Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions #15

Transcript

Listener Questions #15 · Daniel and Kelly’s Extraordinary Universe

0:00
Speaker 1: Hey, they're extraordinaries. Kelly.
0:02
Speaker 2: Here my book, A City on Mars? Can we settle Space?
0:05
Speaker 2: Should we settle space? And have we really thought this through?
0:09
Speaker 2: Comes out in paperback on July twenty ninth, So if
0:13
Speaker 2: you've been interested in reading it but the hardback version
0:15
Speaker 2: was just too expensive or the wait list at your
0:18
Speaker 2: library was intolerably long, then you're in luck. In this
0:22
Speaker 2: book we answer questions like where are we likely to
0:25
Speaker 2: settle in space? Can we make babies in space? Why
0:28
Speaker 2: do astronauts love taco sauce? And what's the legal status
0:32
Speaker 2: of space cannibalism? So grab yourself a copy of A
0:35
Speaker 2: City on Mars wherever fine books are sold. Conflicting advice
0:48
Speaker 2: is making me twitch?
0:50
Speaker 1: Is it good or is it bad? To scratch my itch?
0:53
Speaker 3: If the ort cloud is filled with icy rocks? Why
0:57
Speaker 3: isn't our view of the stars blocked?
1:00
Speaker 2: Are honeybees Nature's mathematicians? Or can nature forge hexagons without cognition?
1:06
Speaker 3: Whatever questions keep you up at night, Daniel and Kelly's
1:09
Speaker 3: answers will make it right.
1:11
Speaker 1: Welcome to Daniel and Kelly's Extraordinary Universe.
1:27
Speaker 3: Hi, I'm Daniel, I'm a particle physicist and I love
1:30
Speaker 3: hearing questions from the public. What people are wondering about,
1:33
Speaker 3: what they're curious about, what they are confused about. Right
1:36
Speaker 3: to be please and share with me your confusion.
1:40
Speaker 4: Hello.
1:40
Speaker 1: I'm Kelly Winer Smith.
1:41
Speaker 2: I study parasites and space, and I totally agree with Daniel.
1:44
Speaker 2: And also I have to note that these questions have
1:47
Speaker 2: pointed out to me how many things I don't think
1:50
Speaker 2: hard enough about. Like today we have some very basic
1:54
Speaker 2: questions about like why do we itch? And I you know,
1:57
Speaker 2: I must scratch ten or so times and like, yeah,
2:01
Speaker 2: maybe even more without thinking about it. And I've never
2:03
Speaker 2: really thought about why. And so I am loving the
2:06
Speaker 2: opportunity to dig into all of these different questions.
2:09
Speaker 3: Yeah, it's fun on so many levels, Like we get
2:11
Speaker 3: an opportunity to learn more about areas that we've always
2:14
Speaker 3: been curious about but never had an excuse to dig into,
2:17
Speaker 3: Like yeah, when have you told yourself I have an
2:20
Speaker 3: hour free, I'm a to read about itching? But now
2:22
Speaker 3: you have a reason, right, Yep. You also discover how
2:24
Speaker 3: many basic things in science we're still pretty clueless about,
2:28
Speaker 3: you know, like how many things we understand at really
2:30
Speaker 3: just the surface level. Yeah, which means that there's lots
2:33
Speaker 3: of things to figure out for all you young scientists
2:35
Speaker 3: out there.
2:36
Speaker 2: Yeah, that's right, all the kids who are listening, there's
2:38
Speaker 2: a lot of work for you to do, and just
2:40
Speaker 2: keep a list as we go through these episodes of
2:42
Speaker 2: questions that need answers that you might be the one
2:44
Speaker 2: to answer.
2:45
Speaker 3: That's right. The forefront of human knowledge is not that
2:48
Speaker 3: far away from where you are right now in lots
2:50
Speaker 3: of cases. I mean, yeah, we've been doing physics for
2:53
Speaker 3: a long time and we've made some progress, and it
2:55
Speaker 3: takes a while to understand all the details of particle physics,
2:58
Speaker 3: but they're still very basic questions even about particle physics,
3:01
Speaker 3: that we don't know the answers to. Why are there
3:04
Speaker 3: so many particles? What do they all do? What is
3:06
Speaker 3: the rest of the universe made out of? You know,
3:08
Speaker 3: basic stuff everybody wants to understand. And so if you
3:11
Speaker 3: have a question about the universe or parasites or parasites
3:13
Speaker 3: in the universe, you might be asking a question right
3:16
Speaker 3: at the forefront of our knowledge. So don't be shy, ask.
3:19
Speaker 2: Away and let us do the research for you. So
3:23
Speaker 2: I have an answer I'm just itching to share with you.
3:27
Speaker 2: We got we got there must have been something itchy
3:31
Speaker 2: in the air, because within a very short amount of
3:33
Speaker 2: time we got two different questions about itching and scratching.
3:37
Speaker 1: So let's go ahead and hear the questions.
3:39
Speaker 5: I'd like to know what causes itches and why does
3:43
Speaker 5: scratching stop them. I don't mean itches that have a
3:46
Speaker 5: clear source medicine, side effects, bug bites, rashes, irritating clothing scenes,
3:52
Speaker 5: et cetera. I mean when you're just going about your
3:55
Speaker 5: day and suddenly some random part of you itches. How
3:58
Speaker 5: will you scratch it the itch stops?
4:00
Speaker 4: What's up with that? Hey, I'm loving the show. I
4:04
Speaker 4: wonder if you could answer a question for me. This
4:07
Speaker 4: might be one for Kelly. I've heard recently about a
4:10
Speaker 4: study which said, I think it was in mice, that
4:14
Speaker 4: if you scratch an itch, then it's beneficial because that
4:18
Speaker 4: allows antibodies to go to the site and to clear
4:22
Speaker 4: up any infection. But then there was another study, also
4:25
Speaker 4: in mice, saying that scratching and itch is problematic because
4:30
Speaker 4: it activates pain nerves, which then causes more riching and
4:33
Speaker 4: more inflammation. Which is it, Should I ignore the urge
4:38
Speaker 4: to scratch an itch or should I just go ahead
4:41
Speaker 4: and scratch it. Keep up the good work. Thanks.
4:45
Speaker 3: I think these questions are pretty deep. They're not really
4:47
Speaker 3: just surface level, you know. I think they're really dig
4:49
Speaker 3: down into what's going on. I didn't eat the skin, yeah.
4:53
Speaker 1: And I had a ton of fun digging in.
4:55
Speaker 2: And actually, it turns out that our understanding of itching
4:58
Speaker 2: has apparently undergone some pretty major changes in the last
5:02
Speaker 2: few decades. So initially we thought that itching was a
5:07
Speaker 2: minor form of pain, which would suggest that it's using
5:10
Speaker 2: the same pain receptors. And it's just sort of like,
5:14
Speaker 2: if you tickle the pain receptors just a little bit,
5:16
Speaker 2: you get an itch, but when you really hurt them,
5:18
Speaker 2: then you get pain.
5:19
Speaker 3: But back up and give me the bigger picture here.
5:21
Speaker 3: When you say pain receptors, you're talking about like nerve
5:24
Speaker 3: endings just under the skin. And I don't know enough
5:27
Speaker 3: biology to even know, like, are there different nerves for
5:30
Speaker 3: pain and for like cold and for other stuff? How
5:32
Speaker 3: does that all work?
5:33
Speaker 1: Oh? Yeah, great questions.
5:35
Speaker 2: So there are different nerves for different things, and so
5:37
Speaker 2: we do have some nerves that specifically are there to
5:40
Speaker 2: tell us about pain. And so for anyone who's gotten
5:42
Speaker 2: tattoos out there, you know, that there are some areas
5:45
Speaker 2: that hurt to get tattooed more than others. Daniel, you're
5:48
Speaker 2: shaking your head, yes, knowingly. Do you have tattoos?
5:51
Speaker 3: I do not, but I have a teenager who wants
5:54
Speaker 3: to get tattoos, and so we've had lots of conversations
5:57
Speaker 3: about making ferman decisions for your body.
6:00
Speaker 1: Got it okay.
6:01
Speaker 2: So there are some parts of your body that have
6:02
Speaker 2: more pain receptors than others, and those areas tend to
6:05
Speaker 2: hurt a little bit more when you get tattoos. And
6:07
Speaker 2: what these receptors do is they deliver messages from like
6:11
Speaker 2: the surface of your skin up to your brain to say, oh,
6:14
Speaker 2: something hurts, and then you respond to it, and often
6:16
Speaker 2: you respond to it without even really thinking about it.
6:19
Speaker 1: You have sort of a reflexive response.
6:20
Speaker 3: And so, for example, I know that I have a
6:22
Speaker 3: lot of nerves and the tips of my fingers, so
6:25
Speaker 3: I could tell the difference between one needle and like
6:27
Speaker 3: two needles very close together, and the tips of my
6:29
Speaker 3: finger has been not like on my elbow because I
6:32
Speaker 3: have fewer nerves there. I can't resolve it. But that's
6:34
Speaker 3: a different nerve system than the ones that help me
6:37
Speaker 3: sense pain.
