Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions #26

Transcript

Listener Questions #26 · Daniel and Kelly’s Extraordinary Universe

• 0:07
  Speaker 1: Tornadoes always touched down on the plains. Is that because
• 0:11
  Speaker 1: hills block all the rains?
• 0:13
  Speaker 2: When we treat water, we rotate, filtrate, and aerrate. Tell
• 0:17
  Speaker 2: me more, but be careful how you pronounce floculate?
• 0:22
  Speaker 1: How large can a moon appear in our sky without
• 0:25
  Speaker 1: being shredded by gravity's tides?
• 0:28
  Speaker 2: Whatever questions keep you up at night, Daniel and Kelly's
• 0:31
  Speaker 2: answers will make it right.
• 0:32
  Speaker 1: Welcome to Daniel and Kelly's Extraordinary Universe.
• 0:49
  Speaker 2: Hello. I'm Kelly Windersmith. I study parasites and space, and
• 0:52
  Speaker 2: I am afraid of tornadoes.
• 0:56
  Speaker 1: Hi. I'm Daniel. I'm a particle physicist, and I'm afraid
• 0:59
  Speaker 1: of Zach's comments on our poetic introductions.
• 1:02
  Speaker 2: Oh? Are we going to let the listeners know that
• 1:05
  Speaker 2: Zach skips the introductions for the listener question episodes because
• 1:08
  Speaker 2: he is actually really good at poetry and finds our
• 1:11
  Speaker 2: poetry sort of nauseating.
• 1:14
  Speaker 1: It's not what we're famous for. Let's just put it
• 1:16
  Speaker 1: that way.
• 1:17
  Speaker 2: We're having fun.
• 1:18
  Speaker 1: But let me put it this way. At least your
• 1:20
  Speaker 1: spouse listens to our podcast.
• 1:22
  Speaker 2: Oh, Katrina dozen Oh no, Oh, I'm mortified. Oh do
• 1:29
  Speaker 2: we really want to keep having her on our show.
• 1:32
  Speaker 2: The answer is yes, we absolutely do.
• 1:33
  Speaker 1: This is my secret plan to pull her in to
• 1:35
  Speaker 1: hook her on the podcast.
• 1:36
  Speaker 2: Oh fantastic, this is we're talking about tornadoes today. Let's
• 1:41
  Speaker 2: share our scariest tornado story. Do you have any tornado stories?
• 1:46
  Speaker 1: Ooh, I do have a tornado story, though I wasn't
• 1:48
  Speaker 1: very scared. I was in my dorm room at Rice
• 1:51
  Speaker 1: in Houston and studying really hard for a test, and
• 1:54
  Speaker 1: I heard a bunch of shouting in the hallways and
• 1:57
  Speaker 1: I ignored it because I was busy. And then later
• 1:59
  Speaker 1: I just got there was a tornado that went right
• 2:02
  Speaker 1: through Houston and within about a mile of the campus.
• 2:05
  Speaker 1: And I didn't know anything about it. Yeah, and that's
• 2:08
  Speaker 1: not very typical for tornadoes to pass through cities, so
• 2:11
  Speaker 1: it was something of an event. How about you, what's
• 2:13
  Speaker 1: the closest you've been to a tornado?
• 2:15
  Speaker 2: So Zach and I moved to Tuscaloosa, Alabama, right after
• 2:18
  Speaker 2: like the big tornado that like knocked out a bunch
• 2:21
  Speaker 2: of the city, and we were in a hotel before
• 2:23
  Speaker 2: we got our keys to our place, and there was
• 2:26
  Speaker 2: a tornado warning in the area, and I was like,
• 2:29
  Speaker 2: oh my gosh, another tornado is going to take out
• 2:31
  Speaker 2: half the city. And Zach was not worried at all,
• 2:34
  Speaker 2: and I was panicking. And Zach's like, all right, well,
• 2:37
  Speaker 2: you're obviously not going to sleep, so well you're panicking.
• 2:39
  Speaker 2: I'm going to take a shower. And I was looking
• 2:41
  Speaker 2: up what do you do if there's a tornado and
• 2:42
  Speaker 2: you're supposed to like get in a tub. Oh, And
• 2:45
  Speaker 2: so Zach finishes the shower, he comes out, and I'm
• 2:48
  Speaker 2: panicking and I was like, I think we should get
• 2:49
  Speaker 2: in the tub. And Zach is like almost asleep already.
• 2:52
  Speaker 2: And I go into the tub and like the tub
• 2:54
  Speaker 2: is filled with water, like something can happen with the drain,
• 2:57
  Speaker 2: and I was like, now we're gonna drown. And I
• 3:01
  Speaker 2: was more worried about, like Zach hampering our ability to
• 3:04
  Speaker 2: survive the tornado. And anyway, we were totally fine, and
• 3:06
  Speaker 2: I am kind of nuts.
• 3:08
  Speaker 1: Is the point sounds like a swirling panic attack?
• 3:14
  Speaker 2: I'm known for those.
• 3:15
  Speaker 1: Actually yeah, yeah, well today you don't have to panic
• 3:19
  Speaker 1: because you are not going to experience a tornado. Instead,
• 3:21
  Speaker 1: you're going to experience an explanation of how tornadoes work
• 3:24
  Speaker 1: and where they form. Because we are answering questions from
• 3:28
  Speaker 1: listeners like you. People just like you who listen to
• 3:30
  Speaker 1: the podcast and want to know how things work out
• 3:33
  Speaker 1: there in the universe. They can't find answers online. They
• 3:36
  Speaker 1: ask JATGBT. They're not satisfied, so they write it to us,
• 3:39
  Speaker 1: and we are very happy to provide some answers.
• 3:42
  Speaker 2: Daniel, how can you know for sure they're not going
• 3:44
  Speaker 2: to be experiencing a tornado. They could be listening to
• 3:47
  Speaker 2: this at any time. There could be a tornado when
• 3:49
  Speaker 2: they're listening.
• 3:50
  Speaker 1: No, this is a tornado free podcast. I'm providing my guarantee.
• 3:53
  Speaker 2: I think you are violating the rules of physics, and
• 3:56
  Speaker 2: I I'm going to write the physicist board and they're
• 3:59
  Speaker 2: gonna going to lose your job. Man.
• 4:01
  Speaker 1: I'm going to hedge because everything is statistical in particle physics.
• 4:04
  Speaker 1: So I'm gonna give you my ninety five percent guarantee,
• 4:06
  Speaker 1: and that's my highest guarantee.
• 4:08
  Speaker 2: All right, Well, that that's a pretty high guarantee. It
• 4:11
  Speaker 2: sounds to me like you just pulled that number out
• 4:13
  Speaker 2: of us swirling thin.
• 4:14
  Speaker 1: Air all of statistics sounds like that, But really there's
• 4:17
  Speaker 1: a lot of rigorous calculations behind it. Trust me. All right, Well,
• 4:22
  Speaker 1: let's move on to more solid ground and answer some
• 4:24
  Speaker 1: questions from listeners. Here's a question from Patrick about tornadoes.
• 4:29
  Speaker 3: Hi, Daniel, and Kelly. We had some tornadoes touched down
• 4:33
  Speaker 3: outside of Cincinnati recently, and I've noticed tornadoes seem to
• 4:36
  Speaker 3: hit the flatter, more open areas outside the city more
• 4:40
  Speaker 3: often than the city itself. I was thinking about why
• 4:43
  Speaker 3: this might be and wondering if I'm on the right track. So,
• 4:47
  Speaker 3: the weather system builds up enough power to form a
• 4:49
  Speaker 3: tornado over the unobstructed flat land, but in hilly areas
• 4:54
  Speaker 3: and populated areas, the power is attenuated by the hills
• 4:58
  Speaker 3: and buildings or alter the tornado's oscillation is damped by
• 5:02
  Speaker 3: the obstacles. So thanks for taking my question and let
• 5:07
  Speaker 3: me know if I'm on the right track.
• 5:09
  Speaker 2: Whoa tornado's in Cincinnati. I grew up in Ohio, and
• 5:12
  Speaker 2: I don't feel like tornado should be allowed in Ohio.
• 5:15
  Speaker 2: I'm sorry you had to go through that. Patrick.
• 5:18
  Speaker 1: Well, Cincinnati's like kinda on the border, isn't it's like
• 5:20
  Speaker 1: partly in Ohio, partly in Kentucky.
• 5:23
  Speaker 2: Right, No, it's in Ohio.
• 5:25
  Speaker 1: Isn't it a river that runs through it.
• 5:28
  Speaker 2: Oh, maybe maybe I'm wrong. It might be a little
• 5:31
  Speaker 2: bit in Kentucky.
