Listener Questions #15

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Speaker 1: Hey, they're extraordinaries. Kelly.

00:00:02
Speaker 2: Here my book, A City on Mars? Can we settle Space? Should we settle space? And have we really thought this through? Comes out in paperback on July twenty ninth, So if you've been interested in reading it but the hardback version was just too expensive or the wait list at your library was intolerably long, then you're in luck. In this book we answer questions like where are we likely to settle in space? Can we make babies in space? Why do astronauts love taco sauce? And what's the legal status of space cannibalism? So grab yourself a copy of A City on Mars wherever fine books are sold. Conflicting advice is making me twitch?

00:00:50
Speaker 1: Is it good or is it bad? To scratch my itch?

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Speaker 3: If the ort cloud is filled with icy rocks? Why isn't our view of the stars blocked?

00:01:00
Speaker 2: Are honeybees Nature's mathematicians? Or can nature forge hexagons without cognition?

00:01:06
Speaker 3: Whatever questions keep you up at night, Daniel and Kelly's answers will make it right.

00:01:11
Speaker 1: Welcome to Daniel and Kelly's Extraordinary Universe.

00:01:27
Speaker 3: Hi, I'm Daniel, I'm a particle physicist and I love hearing questions from the public. What people are wondering about, what they're curious about, what they are confused about. Right to be please and share with me your confusion.

00:01:40
Speaker 4: Hello.

00:01:40
Speaker 1: I'm Kelly Winer Smith.

00:01:41
Speaker 2: I study parasites and space, and I totally agree with Daniel. And also I have to note that these questions have pointed out to me how many things I don't think hard enough about. Like today we have some very basic questions about like why do we itch? And I you know, I must scratch ten or so times and like, yeah, maybe even more without thinking about it. And I've never really thought about why. And so I am loving the opportunity to dig into all of these different questions.

00:02:09
Speaker 3: Yeah, it's fun on so many levels, Like we get an opportunity to learn more about areas that we've always been curious about but never had an excuse to dig into, Like yeah, when have you told yourself I have an hour free, I'm a to read about itching? But now you have a reason, right, Yep. You also discover how many basic things in science we're still pretty clueless about, you know, like how many things we understand at really just the surface level. Yeah, which means that there's lots of things to figure out for all you young scientists out there.

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Speaker 2: Yeah, that's right, all the kids who are listening, there's a lot of work for you to do, and just keep a list as we go through these episodes of questions that need answers that you might be the one to answer.

00:02:45
Speaker 3: That's right. The forefront of human knowledge is not that far away from where you are right now in lots of cases. I mean, yeah, we've been doing physics for a long time and we've made some progress, and it takes a while to understand all the details of particle physics, but they're still very basic questions even about particle physics, that we don't know the answers to. Why are there so many particles? What do they all do? What is the rest of the universe made out of? You know, basic stuff everybody wants to understand. And so if you have a question about the universe or parasites or parasites in the universe, you might be asking a question right at the forefront of our knowledge. So don't be shy, ask.

00:03:19
Speaker 2: Away and let us do the research for you. So I have an answer I'm just itching to share with you. We got we got there must have been something itchy in the air, because within a very short amount of time we got two different questions about itching and scratching.

00:03:37
Speaker 1: So let's go ahead and hear the questions.

00:03:39
Speaker 5: I'd like to know what causes itches and why does scratching stop them. I don't mean itches that have a clear source medicine, side effects, bug bites, rashes, irritating clothing scenes, et cetera. I mean when you're just going about your day and suddenly some random part of you itches. How will you scratch it the itch stops?

00:04:00
Speaker 4: What's up with that? Hey, I'm loving the show. I wonder if you could answer a question for me. This might be one for Kelly. I've heard recently about a study which said, I think it was in mice, that if you scratch an itch, then it's beneficial because that allows antibodies to go to the site and to clear up any infection. But then there was another study, also in mice, saying that scratching and itch is problematic because it activates pain nerves, which then causes more riching and more inflammation. Which is it, Should I ignore the urge to scratch an itch or should I just go ahead and scratch it. Keep up the good work. Thanks.

00:04:45
Speaker 3: I think these questions are pretty deep. They're not really just surface level, you know. I think they're really dig down into what's going on. I didn't eat the skin, yeah.

00:04:53
Speaker 1: And I had a ton of fun digging in.

00:04:55
Speaker 2: And actually, it turns out that our understanding of itching has apparently undergone some pretty major changes in the last few decades. So initially we thought that itching was a minor form of pain, which would suggest that it's using the same pain receptors. And it's just sort of like, if you tickle the pain receptors just a little bit, you get an itch, but when you really hurt them, then you get pain.

00:05:19
Speaker 3: But back up and give me the bigger picture here. When you say pain receptors, you're talking about like nerve endings just under the skin. And I don't know enough biology to even know, like, are there different nerves for pain and for like cold and for other stuff? How does that all work?

00:05:33
Speaker 1: Oh? Yeah, great questions.

00:05:35
Speaker 2: So there are different nerves for different things, and so we do have some nerves that specifically are there to tell us about pain. And so for anyone who's gotten tattoos out there, you know, that there are some areas that hurt to get tattooed more than others. Daniel, you're shaking your head, yes, knowingly. Do you have tattoos?

00:05:51
Speaker 3: I do not, but I have a teenager who wants to get tattoos, and so we've had lots of conversations about making ferman decisions for your body.

00:06:00
Speaker 1: Got it okay.

00:06:01
Speaker 2: So there are some parts of your body that have more pain receptors than others, and those areas tend to hurt a little bit more when you get tattoos. And what these receptors do is they deliver messages from like the surface of your skin up to your brain to say, oh, something hurts, and then you respond to it, and often you respond to it without even really thinking about it.

00:06:19
Speaker 1: You have sort of a reflexive response.

00:06:20
Speaker 3: And so, for example, I know that I have a lot of nerves and the tips of my fingers, so I could tell the difference between one needle and like two needles very close together, and the tips of my finger has been not like on my elbow because I have fewer nerves there. I can't resolve it. But that's a different nerve system than the ones that help me sense pain.