6:38
Speaker 2: Yeah, so we're getting a little bit outside of my
6:40
Speaker 2: area of expertise here, but I think that those are
6:42
Speaker 2: touch receptors that you would be detecting there, unless you
6:45
Speaker 2: were like stabbing those needles into your fingers, which I
6:48
Speaker 2: assume you're not. I think we're talking about touch receptors there,
6:51
Speaker 2: and we've got receptors for cold and for hot and
6:53
Speaker 2: stuff like that.
6:54
Speaker 3: So you were saying that people used to think that
6:56
Speaker 3: itching or stimulating the pain receptors the nerves that when
7:00
Speaker 3: something hurts, Yeah, that doesn't really make a lot of
7:02
Speaker 3: sense to me, because itching doesn't feel like pain. It
7:04
Speaker 3: feels like uncomfortable and enjoys me crazy, but doesn't hurt
7:08
Speaker 3: the same way.
7:08
Speaker 1: Yeah.
7:09
Speaker 2: Well, so I wonder if it was because sometimes if
7:12
Speaker 2: you itch for a really long time, you scratch and
7:14
Speaker 2: then it starts to hurt. And so maybe people were
7:16
Speaker 2: just like imagining a continuum there that doesn't exist. But also,
7:20
Speaker 2: it's not so surprising we got these two systems sort
7:23
Speaker 2: of mixed up because they have a lot of cross talk.
7:26
Speaker 2: There's a lot of times when you stimulate one system
7:29
Speaker 2: and it sort of interacts with the other. For example,
7:32
Speaker 2: when I got an epidural when I was pregnant with
7:35
Speaker 2: my second. The first one was natural, second one, I
7:37
Speaker 2: had an epidural.
7:38
Speaker 3: Uh not just like a Friday night epidural.
7:40
Speaker 2: No, yeah right, No, I mean fun not recreational.
7:44
Speaker 1: Recreational.
7:45
Speaker 3: Yeah, no judgments to anybody out there who does that,
7:48
Speaker 3: you know, just clarifying here.
7:50
Speaker 2: Yeah, fair enough, But that would be an expensive habit,
7:52
Speaker 2: I'm guessing, because I think you'd need to get insured.
7:55
Speaker 2: But anyway, so when I got my epidural, I started
7:59
Speaker 2: itching like crazy.
8:01
Speaker 1: And I didn't.
8:02
Speaker 2: Find like a paper that specifically said some people who
8:05
Speaker 2: get epidural.
8:05
Speaker 1: Scratch like crazy.
8:06
Speaker 2: But I found a couple of papers that were referencing
8:09
Speaker 2: how sometimes when you do something for pain, you get
8:12
Speaker 2: this weird itchy side effect, and sometimes when you do
8:14
Speaker 2: something for itching, you get this weird pain side effect.
8:17
Speaker 2: And so these two systems seem to have a lot
8:19
Speaker 2: of cross talk, and they interact, but they are separate. Interesting,
8:23
Speaker 2: and so we do have specific receptors for itch.
8:26
Speaker 3: We do, so we've like evolved a whole system to
8:29
Speaker 3: make you uncomfortable.
8:30
Speaker 2: Well, okay, so I would say that a lot of
8:32
Speaker 2: times it does seem like our itch system does things
8:36
Speaker 2: that are maladaptive. Give me a second to do a
8:38
Speaker 2: little bit more explaining, and then we'll get back to that.
8:40
Speaker 2: So you've got these itch receptors and they can be
8:43
Speaker 2: stimulated externally or internally. So externally would be like there's
8:48
Speaker 2: a tick crawling on your skin and you feel itchy,
8:52
Speaker 2: and your immediate response is to try to brush it off,
8:55
Speaker 2: and that is pretty adaptive. You know, you move it off,
8:59
Speaker 2: and now you don't have that tick on there anymore.
9:01
Speaker 2: And I'm very proud of my body because I feel
9:03
Speaker 2: like I am really tuned to ticks. I've almost never
9:07
Speaker 2: had one bite me, but I've taken loads off of me,
9:09
Speaker 2: so like I feel them when they're moving around, So
9:11
Speaker 2: that's good.
9:11
Speaker 3: That's definitely a plus. I understand that, like your body
9:14
Speaker 3: wants you to feel uncomfortable having that critter crawl over you.
9:18
Speaker 2: Yes, exactly, Like your attention needs to be drawn to
9:20
Speaker 2: that you need to take care of it right away.
9:23
Speaker 2: We also have responses to internal things like histamines and
9:29
Speaker 2: various things that your immune system does. So for example,
9:32
Speaker 2: if you in the winter have really dry hands and
9:35
Speaker 2: you like make a fist and your skin cracks and
9:37
Speaker 2: bleeds like mine does, your immune system responds to those
9:41
Speaker 2: cracks and it recruits to where those cracks are, and
9:45
Speaker 2: the presence of those immune system cells trigger your itch receptors.
9:50
Speaker 2: And that's why your hand gets itchy when it's all
9:52
Speaker 2: broken and bleeding.
9:54
Speaker 3: Help me understand why internal histamines trigger the same receptors
9:58
Speaker 3: as a tick crawling across myself. Does that make sense.
10:01
Speaker 2: For some reason, I'm not sure that it does make sense.
10:05
Speaker 2: So there's a couple of different hypotheses here. So one
10:09
Speaker 2: hypothesis is that our species itches as.
10:14
Speaker 1: Sort of like an evolutionary hold over.
10:17
Speaker 2: So we used to have fur, and it used to
10:19
Speaker 2: be that we would when we would itch, we wouldn't
10:21
Speaker 2: damage ourselves because the fur got in the way. But
10:24
Speaker 2: now we don't have fur, and so when we itch,
10:26
Speaker 2: we damage ourselves. And so it could be that most
10:28
Speaker 2: of the time when there was an immune response, maybe
10:32
Speaker 2: it was because, for example, there was a tick that
10:34
Speaker 2: had bit and the immune system was responding to it.
10:37
Speaker 2: And so if you scratch, and you scratch through your fur,
10:39
Speaker 2: you get that tick off. And you know, I can
10:41
Speaker 2: still imagine the immune system drawing your attention to the
10:45
Speaker 2: presence of a tick, and you know, the sooner you
10:47
Speaker 2: remove a tick, the better, because some of them don't
10:49
Speaker 2: give you the diseases they're carrying until they've been on
10:51
Speaker 2: there for a while. And now I feel like I'm
10:54
Speaker 2: crawling with ticks because we're talking about it.
10:56
Speaker 3: I hope everybody out there getting itchy and ticky.
10:59
Speaker 2: Yes, guys and gals, So yeah, I mean I think it.
11:03
Speaker 2: Sometimes scratching is good because it removes something, or maybe
11:07
Speaker 2: it recruits more immune cells.
11:09
Speaker 1: But sometimes scratching is just bad.
11:10
Speaker 3: So I think you're saying that itching on the surface
11:13
Speaker 3: is very clear. It's to help us get rid of
11:16
Speaker 3: something that's crawling across us and might bite us and
11:18
Speaker 3: is bad for us, And that itching internally might also
11:21
Speaker 3: be good because it's a signal that something is already
11:24
Speaker 3: bitten us, and if we scratch it, we could get
11:27
Speaker 3: rid of it. So it's not that they trigger exactly
11:30
Speaker 3: the same mechanism. It's like two ways to protect us
11:32
Speaker 3: from critters. But are they biochemically the same mechanism, Like
11:36
Speaker 3: does it tick crawling across your skin trigger the same
11:39
Speaker 3: histamines and that whole same channel, or are they two separate.
11:41
Speaker 2: Mechanisms Both mechanisms trigger the same itch receptors to send
11:46
Speaker 2: a message to your brain that says scratch. And I
11:49
Speaker 2: think in both cases you can get good information that
11:52
Speaker 2: tells you to scratch when you should scratch, but both
11:55
Speaker 2: externally and internally you can also get bad information. So,
11:58
Speaker 2: for example, your skin might be particularly sensitive to certain
12:02
Speaker 2: kinds of allergens, or you know, certain kinds of compounds
12:05
Speaker 2: and soap, right, and then you might start scratching for
12:07
Speaker 2: no good reason. And you know, same thing with your
12:10
Speaker 2: body responding internally by releasing histamines at places where you
12:14
Speaker 2: really don't need to be scratching. And additionally, when you
12:17
Speaker 2: start scratching, you can initiate what's called the itch scratch cycle.
12:21
Speaker 2: And here's what happens there.
12:23
Speaker 3: So this sounds like a nightmare.
12:24
Speaker 2: So you start itching, and when you start itching, we
12:27
Speaker 2: all know that it feels amazing often, and so what's
12:32
Speaker 2: happening there is that your itch signal is being overridden
12:36
Speaker 2: by a pain signal, because when you scratch, you're causing
12:39
Speaker 2: yourself a little bit of pain. And I think the
12:42
Speaker 2: rest of this explanation is a little bit like, here's
12:44
Speaker 2: what we think is happening, but we're not one hundred
12:46
Speaker 2: percent sure. But they think that after you scratch and
12:48
Speaker 2: your pain signal overrides the itch signal, you also release
12:52
Speaker 2: some serotonin, which makes you feel better and sort of
12:56
Speaker 2: makes the pain eventually go away. And so scratching feels good.
