Listener Questions #50

0:00This is an iHeart Podcast. Guaranteed Human. Meet the Red Bull Dragonberry Emergizer. It's one of the many new drinks out now. Who knew ice cold drinks could be so fire. Try them all only at my dogs. Forming a business seems easy until influencers forums and AI give different advice. Legal Zoom has helped 5 million business owners get it right. Because after 25 years we know what getting it wrong can cost. We stand behind every formation we file and we'll be there after you've launched. When you need a legal hand visit Legal Zoom. Legal Zoom provides access to independent attorneys and cell service tools. Legal Zoom is not a law firm and does not provide legal advice. Hey everyone the last question on today's episode has to do with the birds and the bees which we only mention in case there are young ears around which you prefer to temporarily shield from

1:00this information. So FYI. Dialects can be heard in birds from different places. Do animals have sent dialects if they live in different spaces? Can a nuclear heater melt through the crust and dive for your opus ocean or come up bust? Now I'm not complaining because it's certainly as fun. But other animals lack a penis so why do I have one? I get the best questions. Wow. Whatever questions keep you up at night, even that one. Daniel and Kelly's answers will make it all right. Welcome to Listener Questions episode number 50. 50.

2:08We've almost hit my age in Listener Questions episodes. I thought you were a hundred. Because you always roamed up. You lost 30, 35. Oh I see. Okay. Well then I can round up Listener Questions episode 200 also. See, at some point the differences just don't matter. That's right. Sure. Yes, we've done a hundred of these and they've all been great. Just like, you know, at some point you stop counting your babies' age in days, right? And then you stop counting in months. So why don't we ever stop counting in years? Yeah, sure. Yeah. Sure. It's a lot to keep track of. You agree with me. Every episode from here on out will be episode 100 so that it's easy for us to remember. Until we had episode 1000, you know, it should be logarithmic. Anyway, welcome to Daniel and Kelly's extraordinary universe. Listener Questions episode number a lot. We have some really fun questions today. I'm excited. For those of you who knew the podcast, I'm Daniel. I'm a particle physicist and I love answering questions from listeners.

3:11I'm Kelly Weiner-Smith. I am a parasitologist. I study parasites and I also love answering questions from listeners. Even if they're not about parasites. I got an email test this week. Go on. Somebody wrote it and said, Kelly says you answer emails within 30 seconds. So here I'm writing to you. And I wrote back in about 24 seconds and answered their question. No way. I mean, I totally believe it, but that's amazing. I happen to be looking in my inbox and when it landed, so I was like, oh, I can't miss this opportunity to prove Kelly right. Amazing. And I guess, unfortunately, now might be a time to remind listeners that I am not taking new questions until sometime in 2027. I'll let you know when, but you all ask so many amazing questions that are outside of the wheelhouse of parasites that I need a little time to catch up on all of them. I'm about six months behind. Because everybody out there is just so curious about the universe. It's wonderful. It's beautiful. It's extraordinary.

4:12And it invites curiosity. You can't help but wonder how this works and how that works and why this doesn't work this other way when you just live and take in the universe. It's wonderful. It's wacky. There's lots of things we'd like to know. And I love the kind of questions where a listener listens to one episode and it got them wondering about something tangentially related. Yes. And so our first question today is from Zach who heard us talking about dialects and he started wondering are there dialects of scent like smells for animals that communicate by smell? Let's go ahead and hear his whole question but I was super excited because I didn't know the answer when I read this question. Hi Daniel and Kelly. This is Zach from Atlanta, Georgia. Thank you so much for taking my question. I'm stoked. I feel honored and I love everything that you guys talk about on the pod. So thank you for all that you do for science communication and for my daily commute. So here's my question. I'm a speech therapist so I'm often thinking about communication in particular verbal communication or using our mouth and our ears but I don't really know anything about

5:16all factory communication and communicating via scent and pheromones and those sorts of mechanisms. So I'm very curious if those forms of communication across the animal kingdom have something akin to dialects in the same way that we have variety across our spoken languages. I want to know if there are different ways of smelling or tossing our scent or shaking about and sharing our pheromones that is communicatively meaningful across different communities of the same species and if there's anything that looks something like dialects in those forms of communication. I'm very excited for your answer. I've been wondering this for a long time and I thought the pod would be the perfect place to get an answer. So thank you in advance. Great question. You're right. I love this generalization. This thing happens in speech. Why doesn't it also happen in dance or in smell or in something else? It's exactly the way we make progress in science. It's like bring two ideas together and see do they click or do they clash?

6:17When this is why I always try to encourage graduate students that I mentor to read broadly. Because you never know like when you're reading something that's not at all related to what you're doing, like what questions it could bring to mind that you had never thought of that are actually very much related to what you're working on. And so yes, you should read broadly because it gives you lots of cool ideas. Absolutely. So I don't know too much about sent communication but I found two papers that found stink dialects in mammals and I was very excited. Can we back up and just be like what is sent communication? I mean, I have an odor but I don't like control it. It's not like I'm deciding to smell this way or that way on a certain day. How do animals in general use sense to communicate? Well, ants, I think are famous for using sense for like just about everything. But in general, animals can use sense for things like marking territory. So for example, lots of big cats will leave their sense so that other cats know, hey, this is mine. Sometimes it's used for things like mate attraction.