00:06:38
Speaker 2: Yeah, so we're getting a little bit outside of my area of expertise here, but I think that those are touch receptors that you would be detecting there, unless you were like stabbing those needles into your fingers, which I assume you're not. I think we're talking about touch receptors there, and we've got receptors for cold and for hot and stuff like that.

00:06:54
Speaker 3: So you were saying that people used to think that itching or stimulating the pain receptors the nerves that when something hurts, Yeah, that doesn't really make a lot of sense to me, because itching doesn't feel like pain. It feels like uncomfortable and enjoys me crazy, but doesn't hurt the same way.

00:07:08
Speaker 1: Yeah.

00:07:09
Speaker 2: Well, so I wonder if it was because sometimes if you itch for a really long time, you scratch and then it starts to hurt. And so maybe people were just like imagining a continuum there that doesn't exist. But also, it's not so surprising we got these two systems sort of mixed up because they have a lot of cross talk. There's a lot of times when you stimulate one system and it sort of interacts with the other. For example, when I got an epidural when I was pregnant with my second. The first one was natural, second one, I had an epidural.

00:07:38
Speaker 3: Uh not just like a Friday night epidural.

00:07:40
Speaker 2: No, yeah right, No, I mean fun not recreational.

00:07:44
Speaker 1: Recreational.

00:07:45
Speaker 3: Yeah, no judgments to anybody out there who does that, you know, just clarifying here.

00:07:50
Speaker 2: Yeah, fair enough, But that would be an expensive habit, I'm guessing, because I think you'd need to get insured. But anyway, so when I got my epidural, I started itching like crazy.

00:08:01
Speaker 1: And I didn't.

00:08:02
Speaker 2: Find like a paper that specifically said some people who get epidural.

00:08:05
Speaker 1: Scratch like crazy.

00:08:06
Speaker 2: But I found a couple of papers that were referencing how sometimes when you do something for pain, you get this weird itchy side effect, and sometimes when you do something for itching, you get this weird pain side effect. And so these two systems seem to have a lot of cross talk, and they interact, but they are separate. Interesting, and so we do have specific receptors for itch.

00:08:26
Speaker 3: We do, so we've like evolved a whole system to make you uncomfortable.

00:08:30
Speaker 2: Well, okay, so I would say that a lot of times it does seem like our itch system does things that are maladaptive. Give me a second to do a little bit more explaining, and then we'll get back to that. So you've got these itch receptors and they can be stimulated externally or internally. So externally would be like there's a tick crawling on your skin and you feel itchy, and your immediate response is to try to brush it off, and that is pretty adaptive. You know, you move it off, and now you don't have that tick on there anymore. And I'm very proud of my body because I feel like I am really tuned to ticks. I've almost never had one bite me, but I've taken loads off of me, so like I feel them when they're moving around, So that's good.

00:09:11
Speaker 3: That's definitely a plus. I understand that, like your body wants you to feel uncomfortable having that critter crawl over you.

00:09:18
Speaker 2: Yes, exactly, Like your attention needs to be drawn to that you need to take care of it right away. We also have responses to internal things like histamines and various things that your immune system does. So for example, if you in the winter have really dry hands and you like make a fist and your skin cracks and bleeds like mine does, your immune system responds to those cracks and it recruits to where those cracks are, and the presence of those immune system cells trigger your itch receptors. And that's why your hand gets itchy when it's all broken and bleeding.

00:09:54
Speaker 3: Help me understand why internal histamines trigger the same receptors as a tick crawling across myself. Does that make sense.

00:10:01
Speaker 2: For some reason, I'm not sure that it does make sense. So there's a couple of different hypotheses here. So one hypothesis is that our species itches as.

00:10:14
Speaker 1: Sort of like an evolutionary hold over.

00:10:17
Speaker 2: So we used to have fur, and it used to be that we would when we would itch, we wouldn't damage ourselves because the fur got in the way. But now we don't have fur, and so when we itch, we damage ourselves. And so it could be that most of the time when there was an immune response, maybe it was because, for example, there was a tick that had bit and the immune system was responding to it. And so if you scratch, and you scratch through your fur, you get that tick off. And you know, I can still imagine the immune system drawing your attention to the presence of a tick, and you know, the sooner you remove a tick, the better, because some of them don't give you the diseases they're carrying until they've been on there for a while. And now I feel like I'm crawling with ticks because we're talking about it.

00:10:56
Speaker 3: I hope everybody out there getting itchy and ticky.

00:10:59
Speaker 2: Yes, guys and gals, So yeah, I mean I think it. Sometimes scratching is good because it removes something, or maybe it recruits more immune cells.

00:11:09
Speaker 1: But sometimes scratching is just bad.

00:11:10
Speaker 3: So I think you're saying that itching on the surface is very clear. It's to help us get rid of something that's crawling across us and might bite us and is bad for us, And that itching internally might also be good because it's a signal that something is already bitten us, and if we scratch it, we could get rid of it. So it's not that they trigger exactly the same mechanism. It's like two ways to protect us from critters. But are they biochemically the same mechanism, Like does it tick crawling across your skin trigger the same histamines and that whole same channel, or are they two separate.

00:11:41
Speaker 2: Mechanisms Both mechanisms trigger the same itch receptors to send a message to your brain that says scratch. And I think in both cases you can get good information that tells you to scratch when you should scratch, but both externally and internally you can also get bad information. So, for example, your skin might be particularly sensitive to certain kinds of allergens, or you know, certain kinds of compounds and soap, right, and then you might start scratching for no good reason. And you know, same thing with your body responding internally by releasing histamines at places where you really don't need to be scratching. And additionally, when you start scratching, you can initiate what's called the itch scratch cycle. And here's what happens there.

00:12:23
Speaker 3: So this sounds like a nightmare.

