-mo videos of woodpeckers. What did the footage reveal about their biology? Yeah, so the videos are actually available online. So I definitely would recommend checking them out if you had some time because they're pretty cool. But yeah, the video showed some remarkable details. So for example, you can see that the birds actually close their eyes at the moment of impact. And this is to protect themselves from any splinters that might jump out at them. But perhaps the most interesting thing is that the woodpecker's heads remain stiff upon impact. So it's a bit like what happens when a hammer hits a nail. In other words, the birds' heads don't come to a stop any slower than their beaks. Now, if you compare this to what happens when a rugby player rams into his opponent, his head comes to a stop, but his brain continues moving forward. So the brain compresses in the front, but stretches out at the back, which is why you get brain damage or a concussion. But for woodpeckers, deceleration happens at the same speed in their beaks and brains. So that means that the spongy bone isn't actually providing any sort of cushioning effect. And what's amazing is that this deceleration is five times higher than what it would take to cause a concussion in a human brain. That's just unreal, isn't it? So how, if they're not using this cushioning effect, how are they able to withstand all of the force from those impacts if just a fraction of that would knock one of us out? It turns out that the answer lies in their tiny size. And basically, biomechanics states that the smaller an animal's size, the greater the deceleration it can withstand. So think of how a fly hits a window, but it manages to pick itself up and shake it off and fly away again. Now, if a bird hit that same window, it would probably suffer some injuries at the very least. Yeah, that's a good point, actually. I mean, if I ran into a wall at 20 kilometres an hour, I don't think I'd be carrying on with my day. So what are the numbers then for the woodpecker in terms of the force that they experience? Yeah, same for me. I would not be carrying on with my day either. But for the woodpeckers, basically their brain is about seven times shorter in length compared to a human brain. And that means that they can withstand forces seven times higher than what humans can. And when Sam and the team used a computer simulation to calculate what it would take for the woodpeckers to actually suffer a concussion, they found that the birds would have to hit a tree at twice their current speed. And coming back to the original theory, the spongy shock absorber bone theory, do we think that that is just not what they're doing and it's just this size factor that's protecting them? Yeah, so this team of scientists concluded that the shock absorption theory is wrong. In fact, they said that if any cushioning was going on, the birds wouldn't be able to exert as large a force as they do. So think of it like if you're trying to hang a painting on a wall, but you put a pillow between your hammer and the nail. It just makes everything less efficient to have that shock absorber there. Yeah, I think putting it that way makes you realise that, you know, for an American football helmet, the aim is to reduce the impact. But woodpeckers, they want to achieve maximum impact right for them to actually you know find their food or or make a home for themselves yeah exactly yeah well what a cool story thanks for sharing that with us sandy now we're going to move on from brains taking a beating to brains generating a rhythm all of their own and ed you've got another story for us yes there's a new study which shows how brainwave rhythms impact your perception of your own body so anand have you ever really thought about what makes it feel like your hand is your own if you go and touch something that's just in front of you how do you know kind of whatever you're touching is from the outside world and not part of your body yes good question if i touch the microphone in front of me you can hear that but i mean i can tell that's not part of me but i don't really know how i know that well so that feeling it turns out is because of brainwave rhythms so it's something that we take for granted every day but it's also something that can be easily disturbed, such as something known as the rubber hand illusion. This sounds a bit like a magic trick. I'm always on board for a magic trick. Tell me more about it. Yeah, so it basically is a magic trick that psychologists sometimes play on their subjects. So basically, the idea is that the person's real hand is hidden from view, sometimes in a box, and then a rubber hand is placed kind of in full view where they would expect their hand to be in front of them and then both the rubber hand and the real hand are either tapped or stroked at the same time and when you do that it can begin to feel like the rubber hand is your own but when the timing is kind of not synced up properly then that feeling starts to fade and that's because your brain's sense of body ownership relies on integrating lots of different sensory stimuli in particular kind of visual and tactile information which is kind of what you can see and what you can feel so if you sync up the feeling of being tapped on your real hand with the visual cue of the fake hand being tapped then the brain gets confused and assumes that they're linked i think i have actually seen videos of this um listening to your description and what i've