7:19There have been some speculation that humans have pheromones and we sort of cue into each other's smell and that can impact attraction. But I think when we actually dug in and look for like scientific evidence, we don't see a lot of evidence for that. But in other species, sometimes mate choice decisions are to some extent impacted by how an organism smells. And for example, like moths, we had Andy C on the show the other day talking about how female moths can release sense that then males can detect from really far away and then they know that there is a receptive female out there somewhere. I just need to follow this scent to get to her. So it's used for a lot of different things in the animal kingdom. It's a little foreign to us because we as the species don't use scent nearly as much as some other animals do. Although I realize I don't do it biologically in the sense that I can't like control it internally. But obviously I do use it technologically. I mean, I wear a deodorant to control the scent or some people put on a certain perfume to communicate X or Y or Z and that must be cultural as well. So yeah, obviously humans must use sense to communicate.

8:20I don't know what I was talking about. What? Anyway, tell us. We're not using our biological scent. Like we're trying to tamp down our biological scent and we don't want that to get nailed there too much. But yes, you're right. Like deodorant, sorry, perfumes or whatever. So tell us about animals. Okay, so this question is trying to figure out if sense differ between the same species that live in different areas. And there's a couple different reasons you could imagine that happening. So for example, if you have the same species living in two different environments, those environments might impact the way their scent works. So for example, if you're in an area that has, I don't know, more humidity or different temperatures than another group of individuals in your species, maybe it's harder to get your scent from one individual to another when the humidity is like 99% in the temperature is 110 degrees Fahrenheit or something. So are you suggesting more broadly that having dialects, having variation in the behavior across the species is always in response to environmental differences? Because like do people in the south have that particular way of talking and people in

9:25New Jersey speak that way because of what it's like to live in New Jersey or can't it also be explained by just like random evolutionary walk? Absolutely. So this is one of three hypotheses. Okay. And there's probably even more. But so the idea behind this first one is that if you live in an environment where, for example, it's hard to get your scent out there, you might be selected to be stinkier or have a particular sort of scent that sort of cuts through. I don't know, the humidity or whatever better. So that does explain New Jersey. You know, funny New Jersey story. I was born in New Jersey and I love New Jersey, right? And my husband loves picking on New Jersey. It's just so easy. I know. And we stopped at a rest stop in New Jersey. And I was like, they're going to see how great New Jersey is, right? And as soon as we step out to the rest stop, it smells like urine. And I don't know how most rest stops don't have the overpowering scent of urine. But this one did. And then the sign that we parked in front of said something like this is a waste cleanup

10:28area. Please stay on the sidewalks. And it's like, oh, man, totally failed here. I still love New Jersey, but that New Jersey didn't show up for me on that day. I wanted it too. We took our kids to New Orleans once and we like had binny a's and we took them to hear music and we saw the art, et cetera. And then we asked them, what do you think of New Orleans? And Hazel said, it smells like vomit. Oh, yeah. Yeah, that's true too. There's a little of that also. But all right. So off of stinky cities were states and back to animal communication. So you said you had pointed out that you can have like sort of random differences. You can have like genetic drift where populations sort of change genetically over time, maybe not necessarily in response to like an environmental pressure, but they just sort of like drift in different directions. And maybe when those populations come back together, it would be hard for them to notice each other's sense or they'd have different dialects. Right. Another reason you could have a dialect is if you have different kinds of microbes that are impacting your smell and different areas could have different microbes.

11:31Right. Makes sense. And that's why you might expect there to be dialects in stinkingness between populations of the same species. Very cool. Okay. So I found two studies that I thought would be fun to talk about today. The first one was looking at otters in the United Kingdom. And otters have that otter be interesting. Oh, but a bump. Can you put a bump or a bit of in their mat for us? Okay. So otters have anal sacs on either side of their butthole and these anal sacs produce sense. And when this scent comes out with the poop, they call that sprain. And I'm sorry, they call it sprain. That's a word. That is a word. And I put that in bold in my outline because I was like, I have to make sure that everybody knows the word sprain. And it's weird that it sounds like a combination of sprain and paint, but it's neither. That it does get sprained. It gets deposited with feces.

12:33I don't know how far it sprays from the location. But yes, it helps scent the feces because the feces don't scent enough otherwise. Well, I guess this is, you know, this is meant to tell other otters that, hey, this is my territory. It also has information about the sex and the age of the individual so you can. Oh. So the spraint of a reproductively mature male otter. I do. I love it. I love it though. It's a wonderful, wonderful word. The spraint. Yes. Right. So you can tell a reproductively mature male and a reproductively immature female, for example, by their spraint. So there's a lot of information in that spraint. But the United Kingdom tends to have about four different populations that are genetically similar. And the reason you've got these four populations is because there was a time when the otter population went way down and it tended to recover in these four areas and then there were reintroductions and it sort of has grown back out from there. So you've got this like genetic structuring with four different populations.