13:00
Speaker 2: But when you scratch, you often damage the skin a
13:03
Speaker 2: little bit, especially if you're giving it a really strong scratch.
13:06
Speaker 2: And if you give it too hard of a scratch,
13:08
Speaker 2: now you've caused damage, and that damage recruits more immune cells,
13:12
Speaker 2: which makes you itch even more. And so by itching,
13:17
Speaker 2: you can make yourself itchier. And so there are people
13:20
Speaker 2: who have chronic itching issues and they get stuck in
13:24
Speaker 2: this itch scratch cycle. You know, if you tell someone
13:26
Speaker 2: who's itchy, oh, just don't scratch it. The scratching is
13:29
Speaker 2: what's causing the problem. That's like maddening, I think to
13:32
Speaker 2: tell someone because once you've got an itch, how do
13:34
Speaker 2: you avoid scratching that itch?
13:36
Speaker 1: That's like all you can think about.
13:37
Speaker 3: This is fascinating to me to understand exactly what happens
13:40
Speaker 3: when you scratch an itch, because I do this all
13:42
Speaker 3: the time. I'm the kind of person who's very sensitive
13:44
Speaker 3: to mosquito bites. They like torture me, and if I
13:47
Speaker 3: have one that's like really buzzing, and I scratch it.
13:50
Speaker 3: It's like the greatest relief in the world. Oh my god,
13:53
Speaker 3: that feeling is just like it's not just that the
13:55
Speaker 3: itch goes away, like actually feels really good, but you're right,
14:00
Speaker 3: scratch it hard, then that really fades, and then the
14:03
Speaker 3: pain comes through and then it gets itchy again. And
14:05
Speaker 3: scattered through my house are like dozens of these itch
14:08
Speaker 3: relief sticks, oh, which I totally rely on, and their
14:11
Speaker 3: lile benagyl sticks, and they are antihistamines. So I think
14:15
Speaker 3: that personal piece of data that the anecdote supports your
14:18
Speaker 3: hypothesis there. But it's fascinating to hear about like the serotonin,
14:22
Speaker 3: Like that's why I feel good, Right, It's not just
14:24
Speaker 3: that the itch has stopped and the discomfort has gone,
14:26
Speaker 3: but there's something in my body that is making me
14:29
Speaker 3: actually enjoy it.
14:30
Speaker 2: That is the current hypothesis. Yes, I don't know that
14:32
Speaker 2: we've absolutely nailed that down. And it's interesting that you
14:34
Speaker 2: mentioned antihistamines because one of the reasons that we know
14:39
Speaker 2: we don't really understand itch well is that you can
14:42
Speaker 2: give somewhat antihistamines in a case where you think that
14:45
Speaker 2: should solve the problem. Yeah, and it doesn't, and so
14:48
Speaker 2: it is more complicated. And you know, for some people,
14:51
Speaker 2: if you've got an itch, you scratch it, that's the
14:53
Speaker 2: end of the story. But for other people, their immune
14:55
Speaker 2: systems are a little bit more sensitive. You scratch it,
14:58
Speaker 2: that recruits more immune cells and you start getting in
15:00
Speaker 2: the cycle. You also can get chronic itch for reasons
15:04
Speaker 2: that you know, we again don't understand really well.
15:06
Speaker 3: So, for example, chronic itch.
15:08
Speaker 1: I know chronic itch.
15:09
Speaker 3: I would never wish that on my worst enemy.
15:11
Speaker 2: I was listening to an interview on NPR's Fresh Air
15:13
Speaker 2: from a woman who has a disease. I think it
15:17
Speaker 2: was of her liver or kidneys, and it creates chronic itch.
15:21
Speaker 2: And we don't understand why that particular issue should result
15:23
Speaker 2: in chronic itch, but she itches all the time. There's
15:27
Speaker 2: also folks who have chronic itch related to mental health issues,
15:32
Speaker 2: so like when they get depressed or anxious, it kind
15:35
Speaker 2: of makes them itchy, and so they scratch.
15:36
Speaker 1: A lot more.
15:37
Speaker 3: What's the connection there, I don't think we know. Just
15:39
Speaker 3: another amazing mind body connection. You know, it's incredible to
15:43
Speaker 3: me how much your mental state influences your body's health.
15:47
Speaker 3: And vice versa.
15:48
Speaker 2: Yeah, I mean the only reason I ended up on
15:49
Speaker 2: anxiety medication is because I went to my doctor and
15:52
Speaker 2: was like, everything hurts, my stomach hurts, and why is it?
15:56
Speaker 2: And she was like, I think it's uh, you know.
15:59
Speaker 2: She didn't say I think it's in your head. She
16:00
Speaker 2: was much nicer about it. But yes, when we're stressed
16:03
Speaker 2: out or anxious or depressed, it impacts our body in
16:06
Speaker 2: weird ways. So yeah, the studying of chronic itching and
16:09
Speaker 2: how to relieve it is a big area where there's
16:12
Speaker 2: a lot of work that we still have left to do.
16:14
Speaker 2: So the first question that we had was why do
16:17
Speaker 2: you itch when there's nothing there to make you itch?
16:22
Speaker 2: And I think part of the answer could be that,
16:24
Speaker 2: you know, for some people it's a mental health thing.
16:26
Speaker 2: Maybe they're anxious and stressed and there is nothing there.
16:29
Speaker 2: But I think a lot of the times it's something
16:32
Speaker 2: did cause you to need to itch, But maybe it's
16:36
Speaker 2: just escaping your consciousness. So for example, maybe there's like
16:40
Speaker 2: some fiber in your shirt that your body is confusing
16:43
Speaker 2: as a tick, or there was something in your soap
16:46
Speaker 2: that's creating a little bit of an allergic reaction in
16:48
Speaker 2: your back.
16:49
Speaker 1: That you didn't know about.
16:50
Speaker 2: You know, I think in general, something usually initiates this
16:54
Speaker 2: need to scratch, but we just can't always tell what
16:57
Speaker 2: it was.
16:58
Speaker 3: And the second question I think is one that's to
17:00
Speaker 3: my heart, which is, tell me, Kelly, from the point
17:02
Speaker 3: of view of science, should I scratch or should I resist?
17:04
Speaker 3: Am I a bad person for scratching my itches? All?
17:07
Speaker 1: Right?
17:08
Speaker 2: One, you are not a bad person for scratching your itches.
17:10
Speaker 2: There is no judgment here U.
17:13
Speaker 4: Two.
17:13
Speaker 2: I think it depends on why you're itching. So the
17:16
Speaker 2: listener mentioned that there was a study in mice that
17:19
Speaker 2: found that if you scratched, it recruited immune cells to
17:22
Speaker 2: the area, and that maybe that immune cell helped you
17:25
Speaker 2: deal with an infection or something. So it's possible that
17:28
Speaker 2: under some conditions, maybe you're able to recruit more immune
17:32
Speaker 2: cells if you've got like an infection or something that's itchy.
17:36
Speaker 2: But I think in a lot of cases, itching will
17:39
Speaker 2: feel good, but there's some chance that something bad will
17:42
Speaker 2: happen afterwards, and that something bad would be you could
17:44
Speaker 2: maybe open up a wound and give yourself an infection,
17:47
Speaker 2: or you could start off a new round of the
17:49
Speaker 2: itch scratch cycle, and so well, I think there's nothing
17:52
Speaker 2: wrong with like giving a light scratch to a mosquito bite,
17:55
Speaker 2: or if you've got an itch, making sure you don't
17:57
Speaker 2: have an insect crawling on you or tick crawling on you.
18:00
Speaker 2: But in general, I think the answer, because it's biology,
18:03
Speaker 2: is it depends. And if you are going to scratch,
18:06
Speaker 2: if you can scratch with like I don't know, your
18:08
Speaker 2: knuckles or something to try to like not break the
18:12
Speaker 2: skin so much, that would be great. But you know,
18:14
Speaker 2: just at the end of the day, some of us
18:16
Speaker 2: we can't help but scratch, and it's it's just hard
18:19
Speaker 2: to avoid.
18:20
Speaker 3: All right. Well, now I have a question which you
18:22
Speaker 3: may be the only person in the world qualified to answer.
18:25
Speaker 3: What because it connects itches in space? Are there cases
18:30
Speaker 3: where astronauts had crazy itches they couldn't scratch because they
18:34
Speaker 3: were in a space suit? And what are you supposed
18:36
Speaker 3: to do?
18:36
Speaker 1: Oh, oh my gosh, that must have happened.
18:40
Speaker 2: So you know, you can, like I guess you could
18:42
Speaker 2: try to like rub your skin against the inside of
18:45
Speaker 2: the suit.
18:45
Speaker 3: And so I wish you all could see the dance
18:48
Speaker 3: Kelly is doing right now to mimic how to scratch
18:50
Speaker 3: your back inside a spacesuit.
18:52
Speaker 2: Yeah, there are so many things that sound uncomfortable about
18:55
Speaker 2: being in a spacesuit, and the most uncomfortable of which
18:59
Speaker 2: is elamination.
19:00
Speaker 1: Have we talked. Do you know what that means?
19:04
Speaker 3: No, it sounds like you're removing your skin.