seen is where the experimenters take a hammer and basically smash the rubber hand with it and people get really freaked out because they've they've been tricked and thinking it's their real hand but obviously it's not yeah yeah yeah i'm not entirely sure how they managed to get that passed the ethical review board. So what was this new research looking into with this illusion? They were linking this to some previous research which has shown that the accuracy with which people can judge the timing of sensory signals is linked to the speed of alpha brain waves. So these are electrical patterns of brain activity that often appear when the brain is alert but relaxed. So when you're kind of in idle mode basically. So they subjected 106 people to the illusion while they simultaneously measured alpha brain waves in the parietal cortex. What is the parietal cortex? Remind me. That's the part of the brain that's responsible for processing things like touch and other sensory information. And what they did in this experiment was that they manipulated the timings of the taps given to the real hand and the fake hand by adding either a delay or an acceleration of up to half a second and then they asked the participants whether the rubber hand felt like it was their own and so how well did people figure this out so the frequency of alpha waves can vary from person to person and what the researchers found was that those with faster waves saw through the illusion more easily so they were more likely to be able to tell that the fake hand was not theirs when there were slight delays or accelerations in the frequency of the taps. And then they also, just to establish that this correlation was due to the alpha waves rather than something else, they also used non electrical stimulation to artificially increase the speed of participants alpha rhythms And then again they found the same result The faster the alpha waves the more precise the sense of body ownership That last part is really interesting So could potentially manipulating people's alpha brainwave speed in this way actually have some benefit in the real world, apart from just, you know, telling if a rubber hand belongs to you or not? Yeah, I mean, obviously it's early days, but I think the researchers suggested that it could potentially have important implications for conditions like schizophrenia, where sometimes the sense of self is disturbed. And these patients often have alpha waves that are lower frequency than the general population. And they also suggested that it might help with the design of better sensory systems for either prosthetics or, if you're into gaming, more immersive virtual reality. Very cool. Thank you, Ed. And thank you, Sandy, as well, for taking us through those stories so deftly without missing a beat. Coming up, we'll be hearing about the healing power of rhythm. That's after this. Hello, I'm Sophie and it's time for the Unexpected Elements quiz. This week, we're talking about the unexpected science of rhythm. In 1823, a German beekeeper noted how bees indulge in certain pleasures and jollity, but that what this dance really means I cannot yet comprehend. The bewildered beekeeper was referring to what scientists now call a honeybee's waggle dance. So, I want to know, why do honeybees do a waggle dance? Is it A, to communicate distance from a food source, B, to spread scent, or C, as a mating call? Why do honeybees do a waggle dance? Is it A, to communicate distance from a food source, B, to spread scent, or C as a mating call? Have a think. I'll be back soon with the answer. You're listening to Unexpected Elements from the BBC World Service. I'm Anand Jagatia. We started off this show with a diplomatic drumming duet and then explored how the drummers of the bird world, woodpeckers, stay safe from concussion, and then how the rhythm of our brainwaves helps us to perceive our own physical bodies. And now we're jumping into the way rhythm can be used as medicine. Here to explain is neuroscientist and musician Daniel Levitin. Welcome, Daniel. Thank you for having me. So, Daniel, you've written a book called Music as Medicine, where you describe how music can have a therapeutic benefit. And on this show, we're focusing in particular on rhythm. So are there conditions where rhythm can be of help to people? There are. And maybe the easiest one to wrap your head around is Parkinson's disease. At some point, many Parkinson's patients lose the ability to walk because the disease attacks structures in the basal ganglia of the brain that are required to coordinate movement in a particular order and at a particular time, which is what walking is. You can't have both legs up in the air at the same time. Or in the case of Parkinson's, when this timing circuit becomes degraded, they freeze and they can't get started. And we found that playing the music that has the tempo of their natural walking speed, their gait, allows them to walk again. Whether you know it or not, whether you're a musician or not, whether you think you have a sense of rhythm or not, there are clusters of millions of cells in the brain that automatically synchronize to the beat of music, to anything that's repetitive like that. They do that for free. And then the brain scaffolds on that, the realization that, oh, well, there's an external timer. My internal timing circuit's broken. I can use that. Then people start walking along with the music. And rhythmic auditory stimulation training, which is the