13:37You had a bottleneck and now the populations are based on those surviving small populations. Got it. Plus some reintroductions and maybe some, yeah, other introductions and stuff like that. And so there are these four different genetically somewhat distinct populations in different parts of the United Kingdom. And so they thought that maybe you would get dialects. And so what they did was... Sprint dialects. We're talking about here. We are talking about spraint dialects. We are indeed. Yes. Presumably they thought that it would be a bit rude to catch the otters and express the spraint from their anal glands. And so what they did instead was they serendipitously took advantage of situations where unfortunately an otter had died. They managed to get their hands on the carcass before the otter had started to decay. And they put everything in a freezer. And then when it came time to do the analysis, they removed all of the anal glands from these frozen specimens and they analyzed them all at once. And what they found was that there does seem to be dialects in spraint scent between these

14:40four different populations. And they tried to see... Okay. Does it differ geographically? So like, you know, within a population, how much variability is there? And if you're looking at two different populations, is the spraint profile more different for individuals that are farther apart in these two populations relative to individuals that are like living closer together, even though they're in separate populations. And there wasn't a clear sign of geography. And so it looks like something about genetics has resulted in different spraint dialects in otters in the United Kingdom. So for example, if you took an otter from one of the populations and put it into another one, it probably would retain its original dialect. Its otter friends would be making fun of it at school for the way that it spraints. Yes, that is a reasonable hypothesis. But this study did not look at behavioral impacts of these differences. So does that mean that we don't really know how important it is? Like, you know, we haven't seen otters from one population reacting weirdly to New Jersey

15:44otters or the equivalent. And so it might just be like, ignorable differences. Yeah, it could be, or at least if there were follow-up studies, I didn't find them. But I don't think that New Jersey otters are crossing the ponds to go to the United Kingdom, but there could be communication implications within the United Kingdom for these different spraint profiles. Well, I wonder if they find foreign spraints exotic and attractive or just like weird enough putting. Could be, could be. I don't know. Well, we have the answer to that question in Himalayan leaf nose bats because they did do those follow-up studies. Tell us about the bats. I would love to. So here, these scents are not coming from glands on either side of the anus. These bats have glands like in the middle of their forehead where they secrete this stuff that is kind of stinky. It's a, the paper said it was a thick black secretion. And so gross. It's used for things like territorial defense.

16:44Life on earth can sometimes seem so alien. I know, but I love it. I mean, that's way it's so much fun studying this stuff, you know? You think like these animals have such different social lives, you know? Like if I was talking to you and I got too close to your house and you started secreting this black thing from your forehead to let me know that I got a little too close, I would call the cops or something, you know? Like, it's very different. That's just how we roll here in California, you gotta get used to it. Well, I prefer Virginia, I guess. And so I know how to communicate with people here a little bit better. And so do bats from different populations secrete different stuff? Yes. And so they looked and they found that there were distinct compounds that were produced in bats from different areas. And so like there was still some overlap and some of the scent stuff, but there were a handful of populations where there were very distinct things that were being produced in those populations of the same species, though, of the same species. Yep. So, what do you want it to know? Does this seem to be genetic? Is this a response to different environments?

17:47Or is this the result of their microbes? And their evidence suggested that actually this is probably because of different microbes that they harbor that like ferment the ooze coming out of their head in different ways. It's kombucha. That's, oh, face kombucha. Amazing. Katrina has to try to sell them. Then they did some follow up questions to ask, does this matter? And it does look like males can discriminate between the scent that comes from their colony and scents coming from other colonies. And if you give females the opportunity to interact with scents from their colonies or scents from other colonies, they prefer the scents from their own colony. And so it does seem like there's a behavioral implication of these dialects where in this case they're sort of preferring what is familiar. Is there a cool scientific name for this or is it just face secretions? I didn't find a word like sprain. And so let me see. They have a forehead.

18:47Well then let's call it skambucha, how about that? Oh my gosh, it's kombucha. Or is it fumbucha for like face fumbucha? Because I feel like you want to get the face part because that sounds super gross. Yeah, yeah. S fumbucha. S fumbucha. Amazing. And another paper saying that song sparrows also have a gland that produces these oils that they use when they're preening and the microbes that they have seem to impact the scent. And so this micro impact in dialects thing might happen in other places. But it's worth noting that I found another bat species paper on a closely related bat species. And they didn't find that the changes in scent between populations were associated with bacteria. So there's probably a lot of variability in why different populations stink in different ways. And I think we're still trying to understand the implications of this at least in mammals. But the answer is there are stink dialects, which is cool. Well, it's really fascinating if the male secretes a certain flavor of sphumbucha, grapefruit