• 5:34
  Speaker 1: What I think technically, you're right because the part of
• 5:39
  Speaker 1: the city that's north of the Ohio River is Cincinnati,
• 5:43
  Speaker 1: but there's definitely lots of city on the other side,
• 5:46
  Speaker 1: whether or not you officially call it Cincinnati.
• 5:48
  Speaker 2: Daniel, I am gonna have to actually, I'm given this
• 5:50
  Speaker 2: point to you. I'm sorry I did not carefully study
• 5:55
  Speaker 2: Ohio geography because I was trying real hard to get
• 5:57
  Speaker 2: out of there.
• 5:58
  Speaker 1: Sorry, Ohio, let me tell you about your home stance.
• 6:06
  Speaker 2: All right, Kelly's betten oh for one? So far?
• 6:08
  Speaker 1: All right?
• 6:09
  Speaker 2: What is the tornado? Daniel? What am I so afraid of?
• 6:14
  Speaker 1: So we've all seen tornadoes in movies, et cetera. They're
• 6:16
  Speaker 1: essentially rotating columns of air in contact with the cloud
• 6:21
  Speaker 1: and the ground. So you see this tube and it's
• 6:23
  Speaker 1: like twisting and flailing around, and they can be very
• 6:27
  Speaker 1: very powerful. The winds can be like up to four
• 6:29
  Speaker 1: hundred and eighty kilometers per hour, super incredible.
• 6:33
  Speaker 2: What is that in freedom units?
• 6:38
  Speaker 1: Fast? It's fast units? Okay, it's destructive. Yeah. And they
• 6:43
  Speaker 1: can be quite narrow or they can be really wide,
• 6:45
  Speaker 1: like big monster tornadoes up to three kilometers wide, and
• 6:50
  Speaker 1: for it to be class as a tornado has to
• 6:52
  Speaker 1: come from the cloud and make contact with the ground,
• 6:55
  Speaker 1: and that's where the destruction happens. These powerful winds, the
• 6:58
  Speaker 1: funnel touching the ground, and that funnel travels across the
• 7:01
  Speaker 1: ground and tear stuff up, and it can go for
• 7:04
  Speaker 1: like up to one hundred kilometers, tearing a path of
• 7:07
  Speaker 1: destruction across Kansas or Ohio or wherever Alabama.
• 7:11
  Speaker 2: Man, do tornadoes always go from the clouds to the ground.
• 7:16
  Speaker 2: They never go from the ground to the clouds, that's
• 7:18
  Speaker 2: right there.
• 7:18
  Speaker 1: Always start in the cloud and then descend to the ground.
• 7:20
  Speaker 1: There are other similar patterns like dust devils you might
• 7:23
  Speaker 1: have seen, which looks similar to tornadoes, but aren't officially tornadoes.
• 7:27
  Speaker 1: Those just are whirling patterns of wind on the ground
• 7:29
  Speaker 1: that touch only the ground and there's no cloud above them,
• 7:32
  Speaker 1: so they're not officially tornadoes. And if it's over water,
• 7:35
  Speaker 1: they can be called a water spout. So there's a
• 7:37
  Speaker 1: few variants of them.
• 7:38
  Speaker 2: Okay, And are those things ever as damaging as tornadoes
• 7:41
  Speaker 2: or they're like tornadoes baby sisters and baby brothers.
• 7:46
  Speaker 1: Well, they can be as powerful because the storms can
• 7:48
  Speaker 1: be powerful, but unless you're living on the water, and
• 7:51
  Speaker 1: they're not damaging houses, right, So the most damaging ones
• 7:54
  Speaker 1: are the ones that touch the ground, because that's where
• 7:56
  Speaker 1: the houses are.
• 7:56
  Speaker 2: Got it, okay? All right? And where so we've noted
• 8:00
  Speaker 2: that they do sort of tend to be like aggregated
• 8:02
  Speaker 2: in certain geographic regions. Why is that.
• 8:06
  Speaker 1: This is something that really America is best at. American
• 8:09
  Speaker 1: exceptionalism has data to back it up. In the case
• 8:13
  Speaker 1: of tornadoes, most of the tornadoes in the world are
• 8:16
  Speaker 1: in the United States. We have like eight hundred per year,
• 8:20
  Speaker 1: and most of them are in a slice of the
• 8:23
  Speaker 1: US in central and southeast corners of the country, which
• 8:26
  Speaker 1: we affectionately call tornado Alley. So there's like four times
• 8:30
  Speaker 1: as many tornadoes in the US as there are in
• 8:32
  Speaker 1: all of Europe. You have a few in like South Africa,
• 8:35
  Speaker 1: some in Europe, Australia, Eastern India, but primarily it's a
• 8:39
  Speaker 1: thing the US is best at.
• 8:41
  Speaker 2: The wind really likes us, all right, So why are
• 8:44
  Speaker 2: we cursed with these tornadoes?
• 8:46
  Speaker 1: Yes, So to understand why tornadoes happen here and less
• 8:50
  Speaker 1: often elsewhere, you have to understand how they form and
• 8:53
  Speaker 1: This is not something where the science is totally settled.
• 8:56
  Speaker 1: People are still working on this. It's a great example
• 8:59
  Speaker 1: of complex city. You're studying a system which has lots
• 9:02
  Speaker 1: of components which interact very strongly. Pulling a simple story
• 9:05
  Speaker 1: out of that is not always possible, but people are
• 9:08
  Speaker 1: working on it. We think that the ingredients are number one,
• 9:12
  Speaker 1: a huge thunderstorm, but not just like a normal thunderstorm,
• 9:15
  Speaker 1: one with like really powerful strong winds, hailstones, et cetera.
• 9:20
  Speaker 1: And in particular a thunderstorm called a super cell, which
• 9:23
  Speaker 1: is a set of tower and clouds up to fifteen
• 9:26
  Speaker 1: kilometers tall, so like a really massive cloud. So that's
• 9:30
  Speaker 1: ingredient number one. It's like a really powerful thunderstorm, a
• 9:33
  Speaker 1: very tall one. And then below that you need warm,
• 9:37
  Speaker 1: moist air on the ground, and we'll talk about how
• 9:40
  Speaker 1: these come together into a tornado in a minute. And
• 9:42
  Speaker 1: the third ingredient is sheer. You need strong changes in
• 9:45
  Speaker 1: the wind speed as you go up or down in altitude,
• 9:49
  Speaker 1: and so these things how they come together and make
• 9:51
  Speaker 1: a tornado. Again, it's not fully understood. There's a bunch
• 9:54
  Speaker 1: of different theories out there. One is that it starts
• 9:58
  Speaker 1: in the storm. You have these pockets of rotation in
• 10:01
  Speaker 1: the storm and then they somehow intensify and touch the ground.
• 10:05
  Speaker 1: And one way this might happen is that the warm
• 10:07
  Speaker 1: moist air on the ground is rising up and there's
• 10:11
  Speaker 1: already like pockets of rotation in the storm, and the
• 10:14
  Speaker 1: rising air connects with those and creates like a horizontal
• 10:17
  Speaker 1: rotation or as you have this rising pattern, sort of
• 10:20
  Speaker 1: like in a hurricane, you have like rising air in
• 10:22
  Speaker 1: the center, which then moves out to the edges, so
• 10:25
  Speaker 1: you get these horizontal rotation which then gets tilted into
• 10:28
  Speaker 1: a vertical column somehow. So that's sort of one cartoon explanation.
• 10:33
  Speaker 2: But that kind of sounds like it's starting from the
• 10:34
  Speaker 2: bottom and like meeting the hurricane halfway, like it's coming
• 10:38
  Speaker 2: from the top and the bottom. So what am I
• 10:40
  Speaker 2: missing there?
• 10:40
  Speaker 1: Yeah, you're right, And again simple stories are never going
• 10:42
  Speaker 1: to describe the complexity. What's happening there is that you
• 10:45
  Speaker 1: have this rising air which is coming up and contributing
• 10:49
  Speaker 1: and helping pull the cloud down. But still a cloud
• 10:51
  Speaker 1: is moving down towards the ground. It's not like there's
• 10:54
  Speaker 1: a tornado forming on the ground and reaching up to
• 10:56
  Speaker 1: the cloud. It's really the cloud coming down to meet
• 10:59
  Speaker 1: the ground. Yes, being pulled down and contributing by stuff
• 11:02
  Speaker 1: on the ground. Okay, there's another idea that maybe there's
• 11:05
  Speaker 1: a sudden down draft, a special kind of downdraft in
• 11:08
  Speaker 1: the cloud that reaches down and squeezes a column of
• 11:12
  Speaker 1: air which happens to be spinning. And now because you've
• 11:15
  Speaker 1: squeezed it, its spinning faster, and that instigates the tornado.
