Science Friday - Songbird Mystery, Sweat, Betelgeuse. July 16, 2021, Part 2

Episode Date: July 16, 2021

Songbirds Suffer Mystery Illness From The East Coast To The Midwest The reports started in late May: Songbirds in Washington, D.C. and neighboring regions were being found dead, often with swollen and crusty eyes. In the days that followed, similar sightings came from many states, including Kentucky, Virginia, Pennsylvania, and New Jersey. Now, the symptoms have been seen as far west as Indiana—but wildlife experts still aren’t sure what’s causing the deaths.  The illness has affected many species, including American robins, blue jays, common grackles, and European starlings. So far, investigators have found no signs of   salmonella and chlamydia; avian influenza virus; West Nile virus and other flaviviruses; Newcastle disease virus and other paramyxoviruses; herpesviruses and poxviruses; or Trichomonas parasites. But unfortunately, their tests have been inconclusive as to the actual cause. Experts are asking people in the affected areas to be on the lookout for birds with crusty eyes or behaving strangely—and in an effort at avian social distancing, they’re suggesting removing bird feeders until the cause of the ‘mortality event’ is known.  Ira talks with Allisyn Gillet, state ornithologist for Indiana, and Lisa Murphy, a toxicologist and co-director of the Wildlife Futures Program at the University of Pennsylvania School of Veterinary Medicine, about what’s known so far about the illness, and about what steps investigators are taking to try to solve the medical mystery.  If you find a bird exhibiting these symptoms, researchers encourage you to report it to the Wildlife Futures Program at the University of Pennsylvania.     Sweating Is Our Biological Superpower Sweat may feel like a constant summer companion, whether or not you exercise frequently. Being damp can feel uncomfortable, but the smells that follow—thanks to the lives and deaths of sweat-munching bacteria—are often socially stigmatized as well. (Deodorant itself is actually a very recent invention!) But sweat isn’t just a cosmetic embarrassment: It’s crucial to keeping us cool, as the evaporating liquid pulls heat energy from our bodies. If you look at animals that don’t sweat, many have evolved alternate adaptations like peeing or even pooping on body parts to achieve that vital evaporative effect. People who are born unable to sweat run a constant risk of heatstroke. Ira talks to Sarah Everts, author of the new book, The Joy Of Sweat, about what makes sweat useful, the cool chemistry of this bodily fluid, and why it’s our evolutionary superpower.      Betelgeuse’s False Supernova Alarm The famous red giant star, Betelgeuse, sits on the left shoulder of the constellation Orion. It’s one of the brightest stars in the night sky, distinguishable by its faint red hue.  In December 2019, the star suddenly dimmed to about a third of its usual brightness. Scientists called this the ‘Great Dimming.’ And there was some speculation in the news that the dimming meant Betelgeuse was about to explode in a giant supernova. But within months, Betelgeuse quietly returned to its original brightness, leaving astronomers perplexed. Now, nearly two years after the initial dimming, a study recently published in Nature proposed a theory for Betelgeuse’s Great Dimming. Supernova expert Sarafina Nance joins Ira to talk about Betelgeuse, give an outside perspective on the new Nature study, and discuss her science communication work.    Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. A bit later in the hour, a look at sweat. No, don't change the doll. You're going to like this. But first, it started back in late May. People in several Mid-Atlantic states reported finding dead songbirds, often with swollen and crusted eyes. Now the illness has been spotted in states from Virginia to New Jersey and as far west as Indiana. and the cause is still a mystery. And while wildlife labs have been able to rule out some diseases, such as salmonella, chlamydia, avian flu, West Nile, I could go on. Songbird deaths are still a bafflement. Joining me now to talk about the outbreak in songbirds

and how you go about diagnosing an unknown wildlife disease. Are my guests, Alison Gillette, state ornithologists for the Indiana Department of Natural Resources, and Lisa Murphy, Associate. Professor of toxicology, co-director of the Wildlife Futures Program, University of Pennsylvania School of Veterinary Medicine, and resident director of the Pennsylvania Animal Diagnostic Laboratory System. Welcome both of you to Science Friday.

Thanks for having me. Yep, thanks for having us. This is great. Let me begin with you, Allison. Tell us the symptoms of this disease. What's happening to these birds? Right. So like you had mentioned, they are experiencing these interesting symptoms,

of swelling and discharge from the eyes. They are also experiencing neurological symptoms, meaning that they tend to kind of move their heads in strange ways. Sometimes they look as if their heads are too heavy, as if their heads are swollen. So their heads will kind of dangle a little bit on the neck. They also experience things like tremors, disorientation, and perhaps even uncontrollable limbs.