19:06
Speaker 1: Maybe you're removing your nails. So those gloves, I'm so
19:11
Speaker 1: so yeah.
19:12
Speaker 2: So those gloves are really hard to bend. And there
19:15
Speaker 2: are some cases where people have tried to bend it
19:16
Speaker 2: and their nails have kind of got stuck in their
19:18
Speaker 2: nails are pulled up from the nailbit.
19:20
Speaker 1: I know, so gross. So anyway, and then.
19:23
Speaker 3: You can't scratch your itches because you have no more fingernails.
19:26
Speaker 1: Oh my gosh. Oh, so many layers of horror. Don't
19:30
Speaker 1: go to space.
19:31
Speaker 3: Well, I haven't been to space, but I've had the
19:32
Speaker 3: situation where I had a cast and had itches inside
19:35
Speaker 3: the cast, and you know, we've all devised that long
19:38
Speaker 3: scratchy tool you can stick underneath the cast. Yeah, but
19:42
Speaker 3: I can't imagine what you would do if you are
19:44
Speaker 3: on in like a six hour EVA and you had
19:46
Speaker 3: an itch and you just had to keep going.
19:48
Speaker 2: I would be so distracted. It would be so hard
19:50
Speaker 2: for me to finish the mission.
19:53
Speaker 3: All right, Well, let's check in with Jane and Kay
19:55
Speaker 3: to see if we scratched their itch, and then we'll
19:58
Speaker 3: take a break before we come back and go into
20:00
Speaker 3: outer space to answer more questions.
20:03
Speaker 4: Oh, Kelly, I'm so sorry for asking such a controversial question.
20:09
Speaker 4: I do hope people weren't scratching too much whilst listening.
20:13
Speaker 4: Did you answer my question? Well, you seem to say
20:16
Speaker 4: that I need to resist the urge to scratch, so
20:19
Speaker 4: I'll try my best. But Kelly, I was so proud
20:22
Speaker 4: of you that you resisted the urge to combine poop
20:26
Speaker 4: and parasites. In the answer, I understand the itch resulting
20:30
Speaker 4: from scabies. My infestation is mainly caused by their waste products.
20:36
Speaker 4: We thank you for answering my question. This is another
20:39
Speaker 4: reason why you're my favorite podcast.
21:02
Speaker 1: Okay, we're back.
21:03
Speaker 2: So imagine you are an itchy astronaut heading towards the
21:07
Speaker 2: ort cloud and Tim from the UK has a question
21:10
Speaker 2: about what that would be like.
21:12
Speaker 6: Hi, Daniel N. Kelly, Tim from the UK here love
21:15
Speaker 6: the podcast. Here's my question. The Orc Cloud surrounds our
21:19
Speaker 6: solar system and is filled with trillions of objects. He's
21:23
Speaker 6: one to three light years thick, so then surely our
21:27
Speaker 6: true view of the universe outside of the cloud must
21:31
Speaker 6: be getting obscured or obstructed. And why is our view
21:35
Speaker 6: of the night sky relatively permanent fixed points of light
21:39
Speaker 6: coming in from the stars. Surely there should be times
21:42
Speaker 6: when the stars are completely obscured by the massive objects
21:46
Speaker 6: in the cloud. If the cloud thins, then more of
21:49
Speaker 6: the stars should be visible. If the cloud thickens, then
21:52
Speaker 6: some of the stars should disappear.
21:54
Speaker 3: That's it.
21:55
Speaker 6: Keep up the good work by.
21:57
Speaker 3: Thanks Tim for this wonderful question and for giving us
21:59
Speaker 3: an opportunity to scratch your orty itch.
22:04
Speaker 2: All right, So when I was looking at your outline,
22:06
Speaker 2: there was a fact in your outline that absolutely blew
22:08
Speaker 2: my mind. So let's get to it. Let's jump into
22:12
Speaker 2: what is the Ork Cloud?
22:13
Speaker 3: So the Orc Cloud is a theoretical cloud of icy
22:18
Speaker 3: mini planets, meaning I.
22:20
Speaker 1: Thought we knew it existed.
22:22
Speaker 2: The fact that it's theoretical is blowing my mind. The
22:24
Speaker 2: Ork Cloud is a maybe.
22:26
Speaker 3: It's a maybe for exactly the reason that Tim is asking,
22:29
Speaker 3: Because we can't see it. Oh my gosh, we can't
22:32
Speaker 3: see it. We've never seen it. There's like one observation
22:35
Speaker 3: of a thing people think might have come from the
22:37
Speaker 3: Ork Cloud, and people think comets maybe probably come from
22:41
Speaker 3: the Ork Cloud. But the Ork Cloud itself is not
22:44
Speaker 3: something we've ever seen, and it's a shame because it
22:46
Speaker 3: would be amazing. So let's back up and remind people
22:50
Speaker 3: what is the Orc Cloud? Anyway? So we're talking really
22:54
Speaker 3: far out in the Solar System. So you know, the
22:56
Speaker 3: Sun is at the center, and the Earth orbits of
22:59
Speaker 3: what we call one a A and the big planets
23:01
Speaker 3: are at like five ish AU, and if you go
23:04
Speaker 3: all the way out to Pluto, it orbits at a
23:06
Speaker 3: radius of like forty ish AU. So like really far
23:10
Speaker 3: out there in the Solar system, right, But the Orc Cloud,
23:13
Speaker 3: if it exists, is two thousand to like one hundred
23:17
Speaker 3: thousand AU from the Sun. Oh my god, we're talking
23:20
Speaker 3: about like one to three light years. This is a
23:24
Speaker 3: big blob of objects that are very very very far
23:28
Speaker 3: away from where we are currently, so they're not technically
23:31
Speaker 3: part of the Solar System. They're sort of like captured
23:34
Speaker 3: by the Sun's gravity, but very very far out there.
23:37
Speaker 2: So when you say two thousand to two hundred thousand,
23:40
Speaker 2: is that a huge error bar or just a huge
23:44
Speaker 2: area that's occupied by the Orc Cloud.
23:47
Speaker 3: It's a huge area. So like if you were going
23:50
Speaker 3: to go visit the Orc Cloud, it would start at
23:52
Speaker 3: like fifty thousand AU and you'd still be going through
23:55
Speaker 3: and come out the other side somewhere around one maybe
23:58
Speaker 3: two hundred thousand AU. Oh my gosh. So it's a
24:01
Speaker 3: huge area exactly, and it has lots and lots of
24:04
Speaker 3: objects in it. Like the Oor Cloud is not like
24:07
Speaker 3: two little pieces of ice. We think. It has like
24:09
Speaker 3: trillions and trillions of little icy bits out there, a
24:14
Speaker 3: lot of them bigger than like one kilometer wide, billions
24:18
Speaker 3: of them bigger than twenty kilometers wide. So it's a
24:22
Speaker 3: lot of stuff. But space is really vast. You know,
24:25
Speaker 3: volume grows very quickly with radius, so as you get
24:29
Speaker 3: far and out there, we're talking about an incredible amount
24:31
Speaker 3: of space. So even though there's a lot of stuff
24:34
Speaker 3: in there, it all adds up to like five times
24:36
Speaker 3: the mass of the Earth if you clump it all together.
24:39
Speaker 3: It's spread out really, really far, so you wouldn't be
24:42
Speaker 3: like dodging asteroids like in Star Wars. You'd be like
24:45
Speaker 3: using telescopes to find an object even if you were
24:48
Speaker 3: in the middle of the Ork Cloud.
24:49
Speaker 2: Whoa so I had imagine that the ork cloud was
24:53
Speaker 2: dust and small rocks, but it makes more sense that
24:56
Speaker 2: the cloud is made of water. Or you said ice,
25:00
Speaker 2: Is that ice made of water? And how did water
25:02
Speaker 2: get out there?
25:03
Speaker 3: Yeah? Water is actually everywhere in the Solar System and
25:06
Speaker 3: in the universe. It's not just water ice though, there's
25:09
Speaker 3: like methane, ice and other frozen stuff. And it's not
25:12
Speaker 3: unusual to find ice or frozen water or frozen other
25:15
Speaker 3: stuff out there in the far Solar System. You know,
25:17
Speaker 3: Neptune and Urinus have a lot of these things in
25:19
Speaker 3: them as well. Anything past the frost line in the
25:22
Speaker 3: Solar System, which is the inner part of the Solar System,
25:25
Speaker 3: where the Sun's radiation is going to melt or vaporize
25:28
Speaker 3: any sort of water that's out there, you're going to
25:31
Speaker 3: find a lot of it. That's why Jupiter and Saturn
25:33
Speaker 3: are bigger, for example, because as those planets started to
25:36
Speaker 3: form in the early Solar System, they could gather ice
25:39
Speaker 3: because it was around, and so they could grow faster
25:41
Speaker 3: than the inner planets. So the sort of more solid
25:44
Speaker 3: stuff out there because the Sun's radiation hadn't blasted it
25:47
Speaker 3: into vapor all right.
25:49
Speaker 2: So there is maybe a massive cloud of ice, but
25:54
Speaker 2: maybe not.
25:57
Speaker 3: And it's sort of the third cloud. In our Solar system.