00:12:24
Speaker 2: So you start itching, and when you start itching, we all know that it feels amazing often, and so what's happening there is that your itch signal is being overridden by a pain signal, because when you scratch, you're causing yourself a little bit of pain. And I think the rest of this explanation is a little bit like, here's what we think is happening, but we're not one hundred percent sure. But they think that after you scratch and your pain signal overrides the itch signal, you also release some serotonin, which makes you feel better and sort of makes the pain eventually go away. And so scratching feels good. But when you scratch, you often damage the skin a little bit, especially if you're giving it a really strong scratch. And if you give it too hard of a scratch, now you've caused damage, and that damage recruits more immune cells, which makes you itch even more. And so by itching, you can make yourself itchier. And so there are people who have chronic itching issues and they get stuck in this itch scratch cycle. You know, if you tell someone who's itchy, oh, just don't scratch it. The scratching is what's causing the problem. That's like maddening, I think to tell someone because once you've got an itch, how do you avoid scratching that itch?

00:13:36
Speaker 1: That's like all you can think about.

00:13:37
Speaker 3: This is fascinating to me to understand exactly what happens when you scratch an itch, because I do this all the time. I'm the kind of person who's very sensitive to mosquito bites. They like torture me, and if I have one that's like really buzzing, and I scratch it. It's like the greatest relief in the world. Oh my god, that feeling is just like it's not just that the itch goes away, like actually feels really good, but you're right, scratch it hard, then that really fades, and then the pain comes through and then it gets itchy again. And scattered through my house are like dozens of these itch relief sticks, oh, which I totally rely on, and their lile benagyl sticks, and they are antihistamines. So I think that personal piece of data that the anecdote supports your hypothesis there. But it's fascinating to hear about like the serotonin, Like that's why I feel good, Right, It's not just that the itch has stopped and the discomfort has gone, but there's something in my body that is making me actually enjoy it.

00:14:30
Speaker 2: That is the current hypothesis. Yes, I don't know that we've absolutely nailed that down. And it's interesting that you mentioned antihistamines because one of the reasons that we know we don't really understand itch well is that you can give somewhat antihistamines in a case where you think that should solve the problem. Yeah, and it doesn't, and so it is more complicated. And you know, for some people, if you've got an itch, you scratch it, that's the end of the story. But for other people, their immune systems are a little bit more sensitive. You scratch it, that recruits more immune cells and you start getting in the cycle. You also can get chronic itch for reasons that you know, we again don't understand really well.

00:15:06
Speaker 3: So, for example, chronic itch.

00:15:08
Speaker 1: I know chronic itch.

00:15:09
Speaker 3: I would never wish that on my worst enemy.

00:15:11
Speaker 2: I was listening to an interview on NPR's Fresh Air from a woman who has a disease. I think it was of her liver or kidneys, and it creates chronic itch. And we don't understand why that particular issue should result in chronic itch, but she itches all the time. There's also folks who have chronic itch related to mental health issues, so like when they get depressed or anxious, it kind of makes them itchy, and so they scratch.

00:15:36
Speaker 1: A lot more.

00:15:37
Speaker 3: What's the connection there, I don't think we know. Just another amazing mind body connection. You know, it's incredible to me how much your mental state influences your body's health. And vice versa.

00:15:48
Speaker 2: Yeah, I mean the only reason I ended up on anxiety medication is because I went to my doctor and was like, everything hurts, my stomach hurts, and why is it? And she was like, I think it's uh, you know. She didn't say I think it's in your head. She was much nicer about it. But yes, when we're stressed out or anxious or depressed, it impacts our body in weird ways. So yeah, the studying of chronic itching and how to relieve it is a big area where there's a lot of work that we still have left to do. So the first question that we had was why do you itch when there's nothing there to make you itch? And I think part of the answer could be that, you know, for some people it's a mental health thing. Maybe they're anxious and stressed and there is nothing there. But I think a lot of the times it's something did cause you to need to itch, But maybe it's just escaping your consciousness. So for example, maybe there's like some fiber in your shirt that your body is confusing as a tick, or there was something in your soap that's creating a little bit of an allergic reaction in your back.

00:16:49
Speaker 1: That you didn't know about.

00:16:50
Speaker 2: You know, I think in general, something usually initiates this need to scratch, but we just can't always tell what it was.

00:16:58
Speaker 3: And the second question I think is one that's to my heart, which is, tell me, Kelly, from the point of view of science, should I scratch or should I resist? Am I a bad person for scratching my itches? All?

00:17:07
Speaker 1: Right?

00:17:08
Speaker 2: One, you are not a bad person for scratching your itches. There is no judgment here U.

00:17:13
Speaker 4: Two.

00:17:13
Speaker 2: I think it depends on why you're itching. So the listener mentioned that there was a study in mice that found that if you scratched, it recruited immune cells to the area, and that maybe that immune cell helped you deal with an infection or something. So it's possible that under some conditions, maybe you're able to recruit more immune cells if you've got like an infection or something that's itchy. But I think in a lot of cases, itching will feel good, but there's some chance that something bad will happen afterwards, and that something bad would be you could maybe open up a wound and give yourself an infection, or you could start off a new round of the itch scratch cycle, and so well, I think there's nothing wrong with like giving a light scratch to a mosquito bite, or if you've got an itch, making sure you don't have an insect crawling on you or tick crawling on you. But in general, I think the answer, because it's biology, is it depends. And if you are going to scratch, if you can scratch with like I don't know, your knuckles or something to try to like not break the skin so much, that would be great. But you know, just at the end of the day, some of us we can't help but scratch, and it's it's just hard to avoid.

00:18:20
Speaker 3: All right. Well, now I have a question which you may be the only person in the world qualified to answer. What because it connects itches in space? Are there cases where astronauts had crazy itches they couldn't scratch because they were in a space suit? And what are you supposed to do?

00:18:36
Speaker 1: Oh, oh my gosh, that must have happened.

00:18:40
Speaker 2: So you know, you can, like I guess you could try to like rub your skin against the inside of the suit.

00:18:45
Speaker 3: And so I wish you all could see the dance Kelly is doing right now to mimic how to scratch your back inside a spacesuit.

00:18:52
Speaker 2: Yeah, there are so many things that sound uncomfortable about being in a spacesuit, and the most uncomfortable of which is elamination.

00:19:00
Speaker 1: Have we talked. Do you know what that means?

00:19:04
Speaker 3: No, it sounds like you're removing your skin.

00:19:06
Speaker 1: Maybe you're removing your nails. So those gloves, I'm so so yeah.

00:19:12
Speaker 2: So those gloves are really hard to bend. And there are some cases where people have tried to bend it and their nails have kind of got stuck in their nails are pulled up from the nailbit.

