Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions #25

Transcript

Listener Questions #25 · Daniel and Kelly’s Extraordinary Universe

0:07
Speaker 1: A new deadly bug has been found in the state
0:11
Speaker 1: for lovers, Should my family and I be quaking under
0:14
Speaker 1: our covers?
0:16
Speaker 2: If Maxwell was right, then magnetic field lines shouldn't ever snap,
0:20
Speaker 2: but field lines break in the sun. So was Maxwell full.
0:24
Speaker 1: Of When Daniel's wife comes on the show, she often
0:29
Speaker 1: talks about poop, which got me thinking of microbes in space.
0:33
Speaker 1: So what's the scoop?
0:36
Speaker 2: Whatever questions have been keeping you up at night, Daniel
0:39
Speaker 2: and Kelly's answers will make it all right.
0:42
Speaker 1: Welcome to Daniel and Kelly's Extraordinary Universe.
0:58
Speaker 2: Hi. I'm Daniel. I'm a particle physicist, and I wish
1:00
Speaker 2: I'd heard this episode before I visited Virginia.
1:03
Speaker 1: Oh come, I'm going to note that the thing I'm
1:05
Speaker 1: going to talk about is a problem for California too,
1:08
Speaker 1: so watch it.
1:10
Speaker 3: Hello.
1:10
Speaker 1: I'm Kelly Waitersmith. I study parasites and space, and this
1:13
Speaker 1: might be the first episode where we talk about parasites
1:16
Speaker 1: and space for me. So we've got it all for me.
1:22
Speaker 2: And reasons to not visit Virginia or California. We'll have
1:27
Speaker 2: to work in some cannibalism and then it'll be the
1:29
Speaker 2: full suite of dKu checkboxes.
1:31
Speaker 1: We're going to talk about poop, so we already know
1:33
Speaker 1: we've got that taken care.
1:34
Speaker 2: Of, all right, So then, Kelly, my question for you is,
1:38
Speaker 2: on average, how much poop does an adult human ingest
1:42
Speaker 2: accidentally in their life?
1:43
Speaker 1: You think I've just got that kind of information, like
1:45
Speaker 1: ready to share with people. I feel like this is
1:48
Speaker 1: less a question and more some insights into what kind
1:51
Speaker 1: of person you think I am. I have no idea, Daniel,
1:55
Speaker 1: it's probably a lot. You're actually your wife seems like
1:57
Speaker 1: she would know. Do you know the answer? Was this
1:59
Speaker 1: a whiz?
2:01
Speaker 2: It's not a quiz. I do not know the answer.
2:03
Speaker 2: But last time you were very happy to talk about
2:05
Speaker 2: the butt to mouth pipeline or whatever you called it.
2:09
Speaker 1: Poop to mouth, poop to mouth, pooped mouth.
2:11
Speaker 2: There you go.
2:12
Speaker 1: I mean, let's just say that a lot of poop
2:15
Speaker 1: to mouth transmitted diseases are very common. So the answer
2:18
Speaker 1: has to be a lot, yea, you know, it's got
2:21
Speaker 1: to be a lot.
2:23
Speaker 2: I'm just wondering what are the correct units? Even before
2:25
Speaker 2: describing it. We're talking kilograms, metric tons, micrograms, Just like,
2:30
Speaker 2: what are we looking at here? If you looked at
2:32
Speaker 2: a pile of all the poop you accidentally ingested in
2:35
Speaker 2: your life, how big would it be?
2:36
Speaker 1: Oh, gosh, gosh, I hope it's grams and not pounds
2:40
Speaker 1: or kilograms. I guess I'll keep the same units. I
2:42
Speaker 1: hope it's grams and not kilograms. But who knows.
2:45
Speaker 2: There you go, things to look forward to, And that's
2:48
Speaker 2: just a little taste ha haha of what you have
2:50
Speaker 2: to look forward to. On today's episode, exactly today, we're
2:54
Speaker 2: answering questions about things people are curious about, things they
2:58
Speaker 2: wonder about, things they desperate they need to know the
3:00
Speaker 2: answers to, but can't find satisfaction on the Internet, including
3:04
Speaker 2: chat GPT, so they write to us, and you are
3:06
Speaker 2: also very welcome to write to us. And please don't
3:09
Speaker 2: ask your physics questions to chat GPT. It doesn't know
3:13
Speaker 2: what it's talking about. Instead, write to us two questions
3:16
Speaker 2: at Daniel and Kelly dot org. We will give you
3:18
Speaker 2: a real answer for real humans that reflects real physics
3:21
Speaker 2: or biology, plus poop jokes. Actually, I bet CHATCHPT could
3:26
Speaker 2: do some good poop jokes.
3:28
Speaker 1: Yeah, I don't know. I've asked it. I asked it
3:29
Speaker 1: to do ten jokes about parasites, and I incorporated that
3:32
Speaker 1: into my speech as president of the Hermathological Society of Washington,
3:36
Speaker 1: and they weren't very funny. I gotta say it wasn't
3:39
Speaker 1: very good.
3:42
Speaker 2: All right, Well, let's get right into it. Our first
3:44
Speaker 2: question comes from Zach and it's a question about a
3:47
Speaker 2: disgusting disease slash parasite.
3:50
Speaker 1: Yay, And I gotta say, I'm you know, Zack, I'm
3:52
Speaker 1: a fan of for a variety of reasons. One of
3:54
Speaker 1: that he found our podcast through SMBC, so he's been
3:57
Speaker 1: a longtime Wienersmith supporter, and and he was the first
4:01
Speaker 1: one to refer to our audience as the extraordinaries, which
4:04
Speaker 1: I have absolutely stolen from him and use regularly.
4:08
Speaker 2: Because our audience is extraordinary.
4:10
Speaker 1: Absolutely, yes, I adore the extraordinaries. And so Zach is
4:14
Speaker 1: an extraordinary And let's hear what.
4:15
Speaker 4: Zach had to ask, Hey, they're extraordinaries. This one is
4:18
Speaker 4: definitely for Kelly. I just saw a headline about a
4:22
Speaker 4: deadly disease being spread in Virginia by something called a
4:25
Speaker 4: kissing bug, and that the disease is some kind of parasite.
4:29
Speaker 4: So I'm wondering if you as a Virginian should be worried?
4:33
Speaker 4: Should I be worried? Looking forward to learning more? I think?
4:37
Speaker 2: All right, Kelly, tell us all about this, and everybody
4:41
Speaker 2: stop eating your breakfast or lunch or whatever it was.
4:45
Speaker 1: I mean probably anytime I opened my mouth to say something,
4:48
Speaker 1: you should do that. But all right, So, the reason
4:51
Speaker 1: you worry about kissing bugs is because kissing bugs can
4:55
Speaker 1: transmit a disease called shagas disease.
4:57
Speaker 2: Well, what is a kissing bug to start with? And
4:59
Speaker 2: why is it called a kissing bug?
5:01
Speaker 5: Gosh?
5:01
Speaker 1: Why is it called the kissing So they are these
5:03
Speaker 1: bugs that are you know, like maybe about the size
5:04
Speaker 1: of a quarter in Latin America. They tend to live
5:07
Speaker 1: in houses like wedged into cracks in the walls. They're
5:10
Speaker 1: called kissing bugs because they tend to bite on your face,
5:12
Speaker 1: for example, around your lips and stuff.
5:14
Speaker 2: So you don't kiss the bugs. The bugs actually keep
5:16
Speaker 2: you from being able to kiss other people because you
5:18
Speaker 2: have these gross bug bites on your lips.
5:20
Speaker 1: I mean, it depends on who you are, you know,
5:21
Speaker 1: no judgment, that's true.
5:25
Speaker 2: If that's your thing, all right.
5:28
Speaker 1: So, but but so, what you really have to worry
5:30
Speaker 1: about with these bugs is that they can be infected
5:33
Speaker 1: by a disease called Chagas disease, and this is a protozoan.
5:38
Speaker 1: It's unicellular. We were talking about malaria a while back,
5:41
Speaker 1: and malaria is also a unicellular protozoin parasite. They both
5:45
Speaker 1: live inside cells. So malaria lives inside our blood cells.
5:50
Speaker 1: Trapanozoma cruisy, which is the parasite that causes Chagas disease,
5:55
Speaker 1: can live inside things like muscle cells. And your heart
5:59
Speaker 1: is a mid for example, and that's going to become
6:02
Speaker 1: a problem. So what happens is a kissing bug bites you,
6:06
Speaker 1: usually while you're sleeping, because they're active at night, so
6:09
Speaker 1: it can.
6:09
Speaker 2: Bite like wait, they're crawling on your face at night
6:12
Speaker 2: while you're sleeping and biting you near the mouth.
6:14
Speaker 1: Yeah, oh no, yeah, I know.
6:18
Speaker 2: Virginia is for lovers.
6:20
Speaker 1: Hey, hey, okay, all right, you know what, backup, where
6:23
Speaker 1: do you find kissing bugs? In twenty nine states in
6:26
Speaker 1: the United States. So if you drew a line, maybe
6:29
Speaker 1: like three quarters of the way up the United States,
6:32
Speaker 1: all the states below that line have kissing bugs, including California.