26:00
Speaker 3: Have the Asteroid Belt, which is past Mars, and it's
26:02
Speaker 3: a bunch of rocks left over that we think can't
26:05
Speaker 3: coalesce into a planet because of Jupiter's gravitational pull in
26:08
Speaker 3: the tidal forces. Then there's the Kuiper Belt which is
26:11
Speaker 3: out there that provides short period comets, and it's just
26:14
Speaker 3: like a bunch of icy rocks. But the Ork Cloud
26:17
Speaker 3: is maybe a thousand times further out than the Kuiper Belt,
26:21
Speaker 3: so it really is like a halo for the whole
26:23
Speaker 3: Solar System.
26:24
Speaker 2: And so the stuff that's out there in that cloud,
26:28
Speaker 2: can you give me a sense for like how much
26:30
Speaker 2: stuff is out there?
26:31
Speaker 1: Like if you mushed it all together, how much would
26:34
Speaker 1: you have?
26:35
Speaker 3: So it's like five times the mass of the Earth.
26:37
Speaker 3: So it's not a tiny amount of stuff, right, It's
26:40
Speaker 3: just spread out over an incredible area, you know how
26:43
Speaker 3: Like when you start with a tub of frosting, you're like, Oh,
26:45
Speaker 3: this is definitely gonna be enough frosting for this cake,
26:48
Speaker 3: and then you start spreading out the cake, You're like, uh, oh,
26:50
Speaker 3: this might not be enough frosting. Like the oork cloud
26:53
Speaker 3: is spread super duper thin. You know, it's like the
26:56
Speaker 3: sun is the most lightly frosted thing you've ever seen.
26:58
Speaker 2: I thought you're this, this is a bit of insight
27:02
Speaker 2: into me. Maybe I thought you were going to say,
27:03
Speaker 2: when you sit down with the frosting and a spoon,
27:07
Speaker 2: this is.
27:08
Speaker 1: Definitely more than enough dessert. And then you're like, no,
27:11
Speaker 1: I wanted more.
27:12
Speaker 3: You know, there's a warning on the side of the
27:13
Speaker 3: frosting that says not to be eaten on its own.
27:16
Speaker 1: Are you serious?
27:17
Speaker 3: I am serious?
27:19
Speaker 1: Why do they are? They like prohibiting joy in.
27:22
Speaker 3: This whole episode of the Hyperfixed podcast about exactly that
27:25
Speaker 3: you should go dig into it. It's a fun story.
27:27
Speaker 1: Oh all right, my family might be in a lot
27:30
Speaker 1: of trouble. I'll dig in anyway.
27:32
Speaker 3: I'm not a doctor, but I don't recommend that you
27:34
Speaker 3: eat all of I'm roasting by yourself. At least share
27:36
Speaker 3: it with your family.
27:37
Speaker 1: I share it with the kids, all right. So moving on, And.
27:40
Speaker 3: We're not one hundred percent sure what the org cloud
27:42
Speaker 3: is made out of because we've never seen it directly. Right,
27:45
Speaker 3: if we could see light bouncing off of it, we
27:47
Speaker 3: could understand how it reflects and absorbs light and we
27:50
Speaker 3: could get some spectrographic information, or if we had a
27:53
Speaker 3: great theory for how it formed, we can understand it.
27:56
Speaker 3: But we have a few various ideas for like how
27:59
Speaker 3: one gets an org cloud. One is that it's sort
28:01
Speaker 3: of the detritus from the formation of the Solar System.
28:04
Speaker 3: There's a lot of like gravitational interactions, and sometimes things
28:07
Speaker 3: get sort of tossed out of the center, you know.
28:09
Speaker 3: We think, for example, there might have been another gas
28:11
Speaker 3: giant that in the early part of the Solar System
28:14
Speaker 3: because of the push in the pull of the various
28:16
Speaker 3: other planets, could have gotten tossed out. It's not that
28:19
Speaker 3: easy to stay in orbit. If you get a big
28:21
Speaker 3: enough push from something else, you might find another orbit
28:25
Speaker 3: or you might just be lost. And so these orc
28:28
Speaker 3: cloud objects might be like little bits that were formed
28:31
Speaker 3: closer to the Solar System and then got kicked out
28:33
Speaker 3: and ended up in a stable orbit very far from
28:36
Speaker 3: the Solar System.
28:37
Speaker 1: Whilst we could have had like another Saturn, yeah, but
28:40
Speaker 1: now it's out in the ork cloud. That's crazy exactly.
28:43
Speaker 3: Or it could have been that as our Sun was forming,
28:46
Speaker 3: there was another star that was forming nearby stars tend
28:48
Speaker 3: to form in clumps. Right, you have a huge cloud
28:50
Speaker 3: of gas that collapses into a solar system, but doesn't
28:53
Speaker 3: usually collapse into one solar system, It collapses into several
28:56
Speaker 3: based on where the over densities were in that gas cloud.
29:00
Speaker 3: And so it could have like exchanged material with sister
29:03
Speaker 3: stars and this old clouds could be like, you know,
29:05
Speaker 3: the last bit of that tug of war between the stars.
29:08
Speaker 1: Huh.
29:09
Speaker 2: So we've got theories for why it exists, but what
29:13
Speaker 2: is our evidence that it exists? Do we just think
29:16
Speaker 2: that it exists because we have some theories saying it should,
29:19
Speaker 2: or has someone like look through a telescope and been
29:21
Speaker 2: like kind of looks like a cloud out there.
29:23
Speaker 3: Yeah, why would anybody imagine this thing exists if we've
29:25
Speaker 3: never seen it? Right, Well, one of the original reasons
29:28
Speaker 3: for this concept was to explain long period comets. So
29:32
Speaker 3: comets are ice balls that plummet towards the center of
29:35
Speaker 3: the Solar system, go around the back of the Sun,
29:37
Speaker 3: and then zoom back out. And they can have shorter periods,
29:39
Speaker 3: you know, years, decades, or they can have longer periods
29:42
Speaker 3: hundreds of years, And people wonder, like, where do those
29:45
Speaker 3: ice balls come from that. They take hundreds of years
29:48
Speaker 3: to orbit the Sun, and so they imagine maybe there's
29:52
Speaker 3: a huge cluster of these balls out there, sort of
29:54
Speaker 3: floating in distant space, and sometimes one of them gets
29:57
Speaker 3: perturbed and falls in towards the inner Old System and
30:00
Speaker 3: becomes a comet. So this is where the hypothesis of
30:03
Speaker 3: the Ork cloud comes from. Oh interesting, yeah, and highlights
30:06
Speaker 3: something which I think is often overlooked, which is comets
30:09
Speaker 3: are a real danger. You know, people think about asteroids
30:12
Speaker 3: hitting us, and we monitor the asteroid belt and that's cool.
30:15
Speaker 3: But like asteroids, we can see, we can predict, and
30:18
Speaker 3: mostly we know where the big ones are. But they're
30:21
Speaker 3: also not that far away from us. So if they
30:23
Speaker 3: hit us, they're not going that fast. But comets they
30:26
Speaker 3: come out of the darkness, right, We have no idea
30:29
Speaker 3: the trillions of them out there. They can just get perturbed,
30:33
Speaker 3: comes suddenly out of the darkness, and by the time
30:35
Speaker 3: they hit the Earth, they're going incredibly fast. And so
30:38
Speaker 3: like in terms of existential danger, like comets in the
30:41
Speaker 3: Ork Cloud are a huge gun loaded with trillions of
30:45
Speaker 3: bullets pointed at the Earth.
30:46
Speaker 2: And if existential dread is your jam, you should check
30:49
Speaker 2: out our earlier interview with Phil Plate where we just
30:52
Speaker 2: talked about the many ways the universe is trying to
30:54
Speaker 2: kill us exactly.
30:56
Speaker 3: And so we've never seen the work Cloud, but we've tried.
30:58
Speaker 3: You know, the Oork Cloud is so far that is
31:00
Speaker 3: past Voyager one, which is the probe the humanity is
31:04
Speaker 3: sent out into space and is the furthest fastest human ship.
31:08
Speaker 3: It might reach the beginning of the Oor Cloud in
31:10
Speaker 3: three hundred more years, though the power on that thing
31:13
Speaker 3: is rapidly running out. But of course we can also
31:17
Speaker 3: try to see the or Cloud from Earth. And this
31:19
Speaker 3: gets really to Tim's question, like why isn't it blocking
31:21
Speaker 3: our view? It's not blocking our view because it's a
31:25
Speaker 3: lot of really really tiny objects super far away. It's
31:29
Speaker 3: like if an astronaut threw sand into space, it wouldn't
31:32
Speaker 3: block your view, right, And that's effectively what's going on here.
31:36
Speaker 3: They're really small. Each object, because it's so far away,
31:39
Speaker 3: would block the tiniest little portion of the night sky.
31:43
Speaker 3: So even though there are so many of them, they
31:45
Speaker 3: don't add up to blocking much of your night sky.
31:48
Speaker 3: But it's something that people are looking for. The way
31:51
Speaker 3: you could see the Ork Cloud is exactly. That is
31:53
Speaker 3: to see, like, can we see an object pass in
31:55
Speaker 3: front of a star? These little mini star eclipses would
32:00
Speaker 3: give us a hint that the Oorkcloud is real. And
32:02
Speaker 3: then it's out there, and there is one tentative observation.