And when we say bird, I mean, long bird. What do we mean by that? Do we know which birds get this and which don't? Yes. So we know that Blue Jays, American Robbins, Common Greckles, and European Starlings have been the ones that have been really affected by this disease. Your typical urban bird, think ones that you actually see, like at your feeders in the suburbs. But there are also other species that actually end up getting this disease, such as things like tufted tip mouses, white breasted nut hatches, and several species of woodpeckers that we've been seeing from public reports. The first reports were in places like Washington, D.C., the surrounding areas.

But Allison, you're out in Indiana. Is this condition spreading from region to region, or are people just getting better at recognizing it? That's a great question. Honestly, I think it's the latter. However, we don't know enough about this disease to really pinpoint whether it is spreading further west. When I talk to my colleagues in, for example, Illinois or Iowa, they haven't been seeing the disease like we have been seeing in our state, meaning they haven't seen it to the extent that we've been seeing it.

So mostly a lot of our detections have been in urban areas, which totally makes sense because a lot of people are in these locations. as well as there are a lot of people feeding birds and watching birds in these locations. And so I don't want to particularly say that it's perhaps spreading because we don't know whether it's contagious or not. But I want to say that it's perhaps people becoming more informed and maybe it has been in our environment for some time before we really detected it and knew about it. Lisa Murphy, you're part of an effort to diagnose what this is, sort of the science sleuth here. How do you even start? I'm thinking of a movie where somebody sends you, you a dead bird and then it takes off from there. That's right. And I'll be honest, you're not

too far off. We kind of joke that, you know, when we get our mail deliveries here, we never know quite what we might open and find sometimes. But I think a lot of time the start may be these public reports that we've been talking about is we hear that there's an issue. But then we have to actually start just taking those public reports and looking at them and sort of figuring out what are they really telling us? And is there a difference between public reports versus can we get to drawing these connections and similarities and actually saying that they are suspect or verified cases of whatever's going on? And I think what that really illustrates is the importance of just a history. What's back to your movie analogy? What's that bird's backstory, right, before we met this bird? And,

And unfortunately, sometimes it's difficult because we come into the story and the bird's already deceased. So, you know, the person that's reporting it hasn't had an opportunity to observe them and see. So some of the things that Allison had mentioned in terms of some of the signs and symptoms that were seen in terms of them acting oddly, we're missing that piece of the story if the animals just found dead. But back to your story, okay, we now have the bird in the box. How do we do that? And I think it's really, really important that we develop a process, right? That we are going through each of these cases very methodically just to make sure that we aren't missing anything, right? That we're approaching them all in the same way to sort of figure out all of the different things that may be going on. I mean, I can speak most easily to toxicology. since that's my area of expertise is we have an animal, there's a concern. Could it have been something

that poisoned it? We may or may not have those historical details that I mentioned. But as we get into the animal doing the examination, what are we finding, looking at it externally? Are there any injuries? Are there any abnormalities? And as we start to work through our different tests, what are we finding that can give us some clues or identify some paths that we want to follow. Is it just an eye problem? Or as we start to look at it more closely, maybe it emerges as a respiratory problem or a liver problem. And we start to build lists. And as we get more information, we can start to refine that list. We can begin to cross some things off. You know, in my movie analogy, there's always some magic tech angle. I mean, can't you just DNA sequence everything and look for what doesn't belong there?

You know, I love your movie analogy, but when you see it on movies or TV, it does. It seems like there's some shiny blue light and about 30 seconds of catchy music. And they've got the name and address and, you know, the type of cologne that the perp wears, you know, you're on it. If it were only that easy. But again, back to, you know, looking at it methodically, like you said, whether it is just, doing PCR testing to look for viruses. In my laboratory, whether it's toxicology testing, to look for heavy metals such as lead, or to look at pesticides, or to look at drugs or what have you, is we go through a process, like I was saying, is based on what we know, this is where we're going to go next. You know, the point isn't just to run a lot of tests.