6:37
Speaker 1: And I would bet you that California has a higher
6:40
Speaker 1: case load than Virginia does for reasons we'll get too later.
6:44
Speaker 1: So watch it all right, I'm getting saucy here.
6:47
Speaker 2: I'm just saying Virginia is for lovers. I don't know
6:49
Speaker 2: what you're going off about here.
6:51
Speaker 1: I saw your face. I knew what you meant.
6:54
Speaker 2: So you're sleeping peacefully, dreaming of vacations in southern California,
6:58
Speaker 2: and some bug is crawling across and bitying you on
7:01
Speaker 2: the lips, and inside of it it's got this protozoin.
7:04
Speaker 1: Yeah. Right, And so when you get bit by a
7:06
Speaker 1: mosquito that has malaria, the virus essentially gets injected into
7:10
Speaker 1: you with the saliva. But here what happens is the
7:13
Speaker 1: parasite takes a really big blood meal and it fills
7:17
Speaker 1: its body up so much that it expels its feces.
7:20
Speaker 1: Oh I know, I'm so sorry everybody. And then and
7:23
Speaker 1: then when you wake up in the morning, the spot
7:25
Speaker 1: where you got bit itches, and so you scratch, and
7:28
Speaker 1: you scratch the feces into your wound, and that's how
7:31
Speaker 1: you get infected. Or maybe you rub your eye and
7:33
Speaker 1: you scratch the feces into your eye, and that's how
7:35
Speaker 1: it gets in.
7:36
Speaker 2: And so I know, my role here is to like
7:38
Speaker 2: digest this and repeat it. But I really just don't
7:41
Speaker 2: even want to say these things coming up. Fact, that's
7:44
Speaker 2: really repulsive. Oh my gosh.
7:46
Speaker 1: All right, it's pretty unpleasant. And there's some other routes
7:49
Speaker 1: that you can apparently get it, Like if you live
7:51
Speaker 1: in areas where there's loads of these insects and they
7:53
Speaker 1: happen to get like ground up into your food, you
7:57
Speaker 1: can get the parasite by ingesting it. Mom can transmit
8:00
Speaker 1: it to baby if she gets it when she's pregnant
8:03
Speaker 1: blood transfusions, but in the United States we check blood
8:06
Speaker 1: for Shagga's disease, so that shouldn't be happening here.
8:08
Speaker 2: So the parasite comes through the feces of the kissing bug,
8:12
Speaker 2: but that's different from the mosquito. Right when the mosquito
8:14
Speaker 2: takes its blood meal, the parasite goes like down, it's
8:17
Speaker 2: little straw, right.
8:18
Speaker 1: Yep, exactly. So like you, you know, if you were
8:20
Speaker 1: a partner woke up and looked at you and was
8:23
Speaker 1: like you just got bit by a kissing bug, hold
8:26
Speaker 1: on and they get like an alcohol wipe and they
8:28
Speaker 1: swipe away from where you got bit. Then you could
8:32
Speaker 1: make sure you got no feces in your wound, and
8:33
Speaker 1: you'd probably be okay. But usually what happens is you
8:36
Speaker 1: wake up garaggy and it kind of itches, so you
8:38
Speaker 1: rub your face and you rub it in there.
8:40
Speaker 2: If your partner wakes up and you have bug poop
8:42
Speaker 2: on your face, and their first instinct is like, I'm
8:44
Speaker 2: going to take care of this for you. You have
8:46
Speaker 2: a nice.
8:46
Speaker 1: Partner, Well, what do you think they should do?
8:50
Speaker 2: No, they should take care of it for you. But
8:51
Speaker 2: if instead they're like, oh my god, that's revolting, get
8:54
Speaker 2: out of bed.
8:55
Speaker 1: But okay, so you might might be imagining like a
8:57
Speaker 1: human size turd.
9:02
Speaker 2: I wasn't until you said that, and now I am,
9:06
Speaker 2: thank you.
9:06
Speaker 1: Sorry, but no, this is like a tiny little speck
9:09
Speaker 1: like you might not know. It's not going to be obvious.
9:13
Speaker 1: Your partner's not gonna that's okay.
9:14
Speaker 2: Yeah, it's a tiny little speck of poop on my face.
9:17
Speaker 2: That's no big deal. Thank you. I feel great about
9:21
Speaker 2: it now.
9:21
Speaker 1: Yeah all right, Well hold on for a later episode
9:23
Speaker 1: where we talk about the mites that are living in
9:25
Speaker 1: your eyebrows, that are pooping on your face all day.
9:27
Speaker 1: So you know you don't always see it, all.
9:29
Speaker 2: Right, so it gets into my blood because I've scratched
9:32
Speaker 2: this bite on my face and rubbed that tiny, little
9:35
Speaker 2: dainty bit of poop into the bite, and then what
9:38
Speaker 2: happens to me?
9:39
Speaker 1: All right, So early symptoms are kind of nondescript things.
9:44
Speaker 1: You can have like a fever, loss of appetite, diarrhea, vomiting,
9:48
Speaker 1: and large lymph nodes fatigue, but most people will present
9:52
Speaker 1: no symptoms. One obvious symptom is that there's this thing
9:56
Speaker 1: called Romanya's sign, and I'm sorry, I'm sure I mispronounced it,
9:59
Speaker 1: which is we all have come to expect from me,
10:01
Speaker 1: which is a swelling around like the eye or the
10:04
Speaker 1: part of the face where you got bit by a
10:06
Speaker 1: kissing bug. And so if you get that, then you
10:09
Speaker 1: should like immediately go to the doctor and be like,
10:11
Speaker 1: I've got chagas and they have anti parasite treatments that
10:14
Speaker 1: you can get, and so if you've got this swelling,
10:16
Speaker 1: you should go in right away and get the parasite
10:19
Speaker 1: wiped out. But what really becomes a problem is if
10:23
Speaker 1: you don't catch the parasite early on, it becomes much
10:26
Speaker 1: harder to treat. And what the parasite does is it's
10:28
Speaker 1: living in cells and it's replicating. I know it's replicating
10:32
Speaker 1: in your cells, and every once in a while it
10:34
Speaker 1: will kill the cell as it breaks out, and your
10:36
Speaker 1: body will produce inflammation around the area where the parasite
10:39
Speaker 1: is living. And so for you know, some people who
10:42
Speaker 1: have this parasite for decades, they'll start to get enlarged
10:45
Speaker 1: hearts from like the inflammation, and they can have heart
10:49
Speaker 1: failure that can result in death, or they can have
10:52
Speaker 1: digestive problems. I think the parasite also lives in like
10:54
Speaker 1: the cells in your digestive tract, and so you can
10:57
Speaker 1: get enlarged esophagus in large colon, or you can have
11:01
Speaker 1: trouble eating or using the restroom. And in these cases
11:05
Speaker 1: it's much harder to treat the parasite. Like you can
11:07
Speaker 1: give some treatment to try to slow the rate at
11:09
Speaker 1: which it's spreading to the other cells, but once it's
11:12
Speaker 1: firmly established in your cells and they're like safe inside
11:15
Speaker 1: your cells, it can be pretty hard to combat. And
11:19
Speaker 1: in that case, you are mostly just trying to reduce
11:22
Speaker 1: the symptoms associated with having it in large heart or
11:25
Speaker 1: enlarged colon and stuff like that. So should I worry.
11:29
Speaker 2: Yeah, don't you worry anyway, whether or not you should.
11:33
Speaker 1: That's right. I worry about everything exactly. And two states
11:38
Speaker 1: that have, you know, more Chagas disease than most of
11:41
Speaker 1: the rest of the United States include Texas and Florida.
11:44
Speaker 1: And for a while I lived in Houston, and so
11:47
Speaker 1: I did a bunch of research because I had a
11:49
Speaker 1: young daughter and I was worried we were gonna, you know,
11:51
Speaker 1: all get Chauga's disease. And I convinced myself that I
11:54
Speaker 1: personally don't have to worry much. Oh here's why.
11:57
Speaker 2: But you've done an internet deep dive that actually swaged
12:00
Speaker 2: your worries. Doesn't always just inflame your worries, you know.
12:03
Speaker 1: I actually feel like for people who worry about parasites, yeah,
12:06
Speaker 1: the more you learn about them, the less you worry,
12:10
Speaker 1: because a lot of them have like very clear paths
12:13
Speaker 1: to infect people. And once you know that gives you
12:16
Speaker 1: the power to avoid them or at least to understand
12:18
Speaker 1: what behaviors are risky and what aren't so. Yes, in
12:21
Speaker 1: this rare case, I decided I'm not gonna worry.
12:25
Speaker 2: And deciding not to worry always makes it possible to
12:28
Speaker 2: not worry.
12:29
Speaker 1: Right, Oh no, those are different things. Those are different things.