32:06
Speaker 3: This object called Sedna, we think is one hundred and
32:09
Speaker 3: forty billion kilometers from the Sun. It's a tentative observation
32:13
Speaker 3: of this thing.
32:13
Speaker 2: Oh my gosh, that's I mean, to be able to
32:15
Speaker 2: see a teeny tiny object passing in front of the
32:18
Speaker 2: Sun seems to me like it would require amazing telescope abilities.
32:22
Speaker 3: Yeah, exactly. And Sedna is really hardest spot. It's twenty
32:26
Speaker 3: times further away from the Sun than Pluto, so its
32:29
Speaker 3: orbit is at about one thousand AU and it's a
32:33
Speaker 3: very very elongated orbit. But you know, it's just probably
32:36
Speaker 3: one of like zillions and zillions of things that are
32:39
Speaker 3: out there that we can just barely spot. But as
32:42
Speaker 3: we improve our telescopes, we'll get a clearer view of
32:45
Speaker 3: what's out there in the Oork Cloud, which is important
32:47
Speaker 3: because the better we understand the Orc Cloud, the better
32:50
Speaker 3: we're able to model in and predict what might happen.
32:53
Speaker 3: You know, every once in a while, another star comes
32:55
Speaker 3: near our star, and when they approach each other they
32:57
Speaker 3: can gravitationally nudge on each other. There's ort clouds potentially
33:01
Speaker 3: stimulating like a shower of comets into the inner Solar System.
33:06
Speaker 3: And yet, doesn't that seem like something we'd like.
33:07
Speaker 2: To understand when you say every once in a while,
33:09
Speaker 2: I hope you mean every like a few billion years,
33:12
Speaker 2: not in my lifetime, or what does everyone's in a
33:15
Speaker 2: while mean?
33:16
Speaker 3: There is a prediction that in one point three million years,
33:19
Speaker 3: another star is going to come within around twenty or
33:22
Speaker 3: thirty light days of our star, and so yeah, it's
33:26
Speaker 3: not going to be for a while.
33:27
Speaker 1: That's good. Yeah, I don't suspect I'll still be around
33:30
Speaker 1: by that point.
33:31
Speaker 3: But you know, the Sun oscillates relative to the galaxy.
33:34
Speaker 3: It doesn't just go around the center of the galaxy.
33:36
Speaker 3: It goes up and down through the plane of the
33:38
Speaker 3: galaxy like every thirty million years or so. So it's
33:41
Speaker 3: not like our galactic neighborhood. It's constant. You know, we're
33:44
Speaker 3: always zooming through the galaxy and changing our neighbors, and
33:47
Speaker 3: so they can come and go, and that affects the
33:49
Speaker 3: ork cloud, and you know, life on Earth.
33:52
Speaker 2: That's so amazing to me, how many things are happening
33:55
Speaker 2: at the very tiny scales and absolutely huge scales that
33:59
Speaker 2: you mess Like the other day, I was walking and
34:01
Speaker 2: I saw this little shimmer in front of my face
34:04
Speaker 2: and it was a baby spider. When they eventually go
34:08
Speaker 2: off to start their lives, they release a tiny little
34:10
Speaker 2: bit of silk that catches the air and they it's
34:13
Speaker 2: called ballooning, and they sort of balloon off. And there's
34:15
Speaker 2: all these little things that are happening that you only
34:18
Speaker 2: get a glimpse of very rarely, and you're missing it
34:21
Speaker 2: on the micro scale, and there's all this Like I
34:24
Speaker 2: just now learned that we're on a carousel around the
34:27
Speaker 2: galaxy and I was missing that too.
34:31
Speaker 1: It's amazing.
34:32
Speaker 3: Well, you're right, there is so much going on in
34:34
Speaker 3: the universe. We perceive a tiny little bit of it.
34:36
Speaker 3: We pay attention to an even smaller slice, and we
34:39
Speaker 3: understand and even smaller slice of that. And so we
34:43
Speaker 3: hope this podcast helps open up your eyes and your
34:45
Speaker 3: mind to what's going on in the rest of the universe.
34:48
Speaker 3: And so Tim tell us, if we have successfully stretched
34:50
Speaker 3: your brain out to the edges of the Ord Cloud,
34:54
Speaker 3: and explained why it doesn't block your view of the
34:57
Speaker 3: beautiful night sky.
34:58
Speaker 6: Let us know, guys, Thanks very much, keep up the
35:02
Speaker 6: good luck.
35:23
Speaker 3: All right, we're back and we're answering questions from people
35:26
Speaker 3: like you who are curious about the universe and want
35:29
Speaker 3: to know how things work. Please send us your questions
35:32
Speaker 3: to Questions at Daniel and Kelly dot org. We'd love
35:35
Speaker 3: to have you on the pod. So we've talked about itches,
35:39
Speaker 3: we've talked about space, and now we're going to zoom
35:41
Speaker 3: back in to talk about something that's happening right in
35:44
Speaker 3: your backyard. Humans aren't the only clever engineers on the planet.
35:48
Speaker 2: Maybe we'll see that's the payoff at the end. So
35:52
Speaker 2: let's go ahead and listen to a question from Eric
35:56
Speaker 2: in Idaho.
35:57
Speaker 7: Hey, Kelly, I was inspired by your passion for byology
36:00
Speaker 7: on the show and came across something called the honeycomb conjecture.
36:03
Speaker 7: Bees create hexagons for a fascinating reason, and in the
36:06
Speaker 7: last couple of decades a gentleman named Thomas Hales prove
36:09
Speaker 7: the conjecture using math.
36:11
Speaker 3: I have a few.
36:12
Speaker 7: Questions for you that I'd love to get your thoughts on.
36:15
Speaker 7: What is the history behind the conjecture, why do bees
36:18
Speaker 7: create hexagons?
36:19
Speaker 3: To begin with? What are the advantages to do in this?
36:22
Speaker 7: Also do biologists see any other species creating hexagons? And
36:28
Speaker 7: also I've been thinking a lot about math, and we
36:30
Speaker 7: all know math and physics go hand in hand. However,
36:32
Speaker 7: I don't hear much about mathe and biology going together.
36:35
Speaker 7: How prevalent is math and biology? Do you use it
36:38
Speaker 7: daily in your research? One thing too, I've been thinking
36:41
Speaker 7: about a lot is that some physicists believe that the
36:44
Speaker 7: universe nature is inherently mathematical. What do biologists say on
36:49
Speaker 7: this matter? What is their opinion? Is the universe? Is
36:52
Speaker 7: nature inherently mathematical? Or is this just the language that
36:55
Speaker 7: we human beings create to describe such crazy things like
37:00
Speaker 7: hexagons in nature? All right, I certainly appreciate everything you
37:04
Speaker 7: and Daniel do. Thank you for considering my questions.
37:07
Speaker 3: Eric is a long time listening to this show and
37:09
Speaker 3: a frequent emailer, and we love hearing from him. If
37:12
Speaker 3: you would like to email with us and have us
37:14
Speaker 3: answer all your science questions, please please please write to
37:16
Speaker 3: us to questions at Daniel and Kelly dot org. We
37:19
Speaker 3: mean it anyway, Kelly, what can you tell us about
37:22
Speaker 3: the honeycomb conjecture and bees. How long have people been
37:25
Speaker 3: thinking about this?
37:26
Speaker 2: Well, first of all, I love this question because it's
37:28
Speaker 2: a nice intersection of physics and biology, and so you know,
37:32
Speaker 2: I'll expect you to give most of the answer here,
37:34
Speaker 2: Daniel totally.
37:35
Speaker 1: No, I'm just kidding. I'm just kidding.
37:37
Speaker 2: I did my research, all right, So this is a
37:39
Speaker 2: question we've been asking.
37:40
Speaker 1: Ourselves for a really long time.
37:42
Speaker 2: So around thirty six BC, this guy, Marcus Tarentius Vero
37:47
Speaker 2: sorry about my pronunciation as ever, was writing a book
37:51
Speaker 2: about agriculture and he mentioned that honey bees make hexagonal
37:56
Speaker 2: honeycombs and that there was some debate about why this happened.
38:00
Speaker 2: And one of the first options was, well, bees have
38:03
Speaker 2: six legs, honeycombs have six sides.
38:07
Speaker 1: Maybe bees are just like using their.
38:10
Speaker 2: Legs to kind of determine the like vertices of the
38:13
Speaker 2: honeycomb and it so maybe it just has something to
38:15
Speaker 2: do with the fact that they have six legs.
38:17
Speaker 1: There was some connection there.
38:18
Speaker 3: Interesting. Well, I mean, you notice simple patterns, you draw
38:21
Speaker 3: dotted lines between them. Sure it makes sense?
38:23
Speaker 1: Yeah, sure, Then you test your conjectures.
38:25
Speaker 3: So how do you test that? You like, cut some
38:27
Speaker 3: legs off of bees and see if they make square honeycombs.
38:30
Speaker 2: I mean, yeah, that you could do that, you could,
38:32
Speaker 2: but we don't. It turns out we don't need to
38:34
Speaker 2: because actually the first thing you should do is make
38:36
Speaker 2: careful observations. And as we're gonna get to later, if
38:39
Speaker 2: you make careful observations, you'll see that actually bees are
38:42
Speaker 2: making circles that then melt into like a hexagonal shape.