It's actually to generate some results. But as we take those results, we understand that people intend to act and make decisions based on those. So it's really important to us that any results that we provide are accurate and timely, but they're actionable. In fact, that's really important to me as well, is it's one thing to have that goal of finding out what it is. But the reason we want to find out what it is isn't.

just to pat ourselves on the back and, you know, congratulate ourselves for figuring it out. But now it's, it's what do we do next to either try to stop it, at least mitigate it, hopefully to prevent it happening next time. You know, that's the end goal. Given that we don't know what it is, we don't know even if it spreads. Allison, I guess the best thing we can do is to, is like we did during the coronavirus pandemic, and that is to clean things up, right? Absolutely. I think it's really good to be diligent about cleaning up things that provide some possibility

for increasing the risk to these birds. So, for example, we've been suggesting that people take down their feeders, mainly because just like we had experience with COVID, we wanted birds to be able to socially distance. And when it comes to feeders, feeders provide this opportunity for birds to come to a single, pretty much a single point and to feed collectively with not only just individuals of your own species, but also individuals of different species. And so it provides a lot of interaction between these birds.

And it also provides this potential for if it is a disease that might be carried on the feeders to pass from not only the bird to bird, but bird to feeder to bird. So we want people to clean up their feeders with 10% bleach solution and then air drying it completely so that there's no potential for mold to grow. And then keeping it inside until you really start seeing the mortality event end, meaning birds are not being seen as sick anymore around your area. and then pretty much being informed about whether areas that are close to your cities are seeing these, because it might be in your area, but you just might not be aware of it. And of course, if you see a dead bird, your actions should be what?

Yes, so I recommend first, when you do see a dead bird, always protect yourself. Either wear disposable gloves or invert a plastic bag. if you have the need to handle that bird, meaning taking it out of the environment so that it won't be able to possibly transmit the disease to you or any other wildlife or pets. And then looking at that bird and seeing, does it have the symptoms that we are describing, such as the gooey eyes, the crusty eyes, the swelling in the eyes? And I guess to see whether perhaps it might exhibit some sort of strange posture or something like that, indicative of a neurologist. issue. And then after that, telling your state agency or your local wildlife agency that you found this bird with these symptoms, we've been getting a lot of reports of dead birds in general. And birds, they live a hard life. Wildlife really experience a lot of different threats and risks

in their environment. So they experience things like buildings and windows that they might not recognize is being very defined walls, and they end up colliding with these buildings and windows and then dying. Or they have predators in their environment, like pet dogs, pet cats, that also threaten them and cause them to ultimately die. And so we have been getting reports

of just like baseline mortality that is not necessarily being indicative of this particular songbird disease. So if you do see the symptoms, please report it. But if you know that this bird definitely died from a car crash or a collision with the building or with a power line. You don't need to report it. I'd like to thank both of you, Alison Gillette, the state ornithologist for the Indiana Department

of Natural Resources, and Lisa Murphy, Associate Professor of Taxicology, co-director of the Wildlife Futures Program, University of Pennsylvania School of Veterinary Medicine, resident director of the Pennsylvania Animal Diagnostic Laboratory System. Thank you both for taking time to be with us today. Thank you. Thank you. We're going to take a break and when we come back, the secrets of sweating. Why we do it, why we might even want to embrace it. We'll get a good schitz after this, as they say. Stay with us. This is Science Friday. I'm Ira Flato. You know, whenever the weather turns hot, the conversation turns to sweat. You hate sweat, right? Your clothes stick. Your head is dripping. your deodorant as well, well, let's not go there.

On the other hand, lots of people seek out sweat. Whether it's hot yoga or a steam bath, there's nothing like a good schitz, as we used to say. So is it good, or isn't it? My next guest is here to suggest you celebrate that sweat, no matter how profuse. Don't be salty. The chemistry is cool, even.

It's our evolutionary superpower as human beings, and if we didn't have it, she adds in a new book, we might be left doing some even less savory things to keep cool. Yes, we'll talk about that. Here with me now is Sarah Everts, science journalist, author of The Joy of Sweat, Strange Science of Perspiration. Welcome, Sarah. Thank you for having me. Let's talk about the joy of sweat for a moment because there are people who do seek it out.

They go into a steam bath. They like hot yoga. It feels good to sweat. Yeah. And in fact, when you sweat profusely, you, you release happy hormones, the same sorts of things that give you the runners high. And so I think, you know, there is sort of an emotional catharsis that we have when we sweat. And, you know, most cultures at one point or another have some sort of sweating ceremony from the sweat lodges

of the indigenous peoples of the Americas or the Jim Jill bangs in Korea or the banyas in Russia or, you know, the saunas in Finland. And so we all seek out some sort of sweaty catharsis at some point or another. Let's get into what sweat really is because I've had for many years a misconception, you know, that sweat is just water and salt, but it's actually very closely related to our blood. Where does it come from? What happens to it before it appears on our skin? Why does it get there? Give us a little bit of the ABCs. Sweat is actually sourced from the watery parts of blood, blood plasma. So, you know, the red blood cells and the platelets. and the immune cells have been filtered out.