therapeutic name it goes by, might be delivered 20 minutes a day for two weeks or so. And then the patients can walk for six weeks without any music playing at all. That's fascinating. So from what you're saying, it basically sounds like normally our brains have a kind of internal rhythm keeper that we use to do things like walking. And if that goes awry, you can basically outsource that to music. And I thought what was really interesting there is that after a while, you don't need the music anymore. You can still sort of improve your internal rhythm and your ability to walk, even if the music isn't playing. So there's two things going on there. One is that some patients imagine the music. They oralize it. They hear it in their mind's ear. And that's enough for them. But in other cases, the therapy has built up new neural capacity, made new connections. The brain is massively redundant. It's got all kinds of ways of doing things. And when one's damaged, another one can kick in. But you've got to figure out how to get those circuits online. And the whole process of the therapy stimulates neuroplasticity, growth of new synaptic connections. That's amazing. And does it matter what the music is, or can you pick any track? Well, it has to have a tempo that's your walking speed. If it's too fast or too slow, that ain't going to work. But it has to be music you like. And the reason for that gets to another brain structure called the amygdala, which is famously the fear center. When you're frightened, that's the part that goes crazy. If you play somebody music they don't like, it kicks in their fight-or-flight response. So, yeah, it has to be music they like. OK, so probably avoid drum and bass because it might be too fast and avoid lift music as well. There's slow drum and bass. And the other thing that you write about in your book is the effect of rhythm on stuttering. Can you tell us a bit about that? What's the neuroscience of having a stutter? So stuttering, stammering is a motor disorder also. Just as in walking, where you have to coordinate movements in a particular order, so do you with speaking. The lips, the tongue, the jaw, the larynx, the diaphragm, all these things are parts of your body that move in order to speak. And the motor cortex in the parietal lobe that Ed was talking about earlier has to send instructions to execute these motor movements in a very particular order and in a very particular time. And when there's damage to the timing circuit that governs all of this, people end up stuttering. They can't quite get the words out in the proper order. They stick on one word. It's really the conceptual equivalent of a Parkinson's patient freezing. But as soon as you give an external clock, like music, that frees up the timing circuit, replaces the damaged one. and what we've seen is many people who are stutterers can sing without stuttering. Elvis Presley famously was a stutterer, but not when he was singing. And there's the famous actor James L. Jones, who did the voice of Darth Vader in Star Wars and also Mufasa in The Lion King. Luke, I am your father. Yeah, well, he also had a stutter, right? He was a terrible stutterer and he approached all of his movie dialogue the way a sonata would, you know, approach a song. He had an internal rhythm to the way he spoke. You know, he was a Shakespearean actor, so he'd been trained in iambic pentameter and that particular rhythm. And that was enough to help him get through his lines. Daniel, this is also fascinating. Are music-based therapies currently being used in the clinics today? Is this something we see or is it still anecdotal at the moment? Oh, it's far more than anecdotal. When I wrote Music as Medicine, I wanted to write it 25 years ago, but the evidence just wasn't there. At that point, it was anecdotal. But a funny thing happened on the way to 2026. There's now 10 years worth of really solid and rigorous work. The studies have been done now with hundreds of thousands of people across different clinics, different kind of disorders and maladies. And it is being used in clinics, not just experimentally. In the United States, the state of New Jersey has private health insurance, and they cover musical therapies like the ones we've been talking about, or for depression or anxiety or post-traumatic stress disorder, multiple sclerosis, MS. The rhythmic aspects of music combined with the melodic aspects seem to promote the bolstering of the immune system. When we listen to music we like with a beat that we like, it's capable of increasing immunoglobulin A, helps to support fighting off infections of the mucosal system. It helps to release T cells, natural killer cells. I was just curious because, I mean, one of the things that I come across that seems kind of connected to this is this idea of binaural beats, which I believe is kind of where slightly different frequency tones are played in both ears. And this is supposed to have various effects, like kind of relaxing people and stuff like that. I was just curious whether that's something that is connected to the research you do or whether this is some hokey pseudoscience. A binaural beat is when you present different inputs to each ear separately. And you have to do it through headphones because if it was through speakers, the opposite ear would still get sound from the speaker. And you play a tone of a steady frequency in one ear and then tones of another frequency. And what you get is a kind of a beating sound because the