00:19:20
Speaker 1: I know, so gross. So anyway, and then.

00:19:23
Speaker 3: You can't scratch your itches because you have no more fingernails.

00:19:26
Speaker 1: Oh my gosh. Oh, so many layers of horror. Don't go to space.

00:19:31
Speaker 3: Well, I haven't been to space, but I've had the situation where I had a cast and had itches inside the cast, and you know, we've all devised that long scratchy tool you can stick underneath the cast. Yeah, but I can't imagine what you would do if you are on in like a six hour EVA and you had an itch and you just had to keep going.

00:19:48
Speaker 2: I would be so distracted. It would be so hard for me to finish the mission.

00:19:53
Speaker 3: All right, Well, let's check in with Jane and Kay to see if we scratched their itch, and then we'll take a break before we come back and go into outer space to answer more questions.

00:20:03
Speaker 4: Oh, Kelly, I'm so sorry for asking such a controversial question. I do hope people weren't scratching too much whilst listening. Did you answer my question? Well, you seem to say that I need to resist the urge to scratch, so I'll try my best. But Kelly, I was so proud of you that you resisted the urge to combine poop and parasites. In the answer, I understand the itch resulting from scabies. My infestation is mainly caused by their waste products. We thank you for answering my question. This is another reason why you're my favorite podcast.

00:21:02
Speaker 1: Okay, we're back.

00:21:03
Speaker 2: So imagine you are an itchy astronaut heading towards the ort cloud and Tim from the UK has a question about what that would be like.

00:21:12
Speaker 6: Hi, Daniel N. Kelly, Tim from the UK here love the podcast. Here's my question. The Orc Cloud surrounds our solar system and is filled with trillions of objects. He's one to three light years thick, so then surely our true view of the universe outside of the cloud must be getting obscured or obstructed. And why is our view of the night sky relatively permanent fixed points of light coming in from the stars. Surely there should be times when the stars are completely obscured by the massive objects in the cloud. If the cloud thins, then more of the stars should be visible. If the cloud thickens, then some of the stars should disappear.

00:21:54
Speaker 3: That's it.

00:21:55
Speaker 6: Keep up the good work by.

00:21:57
Speaker 3: Thanks Tim for this wonderful question and for giving us an opportunity to scratch your orty itch.

00:22:04
Speaker 2: All right, So when I was looking at your outline, there was a fact in your outline that absolutely blew my mind. So let's get to it. Let's jump into what is the Ork Cloud?

00:22:13
Speaker 3: So the Orc Cloud is a theoretical cloud of icy mini planets, meaning I.

00:22:20
Speaker 1: Thought we knew it existed.

00:22:22
Speaker 2: The fact that it's theoretical is blowing my mind. The Ork Cloud is a maybe.

00:22:26
Speaker 3: It's a maybe for exactly the reason that Tim is asking, Because we can't see it. Oh my gosh, we can't see it. We've never seen it. There's like one observation of a thing people think might have come from the Ork Cloud, and people think comets maybe probably come from the Ork Cloud. But the Ork Cloud itself is not something we've ever seen, and it's a shame because it would be amazing. So let's back up and remind people what is the Orc Cloud? Anyway? So we're talking really far out in the Solar System. So you know, the Sun is at the center, and the Earth orbits of what we call one a A and the big planets are at like five ish AU, and if you go all the way out to Pluto, it orbits at a radius of like forty ish AU. So like really far out there in the Solar system, right, But the Orc Cloud, if it exists, is two thousand to like one hundred thousand AU from the Sun. Oh my god, we're talking about like one to three light years. This is a big blob of objects that are very very very far away from where we are currently, so they're not technically part of the Solar System. They're sort of like captured by the Sun's gravity, but very very far out there.

00:23:37
Speaker 2: So when you say two thousand to two hundred thousand, is that a huge error bar or just a huge area that's occupied by the Orc Cloud.

00:23:47
Speaker 3: It's a huge area. So like if you were going to go visit the Orc Cloud, it would start at like fifty thousand AU and you'd still be going through and come out the other side somewhere around one maybe two hundred thousand AU. Oh my gosh. So it's a huge area exactly, and it has lots and lots of objects in it. Like the Oor Cloud is not like two little pieces of ice. We think. It has like trillions and trillions of little icy bits out there, a lot of them bigger than like one kilometer wide, billions of them bigger than twenty kilometers wide. So it's a lot of stuff. But space is really vast. You know, volume grows very quickly with radius, so as you get far and out there, we're talking about an incredible amount of space. So even though there's a lot of stuff in there, it all adds up to like five times the mass of the Earth if you clump it all together. It's spread out really, really far, so you wouldn't be like dodging asteroids like in Star Wars. You'd be like using telescopes to find an object even if you were in the middle of the Ork Cloud.

00:24:49
Speaker 2: Whoa so I had imagine that the ork cloud was dust and small rocks, but it makes more sense that the cloud is made of water. Or you said ice, Is that ice made of water? And how did water get out there?

00:25:03
Speaker 3: Yeah? Water is actually everywhere in the Solar System and in the universe. It's not just water ice though, there's like methane, ice and other frozen stuff. And it's not unusual to find ice or frozen water or frozen other stuff out there in the far Solar System. You know, Neptune and Urinus have a lot of these things in them as well. Anything past the frost line in the Solar System, which is the inner part of the Solar System, where the Sun's radiation is going to melt or vaporize any sort of water that's out there, you're going to find a lot of it. That's why Jupiter and Saturn are bigger, for example, because as those planets started to form in the early Solar System, they could gather ice because it was around, and so they could grow faster than the inner planets. So the sort of more solid stuff out there because the Sun's radiation hadn't blasted it into vapor all right.

00:25:49
Speaker 2: So there is maybe a massive cloud of ice, but maybe not.

00:25:57
Speaker 3: And it's sort of the third cloud. In our Solar system. Have the Asteroid Belt, which is past Mars, and it's a bunch of rocks left over that we think can't coalesce into a planet because of Jupiter's gravitational pull in the tidal forces. Then there's the Kuiper Belt which is out there that provides short period comets, and it's just like a bunch of icy rocks. But the Ork Cloud is maybe a thousand times further out than the Kuiper Belt, so it really is like a halo for the whole Solar System.