12:34
Speaker 1: What I do worry about, though, is most of the
12:36
Speaker 1: people in the United States who have Jagga's disease are
12:39
Speaker 1: people from Latin America. So this disease is a neglected
12:43
Speaker 1: tropical disease. It's much more common in like Central and
12:47
Speaker 1: South America, in areas where the housing tends to have
12:50
Speaker 1: like more nooks and crannies and be less insulated, and
12:54
Speaker 1: so it's easier for the bugs to get inside of
12:56
Speaker 1: the house or inside of like factories that make juice
12:59
Speaker 1: and stuff like that, where the bugs can get sort
13:01
Speaker 1: of ground up with the rest of the juice. So
13:03
Speaker 1: most of the people who have it in the United
13:05
Speaker 1: States are immigrants, and so what I worry about is
13:08
Speaker 1: that our doctors aren't good at recognizing this because it
13:13
Speaker 1: wasn't a problem in the United States, and we're sort
13:15
Speaker 1: of only recognizing that it's a problem because people have
13:18
Speaker 1: moved to the United States with it, and so I
13:20
Speaker 1: think often a lot of people don't get diagnosed when
13:22
Speaker 1: they could get diagnosed, and there's blood tests now, and
13:25
Speaker 1: so I feel like one good thing about the fact
13:27
Speaker 1: that this parasite has made it into the news and
13:29
Speaker 1: I'm hearing from like friends and family members who haven't
13:32
Speaker 1: written in decades because they remembered Kelly studied parasites, and
13:35
Speaker 1: they want to know if they should worry about kissing bugs.
13:37
Speaker 1: And I'm happy to answer those questions. But I think
13:39
Speaker 1: one of the good things is this is getting on
13:41
Speaker 1: people's radars now, and so I'm hoping that people thinking,
13:44
Speaker 1: oh gosh, this could infect me will maybe allow us
13:48
Speaker 1: to raise some money so that we can raise awareness
13:50
Speaker 1: about this, make sure it's on every doctor's radar. Maybe
13:53
Speaker 1: we could get some better treatments, some better medications. But
13:56
Speaker 1: me living in a house that's well sealed, and as
13:59
Speaker 1: someone who would be able to identify a kissing bug
14:02
Speaker 1: in the house if it got in the house, I'm
14:04
Speaker 1: not personally worried. I'm a little worried about like dogs
14:07
Speaker 1: that sleep outside at night, and I have a livestock
14:09
Speaker 1: guardian dog. I mean, this can infect any mammal, so
14:11
Speaker 1: like possums and raccoons tend to have it. I'm sure
14:14
Speaker 1: you know this could be much more of a problem
14:16
Speaker 1: for people who are unhoused. But as a housed person
14:19
Speaker 1: in a well insulated, secure house, I am not personally worried.
14:22
Speaker 2: All right, Well, thank you for the deep download of information,
14:25
Speaker 2: as disturbing as some of it was.
14:27
Speaker 1: Sorry, just real quick, I want to say, uh, I
14:30
Speaker 1: am not a medical doctor, and so if you are
14:33
Speaker 1: concerned that you have jaggas disease, you should talk to
14:36
Speaker 1: a doctor. And you know, just because I'm worried doesn't
14:39
Speaker 1: mean there's absolutely zero risk that it could be in
14:41
Speaker 1: your house. And this is where I reveal that I
14:43
Speaker 1: have anxiety, and so I still worry sometimes a little bit.
14:45
Speaker 1: But I think most of your worries should be about
14:48
Speaker 1: the population of people who might have picked up Jagga's
14:50
Speaker 1: disease from their own countries and brought it here. So
14:52
Speaker 1: we should be trying to help those people, all.
14:53
Speaker 2: Right, So let's check them with Zach and see if
14:56
Speaker 2: this made him more or less worried.
14:58
Speaker 4: Hello again, extraordinary, Thank you so much for answering my
15:01
Speaker 4: question about kissing bugs. You definitely gave a more thorough
15:05
Speaker 4: explanation than I was even hoping for. As usual, it
15:09
Speaker 4: sounds like as a Minnesotan, I don't personally have to
15:12
Speaker 4: worry about this unless I'm traveling somewhere warmer, but I
15:16
Speaker 4: appreciate the opportunity to spread some public health knowledge and
15:20
Speaker 4: maybe get some more visibility for a disease that could
15:23
Speaker 4: really impact people who aren't me. Thanks again.
15:45
Speaker 2: All right, we're back, and we're going to do a
15:47
Speaker 2: major pivot from earthly questions about the butt to mouth
15:51
Speaker 2: pipeline to lines of plasma in the sun.
15:56
Speaker 1: It's hard for me to see how we're going to
15:57
Speaker 1: get to cannibalism with this question, but hopefully we make it.
16:01
Speaker 2: Well, if the Sun absorbs the Earth, is that sort
16:03
Speaker 2: of like solar system cannibalism.
16:05
Speaker 1: Hmmm, it's a stretch. In it's a stretch. I might
16:08
Speaker 1: give it to you, but I think that's not what
16:10
Speaker 1: most people are thinking of.
16:12
Speaker 2: All right, Well, here's a really insightful question about a
16:14
Speaker 2: very subtle point of magnetism from Michael Woodham's.
16:18
Speaker 6: When I was a physics student, I learned about magnetic
16:21
Speaker 6: fields via Maxwell's equations. Magnetic field lines never join, never intersect,
16:27
Speaker 6: and never terminate, so it's impossible for one field line
16:30
Speaker 6: to pass through another. But when I studied astronomy, I
16:33
Speaker 6: learned that in the corona of the Sun, magnetic fields
16:36
Speaker 6: get so twisted that they break and reconnect, resulting in
16:39
Speaker 6: the soil of flare. What's missing from Maxwell's equation description
16:43
Speaker 6: that lets this happen? Can we observe this reconnection happening
16:46
Speaker 6: in a laboratory?
16:47
Speaker 1: Ooh, okay, there's a lot of different ways we could
16:50
Speaker 1: enter this question. Let's start with what is a field?
16:53
Speaker 2: Yeah? So, Maxwell's equations are the ones that tell us
16:56
Speaker 2: how electricity and magnetism work, and specifically how they slow
17:00
Speaker 2: push back and forth between each other, how electric currents
17:02
Speaker 2: can cause magnetic fields, how changing magnetic fields can cause
17:05
Speaker 2: electric currents, all sorts of stuff. It's a brilliant piece
17:08
Speaker 2: of work from one hundred and fifty years ago, which
17:10
Speaker 2: was then updated and quantum mechanic eyed by fine men
17:14
Speaker 2: and other folks to our modern understanding of electricity and magnetism.
17:17
Speaker 1: Yeah, and for more history of Maxwell's equations, folks should
17:20
Speaker 1: listen to our episode with Kathy does Physics because she
17:24
Speaker 1: gave so much great insight into this story. But anyway, sorry,
17:26
Speaker 1: I remember Maxwell got a lot of equations wrong and
17:29
Speaker 1: that made me feel great and someone else had to
17:31
Speaker 1: fix it, so sorry, go ahead.
17:33
Speaker 2: Yeah, his notation was really confusing and he made a
17:36
Speaker 2: lot of mistakes and it was heavy side who came
17:38
Speaker 2: in and cleaned it up. He spent like a decade
17:40
Speaker 2: alone in like an attic working on these equations, and
17:43
Speaker 2: the equations we now know and love are mostly actually
17:45
Speaker 2: due to heavy sides formulation, a lot of important work
17:48
Speaker 2: done by a lot of people. But the central concept
17:51
Speaker 2: of Maxwell's equations are these fields, the electric field and
17:54
Speaker 2: the magnetic field, and how they relate. So let's start,
17:58
Speaker 2: since we're going to be talking about field lines, remind
18:00
Speaker 2: ourselves what is a field anyway?
18:02
Speaker 1: So when I picture a field, I like literally picture
18:06
Speaker 1: a soccer field that maybe undulates sometimes so correct you're laughing,
18:12
Speaker 1: So that must be pretty wrong.
18:14
Speaker 2: No, it's actually pretty accurate. Okay, Yeah, A field in
18:18
Speaker 2: physics is just assigning numbers to space, to saying, let's
18:23
Speaker 2: put the number seven here, let's put the number nine there.
18:25
Speaker 2: And if you have numbers everywhere in space, that's a field.
18:28
Speaker 2: Electricity and magnetism are more complicated fields because at every
18:32
Speaker 2: point in space they don't have a number, they have
18:34
Speaker 2: a vector. They have three numbers, so like a little
18:37
Speaker 2: arrow with a direction and a length. So the electric
18:40
Speaker 2: field is like a little arrow at every point in space,
18:43
Speaker 2: and the same for the magnetic field.
18:44
Speaker 1: Okay, got it, I can picture that all right.
18:47
Speaker 2: Now, this field, it's a very important concept, and physicists
18:50
Speaker 2: talk about it as if it was real, like the
18:52
Speaker 2: field is out there, but we don't really know that philosophically,
18:56
Speaker 2: it's just sort of like a construct we use to
18:58
Speaker 2: explain phenomena we observe, and it's very useful intermediate. We
19:03
Speaker 2: don't really know if the field is physical, like it's
19:05
Speaker 2: a field there when you're not measuring it. You can't
19:08
Speaker 2: see it directly. All you can do is like drop
19:10
Speaker 2: a particle into it and seize effects. So where that
19:14
Speaker 2: a field is sort of like a construct.