• 11:19
  Speaker 1: And this is a third theory that maybe there are
• 11:21
  Speaker 1: a lot of small vortices on the ground, like a
• 11:24
  Speaker 1: bunch of little random ones, which merge together and then
• 11:27
  Speaker 1: start spinning and pull the cloud down. And so there's
• 11:31
  Speaker 1: lots of different explanations. And one reason that we don't
• 11:34
  Speaker 1: have an answer is that it is a complex situation.
• 11:37
  Speaker 1: Even if you have all the data, even if you
• 11:39
  Speaker 1: take lots of measurements, answering the question of like well
• 11:43
  Speaker 1: why did this happen? Is complicated. It We touched on
• 11:46
  Speaker 1: this in our episode on causality, like is there a
• 11:49
  Speaker 1: single reason why it happens? One of the necessary ingredients.
• 11:52
  Speaker 1: Even thinking about like what an explanation would look like
• 11:55
  Speaker 1: is a little bit fuzzy because it's a really complicated environment.
• 11:59
  Speaker 1: It's not like a single Rube Goldberg machine where you say,
• 12:02
  Speaker 1: like A causes B, which causes C, which causes D. Right,
• 12:05
  Speaker 1: you have to have a lot of ingredients in place,
• 12:07
  Speaker 1: and maybe there's ranges of requirements. A lot of people
• 12:10
  Speaker 1: are doing simulation studies where they try to create tornadoes
• 12:13
  Speaker 1: in simulations to see like what ingredients are necessary and
• 12:17
  Speaker 1: how often does it happen. It's very expensive simulations because
• 12:20
  Speaker 1: you have to assimulate like all the rain drops and
• 12:22
  Speaker 1: all the different areas of wind here and there. So
• 12:26
  Speaker 1: it's something people are definitely working on, but not something
• 12:28
  Speaker 1: we fully understand.
• 12:29
  Speaker 2: Well, I love that you've been covering the weather lately,
• 12:32
  Speaker 2: and so now I feel like I can ask you
• 12:33
  Speaker 2: any weather related questions. So this is great for me.
• 12:36
  Speaker 1: So and I'll give you a ninety five percent confident
• 12:38
  Speaker 1: answer on anything.
• 12:39
  Speaker 2: I don't feel great about that. But so, do we
• 12:42
  Speaker 2: understand why you get very strong thunderstorms in some area
• 12:46
  Speaker 2: since that's like ingredient number one that you need. Do
• 12:49
  Speaker 2: we understand that?
• 12:51
  Speaker 1: Not fully weather? It's of course chaotic, but we can
• 12:54
  Speaker 1: model storms reasonably well, the formation of storms, like we
• 12:57
  Speaker 1: can predict when it's going to rain and when it's
• 12:58
  Speaker 1: going to hail. Check back to our episode about predicting
• 13:01
  Speaker 1: the weather we did recently to hear all about that.
• 13:03
  Speaker 1: So those ingredients are reasonably well understood. But why they
• 13:07
  Speaker 1: come together and make a tornado sometimes and not others.
• 13:10
  Speaker 1: It's a bit of a mystery. You have like storm
• 13:11
  Speaker 1: watchers on the ground and they'll be watching a storm like, oh,
• 13:14
  Speaker 1: it feels like it's going to come together, and then
• 13:16
  Speaker 1: it just like fizzles out and no tornado happens, And
• 13:19
  Speaker 1: we don't have a clear understanding of why that is. Sometimes,
• 13:22
  Speaker 1: but these rough ideas that you need a combination of
• 13:25
  Speaker 1: thunderstorms and then warm air on the ground and wind shear,
• 13:28
  Speaker 1: they can help us answer Patrick's question about why tornadoes
• 13:32
  Speaker 1: tend to form in the plains and your question about
• 13:34
  Speaker 1: why Tornado Alley exists.
• 13:36
  Speaker 2: Well, those things that you said, those seem like there
• 13:39
  Speaker 2: are things that happen just about anywhere, right, severe storms,
• 13:43
  Speaker 2: warm moist air, and shear, Like you should be able
• 13:47
  Speaker 2: to get that anywhere, right, Yeah you.
• 13:48
  Speaker 1: Can, and there are tornadoes all over the place. But
• 13:50
  Speaker 1: in lots of places there are mountains which block warm
• 13:53
  Speaker 1: moist air from coming in from the ocean, whereas in
• 13:57
  Speaker 1: the United States. For example, you got the Gulf of Mexico,
• 14:00
  Speaker 1: which is a lot of warm water, and there's a
• 14:02
  Speaker 1: lot of warm moist air that comes in from the
• 14:04
  Speaker 1: Gulf of Mexico, and there's no major mountain range there
• 14:07
  Speaker 1: to block it. Like Louisiana, no mountains there. That whole
• 14:10
  Speaker 1: state is totally flat, right, So that warm moist air
• 14:12
  Speaker 1: just rolls up into the center of the United States
• 14:15
  Speaker 1: and combines with Midwestern thunderstorms to give you tornadoes. And
• 14:19
  Speaker 1: the reason it doesn't extend like further west is we
• 14:21
  Speaker 1: have the Rocky Mountains like running through New Mexico and
• 14:24
  Speaker 1: Colorado and Wyoming and Idaho. The Rockies block a lot
• 14:29
  Speaker 1: of that warm moist air, and so you don't get
• 14:31
  Speaker 1: tornadoes in Utah, for example, as often as you do
• 14:35
  Speaker 1: in Missouri because they're blocked from the warm moist air
• 14:39
  Speaker 1: from the Gulf of Mexico.
• 14:40
  Speaker 2: Yes, California's got something going for it.
• 14:44
  Speaker 1: We got two lines that defense, the Rockies and then
• 14:46
  Speaker 1: the Sierras. So yeah, absolutely, I mean we got earthquakes
• 14:50
  Speaker 1: over here, but yeah, we don't have very often tornadoes.
• 14:53
  Speaker 2: And I just realized we are maybe taking a political
• 14:56
  Speaker 2: stance by calling it the Gulf of Mexico, and I
• 14:58
  Speaker 2: support it on.
• 15:01
  Speaker 1: We're taking a stance on facts.
• 15:02
  Speaker 2: Yeah, well I just looked up Google maps and it
• 15:05
  Speaker 2: says Gulf of America. Now what, Oh my gosh.
• 15:09
  Speaker 1: So the answer to Patrick's question is that we have
• 15:12
  Speaker 1: tornadoes on flat land because you need that warm moist
• 15:15
  Speaker 1: air and mountains blocket and so you need flat land
• 15:18
  Speaker 1: and you need like an open corridor to a warm
• 15:21
  Speaker 1: body of water that's going to provide that warm moist air.
• 15:25
  Speaker 1: So that's why we have Tornado Alley, and that's why
• 15:28
  Speaker 1: you have tornadoes in the city of Cincinnati in Kentucky.
• 15:31
  Speaker 2: And I hope this is but I hope this is
• 15:34
  Speaker 2: the last tornado that hits Cincinnati, Ohio or Cincinnati, Kentucky.
• 15:58
  Speaker 2: And we're back. We're transitioning from tornadoes to biology. Yay. Biology,
• 16:03
  Speaker 2: And I get to talk about parasites a little bit,
• 16:05
  Speaker 2: so that's exciting.
• 16:07
  Speaker 1: But we have a connection. Also, this is all about
• 16:09
  Speaker 1: flowing water, isn't it. Warmth and moist are going to
• 16:12
  Speaker 1: be relevant also for your question.
• 16:14
  Speaker 2: Yeah, you're right, But also there's some chemistry and I
• 16:17
  Speaker 2: feel like this was kind of a trick chemistry question.
• 16:19
  Speaker 2: But I'm going to forgive John because parasites were tied
• 16:22
  Speaker 2: in and so that's okay, all right, So.
• 16:25
  Speaker 1: Let's hear the question from John.
• 16:27
  Speaker 4: This is John from New Mexico. A topic for biology
• 16:30
  Speaker 4: and a smattering of physics is how do you make
• 16:33
  Speaker 4: water safe to drink without OD and on chlorine? You
• 16:36
  Speaker 4: could compare Los Angeles Rural Virginia background through methods and
• 16:41
  Speaker 4: A word of the day in water treatment I understand
• 16:43
  Speaker 4: is floculation, and I bet Kelly Kent state it fast
• 16:47
  Speaker 4: enough without making the shows rating in R instead of
• 16:51
  Speaker 4: a G.
• 16:51
  Speaker 2: All right, So I have practice saying floculation so that
• 16:55
  Speaker 2: this show can remain G instead of R or PG thirteen.
• 17:00
  Speaker 2: So when you're trying to clean water, you've got a
• 17:03
  Speaker 2: couple goals. So one, you want to remove debris like
• 17:07
  Speaker 2: sticks and rocks and rags and stuff like that because
• 17:10
  Speaker 2: you don't want to be drinking that. Of course, you
• 17:12
  Speaker 2: want to kill parasites, viruses and bacteria, and you want
• 17:16
  Speaker 2: to remove toxic stuff like pesticides.