00:26:24
Speaker 2: And so the stuff that's out there in that cloud, can you give me a sense for like how much stuff is out there?

00:26:31
Speaker 1: Like if you mushed it all together, how much would you have?

00:26:35
Speaker 3: So it's like five times the mass of the Earth. So it's not a tiny amount of stuff, right, It's just spread out over an incredible area, you know how Like when you start with a tub of frosting, you're like, Oh, this is definitely gonna be enough frosting for this cake, and then you start spreading out the cake, You're like, uh, oh, this might not be enough frosting. Like the oork cloud is spread super duper thin. You know, it's like the sun is the most lightly frosted thing you've ever seen.

00:26:58
Speaker 2: I thought you're this, this is a bit of insight into me. Maybe I thought you were going to say, when you sit down with the frosting and a spoon, this is.

00:27:08
Speaker 1: Definitely more than enough dessert. And then you're like, no, I wanted more.

00:27:12
Speaker 3: You know, there's a warning on the side of the frosting that says not to be eaten on its own.

00:27:16
Speaker 1: Are you serious?

00:27:17
Speaker 3: I am serious?

00:27:19
Speaker 1: Why do they are? They like prohibiting joy in.

00:27:22
Speaker 3: This whole episode of the Hyperfixed podcast about exactly that you should go dig into it. It's a fun story.

00:27:27
Speaker 1: Oh all right, my family might be in a lot of trouble. I'll dig in anyway.

00:27:32
Speaker 3: I'm not a doctor, but I don't recommend that you eat all of I'm roasting by yourself. At least share it with your family.

00:27:37
Speaker 1: I share it with the kids, all right. So moving on, And.

00:27:40
Speaker 3: We're not one hundred percent sure what the org cloud is made out of because we've never seen it directly. Right, if we could see light bouncing off of it, we could understand how it reflects and absorbs light and we could get some spectrographic information, or if we had a great theory for how it formed, we can understand it. But we have a few various ideas for like how one gets an org cloud. One is that it's sort of the detritus from the formation of the Solar System. There's a lot of like gravitational interactions, and sometimes things get sort of tossed out of the center, you know. We think, for example, there might have been another gas giant that in the early part of the Solar System because of the push in the pull of the various other planets, could have gotten tossed out. It's not that easy to stay in orbit. If you get a big enough push from something else, you might find another orbit or you might just be lost. And so these orc cloud objects might be like little bits that were formed closer to the Solar System and then got kicked out and ended up in a stable orbit very far from the Solar System.

00:28:37
Speaker 1: Whilst we could have had like another Saturn, yeah, but now it's out in the ork cloud. That's crazy exactly.

00:28:43
Speaker 3: Or it could have been that as our Sun was forming, there was another star that was forming nearby stars tend to form in clumps. Right, you have a huge cloud of gas that collapses into a solar system, but doesn't usually collapse into one solar system, It collapses into several based on where the over densities were in that gas cloud. And so it could have like exchanged material with sister stars and this old clouds could be like, you know, the last bit of that tug of war between the stars.

00:29:08
Speaker 1: Huh.

00:29:09
Speaker 2: So we've got theories for why it exists, but what is our evidence that it exists? Do we just think that it exists because we have some theories saying it should, or has someone like look through a telescope and been like kind of looks like a cloud out there.

00:29:23
Speaker 3: Yeah, why would anybody imagine this thing exists if we've never seen it? Right, Well, one of the original reasons for this concept was to explain long period comets. So comets are ice balls that plummet towards the center of the Solar system, go around the back of the Sun, and then zoom back out. And they can have shorter periods, you know, years, decades, or they can have longer periods hundreds of years, And people wonder, like, where do those ice balls come from that. They take hundreds of years to orbit the Sun, and so they imagine maybe there's a huge cluster of these balls out there, sort of floating in distant space, and sometimes one of them gets perturbed and falls in towards the inner Old System and becomes a comet. So this is where the hypothesis of the Ork cloud comes from. Oh interesting, yeah, and highlights something which I think is often overlooked, which is comets are a real danger. You know, people think about asteroids hitting us, and we monitor the asteroid belt and that's cool. But like asteroids, we can see, we can predict, and mostly we know where the big ones are. But they're also not that far away from us. So if they hit us, they're not going that fast. But comets they come out of the darkness, right, We have no idea the trillions of them out there. They can just get perturbed, comes suddenly out of the darkness, and by the time they hit the Earth, they're going incredibly fast. And so like in terms of existential danger, like comets in the Ork Cloud are a huge gun loaded with trillions of bullets pointed at the Earth.

00:30:46
Speaker 2: And if existential dread is your jam, you should check out our earlier interview with Phil Plate where we just talked about the many ways the universe is trying to kill us exactly.

00:30:56
Speaker 3: And so we've never seen the work Cloud, but we've tried. You know, the Oork Cloud is so far that is past Voyager one, which is the probe the humanity is sent out into space and is the furthest fastest human ship. It might reach the beginning of the Oor Cloud in three hundred more years, though the power on that thing is rapidly running out. But of course we can also try to see the or Cloud from Earth. And this gets really to Tim's question, like why isn't it blocking our view? It's not blocking our view because it's a lot of really really tiny objects super far away. It's like if an astronaut threw sand into space, it wouldn't block your view, right, And that's effectively what's going on here. They're really small. Each object, because it's so far away, would block the tiniest little portion of the night sky. So even though there are so many of them, they don't add up to blocking much of your night sky. But it's something that people are looking for. The way you could see the Ork Cloud is exactly. That is to see, like, can we see an object pass in front of a star? These little mini star eclipses would give us a hint that the Oorkcloud is real. And then it's out there, and there is one tentative observation. This object called Sedna, we think is one hundred and forty billion kilometers from the Sun. It's a tentative observation of this thing.

00:32:13
Speaker 2: Oh my gosh, that's I mean, to be able to see a teeny tiny object passing in front of the Sun seems to me like it would require amazing telescope abilities.