And that liquidy part is what keeps your body on the inside wet. So we are salty oceans inside. And when your body gets overheated and you get the temperature directive to start to sweat, your sweat glands source that perspiration from this fluid that is percolated out of blood. It's called interstitial fluid. And so pretty much anything that's small and is circulating around in your blood system can emerge out your sweat pores. I had my sweat analyzed by a forensic scientist actually who took an analysis of even just a fingerprint of mine. So fingerprints are just sweatprints, right?

And she could tell that I had had a morning coffee because there was caffeine that had emerged out in my sweat pores. If I had, for example, added a little shot of whiskey to my coffee or a little something more illegal, all of that also emerges out in your sweat because it is circulating in your blood, as well as glucose, you know, urea, proteins, all sorts of interesting things come out and sweat. Do you think someday we might be able to use sweat as a fingerprint? Because, you know, maybe you have a unique sweat profile or something like that. Well, I do know that forensic scientists are certainly interested in sweat fingerprints. So normally when you think of forensic scientists looking at fingerprints, they're looking at the

whirls and swirls. They're looking at how it physically looks, and they're comparing an image of a fingerprint to that of a database. Well, chemists are now actually analyzing the chemistry of fingerprints. And they're able to find out all sorts of information. And in fact, that scientist who analyzed my fingerprint, she works with law enforcement trying to develop this as a technique. And she, for example, analyzed a single fingerprint lifted from a windowsill where a stalker had tried to break into a house and found that he had been consuming alcohol and actually cocaine. And so I do think that there will be forensic analysis of fingerprints coming up. But I also think a lot of people are really into. personal measurement. And that can also give us super interesting information. So say you have a little band-aid-like sweat patch analyzing what's coming out of your skin or a smart watch add-on. And you get a little push alert because your sweat patch has noticed that your blood alcohol level is probably higher because there's alcohol in your sweat. So it tells you maybe don't drive home after the bar,

take a cab. Or you can imagine coaches on the sideline keeping tabs on the sweating of their players, say in a really important match, a player starts getting stressed and starts releasing stress hormones or signs of fatigue. That might ping the coach to, hey, let's switch out that player for somebody new. There's all sorts of applications like that that are less dystopian than the forensic applications too. We don't just have one kind of sweat either. There's regular sweat and then that funky armpit stuff that we get starting with puberty. But tell us about the differences between those two.

Yeah. So at Crine Sweat, the stuff that we've been talking about, that's responsible for cooling us down. But there is another. And those are the apricrine glands. And those are found anywhere where hair grows at puberty. That kind of sweat isn't watery at all. It's actually more waxy. And when bacteria living in your armpits eat that sweat, they metabolize it into the very stinky odors that, you know, start emerging out our armpits at puberty. So it's kind of like a good news, bad news situation,

right? Most sweat when it emerges from our pores is not smelly. And the thing that's responsible is the bacteria in your armpit. But on the downside, it's actually bacterial, effectively bacterial poop that's making you stinky. So I'll leave you to decide whether you find this heartening or not. So it's not just your armpit then that may be stinky, maybe anywhere where the sweat collects and bacteria can get to it. Exactly. Yeah. You open your book with a story. You have to tell the story of a woman who sweated red and how it baffled medical professionals. Yeah, how alarming is that? So it certainly baffled medical professionals and it stressed her out,

but it also super excited the medical professionals. Because can you imagine how often would you get to analyze red sweat? So she was a nurse, and she started noticing that around the colors of her white uniform and in the armpits, there were kind of red sweat patches. And, you know, she'd have to soak her work clothes for hours to get it out. So when they analyzed her body, they found that she was a super healthy 20-something nurse, could not figure out what was wrong. And at a follow-up appointment was the finally the time where they cracked the case because she shows up. And her fingers have that kind of like reddish brown color that people who roll their own cigarettes

sometimes get that kind of stain. And they knew that she was not a smoker. And so they're like, what, what, what is on your fingers? And she's like, oh, it was, you know, my favorite chips. It's a spicy corn tomato chip. And effectively, she had been eating upwards of 45 bags of chips a week. Wait, wait, 45 bags a week. Yeah. Of, of, Spicy tomato corn chips. And yeah. And because anything that you consume can end up in your blood system and your sweat is sourced from the watery parts of blood, some of that red colored dye had emerged out

her pores. And so when they put her on an elimination diet, her, you know, sweating red cleared up. And she just, you know, went back to the normal complaints we have about sweat, you know, dank odor and wet patches, but not colorful ones. That's interesting. You mentioned urea. How is sweat different from urine if they're both derived from our blood? Right.