brain not only hears the two tones, but the mathematical difference in their frequencies. and the brain will hear in addition to like, and it might hear, and it's believed by some that that woo, woo, woo part has therapeutic effects by helping us to create more alpha waves or beta waves or theta waves or gamma waves. At this point, it's a hokey pseudoscience. I mean, there might be something to it and there are a number of labs looking into it. The results have been mixed. it's all very speculative at this point but it sure is a cottage industry well daniel that's all been absolutely fascinating thank you for sharing all of that with us and well i guess confirming that music really does have healing powers thank you for having me so we've gone from how drumming can help diplomacy to how music can be medicine and to get there we've looked at the headbanging of the woodpecker and the electrical rhythms of our brainwaves. Still to come, a potential change to the fabric of computing history and how the human body clock is affected by long-distance travel. Starting a business can be overwhelming. You're juggling multiple roles – designer, marketer, logistics manager, all while bringing your vision to life. Shopify helps millions of business sell online. Build fast with templates and AI descriptions and photos, inventory and shipping. Sign up for your one euro per month trial and start selling today at shopify.nl. That's shopify.nl. It's time to see what you can accomplish with Shopify by your side. Just on your own TV. This is Unexpected Elements from the BBC World Service, the show that looks sideways at the headlines to bring you the science you didn't realise was there. I'm Anand Jagatia in Cardiff, Wales, and I'm joined by... Dandy Young in Singapore. And Ed Gent in Bengaluru. Now, as science journalists, the three of us consume news stories at a pretty high frequency, and often one of us will come across something that's flown under the radar a bit that we think deserves a bit more attention. Sandy, you've brought this week's story. Yes, I have. And here's a clue as to what it is. Okay, that's quite intriguing. I can't tell what that is. It does have a rhythm. Yeah, tell us. Yeah, it does have a rhythm. You might need to stretch your imagination a bit. So basically, I have a story about what could be the world's oldest computer. So when we talk about the world oldest computer many people point to the machine created by the English mathematician and inventor Charles Babbage in 1837 But last month China largest official scientific body the China Association of Science and Technology contested that claim, saying that the recognition should go instead to a device which dates back to 150 BC. Wow, okay, so that would make it more than 2,000 years old. And is this ancient device what you just played us the audio of? So the device I'm talking about is actually a sophisticated silk weaving machine. And yes, the audio was the sound of a weaving loom, though not this particular 2000-year-old one. So the Chinese loom was unearthed in 2012 from a Western Han dynasty tomb that was discovered by accident when workers were constructing a new metro line in the city. Chinese authorities called this machine Ti Huozi, which translates to figure loom or pattern lifting machine. This is essentially a type of weaving loom designed to create complex patterns and designs in fabrics. So instead of getting plain weaves, you can do lotus flowers, dragons, phoenixes and all sorts of cool geometric shapes. I love that they just discovered that while they were digging a metro tunnel. But how can a silk weaving loom be a computer? So by definition, a computer is any device that can receive instructions, execute a program and provide results. So this could be for complex mathematical equations or for automatically carrying out certain tasks and so on and so forth. So when you think of a computer program today, you immediately think software. But a program can also take the form of pattern cards or punch cards, which are these stiff pieces of cardboard that have a whole bunch of rows and columns. And there are holes punched into specific patterns that carry instructions to tell the computer what to do. It's basically what coders used in the early days of computing, and that is somewhat similar to how the Chinese loom worked. So let's unpack this a little bit. I know very little about weaving apart from the words warp and weft, and I have no idea what they mean, but they are fun to say. Does that have anything to do with what we're talking about? Yes, it does. So there are two basic components to weaving, the warp threads like you mentioned, which are the vertical threads, and the weft threads, which are the horizontal ones. And what a weaver does when he or she sits at a loom is to lift up the warp threads at specific positions to let the shuttle of the loom pass through with the weft threads. And it's this interlacing of the two threads and the sequence of lifting and lowering that creates patterns on the fabric. OK, and so these pattern cards that you mentioned for the loom, are they what defines the pattern of the crisscrossing of the warped and the weft fibres? Yes, it is. So a craftsman would first design a pattern, and these design instructions would then be translated into physical pattern cards using knotted threads or bamboo strips. So these are analogous to the punch cards that we know today. So this is the so-called process of programming the