00:32:22
Speaker 3: Yeah, exactly. And Sedna is really hardest spot. It's twenty times further away from the Sun than Pluto, so its orbit is at about one thousand AU and it's a very very elongated orbit. But you know, it's just probably one of like zillions and zillions of things that are out there that we can just barely spot. But as we improve our telescopes, we'll get a clearer view of what's out there in the Oork Cloud, which is important because the better we understand the Orc Cloud, the better we're able to model in and predict what might happen. You know, every once in a while, another star comes near our star, and when they approach each other they can gravitationally nudge on each other. There's ort clouds potentially stimulating like a shower of comets into the inner Solar System. And yet, doesn't that seem like something we'd like.

00:33:07
Speaker 2: To understand when you say every once in a while, I hope you mean every like a few billion years, not in my lifetime, or what does everyone's in a while mean?

00:33:16
Speaker 3: There is a prediction that in one point three million years, another star is going to come within around twenty or thirty light days of our star, and so yeah, it's not going to be for a while.

00:33:27
Speaker 1: That's good. Yeah, I don't suspect I'll still be around by that point.

00:33:31
Speaker 3: But you know, the Sun oscillates relative to the galaxy. It doesn't just go around the center of the galaxy. It goes up and down through the plane of the galaxy like every thirty million years or so. So it's not like our galactic neighborhood. It's constant. You know, we're always zooming through the galaxy and changing our neighbors, and so they can come and go, and that affects the ork cloud, and you know, life on Earth.

00:33:52
Speaker 2: That's so amazing to me, how many things are happening at the very tiny scales and absolutely huge scales that you mess Like the other day, I was walking and I saw this little shimmer in front of my face and it was a baby spider. When they eventually go off to start their lives, they release a tiny little bit of silk that catches the air and they it's called ballooning, and they sort of balloon off. And there's all these little things that are happening that you only get a glimpse of very rarely, and you're missing it on the micro scale, and there's all this Like I just now learned that we're on a carousel around the galaxy and I was missing that too.

00:34:31
Speaker 1: It's amazing.

00:34:32
Speaker 3: Well, you're right, there is so much going on in the universe. We perceive a tiny little bit of it. We pay attention to an even smaller slice, and we understand and even smaller slice of that. And so we hope this podcast helps open up your eyes and your mind to what's going on in the rest of the universe. And so Tim tell us, if we have successfully stretched your brain out to the edges of the Ord Cloud, and explained why it doesn't block your view of the beautiful night sky.

00:34:58
Speaker 6: Let us know, guys, Thanks very much, keep up the good luck.

00:35:23
Speaker 3: All right, we're back and we're answering questions from people like you who are curious about the universe and want to know how things work. Please send us your questions to Questions at Daniel and Kelly dot org. We'd love to have you on the pod. So we've talked about itches, we've talked about space, and now we're going to zoom back in to talk about something that's happening right in your backyard. Humans aren't the only clever engineers on the planet.

00:35:48
Speaker 2: Maybe we'll see that's the payoff at the end. So let's go ahead and listen to a question from Eric in Idaho.

00:35:57
Speaker 7: Hey, Kelly, I was inspired by your passion for byology on the show and came across something called the honeycomb conjecture. Bees create hexagons for a fascinating reason, and in the last couple of decades a gentleman named Thomas Hales prove the conjecture using math.

00:36:11
Speaker 3: I have a few.

00:36:12
Speaker 7: Questions for you that I'd love to get your thoughts on. What is the history behind the conjecture, why do bees create hexagons?

00:36:19
Speaker 3: To begin with? What are the advantages to do in this?

00:36:22
Speaker 7: Also do biologists see any other species creating hexagons? And also I've been thinking a lot about math, and we all know math and physics go hand in hand. However, I don't hear much about mathe and biology going together. How prevalent is math and biology? Do you use it daily in your research? One thing too, I've been thinking about a lot is that some physicists believe that the universe nature is inherently mathematical. What do biologists say on this matter? What is their opinion? Is the universe? Is nature inherently mathematical? Or is this just the language that we human beings create to describe such crazy things like hexagons in nature? All right, I certainly appreciate everything you and Daniel do. Thank you for considering my questions.

00:37:07
Speaker 3: Eric is a long time listening to this show and a frequent emailer, and we love hearing from him. If you would like to email with us and have us answer all your science questions, please please please write to us to questions at Daniel and Kelly dot org. We mean it anyway, Kelly, what can you tell us about the honeycomb conjecture and bees. How long have people been thinking about this?

00:37:26
Speaker 2: Well, first of all, I love this question because it's a nice intersection of physics and biology, and so you know, I'll expect you to give most of the answer here, Daniel totally.

00:37:35
Speaker 1: No, I'm just kidding. I'm just kidding.

00:37:37
Speaker 2: I did my research, all right, So this is a question we've been asking.

00:37:40
Speaker 1: Ourselves for a really long time.

00:37:42
Speaker 2: So around thirty six BC, this guy, Marcus Tarentius Vero sorry about my pronunciation as ever, was writing a book about agriculture and he mentioned that honey bees make hexagonal honeycombs and that there was some debate about why this happened. And one of the first options was, well, bees have six legs, honeycombs have six sides.

00:38:07
Speaker 1: Maybe bees are just like using their.

00:38:10
Speaker 2: Legs to kind of determine the like vertices of the honeycomb and it so maybe it just has something to do with the fact that they have six legs.

00:38:17
Speaker 1: There was some connection there.

00:38:18
Speaker 3: Interesting. Well, I mean, you notice simple patterns, you draw dotted lines between them. Sure it makes sense?

00:38:23
Speaker 1: Yeah, sure, Then you test your conjectures.

00:38:25
Speaker 3: So how do you test that? You like, cut some legs off of bees and see if they make square honeycombs.

00:38:30
Speaker 2: I mean, yeah, that you could do that, you could, but we don't. It turns out we don't need to because actually the first thing you should do is make careful observations. And as we're gonna get to later, if you make careful observations, you'll see that actually bees are making circles that then melt into like a hexagonal shape. And so so if you just watch, you'd be like, oh, actually, it doesn't matter that they have six legs because they're just making circles.