• 17:19
  Speaker 1: So where is this water coming from. We're drawing it
• 17:21
  Speaker 1: from like random rivers, or we're recycling water that's been used,
• 17:26
  Speaker 1: or we're gathering rain water or what.
• 17:28
  Speaker 2: Yeah, so John wanted to know how you get water
• 17:31
  Speaker 2: for for example, a big city, a rural area and
• 17:35
  Speaker 2: if you're back country hiking and so, but I did
• 17:39
  Speaker 2: do a deep dive into how we treat our sewage.
• 17:41
  Speaker 2: So if Daniel wants to know about treating sewage, I'm
• 17:44
  Speaker 2: happy to tell you because I found that fascinating when
• 17:46
  Speaker 2: I got to that.
• 17:47
  Speaker 1: Well, I happen to know that Orange County leads the
• 17:49
  Speaker 1: world with their toilet to tap system.
• 17:52
  Speaker 2: Oh WHOA, that's excited.
• 17:55
  Speaker 1: Katrina is a big fan. She's always visiting the Orange
• 17:57
  Speaker 1: County sewage treatment plant to get samples.
• 18:00
  Speaker 2: Well that's because she wants the phages that are in there, right,
• 18:02
  Speaker 2: because yes, everyone should check out our episode with Katrina
• 18:06
  Speaker 2: on phage therapy. That was amazing. All right, well let's
• 18:09
  Speaker 2: start with Let's imagine that you are pulling water from
• 18:12
  Speaker 2: a lake or a river or something like that. Okay,
• 18:15
  Speaker 2: and so you've you've got this water. It might have dirt,
• 18:18
  Speaker 2: it might have sticks, it might have parasites, and so
• 18:21
  Speaker 2: the first thing you're gonna do is just like filter
• 18:23
  Speaker 2: out the big stuff. So if there's like a stick
• 18:25
  Speaker 2: in there, you just you get that stuff out. And
• 18:28
  Speaker 2: so now what you've got is water that has a
• 18:30
  Speaker 2: bunch of little tiny particles in there that you don't
• 18:33
  Speaker 2: really want in there anymore. And because they're so small,
• 18:37
  Speaker 2: they're going to take a really long time to settle out.
• 18:40
  Speaker 2: And so what you want to do is figure out
• 18:43
  Speaker 2: a way to get them to settle out faster. And
• 18:45
  Speaker 2: so the first step is called coagulation, because you're trying
• 18:48
  Speaker 2: to get all of these tiny particles to stick together
• 18:51
  Speaker 2: so they'll settle to the bottom. And so these tiny
• 18:54
  Speaker 2: little particles often have charges, and because they're charged, when
• 18:58
  Speaker 2: they get close to one another, they don't tend to
• 19:00
  Speaker 2: stick together because they might repel each other. And so
• 19:03
  Speaker 2: what they do, and this is where the chemistry comes in.
• 19:06
  Speaker 1: H and so I know, gosh, bracing myself.
• 19:08
  Speaker 2: Well, we're not going to get that detailed, so don't worry.
• 19:13
  Speaker 2: So anyway, so they tend to dump stuff in there,
• 19:15
  Speaker 2: like salts or kinds of aluminium or kinds of iron.
• 19:18
  Speaker 2: And essentially the goal is to binds to these charge
• 19:22
  Speaker 2: particles and make them neutral so that when these tiny
• 19:25
  Speaker 2: little particles bump into one another, they're more likely to
• 19:28
  Speaker 2: stick together and form bigger chunks.
• 19:31
  Speaker 1: I see all right, so neutralize their charges, let them
• 19:34
  Speaker 1: happily clump up together so they're easier to filter out.
• 19:37
  Speaker 2: Yes, exactly. Okay, so now you've got these clumps, but
• 19:41
  Speaker 2: you want to make those clumps even bigger actually, because
• 19:43
  Speaker 2: that would make it easier for them to fall down
• 19:45
  Speaker 2: to the bottom so that you can get them all
• 19:47
  Speaker 2: out of there. And so the next step is the
• 19:49
  Speaker 2: step that John mentioned, which is floculation. And essentially what.
• 19:54
  Speaker 1: You're doing is it sounds like a punishment.
• 19:56
  Speaker 2: It does flagellation or something like that, but but no
• 20:01
  Speaker 2: focus on flock. So flock is like a group of things.
• 20:04
  Speaker 2: And the goal here is that you are very gently
• 20:07
  Speaker 2: mixing the water so that the tiny clumps that you've
• 20:11
  Speaker 2: made start bumping into other clumps. And now they start
• 20:14
  Speaker 2: making much bigger clumps. You know. It's like a flock
• 20:17
  Speaker 2: of birds, you know, as they merge in the sky
• 20:19
  Speaker 2: together and all head to their migration site. But here
• 20:22
  Speaker 2: it's junk that you don't want to be drinking, and
• 20:24
  Speaker 2: so they bump into each other form big chunks, and
• 20:28
  Speaker 2: then you bring them to another area like another big pool.
• 20:32
  Speaker 2: And this is the sedimentation step. So you basically just
• 20:35
  Speaker 2: let the heavy stuff fall out by letting the water
• 20:37
  Speaker 2: sit for a while, and you draw the water off
• 20:40
  Speaker 2: the top.
• 20:40
  Speaker 1: And so we've added salts and aluminum and iron in
• 20:43
  Speaker 1: order to help the stuff clump together. And what is
• 20:46
  Speaker 1: the stuff that we're gathering up? What is the stuff
• 20:48
  Speaker 1: that's clumping? Where does it come from? Why is it
• 20:50
  Speaker 1: there anyway?
• 20:51
  Speaker 2: Well, I mean we're collecting from a natural system, and
• 20:53
  Speaker 2: so it could be little bits of poop or little
• 20:57
  Speaker 2: bits of sand, or you know, could it could be
• 20:59
  Speaker 2: just about anything. There's a lot of things in the river.
• 21:02
  Speaker 1: The technical term I think is dirt.
• 21:04
  Speaker 2: Does dirt also cover poop? And that's news to me.
• 21:08
  Speaker 1: I think a big fraction of dirt is poop, isn't it.
• 21:10
  Speaker 2: I don't know. Yeah, you should ask your what I.
• 21:12
  Speaker 1: Think I will, okay, and then we'll ask your husband
• 21:15
  Speaker 1: to write a poem about it.
• 21:16
  Speaker 2: Oh fantastic. Oh this is a family affair. I love
• 21:19
  Speaker 2: it all right. So you let the heavy stuff settle
• 21:22
  Speaker 2: to the bottom. You draw the water from the top
• 21:24
  Speaker 2: because all the heavy stuff is now down at the bottom,
• 21:27
  Speaker 2: and now you start running it through different kinds of filters.
• 21:29
  Speaker 2: So what you've done is you've removed like you know,
• 21:32
  Speaker 2: the poop, the dirt, whatever, the heavy stuff. But now
• 21:35
  Speaker 2: you want to make sure that there's no bacteria, parasites
• 21:38
  Speaker 2: or viruses in there anymore. These things are kind of tiny,
• 21:41
  Speaker 2: and so now you need to start passing the water
• 21:43
  Speaker 2: through different kinds of filters that are going to catch
• 21:46
  Speaker 2: these tiny things.
• 21:47
  Speaker 1: Wow. So even for those super tiny stuff, you're still
• 21:50
  Speaker 1: using physical filters like super tiny meshes to block like viruses.
• 21:54
  Speaker 1: That's insane.
• 21:55
  Speaker 2: Well, we're also going to get to a disinfection step
• 21:57
  Speaker 2: and so they get a little bit more serious eventually.
• 22:00
  Speaker 2: But here we're still trying to remove like the bigger stuff, like,
• 22:03
  Speaker 2: for example, parasites probably get stuck if you make it
• 22:06
  Speaker 2: go through like a big thing of sand, and the
• 22:09
  Speaker 2: water has to sort of like filter through the sand.
• 22:12
  Speaker 2: So you get some of that stuff out that way.
• 22:14
  Speaker 1: But it's basically still the pasta strainer strategy.
• 22:17
  Speaker 2: With a very very fine hole in the pasta strainer. Yeah.
• 22:21
  Speaker 2: So I mean think about like passing water over sand
• 22:24
  Speaker 2: or gravel and in some cases charcoal and charcoal is
• 22:28
  Speaker 2: using like Vanderwall's forces to capture stuff and then you
• 22:32
  Speaker 2: know it, whatever trickles out the bottom is probably pretty clean.