38:47
Speaker 2: And so so if you just watch, you'd be like, oh, actually,
38:50
Speaker 2: it doesn't matter that they have six legs because they're
38:52
Speaker 2: just making circles.
38:53
Speaker 3: You're saying that bees when they originally make their honeycomb,
38:56
Speaker 3: they're making perfect circles or very close to it, and
38:59
Speaker 3: they just relax into honeycombs. Yes, wow, I had no idea.
39:05
Speaker 2: Well wait till we're going to get to in a
39:07
Speaker 2: little bit more details. So one of the interesting questions
39:09
Speaker 2: that arise here than I think, is our bees purposefully
39:12
Speaker 2: making hexagons or not our bees Nature's mathematicians or you know,
39:17
Speaker 2: is that giving them too much credit? But so the
39:19
Speaker 2: reason it's exciting that they're making hexagons is the second option,
39:23
Speaker 2: which is that they are purposefully making hexagon shapes through
39:27
Speaker 2: some mechanism that we'll get to later, because hexagons maximize
39:32
Speaker 2: the area inside. So since Pathagoras's time, we've known that
39:36
Speaker 2: some shapes do what's called tile the plane, which is
39:39
Speaker 2: to say, they fill a flat space without overlapping one
39:42
Speaker 2: another or creating any gaps. Some of the shapes that
39:45
Speaker 2: we've sort of studied the most in terms of tiling
39:47
Speaker 2: the plane are triangles, squares, and hexagons. There are some
39:51
Speaker 2: other shapes that do this.
39:52
Speaker 3: Too, and this is actually a really fascinating area of mathematics,
39:55
Speaker 3: like finding shapes that tile the plane and new shapes
39:58
Speaker 3: that tile the plane. Something this crazy discovery of an
40:02
Speaker 3: object that can tile an infinite plane without ever repeating
40:05
Speaker 3: a pattern, which is super amazing. This call an Einstein shape.
40:09
Speaker 3: And the best part of this story is that wasn't
40:11
Speaker 3: developed by like a professional mathematician, but like a craftsman,
40:14
Speaker 3: a guy who's just like good with stuff, and he
40:16
Speaker 3: built like a physical model to explore this anyway, super fascinating.
40:20
Speaker 3: That's amazing though, total digression though, So you're telling us
40:23
Speaker 3: about people thinking about tiling the plane way back in
40:26
Speaker 3: the time of like Greek geometricians.
40:29
Speaker 2: Yes, right, So people have been talking about tiling the
40:31
Speaker 2: plane for a long time. But one of the cool
40:33
Speaker 2: things about hexagons is that, you know, say you're considering triangles, squares,
40:36
Speaker 2: and hexagons to tile the plane. If you want to
40:39
Speaker 2: maximize the volume inside of the shape, then for the
40:43
Speaker 2: same perimeter for each of those shapes, hexagons maximize the
40:47
Speaker 2: volume inside, which you would want if you're storing honey
40:50
Speaker 2: or babies or something in place in there.
40:52
Speaker 3: Or babies in honey or something honeybabes, honey babes. And
40:57
Speaker 3: I guess the idea here is you want to be economical,
41:00
Speaker 3: and so you want to store as much as possible
41:02
Speaker 3: while using the minimal amount of building materials.
41:04
Speaker 2: That's right, because the building materials is wax that they
41:07
Speaker 2: have to make, and so you want to minimize the
41:09
Speaker 2: building materials you need and maximize the space inside.
41:12
Speaker 3: So I love when mathematics intersects with biology, and it
41:15
Speaker 3: gives us a reason. The hypothesis, I guess is that
41:18
Speaker 3: bees have somehow evolutionarily discovered that this is the most
41:22
Speaker 3: efficient way to store their honey by building hexagons.
41:26
Speaker 2: Yeah right, And it wasn't actually proved mathematically that this
41:29
Speaker 2: was a good strategy for the honeybees until Thomas Hales
41:32
Speaker 2: did it in two thousand.
41:34
Speaker 3: Two thousand AD AD.
41:36
Speaker 1: Yes.
41:37
Speaker 3: Wow, I love these mathematical questions that are like open
41:40
Speaker 3: for millennia and then some dudes like, I'm going to
41:43
Speaker 3: tackle that. Yeah, let's do that tomorrow.
41:46
Speaker 2: I'm guessing it was more than just tomorrow, but it
41:48
Speaker 2: was a like thirty six page proof, which I will
41:50
Speaker 2: admit I just kind of.
41:51
Speaker 1: Like scan scan scan scan scan scan. I didn't check
41:54
Speaker 1: his math.
41:54
Speaker 4: Wow.
41:55
Speaker 3: I love that. That's incredible.
41:57
Speaker 2: I mean, I think for some of these questions it
41:59
Speaker 2: could be because nobody was like I have to know
42:01
Speaker 2: if the honey bees are doing it right, Like there
42:03
Speaker 2: might have been more pressing questions, but it's a fascinating
42:05
Speaker 2: question to answer.
42:06
Speaker 3: All right, So we know now that hexagons are the
42:09
Speaker 3: best way to store honey. Do the bees know that?
42:12
Speaker 1: Yeah?
42:12
Speaker 2: So the answer at the end of the day is
42:14
Speaker 2: that we really don't know. So I watch some videos
42:17
Speaker 2: where people are like, oh, bees are Nature's mathematicians.
42:20
Speaker 1: They make hexagons, and I'm like, oh, I like that.
42:23
Speaker 1: That really sounds beautiful.
42:24
Speaker 2: But so then the question is, like, what do the
42:27
Speaker 2: bees know in terms of what they're doing and of course,
42:29
Speaker 2: you know, we can't ask the bees what they know,
42:31
Speaker 2: so we'll never really know. But as we mentioned a
42:33
Speaker 2: little bit earlier, they do start by making circles out
42:37
Speaker 2: of the wax, and as things sort of heat and
42:40
Speaker 2: then cool, they end up sort of changing their shape
42:44
Speaker 2: into hexagons over time. And I think you see this
42:47
Speaker 2: also with bubble rafts and Daniel, maybe you can explain
42:50
Speaker 2: why this is the case. This is where I thought
42:52
Speaker 2: Daniel's gonna chime in here, but maybe I'm wrong. So
42:55
Speaker 2: you make a bunch of little circular bubbles and they
42:58
Speaker 2: sort of find the spaces in between, and over time
43:00
Speaker 2: they sort of settle into hexagons, and I think that's
43:03
Speaker 2: like surface tension pulling them together into more efficient shapes.
43:06
Speaker 1: Does that sound right?
43:06
Speaker 3: Yeah, So what's happening there is the universe is optimizing it, right,
43:10
Speaker 3: not the bees, not the bubble raft designer. It's just like,
43:14
Speaker 3: if you're gonna squeeze a bunch of bubbles together, they're
43:16
Speaker 3: going to end up forming a hexagon shape because otherwise
43:19
Speaker 3: they're gonna pop, right, And so if you want to
43:22
Speaker 3: keep bubbles open and minimize the amount of popping, then
43:25
Speaker 3: you're going to pack them as hexagons. That just sort
43:27
Speaker 3: of makes sense. Yeah, And so it seems like we
43:29
Speaker 3: can't give credit to the bees for that, right. If
43:31
Speaker 3: they're building circles in the universe, is like, yeah, we're
43:34
Speaker 3: going to turn these into hexagons. Then that's just the
43:37
Speaker 3: mathematics of the universe. Isn't that physics?
43:39
Speaker 2: Well that would be boring, but so, uh, just kidding.
43:43
Speaker 2: So hold on, So when the bees are putting their
43:46
Speaker 2: circles in, they have to place the circles in certain
43:51
Speaker 2: ways so that you get the hexagons.
43:53
Speaker 1: If they put them.
43:53
Speaker 2: In there all randomly, then you wouldn't necessarily get like
43:57
Speaker 2: the the near perfect hexagons that you get. And so
44:00
Speaker 2: I don't think that they are saying, oh, we've got
44:03
Speaker 2: to do it this way, because if you place them
44:05
Speaker 2: this way, when they finally make their final form, they're
44:08
Speaker 2: going to be a hexagon, which is the mathematically ideal
44:11
Speaker 2: shape for our honey storage needs. But I do think
44:15
Speaker 2: they have some programming in there that helps them make
44:17
Speaker 2: sure that they put their circles in in a certain
44:21
Speaker 2: way so that when the wax settles, it will create
44:24
Speaker 2: a hexagon. But here's an interesting side thing. Paper wasps,
44:29
Speaker 2: which make their nests out of like fibers. So, for example,
44:33
Speaker 2: I was sitting on a bench the other day and
44:34
Speaker 2: a paper wasp came by, and it was it's an
44:37
Speaker 2: old wooden bench, and it was starting to like scrape
44:39
Speaker 2: the wood off of the top of the bench, and
44:41
Speaker 2: then it went back and it used it to make
44:42
Speaker 2: its paper nests. You're yawning, and I can't believe you're
44:45
Speaker 2: yawning at paper wasp, Daniel.