loom. These pattern cards were then strung together to form a long chain and mounted on top of the loom where they cycle through using a pole system. So during weaving, the holes in the cards would be read by a series of needles or hooks which slip through the holes and grab or lift up individual warp threads during each pass of the shuttle. It sounds very complicated and intricate, but I can get what you're saying with the computer comparison. So these pattern cards are kind of like software with the instructions and then the loom is the hardware that executes the instructions. Exactly. You can see it as a binary code. So a raised warp would be equivalent to a one, and a lowered warp would be a zero. So the entire fabric pattern transforms into a sequence of ones and zeros. And this mirrors the binary principle, which is the basis of modern computing. So the Chengdu machine was really impressive because it used 10,470 vertical warp threads, which controlled more than 9.6 million intersections with the horizontal weft threads. And once programmed, it could operate simultaneously on 100 devices. So as a result, you get these intricately woven silk patterns with perfect precision. And scientists say that these figured looms help to mechanise the whole weaving process, which is what contributed to China's rise as the world's dominant silk production centre. It's amazing to think that they were doing all of that more than 2,000 years ago on these machines. Ed, you're a tech journalist. What do you make of this? Do you think that machines like that are computers? Yeah, I guess anything which is kind of using a program to manipulate information, I guess, would count. And if you look back at the early computers that we consider computers today, they probably weren't doing much more complex than that. So, yeah, I would say so. Nice. Well, that certainly warped my view of ancient technology. Thanks, Sandy, for sharing that with us. And using slightly more modern computers than 2000 year old looms, we've been reading all of your lovely messages as they fill up the Unexpected Elements inbox. So it's time to hear some of our favourites. In a recent episode, we talked about randomness. And this prompted Liz in London to tell us about her way of using randomness in everyday life to her advantage. Hi, Unexpected. I really loved your section on randomness and how hard it is for humans to be random. And it made me think of a way that I love to use randomness whenever I'm faced with a big life decision, like what job to take or where to send my kids to school or something like that. And I flip a coin. The coin is really random. So that helps with the decision. And what's really critical is to flip it three out of five times. Because when you flip it three out of five times, instead of just once, you learn when you kind of have two heads in a row that you start cheering for the answer. You know, you really either dread getting a third head, and maybe it's not what you wanted, or maybe you feel really relieved and really excited. So the purpose of the randomness is to really find out what it is that you actually wanted. And if you really have no reaction after you flip the coins, then great, you were truly undecided and can just go with a coin flip decision. And if it doesn't work out, you just tell people in the future, yes, I made that decision by flipping a coin. thanks liz that's a really great life hack and yeah the power of the coin flip method is that it reveals to you what you actually think it forces you to make a decision sandy ed do you have any techniques that help you to to make tough decisions do you just flip a coin if you need to make a choice no i i just get paralyzed by indecisiveness and uh and just let events overtake head in the sand great what about you sandy i'm a big fan of making a pros and cons list uh i find journaling helps as well just writing out all the thoughts in my head and sometimes speaking to trusted friends and families uh but i really like the sound of this coin flipping thing because i think it's a good way of tuning into your own intuition so yeah i might have to give that a go the next time awesome now a few weeks ago we also talked about the different roles that introverts and extroverts play when it comes to attending a party. But our listener Pam has taken some pretty decisive action about her own role at parties. Yes, here's what Pam wrote in. I'm one of the world's introverts, though I can cosplay extroversion if I need to, to fulfil a certain role. I was an educator all my working life, but I always needed solitude to recover my equilibrium. Parties, no role to cosplay, are torture, but as a young person in the 1960s they seem to be compulsory. At age 30 I had a revelation. Just because I'm invited doesn't mean I have to go. You asked about party strategies. I'm now 75 and for 45 years now my strategy has been thank you for inviting me but I don't do parties. I'd love to see you though. Could we meet for coffee, lunch a walk it works really well for everyone involved good for you pam yeah you know let's all just sack off going to parties that we don't want to go to in 2026 um ed sandy what about you guys if you get invited to something that you don't really want to go to do you just be honest and say look i actually just don't fancy it i'm not coming or do you sort of make up a lie and say oh i've got to go to the dentist i've got to like take my cat to the vet or do you just go anyway and