19:50or whatever. And a female from the same population prefers that because that makes you wonder if there's like a cogenetic source of that, like the same gene codes for the male to secrete the flavor that the female likes. Or if that's a learned thing, you know, culturally, you grow up smelling grapefruit sphumbucha. And so you look for that, you know, in your mate. Yeah, or it could be that like maybe you don't even recognize as a mate, that's that smell different because part of just like how you recognize your species is by this like particular smell. And you're like, no, you don't smell right. I'm not sure what's going on there. And they just avoid them for that reason. But yeah, there's lots of different possible explanations. It's fun to think about. I have a friend who works on fruit lie meeting. Okay. And there they sing songs. And they're very regional. And so like the male has to sing the right song for the female to choose them. It's fascinating. And the females do they prefer the songs that they grew up with or do they prefer songs

20:51from males that have new interesting tunes. Yeah, they don't like those weird New Jersey imports. Actually, no, all of this research is happening in Princeton. So it's all New Jersey is local there. So those are the good ones. Those are the good ones. Yeah, it's a way to select your population. Yeah, it's fascinating. Yeah, totally. All right. So let's go ahead and send this answer to Zach and see what Zach thinks about mabucha. And sprites. And sprites. Thanks for the fun question. Naturally, I'm going to try my darnest to include the words sprained in all of my future scrabble games just for the opportunity to explain to my friends what that is. And I'll try to throw scumbush in there as well. So thank you for that. And especially thank you for providing me with that fascinating answer. It got me thinking about how useful these forms of communication must be for the organisms they use it across the animal kingdom. It's really helpful, of course, that we can use our voice to speak and our hands to sign,

21:55but those types of communication are very fleeting. And so for animals that in some cases can use communication that literally sticks around has to be so informative for those species. So thank you very much for giving my question a sniff. I hope you have a wonderful, wonderful day. A new planet fitness is now open in Lancaster East. Join today for $1.15 a month. Take advantage of our new best in class strength and cardio equipment in our spacious club. Free fitness training and so much more. Our doors are open and we're ready for you. You ready? Join the new planet fitness in Lancaster East for $1.15 a month. Hurry, deal ends October 4th. Fitness, cardio, strength, recovery, right around the corner. See club for details. Okay, we're back and we're answering amazing questions from listeners that give us a chance

23:07to go off and read about things we've also always been curious about but never had an excuse to dig into. Today we're literally going to drill in to a listener question or things that we did not know that we would be interested in and because it hadn't occurred to us before. So many reasons to thank the listeners for sharing their curiosity with us and let's go ahead and do a question for Daniel from Paul from Lamor, California. Hello, Daniel Kelly. I'm Paul from Lamor, California. My question is when humans finally land on icy moons like in Celerda, Saru, Europa, and something similar to Phil Rodd for a nuclear reactor be used to melt through the icy crust instead of using a drill. I appreciate you taking the time to listen to my question. Thank you. Do you think Lamor is like French like Lamor? Lamor? I don't know. Yes, I imagine it is a very romantic place to live. Well, let's hope so. But today we're not speculating about the romantic lives of Californians.

24:10We are taking our brains out into the solar system to imagine where aliens might be living and where they might be having their own kind of romance right in our backyard. Daniel, I want to know what's happening on Enceladus so bad. Like I really want video from underneath the ocean and Enceladus. Right. Let's spend a minute to remind people why we might go to the icy moons of Jupiter and Saturn. And the reason is that they're an excellent, excellent candidate for life or alien life right here in our solar system. You might be thinking aliens, if they're out there, are way, way out there that will never find them because you have to travel to a distant star. But the truth is we haven't finished looking in our own backyard. Yes, we've driven rovers around Mars and we think Venus is probably uninhabitable. But if you look a little bit further out, there are places where life can start that are very different from the brackish waters of primordial earth. And these are under miles of ice on these frozen moons.

25:13Can you imagine there being like, I don't know, fishy type things swimming around under there? Like how cool would it be to see that? Yes. Oh, yeah. Of course you have. And we can go there. And the reason this is so exciting is that under that ice is not just like some frozen rocky core, but oceans. We think miles and miles of water. And that's because these things are close to giant planets, Jupiter and Saturn. And they're squeezed by the tidal forces of those planets. Remember tidal force comes from gravity, but gravity doesn't just pull on the whole planet or the whole moon. It pulls on the closer bit harder because it's closer and the far away bit weaker because it's far away. And so it tends to make something like into a football. The way that like the moon makes the oceans on the earth kind of into a football shape. It piles them up near the moon and on the opposite side, it makes the oceans thinner on the edges. And then as the moon moves around the earth, the tides follow. In the same way as these giant moons around Jupiter and Saturn move, they get squeezed by

26:16Jupiter and Saturn's intense gravity. And that imparts a lot of heat. And so these oceans can stay unbrows and they can stay liquid under this thick crust, which means that it's a great place for life to perhaps begin. Yes, but unfortunately for us, it's not an easy place to get to because you have to get through, as you said, kilometers of ice. After you go through billions and billions of kilometers to get there, right? Right, right. Yes. What do we have to overcome to get ourselves to that ocean? Yes. Just to get there requires getting to Jupiter or Saturn, which is not easy. We recently had a whole episode about chemical rockets, etc., etc. First you got to convince your government to build this thing. And the whole thing is going to cost hundreds of millions. And then you got to get it there. But even once you get there, let's just skip over all of the political issues and the launch issues and the space travel issues. Say you are lucky enough to land on Europa. Now you're sitting on kilometers of ice and the amazing alien payload is on the other