19:16
Speaker 1: All right, So are we getting philosophical or does this
19:18
Speaker 1: impact like predictions as well?
19:21
Speaker 2: I just can't talk about fields without mentioning that this
19:23
Speaker 2: is something we don't know if it actually exists or not.
19:26
Speaker 1: And I'm here for the philosophy too, m hm.
19:28
Speaker 2: And that's important because the next thing we're going to
19:29
Speaker 2: talk about is extra philosophical, which is a field line.
19:33
Speaker 2: So often we try to describe field. We try to
19:36
Speaker 2: draw fields on paper, and one thing you could do
19:38
Speaker 2: is like draw a bunch of arrows at every point
19:40
Speaker 2: in space, and that technically is a good description of
19:43
Speaker 2: the field, but it's kind of hard to look at,
19:45
Speaker 2: and so instead people develop this concept of a field line,
19:49
Speaker 2: and a field line is a line that points along
19:52
Speaker 2: the direction of the field, So mathematically speaking, it's tangent
19:56
Speaker 2: to the magnetic field vector. More practically, if you're looking
19:59
Speaker 2: at a bar magnet, you can draw like field lines
20:02
Speaker 2: from the north to the south. That shows you the
20:04
Speaker 2: direction of the magnetic field along that line. And you
20:07
Speaker 2: can draw more lines and you put them closer together
20:10
Speaker 2: where the magnetic field is changing a lot, and further
20:12
Speaker 2: apart when it's not changing. So in that sense, there's
20:15
Speaker 2: sort of like lines on a contour map that show
20:17
Speaker 2: you where the height is equal. Here shows you where
20:20
Speaker 2: the magnetic field is constant and the direction along which
20:23
Speaker 2: a compass would point if you put it there.
20:25
Speaker 1: Okay, so I'm imagining my undulating soccer field that is
20:29
Speaker 1: made up of three points, and I've got arrows and
20:33
Speaker 1: they've got different heights. Is there like a line above
20:37
Speaker 1: each arrow, or like above each set of arrows. I
20:40
Speaker 1: guess it could be whatever you decided you want. Is
20:42
Speaker 1: that like a reasonable way to imagine it.
20:44
Speaker 2: It's like if you find a bunch of arrows that
20:46
Speaker 2: are all pointing along the same direction, you would draw
20:50
Speaker 2: a line along them. Okay, so back to our example
20:53
Speaker 2: of contour lines. Imagine if you have a hill and
20:56
Speaker 2: you draw contour lines around it, like as circles. What
20:59
Speaker 2: happened when that hill gets flattened? Where do the contour
21:02
Speaker 2: lines go? How do you draw contour lines on a
21:05
Speaker 2: flat plane? You could draw them in lots of different ways.
21:07
Speaker 2: They're sort of arbitrary. So imagine now you're a hill
21:11
Speaker 2: that becomes flat and then it becomes a divot. So
21:13
Speaker 2: the contour lines in that sense sort of are discontinuous
21:16
Speaker 2: because it's that moment when they're not really well defined
21:20
Speaker 2: in the middle. And that's what's happening with the plasma
21:22
Speaker 2: flux tubes and the magnetic field. They're clear field lines
21:25
Speaker 2: in one direction, but then there's this moment when the
21:27
Speaker 2: flux tubes are crossing and the things cancel out, and
21:30
Speaker 2: you don't really know how to draw the field lines.
21:32
Speaker 2: And then a moment later you know how to draw
21:34
Speaker 2: them again, and so there's a discontinuity from before to after.
21:37
Speaker 2: Got it, okay, But these are lines that we have
21:40
Speaker 2: drawn in our minds. Magnetic field lines not physical things.
21:44
Speaker 2: You can't let go out and touch one, push one, right,
21:46
Speaker 2: somebody else could draw lines differently than you do. So
21:49
Speaker 2: they're helpful for understanding the flow of the magnetic field,
21:53
Speaker 2: but they're not physical things themselves.
21:55
Speaker 1: Got it, Okay, They're a human construct to describe behaviors exactly.
21:59
Speaker 2: Like in the same way that if you're hiking and
22:01
Speaker 2: you're using a contour map, you shouldn't look for those
22:03
Speaker 2: lines in the ground to know where you are, right,
22:06
Speaker 2: that's foolish.
22:07
Speaker 1: That would be confusing.
22:08
Speaker 2: Yeah, we're actually maybe kind of helpful for.
22:10
Speaker 1: Hiking, right, Yeah, sure, I wouldn't want to be the
22:12
Speaker 1: one who had to like draw the contour lines, but yeah.
22:15
Speaker 2: Exactly, all right. So Michael makes this point that contour
22:18
Speaker 2: lines don't terminate, they don't break, right, And this is
22:22
Speaker 2: the property of magnetic fields only, not electric fields, because
22:26
Speaker 2: we don't have magnetic monopoles in our universe. A north
22:29
Speaker 2: pole or a south pole is where a magnetic field
22:31
Speaker 2: would begin. So if you had just like a north
22:33
Speaker 2: pole out in space by itself, the magnetic field lines
22:36
Speaker 2: would all point away from it, the same way if
22:38
Speaker 2: you put an electron in space, the electric field all
22:41
Speaker 2: points away from it or towards it, depending on the
22:44
Speaker 2: charge of the particle. And so in our universe we
22:47
Speaker 2: have no single north poles or single south poles that
22:49
Speaker 2: all come together. They're dipoles. We have no magnetic monopoles
22:53
Speaker 2: in our universe, and we've talked about that on a
22:55
Speaker 2: previous episode, so I'll just leave that there. But what
22:58
Speaker 2: that means is that Megan ggnetic field lines don't start
23:02
Speaker 2: or end. They're always in a loop. So if you
23:04
Speaker 2: have like a bar magnet, there is a magnetic field
23:07
Speaker 2: that starts from the north pole and then goes down
23:09
Speaker 2: to the south pole, but then it goes through the
23:11
Speaker 2: bar magnet between the south and the north pole, so
23:14
Speaker 2: it always forms this continuous loop. In order to have
23:16
Speaker 2: a magnetic field line that ends somewhere, you'd need an
23:20
Speaker 2: isolated north pole or an isolated south pole.
23:22
Speaker 1: You need a monopole, okay, and Maxwell prove that with
23:26
Speaker 1: his equations. Is that right?
23:28
Speaker 2: Oh? Great question. Maxwell's equations show you that you can't
23:31
Speaker 2: have a break or an end to a magnetic field
23:34
Speaker 2: if you have no monopoles. But if you did find
23:37
Speaker 2: a monopole, then that would do that, right, But we've
23:39
Speaker 2: never seen a monopole. As far as we know, there
23:41
Speaker 2: are no monopoles in the universe, So all magnetic field
23:44
Speaker 2: lines are loops for that reason.
23:46
Speaker 1: Got it, okay, but not on the Sun.
23:50
Speaker 2: So now we're set up to talk about the Sun,
23:52
Speaker 2: which is like maybe the most complicated electromagnetic object in
23:58
Speaker 2: the neighborhood, right, because it's plasma. Plasma is an ionized gas.
24:02
Speaker 2: So you take something like hydrogen, which has a proton
24:05
Speaker 2: and an electron, and you heat it up so that
24:08
Speaker 2: the electrons are no longer bound by the protons. They're
24:10
Speaker 2: flying around free. So you have a gas which is
24:13
Speaker 2: already very complicated to model because it's high density, high pressure,
24:17
Speaker 2: it's chaotic. And now you add the fact that there
24:19
Speaker 2: are electric charges on all those particles. So not only
24:23
Speaker 2: do you have to deal with complicated fluid dynamics, plus
24:26
Speaker 2: you have electric and magnetic fields in there. So this
24:28
Speaker 2: is a whole area of study. It's called magneto hydrodynamics,
24:32
Speaker 2: and it's famously a headache.
24:34
Speaker 1: I mean, but it sounds pretty cool.
24:36
Speaker 2: It has a cool name. Yeah, that's true. So the
24:39
Speaker 2: equations of magnetohydrodynamics are the equations of fluid dynamics, which
24:44
Speaker 2: are famously complicated, plus the equations of electromagnetism, and so
24:49
Speaker 2: you get all these really complicated effects. And in the
24:51
Speaker 2: Sun you get these tubes of plasma that are flowing
24:55
Speaker 2: like currents, and because it's electrically charged, there is an
24:58
Speaker 2: electric current and so you get magnetic fields generated in
25:01
Speaker 2: lines around them, and there's really complicated behavior because the
25:05
Speaker 2: Sun is chaotic and turbulent. So these tubes of plasma
25:09
Speaker 2: sometimes they're flowing nicely alongside each other like lanes on
25:12
Speaker 2: a highway, but sometimes somebody crosses the lane. Everything gets
25:15
Speaker 2: tangled up and the tubes do all sorts of crazy
25:18
Speaker 2: stuff and they snap in their rearrange and when that happens,
25:21
Speaker 2: you get crazy effects from the magnetic fields also.
25:24
Speaker 1: And just to be clear, so I think you told
25:26
Speaker 1: me in a previous episode that we really have never
25:29
Speaker 1: seen a monopole, and so it's not that the Sun
25:31
Speaker 1: is creating monopoles something else. It's just all this craziness
25:35
Speaker 1: when they're intersecting and fluids up.