44:47
Speaker 1: They're so interested.
44:48
Speaker 3: But that's not a judgmental yawn. I was like a
44:52
Speaker 3: woke up too early yawn.
44:53
Speaker 1: No, I get that none of us get enough sleep.
44:55
Speaker 2: And so anyway, they also make hexagonal cells, and they
44:59
Speaker 2: don't get like you know, wax melts into the right shape.
45:02
Speaker 2: They start as circles. So the circles are sort of
45:05
Speaker 2: like up at the top point where the nest starts,
45:07
Speaker 2: and then as they build it out, you get hexagons.
45:09
Speaker 2: And so to me that's even a little bit more
45:12
Speaker 2: impressive because they do end up building the hexagons. But anyway,
45:15
Speaker 2: so it's all about positioning and not necessarily about going
45:19
Speaker 2: for hexagons in particular.
45:20
Speaker 3: Interesting and so in the end, are you going to
45:22
Speaker 3: give the bees credit? Do you think the bees are geometers?
45:26
Speaker 2: I give bees a lot of credit for a variety
45:28
Speaker 2: of reasons. Studies have shown that bees are really good
45:31
Speaker 2: at making economical decisions about which flowers to visit and
45:35
Speaker 2: how many times to visit them.
45:36
Speaker 1: They're good at communicating with one another.
45:38
Speaker 2: Where the great food sources are, and they are able
45:42
Speaker 2: to pull this trick off that maximizes the volume where
45:45
Speaker 2: they store their stuff. So I think they're impressive. Maybe
45:48
Speaker 2: not as impressive as we had initially imagined, but you know,
45:52
Speaker 2: nature doesn't need to find the most complicated solution to
45:54
Speaker 2: a problem if an easier mechanism gives you the right solution, amazing.
45:58
Speaker 3: The real question in my mind, though, is our b
46:01
Speaker 3: geometers or geometricians, which is the correct word.
46:05
Speaker 2: It feels like it's more your wheelhouse than mine, But.
46:11
Speaker 1: I think they're geometricians.
46:13
Speaker 3: Maybe in two thousand more years somebody will come along
46:15
Speaker 3: and figure that one out.
46:16
Speaker 2: You know what's really cute, though, there's these moths on
46:19
Speaker 2: my property, the inch worms, and the I think it's
46:23
Speaker 2: the family of inchworms are called geometer moths because they
46:27
Speaker 2: are like measuring the earth the way they move along,
46:30
Speaker 2: which I thought.
46:30
Speaker 1: Is super cute.
46:31
Speaker 3: It's cool, it's cute.
46:33
Speaker 2: So our listener had a couple different questions. One he
46:36
Speaker 2: wanted to know about the honeycomb conjecture. Two he wanted
46:40
Speaker 2: to know if other species create them. And we've talked
46:43
Speaker 2: about how paper wasps do. My husband Zach sent me
46:46
Speaker 2: a picture of tadpole eggs in our ponds that had
46:49
Speaker 2: naturally come together their form of hexagon.
46:51
Speaker 1: Oh, pretty cute.
46:53
Speaker 2: You see some plants make sort of hexagon shapes. So
46:57
Speaker 2: we do see this in nature in a couple different places,
47:00
Speaker 2: including in the bubble raft example. And then the final
47:03
Speaker 2: question was, you know math and physics go hand in hand,
47:06
Speaker 2: but you don't hear much about math and biology, you know.
47:09
Speaker 1: Yeah, Daniel jumps in there.
47:10
Speaker 2: I've heard Daniel critique biologists for not having error bars
47:14
Speaker 2: on our graphs and presentations.
47:16
Speaker 3: That's a difference. I'm criticizing biologists, not biology.
47:19
Speaker 1: Oh okay, got it, got it all right.
47:21
Speaker 2: So biologists do think a lot about math. So, for example,
47:27
Speaker 2: theoretical ecologists think a lot about how we can write
47:31
Speaker 2: equations that describe dynamics in a system, like predator or
47:34
Speaker 2: prey equations, or how an epidemic moves through a system.
47:38
Speaker 2: And so that requires a lot of maths, so they're
47:40
Speaker 2: thinking mathematically. There, we use a lot of statistics to
47:43
Speaker 2: try to understand what we observe, and you know, there
47:47
Speaker 2: are a lot of people who think about the world mathematically.
47:50
Speaker 2: And I think over the course of my twenty year
47:52
Speaker 2: career where I've been an ecologist, I've seen a much
47:55
Speaker 2: greater emphasis on trying to describe what we see, not
47:59
Speaker 2: just in terms of, you know, a qualitative description that's
48:02
Speaker 2: maybe a little poetic, which you know, I love reading
48:05
Speaker 2: those qualitative, poetic descriptions, but also trying to capture what
48:08
Speaker 2: you want in a more quantitative way and describing what
48:11
Speaker 2: you're seeing mathematically and then trying to explain why nature
48:14
Speaker 2: has resulted in that sort of equation.
48:16
Speaker 1: So, yes, biologists do use math a lot.
48:18
Speaker 3: On his last question, that's sort of a philosophy question,
48:21
Speaker 3: you know, is nature inherently mathematical? And the sort of
48:24
Speaker 3: an important philosophical question that we don't know the answer to,
48:26
Speaker 3: which is why we can use math to describe the universe.
48:31
Speaker 3: You know, you might imagine that math naturally describes the
48:34
Speaker 3: universe at the smallest scale, that fundamentally, the some equation
48:37
Speaker 3: you can write down to describe fundamental physics. But then
48:40
Speaker 3: why can you use math to describe like, you know,
48:43
Speaker 3: the predator preye reaction, or the geometry of hexagons, or
48:47
Speaker 3: you know, the shape of birds eggs or something. And
48:51
Speaker 3: that's the sort of mystery, like why these fairly simple
48:53
Speaker 3: mathematical stories emerge from the crazy, chaotic combination of fundamental
48:58
Speaker 3: bits of the universe. It's not something philosophers really have
49:02
Speaker 3: a handle on, so we don't know if it's something
49:04
Speaker 3: that is inherently part of the universe or sort of
49:07
Speaker 3: the way we are framing these questions, the way we
49:09
Speaker 3: think about things, you know, the sort of our mental language.
49:12
Speaker 2: Yeah, And one of the most popular phrases amongst people
49:15
Speaker 2: who do modeling in biology is that all models are wrong,
49:19
Speaker 2: some are useful.
49:20
Speaker 3: That's exactly correct, even of fundamental physics. Right, as far
49:24
Speaker 3: as we know, our description of the tiniest particles, it's
49:27
Speaker 3: not the end of the story. It's a model, and
49:29
Speaker 3: it's not true in the sense that it's not describing
49:32
Speaker 3: everything that's happening inside of it, but it's still useful.
49:36
Speaker 3: And you know, from a philosophical point of view, might argue,
49:38
Speaker 3: like what's the difference between true and useful, and model
49:41
Speaker 3: is just supposed to be useful. It's just supposed to
49:42
Speaker 3: predict the results of experiments. There's no deeper truth than that.
49:47
Speaker 3: But that's a whole nother philosophical rabbit.
49:50
Speaker 2: That's right, all right, Well, Eric, this was a fantastic question.
49:54
Speaker 2: It was great to hear from you again. Let's see
49:56
Speaker 2: if we scratched your itch on this be question.
50:00
Speaker 7: And Daniel, I just wanted to say a huge thank
50:02
Speaker 7: you for taking the time to answer my questions about
50:04
Speaker 7: the honeycomb conjecture on your show. I was fascinated to
50:07
Speaker 7: learn more about why best create hexagons and the advantage
50:10
Speaker 7: of that structure. It's incredible to think about how nature
50:12
Speaker 7: organizes like that. Hearing about whether other species create hexagons
50:16
Speaker 7: was really eye opening. In Your insights on how math
50:19
Speaker 7: plays a role and biology gave me a whole new perspective.
50:22
Speaker 7: I've always thought of math as more tied to physics,
50:24
Speaker 7: but now I can see how deeply it connects to
50:26
Speaker 7: the natural world in the universal ways I.
50:28
Speaker 3: Hadn't considered before.
50:30
Speaker 7: I did share what I learned with my wife, hoping
50:32
Speaker 7: it might ease her discomfort around bees, but I'm afraid
50:36
Speaker 7: she still doesn't feel any better about them. She says
50:39
Speaker 7: they're buzzing in geometry ways still gives her the creeps.
50:44
Speaker 7: Even so, your passion for biology really shines through, and
50:47
Speaker 7: I'm so grateful to have my curiosity spark.
50:49
Speaker 3: In such an amazing way.
50:50
Speaker 7: Thanks again for sharing your knowledge on the show.
50:53
Speaker 3: All right, Thanks very much everyone who engages with the
50:55
Speaker 3: podcast and sends us your questions, why don't you join
50:58
Speaker 3: their ranks? What is the question and that you most
51:00
Speaker 3: want an answer to that you think maybe it's impossible
51:03
Speaker 3: to answer, Send it to us. We'll give it a shot.
51:06
Speaker 3: Questions at Danielankelly dot org. Thanks for tuning in, Thanks.
51:10
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51:18
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51:28
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