So this gets to, you know, probably my biggest pet peeve, which is when people talk about going for a good sweat as a detox strategy. This is total hogwash. So effectively, because anything. in your blood can emerge out in your sweat. Lots of good stuff comes out like, you know, glucose and hormones as well as bad stuff. But if you were to detox by sweating profusely, you would literally have to get rid of all the water in your blood out your sweat pores. That would completely dehydrate you and you would dry up and die. Instead, your kidney filters your blood for that nasty stuff floating

around your bloodstream, filters it out, and then dispatches it out in urine. And so, you know, sometimes there's urea in your blood and that gets siphoned off by the kidneys and dispatched out in pee, as well as like all the other bad stuff. That's why we evolved the kidney. Sweat is entirely, at least that salty stuff that is entirely just for cooling down. Speaking of unusual sweat, let me go to a clip we have. A clip we have. from Brant from Brooklyn. He has a question on the sci-fi Voxpop app. I don't just sweat in the summer. I sweat year-round. I do have sweaty armpits, but they don't bother me as much as my excessively sweating hands because I have to use my hands for things.

I have had Botox injections to help with the sweating. They do work, but they're expensive, they're painful, and they only last for about five months, and then the sweating comes right back. And he wants to know if there's anything more effective or inexpensive on the horizon. So what he's describing hyperhydrosis is a pretty serious sweating condition. And, you know, people who have it, you know, some can't even hold a cell phone or a pencil because it slips out of their hands. And I am, you know, really sad in that there has not been more research on this. Botox is one solution, but it's only a temporary one and it's expensive. Some people try to take drugs to control their sweating, but there's often a lot of side effects. Quite honestly,

I wish that there were more strategies available. And I wish that more research that more researchers dug into hyperhydrosis. One would think with all the people who have this that the drug companies would be solviting, and maybe it's the wrong analogy, to find a drug for this. You know? Yeah. Yeah. Let's go into other kinds of disordered sweating.

Tell us about any other ones. Well, you know, there are some individuals who don't actually sweat at all. They have a genetic condition that interrupts the development of sweat glands in utero. And actually, that is really debilitating because whether you find sweat annoying or not, it is essential for keeping you alive because effectively you are sweating a tiny bit at all times, making micro adjustments to your body temperature. because as that sweat is dispatched onto your skin, the evaporation of the water whisks away. It pulls away the heat from the surface of your skin. Meanwhile, your blood is rushing by. So have you ever noticed when light-skinned people get really hot, they turn red? That's because their vascular system has pushed up veins as close to the surface of the skin as possible,

so that the cooling evaporation of sweat can cool the blood rushing by. And so then that blood can go back into the interior and cool you down. And so people who don't have sweat glands at all, they have to, you know, spritz themselves with water constantly. It's very uncomfortable to live in even a slightly warm climate because their body can't make those micro adjustments to body temperature. So it must be dangerous. Oh, yeah.

Yeah, it's life-threatening. I mean, you know, as much as it's kind of annoying to be drippy on a hot day, it's your body just trying to do its thing to keep you alive. Heat stroke is a terrible way to die. I knew before I read this book that people are some of the only animals that sweat, but you really want us to see sweating as what makes us special, our evolutionary superpower even. What makes it so super for us?