25:38
Speaker 2: Exactly. The Sun is not creating monopoles as far as
25:40
Speaker 2: we know, but many popular science treatments describe this behavior
25:45
Speaker 2: where complicated tubes of plasma are crossing and snapping, doing
25:48
Speaker 2: all sorts of stuff as magnetic field lines tangling and breaking. Ok,
25:54
Speaker 2: and this is what Michael is asking about. He's like,
25:56
Speaker 2: doesn't that violate Maxwell's equations? And the answer is no,
25:59
Speaker 2: it doesn't violate Maxiwell's equations. Though the description is a
26:01
Speaker 2: little bit confusing, and we're going to take it apart
26:04
Speaker 2: and make it clear.
26:05
Speaker 1: All right, take it apart, Daniel.
26:08
Speaker 2: So what's happening is that you get plasma currents and
26:11
Speaker 2: sometimes they're going in opposite direction. Sometimes they're the same directions,
26:15
Speaker 2: but they come near each other, and sometimes when they
26:17
Speaker 2: come close to each other, the magnetic field between them
26:19
Speaker 2: can cancel. Remember that magnetic fields are a vector and
26:23
Speaker 2: they're linear. So if you have like a magnetic field
26:26
Speaker 2: generated by one object that's in one direction, and a
26:29
Speaker 2: magnetic field and the exact opposite direction generated by something else,
26:32
Speaker 2: they can cancel each other out. So you can have
26:35
Speaker 2: an area between two like tubes of plasma with no
26:38
Speaker 2: magnetic field in it. The two things can cancel. Even
26:41
Speaker 2: if you're in an area a very strong magnetic activity. Right,
26:45
Speaker 2: This is just like destructive interference between waves, Right, You
26:49
Speaker 2: can have a point in a wave where there's no amplitude,
26:52
Speaker 2: and so that's what's happening that there are locations between
26:55
Speaker 2: these plasma flux tubes that have no magnetic field because
26:59
Speaker 2: of this cancelation. And at that point, the direction of
27:02
Speaker 2: the field lines are not well defined. You could draw
27:05
Speaker 2: them in lots of different directions because the field is
27:08
Speaker 2: zero there and the derivative can be zero as well.
27:11
Speaker 2: And so if you're going to sit down and draw
27:13
Speaker 2: the field lines, you have some arbitrary choices to make,
27:15
Speaker 2: and the moment before that happens and the moment after
27:18
Speaker 2: that happens, the field lines you would draw are very different. So, yes,
27:22
Speaker 2: the field lines from one moment to another having like
27:26
Speaker 2: a discontinuity where you're like, before this thing happens, I
27:29
Speaker 2: would draw the field lines here, just after it happens,
27:32
Speaker 2: I would draw the field lines there. And there's not
27:34
Speaker 2: a smooth transition where you can say at every moment
27:36
Speaker 2: the field lines move. But remember, field lines are arbitrary.
27:40
Speaker 2: They're what we make up in our minds, just like
27:43
Speaker 2: our description. It's like back to our contour example. If
27:46
Speaker 2: you had an earthquake and you have to draw contour
27:48
Speaker 2: lines over a peak somewhere. You're like, well, I could
27:50
Speaker 2: draw contour line in many different directions as this peak
27:54
Speaker 2: is shifting and going up and down, and so there's
27:56
Speaker 2: a moment there where you don't know exactly how to
27:58
Speaker 2: draw the field lines. So what's really happening is the physics,
28:02
Speaker 2: the physical things. That's happening is that these flux tubes
28:04
Speaker 2: are breaking and snapping and doing all sorts of crazy stuff,
28:07
Speaker 2: and that's creating the solar flare, where the Sun is
28:10
Speaker 2: going to spit out a huge archa plasma that maybe
28:12
Speaker 2: is going to eat the Earth in an active astronomical cannibalism.
28:15
Speaker 1: Oh nice.
28:19
Speaker 2: And the field lines are confusing, But the field lines
28:22
Speaker 2: are not breaking. There's no divergence there. There's no source
28:25
Speaker 2: of the field lines. It's just that the field lines.
28:27
Speaker 2: You draw them one way and then you would draw
28:28
Speaker 2: them another way a moment later, so they are not
28:31
Speaker 2: actually breaking. There are no monopoles in the sun.
28:34
Speaker 1: Okay. So I'm trying to decide, does the fact that
28:38
Speaker 1: we're not calling this a break like make this concept
28:42
Speaker 1: less useful because it's clearly a human construct or does
28:46
Speaker 1: this just teach us something particularly important about the Sun
28:51
Speaker 1: in this framework that we've created.
28:53
Speaker 2: I think it also teaches us something about the limitations
28:55
Speaker 2: of language. You know, the field lines transition from here
28:58
Speaker 2: to there, but they're never have any divergence. They are continuous,
29:01
Speaker 2: there's never an end point, even though there's a discontinuity
29:05
Speaker 2: from moment to moment about how you would draw them. So, yes,
29:08
Speaker 2: the Sun is chaotic, and we have a lot to
29:10
Speaker 2: learn about how plasma works and how to keep it stable.
29:13
Speaker 2: And we've done a bunch of experiments to see these
29:16
Speaker 2: kinds of effects here on Earth. That's the second part
29:19
Speaker 2: of Michael's question. Yes, we see this kind of stuff
29:21
Speaker 2: happening all the time in magnetic confinement fusion when we
29:24
Speaker 2: build tokamacs to try to recreate the conditions of the
29:26
Speaker 2: Sun so that we can have fusion here on Earth.
29:30
Speaker 2: And this is something people work on and struggle with.
29:32
Speaker 2: They try to minimize the chaos and keep those flux
29:34
Speaker 2: tubes steady, and so there's lots of observations of these
29:38
Speaker 2: kinds of effects in the lab. Usually it's what you
29:41
Speaker 2: don't want to happen, but we see it anyway. So
29:44
Speaker 2: plasma turbulence is definitely something we've seen in the lab
29:47
Speaker 2: we can recreate. We struggle to model it because turbulence
29:50
Speaker 2: is very difficult. It requires serious computation because it's chaotic,
29:54
Speaker 2: so it's very, very sensitive to the initial conditions. But
29:57
Speaker 2: it's not new physics in the sense that it's like
30:00
Speaker 2: a magnetic monopole or violating Maxwell's equations.
30:03
Speaker 1: Can we still apply Maxwell's equations in these conditions or.
30:08
Speaker 2: Oh yeah, okay, absolutely. The only time you can't apply
30:11
Speaker 2: Maxwell's equations is when you have quantum effects, like at
30:14
Speaker 2: the level of photons and individual particles doing quantum stuff.
30:17
Speaker 2: But the Sun is big and basically classical, and so
30:20
Speaker 2: you can definitely use Maxwell's equations to describe it. And
30:23
Speaker 2: then when there are quantum effects, you use quantum electrodynamics,
30:26
Speaker 2: which is just the quantum version of Maxwell's equations anyway,
30:29
Speaker 2: So yeah, Maxwell was right as far as we know.
30:32
Speaker 1: Okay, and so that wouldn't be quantum magnetohydrodynamics, which sounds
30:36
Speaker 1: even cooler, right, That's that would be a different field.
30:42
Speaker 2: I'm not aware of that, but that's a cool title
30:44
Speaker 2: for a grant proposal.
30:45
Speaker 1: There you go. All right, let's see if Michael feels
30:48
Speaker 1: like he understands Maxwell's equations a little better now.
30:51
Speaker 6: Thank you. That was an informative answer. I enjoyed the
30:54
Speaker 6: description of magnetic field lines if a sending in this
30:59
Speaker 6: Christian being one in how you'd handled that, I am
31:02
Speaker 6: mildly surprised that the magnetic field lines manage their realignment
31:06
Speaker 6: treck without resorting to quantum mechanics.
31:28
Speaker 2: All right, we're back. We started on Earth understanding kissing
31:31
Speaker 2: bugs and poop, then we went out into space to
31:34
Speaker 2: understand what's happening in the sun, and now we're gonna
31:37
Speaker 2: bring that all together to talk about poop in space.
31:42
Speaker 1: Yeah, you know, I love I study parasites and space.
31:45
Speaker 1: We've got both of them in one episode, and poop
31:48
Speaker 1: is what connects them. Amazing, and that is a good
31:50
Speaker 1: summary of my life.
31:51
Speaker 2: So we should have invited our vice president for poop
31:55
Speaker 2: research on this podcast.
31:56
Speaker 1: Yeah, why is she not president of poop researcher. Clearly
32:00
Speaker 1: not president of poop research.
32:02
Speaker 2: Well, we got a lot of vice presidents, you know,
32:04
Speaker 2: and so I was president for this, vice president for.
32:06
Speaker 1: That, got it all right, Well, but.
32:08
Speaker 2: You're right she should be president. Yeah, I'll propose that
32:11
Speaker 2: to the next board meeting.
32:12
Speaker 1: Okay, Yeah, that sounds good. It doesn't seem like anyone
32:14
Speaker 1: else in your family's qualified. I'll just say, but all.