• 22:37
  Speaker 2: But viruses are really tiny, and so the viruses and
• 22:40
  Speaker 2: stuff probably got through there, and so the next step
• 22:43
  Speaker 2: is disinfection, where they usually add like chlorine, chlorine, chlorine dioxide,
• 22:49
  Speaker 2: chlorine stuff to try to kill whatever is left in
• 22:52
  Speaker 2: there that might be alive. They can also pass it
• 22:55
  Speaker 2: through like some UV light to try to like break
• 22:58
  Speaker 2: up the DNA in these organisms to kill them. But
• 23:01
  Speaker 2: most places, as far as I can tell, use some
• 23:03
  Speaker 2: version of like you know, bleach, some version of like chlorine.
• 23:08
  Speaker 2: And the other benefit of using chlorine is that it
• 23:11
  Speaker 2: continues to kill things as the water is passing through
• 23:14
  Speaker 2: your local like municipal pipes to get to your house well.
• 23:17
  Speaker 1: At the Orange County Water Treatment plant, they walk you
• 23:20
  Speaker 1: through the whole process and at the end they have
• 23:21
  Speaker 1: a tap and they like pour you a glass of water,
• 23:23
  Speaker 1: and they're like here you go, and you've seen it
• 23:25
  Speaker 1: come from like raw sewage, oh man, and it's crystal clear,
• 23:29
  Speaker 1: beautiful water and you and you drink it. Oh yeah.
• 23:33
  Speaker 1: A lot of our water comes from toilets, which is
• 23:35
  Speaker 1: actually the connection with our first question, because you know,
• 23:39
  Speaker 1: how does that water get to the seward treatment plant
• 23:41
  Speaker 1: will flush it down the toilet. We create a little
• 23:43
  Speaker 1: toilet tornado.
• 23:45
  Speaker 2: Okay, I didn't see where that was going until you
• 23:47
  Speaker 2: got there.
• 23:48
  Speaker 1: But it's a bit of a reach, ye, all right.
• 23:51
  Speaker 1: So does that mean that the water that's coming out
• 23:53
  Speaker 1: of our tap has chlorine and these chemicals in it
• 23:55
  Speaker 1: and also like destroyed carcasses of bacteria and by because
• 24:00
  Speaker 1: they can't actually remove it, right, it's still in there.
• 24:03
  Speaker 2: Yeah, that's right. And according to the Center for Disease
• 24:05
  Speaker 2: Control or the CDC, low levels of disinfectants like chlorine
• 24:10
  Speaker 2: in your water don't make people sick, but some people
• 24:12
  Speaker 2: are more sensitive to this kind of stuff than other people.
• 24:15
  Speaker 2: If you're worried, you should talk to your physician. But
• 24:18
  Speaker 2: we have been treating water like this for about one
• 24:20
  Speaker 2: hundred years and for most people it's not a problem.
• 24:24
  Speaker 1: And are these strategies different from what you might do
• 24:26
  Speaker 1: in a rural region or if you're like in the
• 24:29
  Speaker 1: back country.
• 24:30
  Speaker 2: Super different?
• 24:31
  Speaker 1: Really?
• 24:31
  Speaker 2: Yeah? So for example, I live in a very rural region.
• 24:35
  Speaker 2: I say that I live in Charlottesville, but I actually
• 24:37
  Speaker 2: live on a farm, you know, a bit away from Charlottesville,
• 24:40
  Speaker 2: and what we use is groundwater. So we talked about
• 24:44
  Speaker 2: how in a city you'd go through a bunch of
• 24:46
  Speaker 2: different kinds of filtration methods, but here the filtration method
• 24:50
  Speaker 2: that we use is nature. You know, rain water falls
• 24:54
  Speaker 2: on the ground and it has to trickle through loads
• 24:57
  Speaker 2: of dirt and sand and stuff, and a bunch of
• 24:59
  Speaker 2: the stuff that you don't want to be drinking sort
• 25:01
  Speaker 2: of gets stopped by the sand on the way down
• 25:04
  Speaker 2: to become part of the groundwater. So the groundwater is like,
• 25:07
  Speaker 2: you know, there's like a hard rock underneath groundwater accumulates
• 25:10
  Speaker 2: on top of it, and then you can dig a
• 25:12
  Speaker 2: well that goes into the area where water is stored
• 25:15
  Speaker 2: underground and you can pump that up into your house.
• 25:18
  Speaker 2: Does that make sense?
• 25:19
  Speaker 1: It's sort of amazing. I mean, you're talking about using
• 25:22
  Speaker 1: nature to filter out nature.
• 25:24
  Speaker 2: Yes, but it doesn't always work fantastically. So if you
• 25:28
  Speaker 2: live in a city, then your water has to pass
• 25:31
  Speaker 2: a bunch of tests before it gets to you, or
• 25:35
  Speaker 2: like the facility needs to regularly do monitoring to make
• 25:37
  Speaker 2: sure that like the levels that it has to hit
• 25:40
  Speaker 2: are being achieved, whereas me I have to collect water
• 25:44
  Speaker 2: samples every year and pay somebody to test our water
• 25:47
  Speaker 2: to make sure that, for example, our septic system isn't
• 25:50
  Speaker 2: leaking bacteria into the groundwater or you know, I live
• 25:54
  Speaker 2: around a lot of farms. If they were using a
• 25:56
  Speaker 2: bunch of pesticides, maybe some of them could seep down
• 25:58
  Speaker 2: into the groundwater and end up in our drinking water.
• 26:00
  Speaker 1: So your groundwater has no filters other than this natural system,
• 26:04
  Speaker 1: like you just pump it up and drink it.
• 26:06
  Speaker 2: Yeah, wow, yeah it does. It goes through like a
• 26:09
  Speaker 2: sedimentation step just to make sure that any dirt has
• 26:11
  Speaker 2: fallen out of it. But we don't do anything after that.
• 26:14
  Speaker 1: And when people visit your farm, you don't ask them
• 26:16
  Speaker 1: to like sign a waiver or anything. I mean, I've
• 26:18
  Speaker 1: drunk this water.
• 26:19
  Speaker 2: I was gonna say, I didn't ask you to sign
• 26:20
  Speaker 2: a Katrina.
• 26:22
  Speaker 1: I wish i'd heard this podcast episode before I visited.
• 26:25
  Speaker 2: But like I said, we get our water tested, and
• 26:28
  Speaker 2: our water always has pristine levels of everything. So country living.
• 26:33
  Speaker 1: It was delicious.
• 26:34
  Speaker 2: Yeah, thank you, country living at its best.
• 26:39
  Speaker 1: Wow. All right, button up your overalls and have a
• 26:43
  Speaker 1: glassy It always sounds good.
• 26:44
  Speaker 2: Well I don't know why I had to go to
• 26:45
  Speaker 2: the overalls, but anyway, all.
• 26:47
  Speaker 1: Right, country living, No, you don't wear overalls around the farm.
• 26:50
  Speaker 2: Not yet, not yet. I'll get there. I'll get there,
• 26:52
  Speaker 2: But so maybe next year when I start with my dairy.
• 26:54
  Speaker 1: Goats and don't misinterpret me. Overalls was a positive comment.
• 26:57
  Speaker 1: I'm not anti overalls.
• 26:58
  Speaker 2: No, they do look very comfy, all right.
• 27:02
  Speaker 1: So what about if you're hiking in the back country
• 27:04
  Speaker 1: and you don't have access to any of these things?
• 27:06
  Speaker 1: What do you do?
• 27:07
  Speaker 2: Okay, Well, first all, note that not everybody is as
• 27:09
  Speaker 2: lucky as I am. They don't always live in an
• 27:11
  Speaker 2: area where the groundwater is clean, and which case they
• 27:14
  Speaker 2: do have to use extra filters or disinfectants and stuff
• 27:17
  Speaker 2: like that. So we're lucky we don't have to add
• 27:19
  Speaker 2: extra steps, but depending on where you are, you might
• 27:21
  Speaker 2: have to. If you are in the back country, maybe
• 27:24
  Speaker 2: what you're doing is you pull up to a river
• 27:26
  Speaker 2: and you pull some water out, and that is the
• 27:28
  Speaker 2: only water you have to drink. So what are you
• 27:30
  Speaker 2: going to do? The first thing you're going to do
• 27:32
  Speaker 2: for all the methods we're going to talk about is
• 27:33
  Speaker 2: strain the big junk out of it. Yeah, take out
• 27:36
  Speaker 2: the rocks, take out the leaves, maybe pass it through
• 27:38
  Speaker 2: a handkerchief or something. And then I check the CDC
• 27:40
  Speaker 2: website and actually have pretty good, pretty detailed instructions for
• 27:44
  Speaker 2: what you're supposed to do, and the best thing to do,
• 27:47
  Speaker 2: if you're able, is to boil it. Boiling will kill
• 27:50
  Speaker 2: the bacteria, it'll kill the viruses, it'll kill the parasites.