just, you know, endure it? I think it depends how well I know the person inviting me. I think if I know them well, then I'll be brutally honest. If I don't know them very well, then I'll definitely come up with some kind of excuse. Nice. And Sandy? I think it's a mix of both. I feel like I'm too much of a people pleaser. So it's sometimes really hard to say no, but I'm trying to reform myself. Trying to follow the guiding principles of saying no to others means saying yes to yourself. It's easier said than done though. sometimes you find that when you actually end up going i mean you dread it and then you go and it's not as bad as you think and you do have a nice time sometimes so it's a bit of a mix that's definitely the case for me i think i tend i tend to just go even if i don't want to because like five like nine times out of ten you end up having fun anyway yeah okay well i actually don't i think we've actually we've made this issue a lot more complicated now we don't we don't have we don't have a um we don't have an answer for you probably just flip a coin i think it's probably is how we're going to end this um so and finally we've heard a lot from listeners who tune into the show to help them fall asleep which sounds a bit rude but luckily that isn't the case for everybody listener simon emailed us to say i'm really annoyed at you i can't sleep because you presented a piece on using your show to get to sleep it was too interesting to quiesce my thoughts. We also got a message from Laura seeing something similar. She says, I had to write in to say that my husband absolutely loves Unexpected Elements, and Marnie in particular. He also listens to podcasts to fall asleep. However, he has said that Unexpected is simply too exciting for bedtime. I thought you'd appreciate knowing you're not putting every listener to sleep. Thanks, Laura. That is good to know. And a couple of new taglines I think for our show there. Unexpected elements, too exciting for bedtime, and so interesting it's annoying. Thank you all very much for your messages. If you do have any stories, thoughts or questions that you'd like to share with us then we'd love to hear them. You can email us at unexpected at bbc.co.uk or you can send us a message or a voice note on WhatsApp at plus 44 330 678 3080. You can even go old school and write us a paper letter to Unexpected Elements, BBC World Service, Cardiff, CF10 4GA. Or if you have access to a 2,000-year-old loom, weave your message and send us the pattern card. Still to come, how flying messes with your body's natural rhythms. That's coming up after this. hello sophie here again earlier i asked you why honeybees do a waggle dance was it a to communicate distance from a food source b to spread scent or c as a mating call the answer is a to communicate distance from a food source when a honeybee returns to its hive after finding a plentiful food source it performs the waggle dance by moving in a figure of eight pattern The straight waggle run is the important bit. The angle of the honeybee's movement communicates the direction of the food source relative to the sun, while the duration of the waggle communicates the distance. The waggle dance was first decoded by Austrian ethologist Karl von Frisch in 1946, who later won the Nobel Prize in Physiology or Medicine for his findings. Well done if you got that right. Why not try your own waggle dance to celebrate? And if not, better luck next week. Up next is the part of the show where we drum up some answers to your science questions. It's time for Ask the Unexpected. This week's question comes from Jessica. Ed, do you want to read this one out? Sure. Sure. Jessica asks, why does a train's horn, or train itself, or any other vehicle's horn and motor, change pitch as it passes by? Yet there's no change in pitch when someone blows a horn when vehicles are still. That's a great question, Jessica. Thank you. Something we've all probably heard while we're out and about. Here is the sound of a fire truck going past to illustrate. You can really hear the pitch change there And to find out what going on we called up Dr Alistair Gunn from the University of Manchester and here what he said Drumroll please So this is a well-known effect. It's known as the Doppler effect. So if you imagine an object which is giving out sound, what's actually happening is it's making the air vibrate, and that vibration makes waves of pressure leave that object, And those travel through the air and eventually they'll hit your ear and you perceive that as a sound. Now, the pitch of the sound that you hear depends on the distance between those pressure waves. So if there is a long distance between those pressure waves, you hear a low sound. If they are much closer together, you hear a higher pitch. So now imagine this object is giving out sound waves and it's stationary relative to you. then those sound waves will propagate through the air and you hear the sound the same as you would if you were at the car it's just propagated through the air now the difference comes if that object is moving imagine that object is giving out these waves and then that object is moving towards you between each wave is giving out it's moving slightly closer to you which that what that means is that the wavelength of those sound waves is then shortened. So you will hear a higher pitch than the pitch that was emitted. If however the object is moving away from you, each time one of those waves is emitted the object