32:17
Speaker 2: Right, and I think that we should send our answer here,
32:19
Speaker 2: not just to John, but also to Katrina for response.
32:24
Speaker 1: I'm nervous.
32:25
Speaker 2: Y'all should have seen Kelly's face.
32:27
Speaker 1: Well, the president of poop research at the whites And Institute.
32:30
Speaker 1: I mean, this is a big deal.
32:31
Speaker 2: Okay, yes, your adjunct status at the whites In Institute
32:34
Speaker 2: might be on the line here.
32:35
Speaker 1: Oh no, I guess the good news is I don't
32:37
Speaker 1: get a lot of perks from that that adjunct status.
32:41
Speaker 2: What what the prestige alone?
32:44
Speaker 1: Oh my gosh, that's right, that's I guess I get friendship,
32:46
Speaker 1: which is the most valuable thing on this planet.
32:49
Speaker 2: All right, let's stop beating around the bush, and let's
32:51
Speaker 2: hear John's question about poop in space.
32:54
Speaker 5: Hello, Daniel and Kelly. I had three questions in regards
32:57
Speaker 5: to the microbiome in space? Do the microbiomes of all
33:01
Speaker 5: the people on the issity given time become the same? Second?
33:05
Speaker 5: How do things change with every supply delivery or crew change?
33:09
Speaker 5: And third, how does zerog affect the microbiome?
33:12
Speaker 7: Thanks?
33:13
Speaker 1: Oh my gosh, loads of amazing questions here. So I
33:17
Speaker 1: split these questions up. So first, let's talk about do
33:20
Speaker 1: the astronaut microbiomes become the same on the International Space Station.
33:25
Speaker 1: And let's start by saying they don't become the same,
33:28
Speaker 1: but they do become more similar. So, you know, the
33:31
Speaker 1: same would imply the exact same species and the exact
33:33
Speaker 1: same abundances. That's not what happens.
33:35
Speaker 2: All right. Well, let's start by reminding people what a
33:37
Speaker 2: microbiome is and why it might become the same anyway.
33:41
Speaker 1: Oh okay, Well, I just assume that all of our
33:44
Speaker 1: listeners have listened to all of Katrina's amazing episodes. I'm
33:47
Speaker 1: going to butter Katrina up here at the beginning of
33:48
Speaker 1: the answer right now. So all right, so, the you know,
33:52
Speaker 1: your your microbiome is the collection of viruses, bacteria, fungi
33:56
Speaker 1: that live all over your body, including in your gut,
34:00
Speaker 1: in your face, in your saliva, you know, in your mouth,
34:03
Speaker 1: on your teeth. They're everywhere, and they can be important
34:06
Speaker 1: for a lot of different reasons. They can, you know,
34:08
Speaker 1: support inflammation, which is bad for you. They can help
34:11
Speaker 1: you digest food, which is good for you. They can
34:14
Speaker 1: help you battle pathogens, which is obviously good for you.
34:17
Speaker 1: And so it's a dynamic community that changes over time
34:21
Speaker 1: for a variety of reasons. And one of the ways
34:23
Speaker 1: that it changes on Earth is if you move in
34:25
Speaker 1: with somebody new and you spend a lot of time
34:28
Speaker 1: with them, you over time have microbiomes that are more similar.
34:32
Speaker 1: Not necessarily exactly the same, because maybe you all are
34:35
Speaker 1: eating different foods when you're at work or something like that,
34:38
Speaker 1: but you have more similar microbiomes when you live with
34:41
Speaker 1: someone over time.
34:42
Speaker 2: So you love someone, you live with them, you end
34:44
Speaker 2: up eating their poop. Yeah, another example of the butt
34:49
Speaker 2: to face pipeline.
34:50
Speaker 1: That's right. I mean, even if you don't love them,
34:53
Speaker 1: but you live with them, you're probably eating their poop.
34:57
Speaker 2: I feel like it's easier to digest that fact if
35:00
Speaker 2: you do love them. But yeah, all right, all right.
35:03
Speaker 2: So then the fascinating question is we know that happens
35:05
Speaker 2: for roommates here on Earth, and the question is what
35:07
Speaker 2: about roommates in space? How does this happen and is
35:11
Speaker 2: affected by supplies or crew changes or zero G?
35:14
Speaker 1: Yeah? All right, so there was I was able to
35:16
Speaker 1: find a study where they looked at astronauts, nine of
35:19
Speaker 1: them that were in space for somewhere between six to
35:21
Speaker 1: twelve months on the International Space Station, and they looked
35:24
Speaker 1: at their microbiomes on different parts of their bodies, and
35:28
Speaker 1: then they compared the microbiomes on different parts of their
35:30
Speaker 1: bodies to each other, to each of the different astronauts,
35:33
Speaker 1: and they did find that when people went into space,
35:35
Speaker 1: first of all, some aspects of their microbiomes got more diverse.
35:39
Speaker 1: So they went into space and they picked up a
35:42
Speaker 1: few new bacterial species, and that could have been from
35:44
Speaker 1: the astronauts that just arrived, or from astronauts that were
35:47
Speaker 1: on there, from the crew before and left some of
35:49
Speaker 1: their microbes behind.
35:51
Speaker 2: Or alien invasive microbes.
35:53
Speaker 1: Probably, yes, Daniel, Probably yes, or no.
36:00
Speaker 2: That voice tells you Kelly is humoring me.
36:05
Speaker 1: Well, we at the Whites and Institute have to have
36:07
Speaker 1: a lot of patients.
36:09
Speaker 2: Ooh wow, you're angling for that patient's award.
36:12
Speaker 1: Huh oh, No, Katrina's got it.
36:14
Speaker 2: She's one of twenty years running. Let me tell you
36:17
Speaker 2: that's right.
36:17
Speaker 1: Yes, it's definitely Katrina's Okay.
36:20
Speaker 2: All right, So they're out there, they're living together, obviously,
36:24
Speaker 2: they're sharing the same air, they're using the same bathroom.
36:27
Speaker 2: So all this stuff's going to get intermingled, it makes
36:29
Speaker 2: sense for their microbiomes to become intermingled, and.
36:32
Speaker 1: That is indeed what they found. They found that if
36:34
Speaker 1: you look at their gut microbes, over time, they became
36:37
Speaker 1: more similar, so they had similar species over time, so
36:41
Speaker 1: like some people picked up some bacterial species, some maybe
36:43
Speaker 1: lost some bacterial species, and so over time they do
36:47
Speaker 1: start having similar community members that they're swapping. And they
36:51
Speaker 1: think that a big part of why this is happening
36:55
Speaker 1: is because they're all eating pretty much the same limited
36:59
Speaker 1: food option. So you know, the International Space Station does
37:02
Speaker 1: have two hundred different items that you can order, but
37:05
Speaker 1: it's all, you know, it's all pretty similar and has
37:07
Speaker 1: a lot of the same ingredients, and so their gut
37:10
Speaker 1: microbiome is being fed pretty similar stuff, and part of
37:14
Speaker 1: what you eat supports different members of your gut community.
37:18
Speaker 1: And so they argued that they thought food was driving
37:20
Speaker 1: a lot of this similarity. But also they're sharing an
37:23
Speaker 1: environment in pretty intimate small quarters. I think the International
37:27
Speaker 1: Space Station. You know, if you put two one bedroom
37:30
Speaker 1: apartments together, the International Space Station probably doesn't have much
37:33
Speaker 1: more room than that, and there's like, you know, six
37:36
Speaker 1: to ten roommates in there, so it's pretty cramped, lots
37:39
Speaker 1: of microbes. You can't shower. You can like wipe yourself down,
37:43
Speaker 1: but you're not like, you know, really getting a nice
37:45
Speaker 1: shower like you would here at home. But they noted
37:47
Speaker 1: that even astronauts that tended to be working in different
37:50
Speaker 1: parts of the International Space Station and didn't spend a
37:53
Speaker 1: lot of time together still ended up with similar microbes,
37:56
Speaker 1: which is why they thought maybe it had something to
37:57
Speaker 1: do with the food.
37:58
Speaker 2: Even if you're just breathing the same area and not enough,
38:00
Speaker 2: even if you're not like often touching the same surfaces,
38:03
Speaker 2: it feels like that should be plenty.
38:05
Speaker 1: Yeah, I agree, they felt like food was pretty important,
38:07
Speaker 1: but I don't see why it wouldn't be. Hey, we're
38:09
Speaker 1: touching the same surfaces and then we touch our food,
38:11
Speaker 1: and that's the kind of you know, that determines what
38:13
Speaker 1: bacteria are going into our body. And at the end
38:16
Speaker 1: of the day, it's almost certainly not just one thing.
38:18
Speaker 1: It's probably a lot of different things.
38:20
Speaker 2: And how they replicated this kind of environment here on
38:22
Speaker 2: Earth in order to test and to understand how long
38:25
Speaker 2: it takes and underweth conditions.
38:26
Speaker 1: Yes, so there have been two like year long analog
38:31
Speaker 1: experiments that they've done here on Earth. It was Mars
38:34
Speaker 1: five hundred, which was done in Russia, and they looked
38:37
Speaker 1: at how the microbe changed. When you have quote unquote
38:40
Speaker 1: astronauts pretending to go on a mission to Mars.