Right. Well, it makes it so super because we can exercise and run and effectively cool down at the same time. So if you think about our evolutionary history, most of our prey sprints way faster than us. But we, because we have this huge naked surface area of skin, right? Most other animals are covered in fur. We're a naked ape. We have a this enormous surface area for cooling down. So our prey would sprint away way faster than us, and we would start running after them. And eventually they would have to stop and cool down so they didn't overheat. And we could catch up, forcing them to sprint again and catch up and sprint again until they were so exhausted or that they were easy to kill or they died of overheating. And so, you know, the modern incarnation of this is marathons, of course, right? We can run great distances and cool down while on the move. And if you just think about dogs, for example, the way a dog cools down is by panting. And it's sticking out its tongue and it's also evaporating

water, but it's evaporating water from saliva. And it's evaporating it off the only naked surface area it has, which is a tiny little tongue in comparison to, you know, their whole body. And, you know, if you think about that, we can, we have such a larger surface area. off of which we can cool down. And this allows us to live in really hot climates. It's allowed humans to, you know, populate a good chunk of the world for better or for worse. I also noticed that some of the options animals have are keeping cool,

or how shall I put it? Pretty gross. Alarming at best is how I would put it. Yeah. Peeing on their feet, pooping even sometimes. Yeah. So this is the thing, right? So evaporation of water off the surface of your body, this is the most efficient way to cool down.

And so, you know, if not sweat, then another bodily fluid. And so dogs use saliva, which is arguably gross, but not as gross as urine or poop. So for example, vultures will poop on their own legs. It's quite a liquidy poop to evaporate the heat off themselves. Seals urinate on themselves. honeybees vomit on themselves to get water onto the surface of their bodies to evaporate away the heat. And so when you know what could have been, when you know what evolution might have bequeathed us, you know, sweat is a lot less gross than all of those other things.

I mean, imagine a subway in the dead of summer where people are peeing, puking, you know, licking themselves so that they can cool down. In contrast, sweating is so much less gross. We have to take a short break, but when we come back, there's more. Yes, we're going to keep on sweating with author Sarah Everts, author of The Joy of Sweat. This is Science Friday. I'm Ira Flato. We're talking about sweat, the chemistry, the physiology, and even the forensics of it. With my guest, Sarah Everts, author of the book The Joy of Sweat, the Strange Science of Perspiration,

and boy, are we finding out just how strange some of this is. I want to bring in a question from Lynette in California. She sent this in via the Sci-Fi Vox Pop app, and it's a question I have too. I recently learned that there are differences between tears depending on why they're produced. I'm wondering if the same is true with sweat. Is the sweat that the body produces because of stress,

the same as the sweat that's produced because of heat? Thank you for that question, Lynette, because I have the same question about nervous sweat. Why do we sweat when we're nervous at all? What does that have to do with cooling off the body? And are there two kinds of sweat? Yes, I love this question. So we can sweat because our body gets hot, right? As soon as our temperature rises and all of our, you know, two to five million sweat glands open up.

But another way to open up the floodgates is stress hormones. adrenaline. And so if you're panicked, you can also start the sweating. And, you know, like, we don't know exactly why that is evolutionarily, but you can imagine that most of the time when you're fearful, or at least in our history, you kind of had to run away really quick or climb a tree or do something like that. And so it's possible that our body is effectively assuming that we're going to need to cool down pronto. But what's really interesting is, about fearful sweat is that there might be a unique odor that we produce when we are stinky. So researchers have followed up on this kind of weird idea that we might produce an anxious

odor. And they gave people t-shirts to wear and put them in front of a television screen. And they watched either a nature documentary or they watched a really scary movie and got the subjects to sweat. And then they took away these odor samples and gave it to a panel of sniffers. And what's really interesting is that these complete strangers could distinguish, you know, just normal B.O. from the body odor produced during an, you know, a moment of anxiety. And so we do sniff out information about others around us. And yeah, chemists are hard at work, trying to to pluck that molecule out. But they haven't been successful yet, but they're certainly working on it. I know you also investigated up close, another mystery of sweat, and that is we can be attracted

to other people's sweat smells. Tell us what you learned about sweat and love. Okay. So I went to Moscow to go to a sweat dating event where people sniffed. body odor as a way to find love and romance. And the idea is that, you know, whether or not you find somebody attractive or likable or the hobbies match, at some point, you're going to smell the body odor of the person you are with, and it's going to be a make or break moment. And so why not cut to the chase or kind of eliminate the chase and do your like filtering for potential dates by body odor. And certainly humans have a body odor print. We know this because dogs can track a specific human based on a sample of their t-shirts, right? And, you know, we do smell one another.

In fact, you know, parents can identify the body odor of their newborns just within hours of birth. Siblings can identify a long-loss brother or sister after two years of being a part. So we do recognize the body odor of others. And in fact, there's been all sorts of tantalizing research that suggests that how our partner smell is involved in whether or not we're attracted to them. So, you know, the famous t-shirt study by Klaus Vedikind is when women were given the t-shirts of men. And by the way, all this research is very heteronormative, with, you know, cisgendered straight couples. And I wish it weren't so.