moves further away so it stretches out those wavelengths. So the pitch you hear is going to be lower. So if that object is then moving towards you and passes you what you actually hear is a higher pitch because those wavelengths are squashed together as it approaches but then as it moves away those wavelengths are stretched out and you will hear a lower pitch and that's why these objects change in pitch as they go past you it's the thing with you know when little um little kids are playing with racing cars they go meow and that's exactly what they're doing they're doing what they actually hear which is the doppler effect as that object that racing car for example moves past you the high pitch becomes low pitch as it goes past you thanks Alistair for that explanation and thanks Jessica for the question I think the Doppler effect should now officially be renamed the meow effect listeners do you have a question that no amount of googling or chat GPT and can answer or maybe you just want to get a shout out on our show if so you can email us on unexpected at bbc.co.uk or send us a message or a voice note on whatsapp The number is plus 44 330 678 3080. Before we go, it's time for one of my favourite parts of the show, where I get to go through the BBC World Service archive to bring you a deep dive into a topic inspired by this week's theme. As a reminder, we started off this episode with the story of a drum duet between the leaders of South Korea and Japan. We jumped from drumming diplomats to pecking birds and then the rhythms in our brains. And that got me thinking about the other rhythms in the human body, known as our circadian rhythms, or our body's natural biological clock. And that led me to a recent episode of CrowdScience, where presenter Caroline Steele looked at how flying affects the body, including how it disrupts our body's natural rhythms to produce jet lag. To explain, here's Tracey Sletton, Senior Lecturer at Monash University in Melbourne, Australia. There are a lot of rhythms in our physiology, our metabolism, in our hormone production, our temperature. Many aspects of our physiology have circadian rhythms that are rhythms that are about 24 hours, about a day, effectively. And so when we travel to a new time zone, suddenly our circadian timing internally is at odds with the external environment. So your temperature rhythm versus hormonal rhythms are actually all mistimed. We call it internal desynchrony, where I guess if you think about it like an orchestra, when you have jet lag, they're all at different rhythms. so sandy ed we're all in different time zones from each other um and i imagine you have to travel as part of your job so how do you cope with flying and jet lag so one thing i definitely try to do is try to sync with the destination's time zone so if you land in the morning which i try not to do like landing at night but you know if you land in the morning try not to nap straight away try to stay up as long as you can and i also find that getting some sunlight or exercise really helps with the jet lag for me yeah no great advice and what about you ed uh i used to i used to kind of try all kinds of tactics and and stuff to to help with this but nothing seemed to really make a difference so now i just just don't think very hard about it and just be tired for a couple of days it resolves itself pretty quickly yeah just accept it's going to happen um well as part of that episode Caroline looked at a couple of things that you can do during a flight to avoid feeling rubbish when you land including the food you eat. If you think about the gastrointestinal system it's primed to receive food in the daytime so that's when all your hormones are there and all your proteases and everything that's breaking up food is active during the day and then your body conserves energy at night by slowing all those things down but then you put food into your system at the wrong time of day and it's all trying to cope. So some experts actually choose not to eat at all and then they're taking that sort of cue away from their body but also just the awful feeling of when you eat at the wrong times and so actually reducing the food that they have on flights they find actually helps them, which is interesting. That sounds awful because I think eating is the only small joy on a local flight. Yes, it's a fair point. so really you should avoid eating at weird times for your body clock when you're in the air to keep your internal rhythms on track but i'm definitely with caroline i'd definitely rather eat than optimize my body clock and actually i think i'm probably in the minority here but i like really like airline food i'm not really into it it's just like it's it breaks the monotony so much i'm always like oh a stale bread roll um what about you guys do you do you how do you feel about airplane food it kind of depends on the airline some of them some of them these days are not too bad i think but i think also i i'm kind of with you because i think the way they present airline food as well is in a way that i would kind of never eat a meal like they have all these kind of like little snacks and a bread roll and like two desserts and none of them are very good but it's quite a quite a spread that they put out for you yeah lots of variety how about you sandy i feel like for me it's it's swung both ways like i've had really bad airline food and really good airline food so not that I'm biased or anything but I think Singapore Airlines