• 27:53
  Speaker 2: And if you bring it up to boiling for just
• 27:55
  Speaker 2: one minute, that's usually all it takes. But if you're
• 27:58
  Speaker 2: at high elevation, like above sixty five hundred feet, you
• 28:02
  Speaker 2: need to boil it for three times as long. And
• 28:04
  Speaker 2: that is because of chemistry. So you can blame chemistry.
• 28:08
  Speaker 1: Because water boils at lower temperatures at high.
• 28:11
  Speaker 2: Yes, exactly, so you need to do it for longer.
• 28:13
  Speaker 1: And I love how thorough they are in their warnings.
• 28:15
  Speaker 1: They say, to avoid burns, allow the water to cool
• 28:18
  Speaker 1: before using it, don't drink boiling water people.
• 28:22
  Speaker 2: Yeah, that's right, that's right. Remember to breathe while you're
• 28:25
  Speaker 2: doing this process, and do.
• 28:27
  Speaker 1: Not take a shower in boiling water, thank you, CDC.
• 28:30
  Speaker 2: Right, don't stick knives in your eye. Yeah, but you
• 28:34
  Speaker 2: know they're covering their tails.
• 28:36
  Speaker 1: Anytime you read one of these, I imagine that there
• 28:38
  Speaker 1: was some instance where somebody needed that warning, you know,
• 28:41
  Speaker 1: and they're responding to them. They're like, all right, we
• 28:43
  Speaker 1: didn't think we had to say this, but apparently here.
• 28:45
  Speaker 2: We are exactly.
• 28:47
  Speaker 5: Yeah.
• 28:48
  Speaker 2: I do feel like anytime there's a tenus like that,
• 28:50
  Speaker 2: there's a story that you probably would want to hear.
• 28:52
  Speaker 2: But anyway, all right, so what if for whatever reason,
• 28:56
  Speaker 2: you can't boil you are hiking and it's raining and
• 28:59
  Speaker 2: you can't startifire or something. In that case, you can
• 29:03
  Speaker 2: hope that you thought ahead to bring a couple different
• 29:06
  Speaker 2: kinds of filters with you. And the problem with filters,
• 29:09
  Speaker 2: or the difficulty with filters, is something we talked about earlier,
• 29:12
  Speaker 2: which is that viruses are really really small, so getting
• 29:17
  Speaker 2: a filter that can filter out viruses is really difficult,
• 29:21
  Speaker 2: very teeny diny little holes that stuff needs to pass through.
• 29:25
  Speaker 2: You can use a reverse osmosis system, where essentially they're
• 29:29
  Speaker 2: like pushing water through a very very very very very
• 29:32
  Speaker 2: fine mesh and just about anything that isn't water doesn't
• 29:36
  Speaker 2: make it through to the other side, and so you
• 29:38
  Speaker 2: end up with like one side that has all the
• 29:39
  Speaker 2: gross stuff mixed with some water, and one side that
• 29:41
  Speaker 2: has clean water. I feel like I got mixed answers
• 29:44
  Speaker 2: on whether or not this will remove parasites. This might
• 29:47
  Speaker 2: work if you're like really in a pinch, but you know,
• 29:49
  Speaker 2: I think you pretty much always want to boil it
• 29:52
  Speaker 2: or maybe use one of these filters followed by a
• 29:54
  Speaker 2: disinfectant that's more likely to kill the viruses, and so
• 29:58
  Speaker 2: disinfectants is another option. This doesn't work as well against parasites.
• 30:02
  Speaker 2: Parasites are like bigger and a little bit harder to kill,
• 30:05
  Speaker 2: so like chlorine or iodine is maybe less likely to
• 30:08
  Speaker 2: kill them, although it might kill some of them. But
• 30:10
  Speaker 2: you can add chlorine or iodine, but if you're pregnant
• 30:14
  Speaker 2: or have some other issues with iodine, you might want
• 30:15
  Speaker 2: to skip iodine. Check the CDC website. But basically you
• 30:19
  Speaker 2: can add some chemicals to also kill parasites. Finally, if
• 30:23
  Speaker 2: you're really in a pinch and all you have is
• 30:25
  Speaker 2: a plastic bottle with no filters, no disinfectants, you can
• 30:30
  Speaker 2: still try to filter it to get the big stuff out,
• 30:33
  Speaker 2: and you want that water to be as clear as
• 30:35
  Speaker 2: possible because you're going to be trying to use the
• 30:37
  Speaker 2: sun's UV radiation to kill stuff that's in there.
• 30:40
  Speaker 1: Particle physics is our last line of defense.
• 30:42
  Speaker 2: Oh this counts as particle physics.
• 30:45
  Speaker 1: Mm hmm.
• 30:46
  Speaker 2: All right, I'll give it to you.
• 30:47
  Speaker 1: These are high energy photons exactly zapping those viruses.
• 30:51
  Speaker 2: I was wondering why you looked like you were getting
• 30:53
  Speaker 2: excited about something, and I realized, now you were getting
• 30:56
  Speaker 2: excited because we were about to get to particle physics.
• 30:59
  Speaker 2: But I'm learning to read you. I should have known
• 31:01
  Speaker 2: particle physics was coming.
• 31:04
  Speaker 1: That's how you know.
• 31:05
  Speaker 2: That's how you know, all right, So anything that makes
• 31:08
  Speaker 2: the water cloudy you want to get out because any
• 31:11
  Speaker 2: suspended particle in there is going to stop UV radiation
• 31:13
  Speaker 2: from hitting the bacteria and viruses that you're trying to kill.
• 31:16
  Speaker 2: If it's a super sunny day and your water super clear,
• 31:20
  Speaker 2: then you can leave a plastic bottle filled with water
• 31:22
  Speaker 2: under the sun for about six hours and that will
• 31:24
  Speaker 2: probably kill everything hopefully.
• 31:26
  Speaker 1: Amazing.
• 31:26
  Speaker 2: Yeah, amazing, totally. And if it's cloudy, you might want
• 31:29
  Speaker 2: to wait, like as much as two days. I think
• 31:31
  Speaker 2: I'd still feel better if I did some other additional
• 31:33
  Speaker 2: treatments to it.
• 31:34
  Speaker 1: What if you launched your water into space so it's
• 31:36
  Speaker 1: exposed to radiation in space? Would that make it safer?
• 31:42
  Speaker 1: How did you not prepare for that question? You're an
• 31:44
  Speaker 1: expert on space.
• 31:45
  Speaker 2: So what I'm wondering is so okay. So we talked
• 31:48
  Speaker 2: about how space can even kill tartar grades, which are,
• 31:52
  Speaker 2: like I supposably indestructible. But what I'm wondering is if
• 31:55
  Speaker 2: you launched it to space, would that, like if there
• 31:57
  Speaker 2: were pesticides in the water, would solve the problem of
• 32:01
  Speaker 2: the chemicals? And so I do think that would kill
• 32:04
  Speaker 2: bacteria and viruses and parasites, But I don't know if
• 32:08
  Speaker 2: it would remove pesticides the same way as like a
• 32:11
  Speaker 2: charcoal filter would. And so I think for any of
• 32:13
  Speaker 2: these things, it's important to keep in mind, like what
• 32:15
  Speaker 2: are my goals? You know, if you're drinking from a
• 32:18
  Speaker 2: waterway and there's a bunch of farms upriver, you might
• 32:21
  Speaker 2: want to worry about pesticides, and maybe you want something
• 32:23
  Speaker 2: like a charcoal filter. But if you're just worried about
• 32:26
  Speaker 2: you don't want to get giardia beaver fever, then maybe
• 32:30
  Speaker 2: disinfecting is the way to go beaver fever.
• 32:32
  Speaker 1: I've never heard of that.
• 32:34
  Speaker 2: Oh no. I think Giardia became famous when some people
• 32:38
  Speaker 2: were camping downstream of a beaver dam and the beavers
• 32:42
  Speaker 2: gave them giardia, which gives them massive diarrhea and had
• 32:46
  Speaker 2: a friend who got giardia once. She called it muddy
• 32:48
  Speaker 2: butthole disease.
• 32:50
  Speaker 1: But the good news is, if you're an astronaut and
• 32:52
  Speaker 1: you're in space, your water is probably not going to
• 32:55
  Speaker 1: give you beaver disease.
• 32:57
  Speaker 2: That's probably true, but you are probably drinking yesterday's coffee.
• 33:01
  Speaker 2: You're drinking recycled urine and sweats.
• 33:04
  Speaker 1: All right, well, let's hear if we have muddied the
• 33:06
  Speaker 1: waters or clarified everything. For John, Oh, that.