I wish that they would evaluate a greater diversity of human sexuality. But when women were given these stinky t-shirts of men to smell, they found the men with the most complementary immune systems to be the most attractive. And by complementary, I don't mean same. I mean different enough that any progeny that they would have together, would have a very strong immune system. And if you think about it, it makes sense. For most of human history, our major foes have been microbial, right?

We've died from plagues and pathogens. And so it behooves us to try and find a mate that will create, you know, children that can survive these pathogens. Let's talk about all the tricks we use to sweat less or reduce the smell of our sweat, anti-perspirants and deodorants. Have we mastered this yet? I mean, are we tired of swiping our armpits? Yeah.

Well, it's interesting because this is actually a relatively new phenomenon. For most of human history, we have either lobbed on perfume if we were anxious about our BO, or we've washed with soap and water or just water and then lobbed on perfume. There's this way in which the last hundred years, deodorant and antiperserent manufacturers have put the fear of sweat. in all of us. Deodorants are actually just antiseptics. And so they kill the population of bacteria in your armpit that eats your apricrine sweat and turns it into stinky odors. Whereas antiperspirants cut off the food supply by blocking your pores. So they, you know, close the buffet so that these bacteria go hungry and can't make the stinky odors. But there are researchers, you know,

trying to find different new strategies to fight odors. So some are looking at, instead of killing the bacteria, blocking the enzymes that the bacteria are using to make those stinky smells. So it would be kind of like a live-and-let-live situation, but just don't do that one thing. What about manipulating the microbiome, maybe some probiotic that's in the odor that competes with the bacteria, right? Yeah, so that's not a totally new idea, but you could imagine people trying it out. And there's one really fascinating researcher who's studied what's called armpit transplantations. But instead of like, you know, lifting the skin, effectively, it's just like lifting the bacteria from one armpit and putting it into somebody else's armpit. So say you produce pretty stinky odors. It could be because, you know, you have a higher proportion of corn of bacteria in your armpit than, you say Staphylococcus and say, I produce less, maybe I could donate my armpit microbiome to you.

He's only had success with twins, like very close family members, because of course the bacteria living in your armpit, they are living there because they love your skin, right? They love all the weird little components that you produce in your sweat, your acrine sweat, that salty stuff. They love that ecosystem and they're probably pretty well established. So it's actually very hard to disrupt a person's microbiome if they're healthy. Maybe putting less smelly bacteria in your armpit might be a solution, but so far it hasn't worked.

Thank you very much for this book. It's a great read. Sarah Everett's author of The Joy of Sweat, the Strange Science of Perspiration. Thank you for taking time to be with us today. Oh, it was such a pleasure. And to our listeners, if you want to read an excerpt from the book, no sweat, just go to Science Friday.com slash sweat. I'm really looking forward to our next story because it talks about my favorite constellation,

Orion. Orion is very easy to pick out in the sky, and it has a star in the upper left part that you can actually see with your naked eye, that it has a faint red color. That's the famous red giant star beetle juice, one of the brightest. stars in the night sky. Something strange happened to its reddishness. In December 2019, the star suddenly dimmed to only one-third its usual brightness. It came to be called the Great Dimming, and there was some speculation that the dimming meant Beetlejuice was about to go supernova, kaboom. But within months, Beetlejuice quickly returned to its original brightness,

leaving astronomers perplexed. And now, nearly two years after the initial dimming, a study recently published in nature proposed a theory for Beetlejuice's strange behavior. Sarafina Nance is a PhD candidate in the Department of Astronomy at the University of California at Berkeley and the Lawrence Berkeley National Lab. And while she is an astrophysicist and a supernova connoisseur, she was not the author on the nature study, but is here to talk about it. Welcome, Sarafina. Thank you so much for having me. I'm so excited to be here. Did you follow it when the first started dimming back then? I did. Yeah, in part because I could see it with my naked eye. I would walk outside at night and I would stare up there and be like, oh my God, what's happening to my star?

So it was a very exciting. This was so you'd call it a rare event then. I mean, it's not something you would see all the time. Is it meaningful? What happened? Do we know what happened to it? Yeah, I think we are working hard to figure that out. And it seems like there's some consensus now on what exactly happened. But it was an interesting sort of progression of trying to understand what's going on within the star and what that means for other red super giants. Could this great dimming happen in other places around our universe? So it seems like we think that dust is the ultimate culprit. And in astronomy, that's actually pretty common and somewhat sad, but also exciting for those who study dust. So we think dust actually probably obscured the star from our line of sight, meaning we saw the star appear dimmer than it actually is.