38:43
Speaker 2: Quote unquote astronauts. Wow, wow, fire there, Kelly.
38:49
Speaker 1: I don't think that there'd be too much debate amongst
38:51
Speaker 1: the community of professional astronauts that they are simulation astronauts
38:55
Speaker 1: instead of astronaut astronauts.
38:58
Speaker 2: But I bet when they introduce themselves they don't say
39:00
Speaker 2: I'm an astronaut, and then they use air quotes.
39:05
Speaker 1: They might call themselves an analog astronaut or something like that.
39:09
Speaker 1: I don't remember exactly what the term is, but you know,
39:11
Speaker 1: I think the FAA has a rule where you have
39:13
Speaker 1: to have, you know, gone past the von Carmen line
39:16
Speaker 1: to be called an astronaut, and so, you know, I
39:17
Speaker 1: think technically I'm not being a.
39:20
Speaker 2: Jerk, no, but I think using scare quotes, but some
39:22
Speaker 2: in the category of like kids who have dressed up
39:24
Speaker 2: as a quote unquote astronaut for Halloween, not really an astronauts.
39:30
Speaker 1: I see, But only you were seeing the scare quotes
39:32
Speaker 1: you outed.
39:33
Speaker 2: Me, but you said, quote unquote astronaut anyway, Oh, shoot,
39:37
Speaker 2: these quote unquote astronauts, should we dig them seriously? Have
39:42
Speaker 2: done this really incredible thing of living isolated for six
39:45
Speaker 2: months or up to a year. So what did we
39:47
Speaker 2: learn from these studies?
39:48
Speaker 1: They found that the dominant species in the microbiome tended
39:52
Speaker 1: to say the same, So like the species that they
39:54
Speaker 1: had the most of when they went in there persisted.
39:57
Speaker 1: But the more rare strains of bacteria that they had
40:00
Speaker 1: when they went into the facility, those tended to become
40:04
Speaker 1: the same. So like your dominant bacterial species, that was
40:07
Speaker 1: pretty similar. But some of the like rare ones started
40:10
Speaker 1: to homogenize between the crew members, and for two of them,
40:14
Speaker 1: they changed back to their original state pretty soon after
40:18
Speaker 1: this analog mission was done. And I won't use quotes
40:22
Speaker 1: around missions so that you don't imply that I'm laughing
40:25
Speaker 1: at people, and all right, and then the other four
40:31
Speaker 1: had a Mars five hundred esque microbiome for up to
40:34
Speaker 1: six months, so those changes persisted for them, and the
40:37
Speaker 1: surfaces inside of Mars five hundred started to look sort
40:41
Speaker 1: of like the microbiome on the exterior, you know, like
40:44
Speaker 1: the skin parts of the crew, which is something we
40:46
Speaker 1: also see on the International Space Station. And then there
40:49
Speaker 1: was also a study on the Hawaiian Space Exploration Analog
40:53
Speaker 1: and Simulation four mission, so that's High Seas four and
40:57
Speaker 1: they found and this is gross that here, let me
41:02
Speaker 1: find the quote microbial diversity of skin samples from the
41:05
Speaker 1: High Seas four crew successively increased and showed a delayed
41:10
Speaker 1: longitudinal homogenization with microbial diversity estimates from surfaces, mainly due
41:16
Speaker 1: to complications with the composting toilet. So the point here
41:23
Speaker 1: is that there was a lot of poop getting on
41:27
Speaker 1: their skin and so they were seeing evidence of that
41:31
Speaker 1: on their skin microbiome. Wow, and that was impacting the results.
41:35
Speaker 1: And space is gross. So this is actually.
41:37
Speaker 2: Poop to skin pipeline, the poop to skin pipeline.
41:40
Speaker 1: So anyway, composting toilet was getting things pretty gross up
41:43
Speaker 1: in there.
41:44
Speaker 2: Do you think in the High Seas they were waking
41:46
Speaker 2: up with poop on their face the way people in
41:48
Speaker 2: Virginia do when they're bitten by a kissing bug?
41:50
Speaker 1: You know, I would bet that La has a lot
41:52
Speaker 1: more cases of kissing bug than all of Virginia.
41:55
Speaker 2: So all right, we're gonna look that up and see
41:58
Speaker 2: look up.
41:59
Speaker 1: Sounds good, all right.
42:00
Speaker 2: So the other part of his question was whether this
42:02
Speaker 2: was affected by deliveries or crew changes.
42:05
Speaker 1: So I don't think it's very affected by delivery. So
42:08
Speaker 1: they're pretty careful to sterilize things before they put them
42:11
Speaker 1: in the modules to send them up to space. They're
42:14
Speaker 1: super careful about that, like sterilizing the food and whatnot,
42:17
Speaker 1: And so there's probably not a ton of microbes in there.
42:19
Speaker 1: I mean, it would be amazing to me if there
42:21
Speaker 1: were no microbes in there, because like, you can never
42:23
Speaker 1: get rid of all the microbes. But I don't think
42:25
Speaker 1: that's a big contributor, and neither did the papers that
42:28
Speaker 1: I read. They didn't imply that was a big contributor either.
42:31
Speaker 1: But there was a study that looked at different surfaces
42:35
Speaker 1: on the International Space Station and they looked at how
42:37
Speaker 1: the microbes on those surfaces changed over time as crew
42:42
Speaker 1: members changed over thirty three months, so crew members tend
42:45
Speaker 1: to change every like three or six months or something
42:47
Speaker 1: like that, and they didn't see that the bacteria on
42:51
Speaker 1: the surfaces of the International Space Station were changing over
42:56
Speaker 1: time in ways that seemed to reflect changes in the crew.
43:00
Speaker 1: So you'd get a change in the crew, and you'd
43:01
Speaker 1: look at their skin microbiome, and a few months later
43:04
Speaker 1: the surfaces of the International Space Station would look more
43:07
Speaker 1: like the microbiome of the crew, And then a new
43:10
Speaker 1: crew would come and that cycle would sort of start again.
43:14
Speaker 1: They had similarity in species, but not necessarily similarity in
43:19
Speaker 1: the abundance. So, for example, maybe the humans and the
43:24
Speaker 1: surfaces both had bacteria species ABC and D hypothetical example.
43:29
Speaker 1: But for humans, maybe ABC and D were at abundances
43:34
Speaker 1: of like, you know, eighty percent, ten percent, five percent,
43:36
Speaker 1: and five percent, respectively, But on the surfaces maybe it
43:40
Speaker 1: was something more like twenty five percent for each species.
43:43
Speaker 1: So different abundances, but similar species. So that at least
43:47
Speaker 1: suggests that when a new crew comes, they're spreading their
43:50
Speaker 1: microbe through the habitat and likely to spread that to
43:53
Speaker 1: whoever else is residing on the station.
43:55
Speaker 2: And something I've learned from our president for micromial research
44:00
Speaker 2: is that the abundance of the bacteria depend essentially on
44:03
Speaker 2: the conditions, like are you feeding at the right thing,
44:05
Speaker 2: is at the right temperature, And so I wonder if
44:08
Speaker 2: the conditions on the space station are different from the
44:10
Speaker 2: conditions in the ground in some important way that you
44:12
Speaker 2: get like the growth of a different bacteria. And the
44:15
Speaker 2: listener asked this great question about zero G does gravity
44:18
Speaker 2: effect the growth of microbes?
44:20
Speaker 1: Yeah, so the listener also pointed out that it's probably
44:23
Speaker 1: a really hard thing to study, and so I'd like
44:25
Speaker 1: to highlight first that, Yeah, it's a really hard thing
44:27
Speaker 1: to study. So, I mean, if you're looking at the
44:29
Speaker 1: microbiome of astronauts, you know, micro gravity is changing, but
44:33
Speaker 1: they're also exposed to a little bit more space radiation.
44:36
Speaker 1: They're probably more stressed out than they are on Earth
44:39
Speaker 1: because they have a very packed schedule of experiments and
44:42
Speaker 1: stuff that are super expensive, and they don't sleep very well.
44:46
Speaker 1: There's data on that. So a lot of stuff is
44:49
Speaker 1: changing when they're up there, and it's hard to sort
44:51
Speaker 1: of isolate things. Yeah, we have done some studies that
44:54
Speaker 1: suggest that microgravity impacts bacteria in a variety of different ways.