• 33:09
  Speaker 2: Was bravo, Daniel, bravo.
• 33:11
  Speaker 4: Thank you Kelly for the insightful answer. You floculated all
• 33:15
  Speaker 4: the little bits and pieces into really understandable podcast. Thank
• 33:20
  Speaker 4: you again.
• 33:41
  Speaker 2: So we've established that you can probably get clean water
• 33:44
  Speaker 2: in space by just exposing it to how horrible space is.
• 33:48
  Speaker 2: Another horrible thing that could happen in space would be
• 33:50
  Speaker 2: if your moon broke into many pieces.
• 33:53
  Speaker 1: But one of the amazing things about space is that
• 33:56
  Speaker 1: it exposes us to other kinds of environment and other
• 34:00
  Speaker 1: kinds of vistas. And we've all seen movies where you
• 34:03
  Speaker 1: have like two stars in the sky or huge moons.
• 34:06
  Speaker 1: And one of our favorite listeners, Joe, has a question
• 34:10
  Speaker 1: about what extremes are possible.
• 34:12
  Speaker 5: Hi, Daniel and Kelly, this is Joe from Florida. Loving
• 34:16
  Speaker 5: the show, but even more really appreciate your willingness to
• 34:19
  Speaker 5: answer random questions from any one of us. To that point,
• 34:24
  Speaker 5: I'm playing games and other imagery of sci fi planets
• 34:28
  Speaker 5: and worlds. It's really common to see a massive planetary
• 34:32
  Speaker 5: body taking much of the sky, kind of like a
• 34:34
  Speaker 5: moon of a gas giant, where it's just the whole
• 34:37
  Speaker 5: thing creates a very alien appearance. So I got to
• 34:41
  Speaker 5: thinking after the Parker solar probe quote touched the Sun,
• 34:44
  Speaker 5: I ran those numbers, and even at closest approach, I
• 34:47
  Speaker 5: think it was only about a twelve degree of the
• 34:50
  Speaker 5: sky field of view, so it'd be big, but not
• 34:54
  Speaker 5: completely taking up your vision big. So my question is,
• 34:57
  Speaker 5: is based on Roch limits and assumptions of standard planetary compositions,
• 35:02
  Speaker 5: what's the largest a body can appear in the sky. Well,
• 35:05
  Speaker 5: your own world is still kind of in a stable
• 35:07
  Speaker 5: orbit and you're not being torn apart or coming into
• 35:11
  Speaker 5: any of those majora's mass kind of situations. Thanks a lot,
• 35:14
  Speaker 5: guys love the show.
• 35:16
  Speaker 1: All right, So this is a super fun hypothetical question.
• 35:19
  Speaker 1: He's essentially asking how close can we get to science fiction?
• 35:23
  Speaker 1: How big in the sky can something appear and still
• 35:27
  Speaker 1: obey the laws of physics?
• 35:29
  Speaker 2: Love it? And so did this require you to do
• 35:31
  Speaker 2: some actual math or was this answer available somewhere.
• 35:34
  Speaker 1: No, I had to do a little bit of calculations here.
• 35:36
  Speaker 1: This is very cool. I liked thinking about this because
• 35:40
  Speaker 1: it's super awesome to have big features in the sky.
• 35:42
  Speaker 1: There's something really powerful about that because you're connected to them.
• 35:46
  Speaker 1: You're like seeing the scale of the Solar System and
• 35:50
  Speaker 1: the universe in the sky. And you know, we're lucky
• 35:52
  Speaker 1: that our moon is so big and so close, and
• 35:55
  Speaker 1: a lot of people aren't aware, but there are bigger
• 35:57
  Speaker 1: things in the sky than the moon. For example, Androma
• 36:01
  Speaker 1: the galaxy is bigger in the night sky than the moon.
• 36:05
  Speaker 1: We think of it as super distant, and it is,
• 36:07
  Speaker 1: but it's also incredibly big. The reason that's a surprise
• 36:11
  Speaker 1: is that most of the time you can't see it
• 36:13
  Speaker 1: because it's dim. But if you train a camera on
• 36:16
  Speaker 1: it and follow it and accumulate light, you can see
• 36:18
  Speaker 1: Andromeda in the sky. So not with your eyes, unfortunately,
• 36:22
  Speaker 1: but it's there, dominating the night sky.
• 36:24
  Speaker 2: Still kind of feels like cheating to compare an entire
• 36:27
  Speaker 2: galaxy to a moon.
• 36:29
  Speaker 1: Well, I mean, we're just talking about angular sizes, right,
• 36:32
  Speaker 1: It's just for a reference. Obviously, the Moon is much
• 36:34
  Speaker 1: smaller than Andromeda, but so much closer, and that's really
• 36:38
  Speaker 1: the trade off here. What we're talking about is the
• 36:41
  Speaker 1: size in the sky, which is what we call angular distance.
• 36:45
  Speaker 1: And the way you calculate this is there's a formula,
• 36:48
  Speaker 1: but essentially it depends on the radius of the object
• 36:51
  Speaker 1: and on the distance from the object. So the bigger
• 36:53
  Speaker 1: the object, the bigger it is in the night sky.
• 36:55
  Speaker 1: The further away it is, the smaller it is in
• 36:57
  Speaker 1: the night sky. So to be big in the night sky,
• 37:00
  Speaker 1: you can be pretty small but very very close, or
• 37:02
  Speaker 1: you can be far away but absolutely enormous. And so
• 37:06
  Speaker 1: that's how you calculate it.
• 37:07
  Speaker 2: Okay, So I haven't stared at the Sun for very
• 37:09
  Speaker 2: long because I've been told not to. Yes, but if
• 37:12
  Speaker 2: I were to stare at the Sun, would the Sun
• 37:14
  Speaker 2: in the moon? Would they be about the same size?
• 37:16
  Speaker 2: How different in size would they be if I stared?
• 37:19
  Speaker 1: Well we know this because we have eclipses. Right, the
• 37:22
  Speaker 1: Moon is almost exactly the same size as the Sun
• 37:25
  Speaker 1: in the sky. They're both about half a degree, which
• 37:28
  Speaker 1: is the unit we use, and that's just an incredible coincidence.
• 37:32
  Speaker 1: Often in science, when we see coincidences, we're like, hmm,
• 37:34
  Speaker 1: what does that mean? Is that a clue? Why is that?
• 37:38
  Speaker 1: But sometimes they're just coincidences, like there's no reason that
• 37:41
  Speaker 1: the Moon and the Sun have to take up almost
• 37:43
  Speaker 1: exactly the same amount of sky. But it does lead
• 37:46
  Speaker 1: to very spectacular eclipses. So we're very grateful for this coincidence.
• 37:51
  Speaker 2: Maybe the aliens knew we would really enjoy eclipses, so they,
• 37:55
  Speaker 2: you know, they work some stuff out for us.
• 37:56
  Speaker 1: Yeah, that or the programmers of the simulation. Oh, I
• 37:59
  Speaker 1: don't know, but it works out.
• 38:00
  Speaker 2: Pretty well, all right, thanks whoever.
• 38:02
  Speaker 1: So, the biggest easily visible thing in our night sky
• 38:04
  Speaker 1: are the Sun and the moon about half a degree,
• 38:07
  Speaker 1: and Joe's wondering about how big things can get. And
• 38:10
  Speaker 1: the physics we have to understand here are the physics
• 38:12
  Speaker 1: of tidal forces. That is, the Earth pulls on the
• 38:16
  Speaker 1: Moon with its gravity, and we tend to think about
• 38:19
  Speaker 1: the Earth as a point and the Moon is a
• 38:21
  Speaker 1: point and forces between those two points, but they're not
• 38:23
  Speaker 1: really points. The Moon has a side that's closer and
• 38:26
  Speaker 1: a side that's further away. It has an extent to it,
• 38:29
  Speaker 1: and the side of the Moon that's closer feels the
• 38:31
  Speaker 1: Earth's gravity more powerfully than the side of the Moon
• 38:33
  Speaker 1: that's further away, because gravity depends on distance, and so
• 38:37
  Speaker 1: because there's a difference in those forces, effectively, it's like
• 38:41
  Speaker 1: the Earth is trying to pull the Moon apart. It
• 38:43
  Speaker 1: is and actually squeezes the Moon and makes it a
• 38:45
  Speaker 1: little bit like a football.
• 38:46
  Speaker 2: And this reminds me of the book Seven Eves.