27:21side of that ice. So you got to drill. And drilling is hard. Even here on earth drilling is hard. You know, if you've like tried to drill into your wall, you know, or if you work like on an oil rig or whatever, it's dangerous. Mechanical drilling is really hard. You have to have a drill bit. Drill bits can break. You have to have an engine. But the engine can choke if you hit something hard. And so you need like transmissions and like basically no drill works without some expert babysitting it and constantly repairing it. But we're not sending people to Europa or in some lattice, not yet at least. So we need some sort of autonomous drill. And that's what the fact that this is ice and not rock is actually a big advantage. Because you can melt it. You can melt it exactly. So instead of like mechanically trying to cut through it, you just melt it and then it becomes liquid and you can slide through it. And you might think that sounds crazy and it extra hard. And shouldn't we figure out how to do that first here on earth? Any answer is yes.

28:21And we've done it. We have done this in the ice of Antarctica. We have this amazing experiment called ice cube. That's a great name for a project. Did ice, oh no it's iced tea. I'm getting my, I'm not very cool. No ice cube is a wrapper. Yes. Oh wait there's iced tea and ice cube. There's iced tea and there's ice cube absolutely. Nice. Is there ice pops? You know there's some rule of the internet where like whatever you can imagine there's probably a wrapper with that name. Okay. That's not how I remember the rule going. I adapted it for this family friendly conversation. But ice cube is an experiment that instruments a cubic kilometer of ice in Antarctica. It's to look for cosmic ray neutrinos and muons and all sorts of stuff where you have super fast particles going through the ice faster than light can go through the ice making this shrink off radiation, this blue cone and to capture it you need cameras in

29:23the ice. So you got to drill down through a kilometer and leave these cameras in the ice. So you got to drill through a lot of ice and tough conditions, right? And so they've done this and they didn't use a big mechanical drill. They used high pressure hot water. Basically they just melt the ice and then they have this string of cameras. It's a kilometer long. It's basically like a long tether and it's got these glass spheres on it inside the spheres is all the delicate particle physics detectors and experimental devices and electronics and stuff. And so they melt it and then they drop this tether down and then they just let it re freeze. Wow. So that you have this equipment down through the ice and they've instrumented a cubic kilometer. It's amazing. It's such a huge experiment. I love it. It's like science fiction. But it's real. And the whole there goes through two and a half kilometers of ice and it's about 60 centimeters wide. Wow. And so our plans on Enceladus, do they involve hot water? Because Paul wanted to know if we were going to use like radioactive materials.

30:25The Antarctica solution seems like it would be difficult to pour it over to Enceladus. Yes. Exactly. I mean, it teaches us that this is possible that you can do it as long as you have a heat source. And the crucial thing to understand is that you're just letting it re freeze. You're not trying to keep the whole column liquid, right? Just the part that you're digging out as things slide down and that's going to turn out to be crucial. And so in the case of drilling through one of these moons, you're not going to have some easy source of hot water. You need to bring some sort of power with you. And so of course, the best option is some kind of nuclear power because that's the densest sort of fuel. And there are a few different options here. One is you can have just like direct nuclear heating. Like if you have some sort of isotope like plutonium 238, it just decays and it gives off particles at like 10,000 miles per second. And so if you surround that with some sort of liquid, it will get heated up. And that's like directly nuclear decay turning into heat.

31:26No power generation, no vision, just like directly radio isotopic decay into heat. And that's pretty cool because you don't need complicated, vision equipment. You don't need to send a nuclear reactor. You don't need to generate electricity, which is very inefficient. It's very nice and it generates heat. And so that's like a really strong option, just like directly produce heat. And so I've got two questions. So one, you said something about we're not going to have an easy source of hot water on Enceladus, but we didn't have an easy source of hot water probably in Antarctica. And so how did they make the hot water? Did they just bring like a generator fueled with gasoline to heat it up? And so the point there is, of course, you don't like have geysers. It's not like Iceland or something where you have an easy source of hot water that way, but you are connected to some kind of existing infrastructure, right? There is power. You can get fuel delivered. It's not that far away. As you guys point out in your book, Antarctica is actually like a lot easier than space. Yeah. Even though it's uncomfortable and unpleasant and I would never want to go there, it's

32:27a lot easier to live there than it is to go to space. And in the case of ice cube, they use fuel power generators to run heaters and melt the snow and spew it out in high pressure streams. And that's not an option. You can't send diesel fuel into the moons of Jupiter. But you can send a radioisotopic heat source. And so then my other question is like so for the Antarctica experiment, they had to like heat quickly, like all the way through and then put their equipment in and then let it freeze. Yes. Does a radioisotopic heat source, is that going to heat all the way through fast enough so that you can put your equipment in there? Like does it give out that kind of heat? No, but it doesn't have to. And so it just needs to melt the part that's in front of it. And so it can re-freeze behind it as it goes. So it needs to like unspool it tether. So it needs to bring with it like three kilometers of line and then unspool it as it goes and let it re-freeze behind it. And so it only needs to be able to melt the bit that's right in front of it.