00:38:53
Speaker 3: You're saying that bees when they originally make their honeycomb, they're making perfect circles or very close to it, and they just relax into honeycombs. Yes, wow, I had no idea.

00:39:05
Speaker 2: Well wait till we're going to get to in a little bit more details. So one of the interesting questions that arise here than I think, is our bees purposefully making hexagons or not our bees Nature's mathematicians or you know, is that giving them too much credit? But so the reason it's exciting that they're making hexagons is the second option, which is that they are purposefully making hexagon shapes through some mechanism that we'll get to later, because hexagons maximize the area inside. So since Pathagoras's time, we've known that some shapes do what's called tile the plane, which is to say, they fill a flat space without overlapping one another or creating any gaps. Some of the shapes that we've sort of studied the most in terms of tiling the plane are triangles, squares, and hexagons. There are some other shapes that do this.

00:39:52
Speaker 3: Too, and this is actually a really fascinating area of mathematics, like finding shapes that tile the plane and new shapes that tile the plane. Something this crazy discovery of an object that can tile an infinite plane without ever repeating a pattern, which is super amazing. This call an Einstein shape. And the best part of this story is that wasn't developed by like a professional mathematician, but like a craftsman, a guy who's just like good with stuff, and he built like a physical model to explore this anyway, super fascinating. That's amazing though, total digression though, So you're telling us about people thinking about tiling the plane way back in the time of like Greek geometricians.

00:40:29
Speaker 2: Yes, right, So people have been talking about tiling the plane for a long time. But one of the cool things about hexagons is that, you know, say you're considering triangles, squares, and hexagons to tile the plane. If you want to maximize the volume inside of the shape, then for the same perimeter for each of those shapes, hexagons maximize the volume inside, which you would want if you're storing honey or babies or something in place in there.

00:40:52
Speaker 3: Or babies in honey or something honeybabes, honey babes. And I guess the idea here is you want to be economical, and so you want to store as much as possible while using the minimal amount of building materials.

00:41:04
Speaker 2: That's right, because the building materials is wax that they have to make, and so you want to minimize the building materials you need and maximize the space inside.

00:41:12
Speaker 3: So I love when mathematics intersects with biology, and it gives us a reason. The hypothesis, I guess is that bees have somehow evolutionarily discovered that this is the most efficient way to store their honey by building hexagons.

00:41:26
Speaker 2: Yeah right, And it wasn't actually proved mathematically that this was a good strategy for the honeybees until Thomas Hales did it in two thousand.

00:41:34
Speaker 3: Two thousand AD AD.

00:41:36
Speaker 1: Yes.

00:41:37
Speaker 3: Wow, I love these mathematical questions that are like open for millennia and then some dudes like, I'm going to tackle that. Yeah, let's do that tomorrow.

00:41:46
Speaker 2: I'm guessing it was more than just tomorrow, but it was a like thirty six page proof, which I will admit I just kind of.

00:41:51
Speaker 1: Like scan scan scan scan scan scan. I didn't check his math.

00:41:54
Speaker 4: Wow.

00:41:55
Speaker 3: I love that. That's incredible.

00:41:57
Speaker 2: I mean, I think for some of these questions it could be because nobody was like I have to know if the honey bees are doing it right, Like there might have been more pressing questions, but it's a fascinating question to answer.

00:42:06
Speaker 3: All right, So we know now that hexagons are the best way to store honey. Do the bees know that?

00:42:12
Speaker 1: Yeah?

00:42:12
Speaker 2: So the answer at the end of the day is that we really don't know. So I watch some videos where people are like, oh, bees are Nature's mathematicians.

00:42:20
Speaker 1: They make hexagons, and I'm like, oh, I like that. That really sounds beautiful.

00:42:24
Speaker 2: But so then the question is, like, what do the bees know in terms of what they're doing and of course, you know, we can't ask the bees what they know, so we'll never really know. But as we mentioned a little bit earlier, they do start by making circles out of the wax, and as things sort of heat and then cool, they end up sort of changing their shape into hexagons over time. And I think you see this also with bubble rafts and Daniel, maybe you can explain why this is the case. This is where I thought Daniel's gonna chime in here, but maybe I'm wrong. So you make a bunch of little circular bubbles and they sort of find the spaces in between, and over time they sort of settle into hexagons, and I think that's like surface tension pulling them together into more efficient shapes.

00:43:06
Speaker 1: Does that sound right?

00:43:06
Speaker 3: Yeah, So what's happening there is the universe is optimizing it, right, not the bees, not the bubble raft designer. It's just like, if you're gonna squeeze a bunch of bubbles together, they're going to end up forming a hexagon shape because otherwise they're gonna pop, right, And so if you want to keep bubbles open and minimize the amount of popping, then you're going to pack them as hexagons. That just sort of makes sense. Yeah, And so it seems like we can't give credit to the bees for that, right. If they're building circles in the universe, is like, yeah, we're going to turn these into hexagons. Then that's just the mathematics of the universe. Isn't that physics?

00:43:39
Speaker 2: Well that would be boring, but so, uh, just kidding. So hold on, So when the bees are putting their circles in, they have to place the circles in certain ways so that you get the hexagons.

00:43:53
Speaker 1: If they put them.

00:43:53
Speaker 2: In there all randomly, then you wouldn't necessarily get like the the near perfect hexagons that you get. And so I don't think that they are saying, oh, we've got to do it this way, because if you place them this way, when they finally make their final form, they're going to be a hexagon, which is the mathematically ideal shape for our honey storage needs. But I do think they have some programming in there that helps them make sure that they put their circles in in a certain way so that when the wax settles, it will create a hexagon. But here's an interesting side thing. Paper wasps, which make their nests out of like fibers. So, for example, I was sitting on a bench the other day and a paper wasp came by, and it was it's an old wooden bench, and it was starting to like scrape the wood off of the top of the bench, and then it went back and it used it to make its paper nests. You're yawning, and I can't believe you're yawning at paper wasp, Daniel.

00:44:47
Speaker 1: They're so interested.

00:44:48
Speaker 3: But that's not a judgmental yawn. I was like a woke up too early yawn.

00:44:53
Speaker 1: No, I get that none of us get enough sleep.