is one of the best food I've actually had chicken rice on a flight and that's like one of our famous dishes that's delicious um yeah but now I actually travel with a bag of snacks just in case this makes me sound like a very old person yeah you've become your parents yeah taking a pack on a on a flight uh yeah i i do think that like i think asian airlines in general the food is often pretty good um yeah middle eastern ones as well i think yeah yeah middle eastern ones i think are pretty good because like a lot of a lot of the dishes are basically just kind of um some kind of biryani type thing which just seems to seems to survive flights pretty well yeah it does i also uh a top tip is i always go for the veggie option because then they they serve you quicker they serve you first so just you know there you go that you can have that one for free um well um you know different airlines aside part of the reason why the food is often quite bad is that our taste buds don't really work very well at such high altitudes and that actually means that airlines often add extra salt to their meals to punch a bit of flavor in there but that in turn can of course dehydrate you which as we're about to hear is especially bad when you're flying here's dr tony shima an aviation medical specialist for the Royal Australian Air Force and a commercial pilot. Nearly everyone that flies could comment on feeling quite dry, feeling quite thirsty, brittle hair and nails. We're dealing with humidity levels of between 10 and 20 percent, which is sort of like a desert, right? Because the air coming in, being pumped into the cabin, it's drawn directly in from the outside. And at 40,000 feet, there's not a lot of moisture in the air, which is part of the reason why it's so dry. Most people, whether they admit it or not, may drink more alcohol, may drink more caffeine, and those are diuretics. So if you're adding those drugs to the mix, they're going to make your body lose more fluid than it normally wants to, essentially. From a physiological perspective, we want you to be drinking water, and in fact, increasing the amount of water that you would normally drink because the ambient environment, the cabin air, is so dry. There's a really good point. The air is so dry that you should avoid alcohol, caffeine, and drink more water than normal when you fly. But that is going to lead to some pretty obvious consequences, which is that you're going to need to pee, right? And there's nothing more awkward, really, than having to get up and go to the bathroom several times during a flight. You have to get your fellow passengers to stand up and then sit down again. And then again, when you come back, what do you guys think is the etiquette in this situation? Should you just not worry about it? Or should you try and be considerate to your passengers basically gonna say the same thing oh yeah i just i bypass the decision and just sit on the aisle so i don't have to think about it and i'm not a big sleeper on plane so i don't have to worry about other people kind of barging past me yeah same i always try to get all seated possible i'm also not very good at following the advice of not drinking too much on the plane as well so i i'm probably making more frequent trips than most people yeah yeah exactly there's not very much else to do on a flight is there apart from um have a tipple so okay despite being a bit awkward, getting up to go to the bathroom is necessary, but also could be good for you because it can reduce the risk of blood clots or deep vein thrombosis. Here's Tony again to explain why that can happen during a flight. The very basics would be you're sitting still, you're not using your muscles, and normally it's all that muscle contraction that pushes all the blood around your body and mainly sends it back up the veins, back into your heart to continue circulation. So if you're just sitting there static, it doesn't move as much, it starts to pull and it can readily start to clot. And it's great to see in my own recent travels that airlines are actively encouraging their passengers to get up and walk around. But for most of the population that are otherwise not elderly and don't have a lot of different risk factors that contribute to blood clots, it's not a major concern. As long as you stay hydrated and you walk around occasionally, you're probably going to be fine. So to beat the jet lag, it's out with coffee and wine and in with water and unashamed trips to the bathroom. And try to align your body's natural rhythms with the time zone you're flying to, which includes when you sleep and when you eat. And the natural rhythm of this programme has now come to an end. That's all we've got time for this week. But first, a huge thank you to Sandy Ong in Singapore. Thank you, Anand. and Ed Gent in Bengaluru. Thank you, Anna. I'm Anna Anjagatia and the producer was Sophie Ormiston with Ella Hubber, Lucy Davies and Imi Harper. Do join us next week for more Unexpected Elements. Starting a business can be overwhelming. You're juggling multiple roles, designer, marketer, logistics manager, all while bringing your vision to life. Shopify helps millions of business sell online. Build fast with templates and AI descriptions and photos, inventory and shipping. Sign up for your one euro per month trial and start selling today at Shopify.nl. That's Shopify.nl. It's time to see what you can accomplish with Shopify by your side. 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.