33:28So it like melts a bit of ice and moves into that liquid. And the liquid it was just in re-freezes behind it. So like there's no going back. It's pretty claustrophobic experience. But we're such a clever species. That's awesome. Yeah, it's pretty amazing. The issue with radioisotopic decay is that it's efficient because it turns a lot of the original energy into heat. But you also need power for other things, right? You don't just need heat. You are a little device. You need the electronics. You need electricity. And so it's tempting to also include something which will produce electricity. And you don't even have to go all the way to efficient reactors for that. You can just use an RTG, which is a radioisotope thermoelectric generator. So again, not yet all the way to efficient reactors use thermocouples. So these have no moving parts. It's just essentially solid state. And it turns radiation directly into electricity. But it's very inefficient. It turns like 6% of the heat into electricity. But you know, if you need some electricity, then that's a nice addition. So you might have like both a radioisotopic heater and you might turn some of it into electricity

34:35to run your system. Or if you want to go whole hog, just build a full on vision reactor, right? These days, the vision industry is really focusing on miniaturization, building small modular reactors. And so the idea is to bring a small one that can actually generate enough electricity that you could both power a heater and you could power the device itself. But it's like a lot more mechanical complexity and weight. And you know, you can't repair it if it's not working. When do we have actual like plans on the books to go do this? Or is this all hypothetical? I wish that we had plans on the books, you know? We do have some plans to visit these planets. Like there's the Europa Clipper, which is en route. It's like heading there right now. And it's going to arrive in 2030, yay. But it's just going to do flybys. People are curious about this moon, like let's take more pictures. Then there's the juice, which stands for Jupiter, icy moons explorer, which is going to go into orbit around Gennadmead in 2031.

35:36Also very, very cool. But again, these are just orbiters. They're going to take pictures. They're going to help us understand the surface. We want to get on the surface and dig down. We want to meet those alien octopi, right? We want to see what alien sprints are all about. Drill, baby, drill. So now we're into the regime of proposed experiments. There's the Europa lander, which is supposed to land on the surface and like scoop up some of it and study it. Because like we've never even been there. Who knows what it's made out of? Even more exciting is the insolatous orbital lander, which is not going to land. It's going to sample the geysers because insolatous has a lot of activity. It sprays. It's inwards out into space. So you might capture like an alien microbe or something just by flying by and flying through one of those plumes and gathering it and then analyzing it on board. Very cool. Not yet approved. So neither these two, the lander or the overlander are approved. There are plans for something called prime, which is a lander with a driller. And also as it drills, it brings a miniature submarine with it so that it drills down through

36:41this hole. It has a tether to go back up to the surface so you can send data, right? Nice. We get through the ice. It releases into the water, a submarine to go off and explore, which then communicates back with the lander up the tether and sends us the glorious information about everything it's discovered. I need that to get approved. I know. Write your congressperson or your member of European Parliament or whatever because we can do this. People we have the money. We have the technology. We know how to do it. We're just choosing not to know these things about the universe because we want to build more aircraft carriers or whatever. So this experiment is called prime. It's not yet approved, which means that we haven't started building it. We haven't. It's not on its way. Which means the earliest this could happen is like, you know, unfortunately 15 years away. By which point will all be a hundred? That's right. That's right. That's right. Well, let's go ahead and send this answer to Paul and see if we have answered his question.

37:42I hope he lures it. But I'm bummed. Hi, Daniel. Hi, Kelly. Daniel, thank you for explaining a few different ways of melting through ice to explore the subterranean ocean to the icy moons of our solar system. I'm looking forward to reading about the Europa Clipper mission in the next few years. But I grew as Kelly and I'm wanting to see some video footage of underneath the ice. I like to imagine byolumines and alien creatures swimming around in the black background of the dark sunless ocean. Thank you again. I appreciate both of you for taking the time to answer my question and sharing a knowledge with all of us listening to your podcast. We're back and we're answering questions from listeners and the one next is super fascinating.

38:42Gask's a really penetrating question, don't you think? Right. This is where we're remind people that we are about to talk about sex. So, yes, Josh had a very penetrating question. Let's go ahead and hear what Josh had to say. Hi, Daniel and Kelly. I was thinking about the way that humans and I guess probably a lot of other species have sperm cells and excels. And the fact that some of us have a penis and others have a vagina. I'm also familiar with some extreme examples of this, like the pigs, corkscrew penis and the arms race of convolution in duck sexual organs. But this made me think, how do we get here? What are the evolutionary stages to get to each reproductive strategy? What are the different ways to do sexual reproduction and what evolutionary drives mean some creatures such as plants just sort of spray their sex cells into space and hope while others have these interlocking parts and specialised cells? So I followed up with Josh to make sure I understood the question and pretty much the question is where did weeners come from?