This new study also proposed that it seems like there could have also been a sort of cooling on one part of the star, a cooling that made the light appear dimmer. And so those two factors sort of came together to make the star appear, as you said, about 35% as bright as it normally is. So is that the consensus now of what happened? I think so, yes. Yeah, it seems like it's dust with some cool convection and temperature changes as well. This is Science Friday from WNYC Studios. So why are we so interested in studying it to see what happened?

Well, I think Beetlejuice is a really fascinating star for a lot of reasons, one of which we already talked about. We can see it. and also because it is a very large red super giant, very close to us, about 724 light years away. And so when it explodes as a supernova, we will be able to see it from Earth. And so it's exciting to try to understand what's going on within the star and to see how long it has before it explodes so that maybe we can try to catch that. I know that seeing a supernova, seeing a star explode is a really rare event too. Are you kind of disappointed? It was not a supernova?

I'm a little sad. I'm a little sad. I didn't have too high of hopes, but I'm a little bummed. Why can you learn by studying supernovas? Why are we excited about them? I can gush about this for hours or days. Supernova are some of the most interesting, exotic. parts of our universe. They eject elements into their surroundings that actually form the basis of most

matter in our universe, including us. You know, when Carl Sagan said, we are star stuff, we are. We are the stuff of stars, thanks to supernova. So that's, you know, one reason. Another reason is there are just some really fascinating physics that goes on in a star before it explodes. And we get to use supernova as laboratories for some of the most interesting and complicated explosion physics that exists. And finally, supernova have really cool applications. I am currently using core collapse supernova, so really big stars that explode at the ends of their lives, just like Beetlejuice will, to try to measure the expansion rate of our universe. So we know the universe is expanding. We know that expansion rate is accelerating with time. And we can use supernova to try to understand exactly

how fast is expanding and how that changes with time. You know, there was a lot of hype about this in social media and wherever because people really love that star and they were wondering what could happen to it. Do you think that serves a purpose, the hype that at least gets the public talking about astronomy? I think that this is why science communication. is so important. I think that getting people interested, engaged, excited, passionate about looking up out at the night sky and thinking about what's out there is incredibly important. I noticed that you're very active in social media. Do you think social media has a special place as opposed to traditional forms of media for being a science communicator? I do. I think that social

media has its pros and cons. But in some ways, how often do you get access to, the best scientists in the world, to some of the people making the most interesting discoveries, and you get to ask them questions, you get to interact with them. And that's totally new. That hasn't been done before social media. And so to me, that means that we can increase the representation of people who are communicating science and who are actually elevated in sharing their work and sharing their discoveries. And that increasing representation is incredibly important, when you want to prioritize different voices, marginalized voices, and allowing people to see that there are many different types of scientists

and anybody can be a scientist. That's really interesting to say that now. You write on your website that as an Arab woman in the sciences, I also hope to change the narrative of who can be a scientist and what a scientist looks like. Yeah, I think for most of my life, I didn't feel like I had a place in astronomy. And, you know, a lot of that is from explicit and implicit messages that I got very early on.

I had a male astronomer tell me when I was about nine years old that I could not become an astronomer when I grow up. Really? Yes. And that sticks with you. You know, I remember that moment very vividly. And that has continued throughout most of my career in various capacities. But on the other hand, I've had some amazing mentors who have helped me in a community of people who have helped me pursue my dreams.

And so my hope is to be the woman, be the scientists that young Serafina would have wanted to look up to when she was a young girl and be that person for anybody who's interested in pursuing their dreams. Well, we wish you all the best of luck. And as one person famously said many years ago, keep looking up. Keep looking up. Thank you so much for having me. Thank you for taking time to be with us today. Serafina Nance, Ph.D. candidate in the Department of Astronomy at the University of California at Berkeley and Lawrence Berkeley National Lab. And that's about all the time we have. Where did that hour go? If you missed any part of this program, or you would like to hear it again, subscribe to our podcasts, or ask your smart speaker to play Science Friday.

And of course, you can say hi to us on social media, Facebook, Twitter, Instagram, or email us the classic way. SciFri at ScienceFriaday.com. Send us feedback. Tell us what you'd like us to cover, too. Have a great weekend. We'll see you next week. I'm Ira Flato.