00:44:55
Speaker 2: And so anyway, they also make hexagonal cells, and they don't get like you know, wax melts into the right shape. They start as circles. So the circles are sort of like up at the top point where the nest starts, and then as they build it out, you get hexagons. And so to me that's even a little bit more impressive because they do end up building the hexagons. But anyway, so it's all about positioning and not necessarily about going for hexagons in particular.

00:45:20
Speaker 3: Interesting and so in the end, are you going to give the bees credit? Do you think the bees are geometers?

00:45:26
Speaker 2: I give bees a lot of credit for a variety of reasons. Studies have shown that bees are really good at making economical decisions about which flowers to visit and how many times to visit them.

00:45:36
Speaker 1: They're good at communicating with one another.

00:45:38
Speaker 2: Where the great food sources are, and they are able to pull this trick off that maximizes the volume where they store their stuff. So I think they're impressive. Maybe not as impressive as we had initially imagined, but you know, nature doesn't need to find the most complicated solution to a problem if an easier mechanism gives you the right solution, amazing.

00:45:58
Speaker 3: The real question in my mind, though, is our b geometers or geometricians, which is the correct word.

00:46:05
Speaker 2: It feels like it's more your wheelhouse than mine, But.

00:46:11
Speaker 1: I think they're geometricians.

00:46:13
Speaker 3: Maybe in two thousand more years somebody will come along and figure that one out.

00:46:16
Speaker 2: You know what's really cute, though, there's these moths on my property, the inch worms, and the I think it's the family of inchworms are called geometer moths because they are like measuring the earth the way they move along, which I thought.

00:46:30
Speaker 1: Is super cute.

00:46:31
Speaker 3: It's cool, it's cute.

00:46:33
Speaker 2: So our listener had a couple different questions. One he wanted to know about the honeycomb conjecture. Two he wanted to know if other species create them. And we've talked about how paper wasps do. My husband Zach sent me a picture of tadpole eggs in our ponds that had naturally come together their form of hexagon.

00:46:51
Speaker 1: Oh, pretty cute.

00:46:53
Speaker 2: You see some plants make sort of hexagon shapes. So we do see this in nature in a couple different places, including in the bubble raft example. And then the final question was, you know math and physics go hand in hand, but you don't hear much about math and biology, you know.

00:47:09
Speaker 1: Yeah, Daniel jumps in there.

00:47:10
Speaker 2: I've heard Daniel critique biologists for not having error bars on our graphs and presentations.

00:47:16
Speaker 3: That's a difference. I'm criticizing biologists, not biology.

00:47:19
Speaker 1: Oh okay, got it, got it all right.

00:47:21
Speaker 2: So biologists do think a lot about math. So, for example, theoretical ecologists think a lot about how we can write equations that describe dynamics in a system, like predator or prey equations, or how an epidemic moves through a system. And so that requires a lot of maths, so they're thinking mathematically. There, we use a lot of statistics to try to understand what we observe, and you know, there are a lot of people who think about the world mathematically. And I think over the course of my twenty year career where I've been an ecologist, I've seen a much greater emphasis on trying to describe what we see, not just in terms of, you know, a qualitative description that's maybe a little poetic, which you know, I love reading those qualitative, poetic descriptions, but also trying to capture what you want in a more quantitative way and describing what you're seeing mathematically and then trying to explain why nature has resulted in that sort of equation.

00:48:16
Speaker 1: So, yes, biologists do use math a lot.

00:48:18
Speaker 3: On his last question, that's sort of a philosophy question, you know, is nature inherently mathematical? And the sort of an important philosophical question that we don't know the answer to, which is why we can use math to describe the universe. You know, you might imagine that math naturally describes the universe at the smallest scale, that fundamentally, the some equation you can write down to describe fundamental physics. But then why can you use math to describe like, you know, the predator preye reaction, or the geometry of hexagons, or you know, the shape of birds eggs or something. And that's the sort of mystery, like why these fairly simple mathematical stories emerge from the crazy, chaotic combination of fundamental bits of the universe. It's not something philosophers really have a handle on, so we don't know if it's something that is inherently part of the universe or sort of the way we are framing these questions, the way we think about things, you know, the sort of our mental language.

00:49:12
Speaker 2: Yeah, And one of the most popular phrases amongst people who do modeling in biology is that all models are wrong, some are useful.

00:49:20
Speaker 3: That's exactly correct, even of fundamental physics. Right, as far as we know, our description of the tiniest particles, it's not the end of the story. It's a model, and it's not true in the sense that it's not describing everything that's happening inside of it, but it's still useful. And you know, from a philosophical point of view, might argue, like what's the difference between true and useful, and model is just supposed to be useful. It's just supposed to predict the results of experiments. There's no deeper truth than that. But that's a whole nother philosophical rabbit.

00:49:50
Speaker 2: That's right, all right, Well, Eric, this was a fantastic question. It was great to hear from you again. Let's see if we scratched your itch on this be question.

00:50:00
Speaker 7: And Daniel, I just wanted to say a huge thank you for taking the time to answer my questions about the honeycomb conjecture on your show. I was fascinated to learn more about why best create hexagons and the advantage of that structure. It's incredible to think about how nature organizes like that. Hearing about whether other species create hexagons was really eye opening. In Your insights on how math plays a role and biology gave me a whole new perspective. I've always thought of math as more tied to physics, but now I can see how deeply it connects to the natural world in the universal ways I.

00:50:28
Speaker 3: Hadn't considered before.

00:50:30
Speaker 7: I did share what I learned with my wife, hoping it might ease her discomfort around bees, but I'm afraid she still doesn't feel any better about them. She says they're buzzing in geometry ways still gives her the creeps. Even so, your passion for biology really shines through, and I'm so grateful to have my curiosity spark.

00:50:49
Speaker 3: In such an amazing way.

00:50:50
Speaker 7: Thanks again for sharing your knowledge on the show.

00:50:53
Speaker 3: All right, Thanks very much everyone who engages with the podcast and sends us your questions, why don't you join their ranks? What is the question and that you most want an answer to that you think maybe it's impossible to answer, Send it to us. We'll give it a shot. Questions at Danielankelly dot org. Thanks for tuning in, Thanks.

00:51:10
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