44:59
Speaker 1: So this isn't talking about microbiomes. This is just looking
45:02
Speaker 1: at bacteria and they form biofilms differently. So biofilms or
45:07
Speaker 1: when bacteria sort of like adhere themselves together, and that
45:11
Speaker 1: makes them a little bit more resistant to the immune
45:13
Speaker 1: system and antibiotics and stuff like that. They also produce
45:16
Speaker 1: different amounts of virulence factors, they have different levels of
45:21
Speaker 1: resistance to antimicrobials. So we do have some evidence that
45:25
Speaker 1: micro gravity impacts bacteria in some ways, but it's not
45:29
Speaker 1: clear what the impact is on the microbiome. So when
45:32
Speaker 1: you're aggregating all of the bacteria, and I was able
45:35
Speaker 1: to find one study that was starting to try to
45:38
Speaker 1: separate these different pieces, and so what they did was
45:41
Speaker 1: it was a study with rodents where they put the
45:44
Speaker 1: rodents in a harness where they were trying to simulate
45:47
Speaker 1: lunar gravity by lifting them up so that only like
45:50
Speaker 1: one sixth of their mass was like touching the grounds
45:54
Speaker 1: with like they weighed one sixth as much. And then
45:57
Speaker 1: they also were doing some radiation experiments and they did
46:00
Speaker 1: find that like some community members and the microbiome shifted
46:03
Speaker 1: a bit. But it's kind of hard for me to
46:06
Speaker 1: know if like feeling like you way less is going
46:09
Speaker 1: to be the same as really being in a microgravity environment.
46:12
Speaker 1: And you're in this harness and that's probably stressful because
46:15
Speaker 1: you know, the rodents are like what that Why am
46:17
Speaker 1: I confined? I can't move around? It's hard to nail
46:20
Speaker 1: this stuff down, and I wasn't able to find studies
46:23
Speaker 1: that tried to nail it down in humans. There's reason
46:25
Speaker 1: to suggest that the low gravity environment probably is impacting
46:30
Speaker 1: bacteria in a way that scales up to the level
46:32
Speaker 1: of the microbiome. But I think at the moment, we
46:34
Speaker 1: don't really understand that.
46:36
Speaker 2: All right, awesome, well that's fascinating. Look at microbiomes in
46:39
Speaker 2: space and the life of astronauts. Let's send this answer
46:43
Speaker 2: over to our president for microbial research and hear what
46:47
Speaker 2: she has to say.
46:49
Speaker 1: And let's hear what John has to say. Absolutely, Oh,
46:52
Speaker 1: I'm worried about what Katrina has to say. I hope
46:54
Speaker 1: I got it right.
46:57
Speaker 7: So Katrina, would you think, Well, I have to say
47:00
Speaker 7: I was playing in my mind the studies that Kelly
47:03
Speaker 7: brought up like seconds before she said them. So that
47:06
Speaker 7: was very satisfying. So nice job with your research, Kelly.
47:09
Speaker 7: In some cases, that's.
47:10
Speaker 2: Some real approval right there from the president.
47:13
Speaker 7: In some cases those are like talks I have seen,
47:17
Speaker 7: like I met the scientists who led the studies. So,
47:19
Speaker 7: for example, the microgravity studies with the bacteria showing the
47:23
Speaker 7: changes in biofilm formation and urulence factor expression.
47:28
Speaker 3: I met the scientist, a scientist who led a study
47:30
Speaker 3: like that.
47:31
Speaker 7: It was published in Nature Gravity, and she had these
47:35
Speaker 7: crazy contraptions where they would kind of like at the
47:38
Speaker 7: at an amusement park where they like spin you in
47:40
Speaker 7: circles and then there's less gravity.
47:42
Speaker 3: They did that to the microbes.
47:44
Speaker 7: So she was conducting those experiments on Earth but changing
47:47
Speaker 7: the gravity that the microbes felt.
47:49
Speaker 3: And so that was a cool way that those experiments
47:51
Speaker 3: were done.
47:52
Speaker 7: And yeah, I think there are changes that we've only
47:54
Speaker 7: studied at the smaller scale and we don't know how
47:57
Speaker 7: they synchronize up at the bigger scale, which I know
47:59
Speaker 7: is theme for you guys. So you know, does one
48:02
Speaker 7: microbe by itself when put together with ten to the
48:05
Speaker 7: twenty nine microbes as.
48:07
Speaker 3: There like a new simplicity that emerges, I don't know.
48:10
Speaker 7: And then just on the space analog front, I also
48:13
Speaker 7: I was really interested in that for a long time.
48:15
Speaker 7: In fact, I wrote proposals to the Australian and Arctic
48:19
Speaker 7: Division many times with the hope of studying the Australian
48:24
Speaker 7: Antarctic researchers who live on some of the most isolated
48:28
Speaker 7: bases down in Antarctica, sometimes only like ten people will
48:32
Speaker 7: spend the whole winter eight months together with no new
48:35
Speaker 7: shipments coming in, and so it's a way of learning
48:39
Speaker 7: about people in close quarters and experiencing stress. That's similar
48:44
Speaker 7: to what astronauts experience minus the whole gravity thing. And
48:48
Speaker 7: I think they have a little more access to fresh air,
48:50
Speaker 7: for example. But anyway, I never did get the proposal
48:54
Speaker 7: to do that, but I think it's really interesting. They
48:56
Speaker 7: have definitely seen changes in how your immune system misfunctioning.
49:01
Speaker 7: And just keep in mind that your microbes and your
49:03
Speaker 7: immune cells are a big a lot going on with
49:07
Speaker 7: the interactions between the immune cells and the microbes. So
49:10
Speaker 7: as stress and environment change in your immune system changes,
49:14
Speaker 7: that's a big pressure that will influence which microbes can
49:19
Speaker 7: thrive in your body. So I'm very sure that's a
49:21
Speaker 7: big part of how the.
49:23
Speaker 3: Microbiomes change and all around.
49:25
Speaker 7: I think, yeah, it's just about exposure to the microbes
49:29
Speaker 7: from other people around you, and the conditions like the
49:33
Speaker 7: food will also have an impact. But it's like you
49:36
Speaker 7: need the microbes and the nutrients together to shape the community,
49:41
Speaker 7: So I'm sure both of those forces are really important.
49:44
Speaker 7: I actually also recently saw a NASA scientist give a
49:48
Speaker 7: talk about contamination from even astronauts wearing their spacesuits going
49:55
Speaker 7: out on like spacewalks and on the surfaces of the
49:58
Speaker 7: International Space Station, for example, and if you take swabs
50:02
Speaker 7: out there, you find that there are microbes being dribbled,
50:07
Speaker 7: which is like, there's a real goal of the whole
50:09
Speaker 7: space community to avoid contaminating the universe with our Earth's microbes,
50:14
Speaker 7: and that's.
50:15
Speaker 3: A really big challenge.
50:17
Speaker 7: So even the space suits, which are pretty well contained,
50:21
Speaker 7: do not entirely prevent microbes from dribbling out. So if
50:24
Speaker 7: we went up to Mars, I mean this is obviously
50:27
Speaker 7: I have no idea when we might be doing this,
50:28
Speaker 7: But if we were to send people in space suits
50:32
Speaker 7: up to Mars to sample the rocks and try to
50:33
Speaker 7: learn about life, we would have a hard time not
50:36
Speaker 7: contaminating with our own microbes. And a lot of our
50:39
Speaker 7: methods are for low abundance, low biomass samples.
50:44
Speaker 3: They are right at.
50:45
Speaker 7: The limit of detection, so it starts to become impossible
50:48
Speaker 7: to distinguish what's showing up in the kit reagents versus
50:52
Speaker 7: what's actually coming from the environment that you're sampling. So
50:55
Speaker 7: those are the things that the space microbiology community are
50:58
Speaker 7: thinking about.
50:59
Speaker 2: I think, So what grade would you give Kelly?
51:01
Speaker 7: Oh, my gosh, I mean one hundred percent? Maybe actually
51:05
Speaker 7: a plus?
51:07
Speaker 2: All right, good job Kelly.
51:09
Speaker 5: Hello Daniel and Kelly. Yes, you answered my questions, the
51:13
Speaker 5: most interesting point being that the major components of people's
51:16
Speaker 5: microbiomes remain stable under such close and isolated conditions. The
51:21
Speaker 5: immediate follow ups that king to mind were whether the
51:24
Speaker 5: same effect was visible on the surfaces of the ISS.
51:28
Speaker 1: Thanks hey, John, great follow up question. So the microbiome
51:32
Speaker 1: on the surface of the International Space Station, like you know,
51:35
Speaker 1: the various computer screens and stuff like that, do tend
51:39
Speaker 1: to change over time in ways that reflect the makeup
51:42
Speaker 1: of the crew that's on the International Space Station. So
51:45
Speaker 1: there's a lag between new crew members coming on and
51:49
Speaker 1: all of the microbes that are covering their hands and
51:51
Speaker 1: their arms sort of getting on all of the surfaces.
51:54
Speaker 2: Thanks John, all right, Thanks everybody for these wonderful questions.
52:03
Speaker 2: We thoroughly enjoy these discussions and gives us the opportunity
52:06
Speaker 2: to dig deep into a question we have sometimes wanted
52:09
Speaker 2: to understand better ourselves. So thank you very much for
52:12
Speaker 2: sharing your curiosity. Remember that science moves forward because of
52:16
Speaker 2: human curiosity and that includes you.
52:19
Speaker 1: So send us your questions at questions at Daniel and
52:21
Speaker 1: Kelly dot org, or you can join us on our
52:24
Speaker 1: discord channel. You can find an invitation to our discord
52:26
Speaker 1: channel on our website danieland Kelly dot org, or follow
52:31
Speaker 1: us on Instagram, Twitter, or blue Sky at D and
52:35
Speaker 1: K Universe.
52:36
Speaker 2: Have a great day, everyone,