39:44Which is a great question. Especially to somebody named Weenersmith. That's right. I am clearly the right person to send this question to. And so I will note that my research for this question involved reading a book called Fallacy and Auto Correct turned the spelling correct, but the book is P-H-A-L-L-A-C-Y. Nice. Something like that. Anyway, you know, I've been to the Fallacy Museum in Iceland. It's quite impressive. I really want to go there to see. They've got the penis bone from a whale there and I amongst other amazing penis related memorabilia. And I would like to see all of them. There are so many things to mention from that, including for example, they have molds of the penises of Iceland's most successful Olympic athletes ever. Wow. Which is I think the Icelandic handball team who got the bronze medal or something and then they have a picture of the whole team and then they have molds of all the penises arranged in the same order as the team. So you can be like, oh, interesting.

40:45I feel like that's totally unrelated to handball, but congratulations to those people. I mean, there's an obvious handball joke to make there. But I think the most interesting sociological part of that museum is the history of it. It started in some guys garage and then apparently took over his house and his wife was like, out. I cannot have this in my house. And so we have to move it into a museum. We out to him and the specimens or just the specimens. Didn't say at least the specimens of the minimum. But back to the biology, tell us Kelly, how long have we had penises on earth? When was the first penis? I did not get when was the first penis because actually what is a penises complicated question? And so instead of talking about penises in particular, we're going to talk about intra-mitten organs. And so the point here is there's a couple different ways of mixing sperm and eggs. A lot of fish do what's called external fertilization where a female will essentially like excrete some eggs into the environment and a male will plop some sperm on top of that.

41:47And that's how everything gets fertilized. And you do that. Those fertilized eggs now need to be guarded in a lot of cases because they're like delicious snacks for a lot of other organisms. So it's not very safe for the offspring to do things that way unless you've got someone who's willing to stay there and watch them. Another problem is when you're doing external fertilization, when the male releases his sperm onto the eggs, often other males called sneaker males or satellite males will like come by and deposit their sperm as well. It's sort of unwanted, but they snuck in there and they got it. So this is another problem with external fertilization. A third problem with external fertilization is that it works really well in wet or moist environments. But if you have eggs and sperm meeting together in an open area like on land, they dry out really quick. And so the way that amniotes have solved this problem is that fertilization happens inside of the female. Because then we can either slap a calcium shell on there for the birds and then send it

42:48out into the environment and it's fine. Or in mammals, we've got a placenta and everything sort of happens inside the mom until the baby's ready to go. So we have found solutions for that environmental problem by having a lot of the stuff happen inside of mom. And that's what we call internal fertilization. There's a couple of different ways to do internal fertilization that don't involve anything that's weiner-like. One of them is what's called a clowaco kiss, which is not as romantic as you might imagine. So some birds have openings called clowaco, which I think is the Latin word for sewer, because not only do like sperm and eggs come out through here, but also so does feces and urine and all of the waste. It's like an all purpose hole for birds. And when they want to reproduce, they will stick the clowacas together and the male will excrete some sperm and then just kind of hope that it ends up where it needs to go up inside of the female.

43:49But you can imagine that having an appendage that allows you to place the sperm in a little bit more specific way could be helpful for increasing the probability that your sperm actually fertilize an egg. Aim it a little bit. Aim it a little bit. Right. And so throughout the animal kingdom, there are lots of different ways that animals accomplish this. No, anybody who's like cleaned a bathroom that men use, know that having a penis does not mean you can aim. No, no. I mean, if you're paying attention, you can aim. My first job was I was a bagger at Kroger's and my job also was often to clean the rest rooms. And there is just, there is feces in places that you just, I can't even fathom how they got there. Our species is disgusting. And you know, I always, I didn't like cleaning the ladies room, but I really didn't like cleaning the men's room. You guys are gross. I don't know what's happening in there. It was, it was like a different species. Criticism accepted. I have no defense.

44:50Yeah. Absolutely. Totally agree. Dudes are gross. Yeah. Super gross. All right. And so millipedes, for example, have what are called gonopods, which are like weiner feet. And so their eighth pair of legs actually is able to take sperm and insert it into the female. Wow. And so that's not like technically a penis, but I don't know, maybe it is. There's actually some debate about, you know, how do you define the term penis, but the broader term is intermittent organ. So are there conferences where people like have shopping matches about this? Probably. I don't know. We get upset about all kinds of stuff. Whatever it is, there's some academic conference where they argue about it. That's the new internet rule. Absolutely. Yes. And there's other ways of getting the stuff up there. So for example, males, I know. Such a delicate way to put it, Kelly. Thank you. I mean, I went to school for animal behavior. We don't take this stuff very, I mean, we take it seriously, but we don't like have any reverence for the topic. But so you can make things called spermatifors, which are packets of sperm plus other stuff

45:52that can be like placed in the environment temporarily. And then the female will in some cases take it up by like, I don't know, squatting over it and then sort of pulling it up into her body. Or males have like organs that help them sort of insert it into her body. And so that's another way of like getting sperm inside of a female. One of the benefits for the female of internal fertilization though is that females have evolved very complicated ways to either store sperm for when they need it if they found like a really great guy, but they're not really ready to have babies yet. They can hold onto that stuff for when the moment feels right. Yeah. Wow. For how long? It depends on the species, but I definitely days for some species. I think there were somewhere it was weeks or months. Amazing. It can be a really long time. And then there's also some that have like extra compartments where they can choose like they can mate with multiple males. And afterwards they can pick their favorite and use the sperm from that one and not use the sperm from the others. Wow. So complicated. And in other species it's even more complicated.

46:54Even more, although you know, you don't really know if you were rejected in that case, right? And so that's nice, I guess. So the lady can swipe right or left or whatever it is even after you're done. That's right. That's right. Life is good. And I should note that in this book fallacy Emily Wilmingham makes the point that we've studied penises a lot. But ginas are almost certainly equally interesting, but have been massively understudied relative to penises. So I wanted to get a plug in for vaginas where we were here and the fascinating things that we learned about animal behavior when we study female vaginas. If you are a young scientist trying to figure out where in this wide world you want to devote your energy, Kelly suggests the vagina. I think we have loads left to learn about vaginas. And I think a copia of data left to collect there. So the question is like, why do we have internal fertilization and why in particular do we have devices that are used to insert sperm into the female?

47:58One of the hypotheses is this idea of a lock-in key. So if you're trying to figure out if you have picked a member of your own species to mate with, then seeing if a penis fits in a vagina is one way to do that, to make sure that you're mating with the right species. Should say the evidence for this hypothesis is kind of mixed. You see plenty of closely related species mating with one another anyway. It doesn't seem like this lock-in key is very specific, but there's some idea that this is a first pass at trying to make sure that you're mating with a member of the right species. Another benefit of internal fertilization, which we've talked about, is that now you've got it in an environment that is sort of moist so the sperm and the eggs aren't going to dry out. But in particular, if you have a penis, then you can increase the probability that you actually get the sperm into the female at the right spot relative to something like a colloagal kiss, which does work a lot of the time, but it might be nice to have a little bit of extra confidence that it's getting to where it needs to go. Another nice thing about internal fertilization is that the eggs tend to be bigger, and especially

49:00if the females are holding on to the offspring inside of them until the offspring are bigger than when you finally release them into the environment, they have a better chance of survival. So there's lots of benefits to internal fertilization. Some of them are even more beneficial when you have a device that can insert right up into the vagina, but plenty of organisms make do without it. They just kind of come up with some clever ways of doing it. So do you feel like that answered the question? Do you understand why penises exist to some extent? Yeah, I do. I think it gives me an idea for why there are penises. And also though, I don't think you talked about this, helps me understand why there's like a plethora of kinds. Yeah. Exploring evolutionarily, like what things might work. And I know there are like long ones, and spiral ones, and you know, multi-tipped ones or whatever. Or with horns, lizards and snakes have hemipines. Sure. They have two penises that they can alternate between which one they use. Amazing. Yes, exactly.

50:00Evolution is the greatest experimenter. That's right. Yes. So intermittent organs have popped up, if you will. Total times throughout evolution. And yeah, they've got lots of different shapes, lots of different forms. And again, because this is ecology, the answer is it depends. So we were talking about how if you're in an aquatic environment, it's fine to release sperm and eggs out into the environment because it's wet there. But there's plenty of fish species that have organs that allow males to play sperm inside of a female. And we think that that, you know, increases the probability of fertilization, increases certainty that you're the only one, at least in that moment, who is attempting to fertilize the eggs. And so, you know, even in aquatic environments, you find organisms that have intermittent organs because nature is complicated. Nature is complicated. All right. Let's send this answer back to Josh and see if your answer has gotten up in there to the place where his questions were reading. Josh, let us know if you're okay with that.

51:01Hello again. Thank you so much for sharing the ins and outs of this fascinating topic. The world of reproductive organs is even more varied than I realized and I'll definitely be checking that book out. All right. Thank you everybody for your amazing questions. I know I had a ton of fun today, probably more fun than should be legal. Yeah, thanks for sharing your time and your curiosity with us. And if you have a question about how the universe works, it's Sprint Too Late to send it to us. Oh no! And I'm sorry, remember, it's Sprint Too Late to send it to Daniel. Kelly's on hiatus for a little while, but looking forward to catching up so I can get new questions from you all soon. Stay tuned, everyone. Thanks everybody for listening. Please go and do us a favor and rate the show on whatever podcast app you're using. It really helps people find us. Daniel and Kelly's extraordinary universe is edited by the amazing Matt Kesselman. He really is a wizard.

52:02You can also find us online on Blue Sky, Instagram and X, D&K, and Universe. Come engage with us. You can email us at questions at Daniel and Kelly.org. We really do want to hear from you. And you can find our website www.DanielandKelly.org where you'll also find the invitation to join our Discord where everybody comes and talks about the amazing universe. And we also have the most amazing moderators. This is an iHeart Podcast. Thanks for joining us. This is an iHeart Podcast. Guaranteed Human.