• 38:50
  Speaker 1: Yes exactly, Neil Stevenson's really fun novel about what would
• 38:52
  Speaker 1: happen if the Moon was destroyed. And in that novel,
• 38:56
  Speaker 1: it's not really much of a spoiler to say it's
• 38:58
  Speaker 1: destroyed by some like alien impactor, But in reality, the
• 39:02
  Speaker 1: Moon would be destroyed if it got too close to
• 39:04
  Speaker 1: the Earth, because the closer you get to the Earth,
• 39:06
  Speaker 1: the greater the difference between the forces on your edges,
• 39:09
  Speaker 1: and so effectively, the greater the force trying to pull
• 39:12
  Speaker 1: you apart, and eventually you approach what we call the
• 39:14
  Speaker 1: Roche limit, which is the closest you can get without
• 39:18
  Speaker 1: being pulled into little bits, and essentially form a ring,
• 39:21
  Speaker 1: and for two objects of equal density of a planet
• 39:24
  Speaker 1: and a moon, that radius is about two and a
• 39:26
  Speaker 1: half times the radius of the planet, which is actually
• 39:30
  Speaker 1: quite close. That would be like eighteen thousand kilometers from
• 39:33
  Speaker 1: the center of our planet, but the moon currently is
• 39:37
  Speaker 1: like three hundred and eighty thousand kilometers away, So the
• 39:40
  Speaker 1: Moon could get a lot closer and be a lot
• 39:43
  Speaker 1: bigger in our sky without being torn into rings.
• 39:46
  Speaker 2: I am feeling like I'll sleep better tonight knowing that
• 39:49
  Speaker 2: it's not close to the roach limit.
• 39:51
  Speaker 1: That's good, not at all. And so if you somehow
• 39:54
  Speaker 1: engineered the moon, you put a rocket on it, and
• 39:56
  Speaker 1: you brought it in closer to the Earth and all
• 39:59
  Speaker 1: the way to the roach limit, it would be about
• 40:01
  Speaker 1: twenty times bigger in the sky than it is currently. Wow, right,
• 40:05
  Speaker 1: about ten angular degrees, about the size of one or
• 40:09
  Speaker 1: two outstretched hands. It would be pretty big. It would
• 40:11
  Speaker 1: be awesome.
• 40:12
  Speaker 2: Would that really mess up astronomy because it would be
• 40:14
  Speaker 2: all right, so Daniel and I both have our hands
• 40:16
  Speaker 2: out stretched right now and we're looking at that. Yeah,
• 40:18
  Speaker 2: So how bad would that be for astronomy?
• 40:20
  Speaker 1: That would be pretty bad because it would make moonlit
• 40:23
  Speaker 1: nights much brighter, right, you'd have much more powerful moonshadows.
• 40:28
  Speaker 1: And already moonlit nights are bad for astronomy because that's
• 40:31
  Speaker 1: light pollution. Right, It's like having a big light in
• 40:34
  Speaker 1: the sky. It's like a second sun. You are reflecting
• 40:36
  Speaker 1: the sun, a mini version of it. So this would
• 40:38
  Speaker 1: be twenty times as powerful, So it would be bad
• 40:41
  Speaker 1: for astronomy.
• 40:42
  Speaker 2: I thought you were going to say moonlit nights are
• 40:43
  Speaker 2: bad for astronomers because they're not very romantic or something
• 40:46
  Speaker 2: like that, because the rest of us love moonlit nights.
• 40:51
  Speaker 1: Well, a moonlit night is romantic because the light is dim, right,
• 40:53
  Speaker 1: It's like why you turn down the lights to make
• 40:55
  Speaker 1: them romantic. And so at some point cranking that thing
• 40:58
  Speaker 1: up by factor twenty no longer as romantic.
• 41:01
  Speaker 2: Okay, yeah, I could see that. You're gonna need much
• 41:03
  Speaker 2: better curtains.
• 41:05
  Speaker 1: Yeah, but let's do a little bit more engineering to
• 41:07
  Speaker 1: try to make this bigger. What if we didn't just
• 41:10
  Speaker 1: use our moon. What if we took a bigger object,
• 41:12
  Speaker 1: Like what if we somehow pulled Mars into our orbit,
• 41:16
  Speaker 1: then we used it as a second moon, and we
• 41:18
  Speaker 1: brought it in just outside Mars's roach limit. Well, that
• 41:22
  Speaker 1: would be about twice as big in the sky as
• 41:24
  Speaker 1: the Moon at the roach limit, because Mars is bigger
• 41:27
  Speaker 1: than the moon, so it'd be about forty times the
• 41:29
  Speaker 1: size our moon currently is in the sky, an angular
• 41:32
  Speaker 1: distance of about twenty degrees.
• 41:34
  Speaker 2: Maybe it's just that I grew up with the Moon
• 41:36
  Speaker 2: being so far away, but I'd feel like a little crowded,
• 41:39
  Speaker 2: you know, like you need to give me some space. Mars.
• 41:41
  Speaker 2: You're getting too close. You're kind of freaking me out.
• 41:44
  Speaker 1: All right, Well, then you're not gonna like the next scenario.
• 41:47
  Speaker 1: I did a calculation to try to think about how
• 41:49
  Speaker 1: close you could bring any object, forget the Moon, forget Mars.
• 41:53
  Speaker 1: What if we're engineering something that we want to fill
• 41:55
  Speaker 1: our sky and you could make it out of some
• 41:58
  Speaker 1: natural material. Roach limit depends on density, because something that's
• 42:03
  Speaker 1: denser holds itself together better. So if you make it,
• 42:05
  Speaker 1: for example, out of iron, you can get it closer.
• 42:08
  Speaker 1: But then iron is also denser, and so the object
• 42:10
  Speaker 1: becomes smaller, so it doesn't take up as much in
• 42:13
  Speaker 1: the sky. So I imagined, what if we had a
• 42:16
  Speaker 1: object the mass of the Earth, And my calculation suggests
• 42:20
  Speaker 1: that if you make it about three times as dense
• 42:22
  Speaker 1: as the Earth, so use like pure iron. Then its
• 42:26
  Speaker 1: roch limit would be about one and a half times
• 42:28
  Speaker 1: the Earth's radius. And this new moon we build because
• 42:32
  Speaker 1: it's denser than the Earth but it still has the
• 42:34
  Speaker 1: same mass, would have a radius of about one half
• 42:37
  Speaker 1: of the Earth's radius. So this thing would be orbiting
• 42:41
  Speaker 1: just above the ground.
• 42:42
  Speaker 2: What just above the Earth?
• 42:45
  Speaker 1: Just above the ground on Earth, you'd have to like
• 42:48
  Speaker 1: duck as this thing goes by.
• 42:49
  Speaker 2: Oh yeah, that's no way to live.
• 42:53
  Speaker 1: But you know, and these are simplified calculations that we're
• 42:56
  Speaker 1: really pushing to the extreme. We're assuming that the Roch
• 42:59
  Speaker 1: limit formula applies here, and I'm not sure it really does.
• 43:04
  Speaker 1: And of course, you know you've got any mountains, those
• 43:06
  Speaker 1: are gonna get rubbed right off. But about your answer. Sure,
• 43:11
  Speaker 1: So if you're out there and you have an earth
• 43:13
  Speaker 1: mass worth of iron, and you're thinking about building this
• 43:17
  Speaker 1: moon and having an orbit just above the surface, you
• 43:19
  Speaker 1: should know that I only give you my ninety five
• 43:22
  Speaker 1: percent guarantee, which is my highest guarantee, by the way,
• 43:25
  Speaker 1: But if you did this, it would fill half the sky.
• 43:28
  Speaker 2: Please don't listen to Daniel. Everyone look at he would
• 43:32
  Speaker 2: sell us all out to the aliens if it would
• 43:34
  Speaker 2: explain gravity, like, absolutely, we can't depend on Daniel for
• 43:38
  Speaker 2: our safety, everyone.
• 43:40
  Speaker 1: Ninety five percent, you can't. Now you can also imagine
• 43:44
  Speaker 1: the opposite scenario. What if you're on the Moon, right,
• 43:47
  Speaker 1: and you're not on the planet. So in our Solar system,
• 43:50
  Speaker 1: if you were to land on Io and look up
• 43:52
  Speaker 1: at Jupiter in the sky, it already fills twenty angular degrees, right,
• 43:57
  Speaker 1: that's the size we're talking about of having like Mars
• 44:00
  Speaker 1: in our sky. So that's already the case. Jupiter is
• 44:03
  Speaker 1: huge in the sky above Io, and in comparison, like
• 44:06
  Speaker 1: if you're on Titus, Saturn is only like five and
• 44:09
  Speaker 1: a half degrees, which is still big, right, a lot
• 44:11
  Speaker 1: bigger than the Moon is in our sky, but not
• 44:14
  Speaker 1: as dramatic. But I calculated what would happen if you
• 44:16
  Speaker 1: brought Io close to its roch limit with Jupiter, and
• 44:20
  Speaker 1: then it would be like sixty degrees in the sky,
• 44:23
  Speaker 1: So that would be like, wow, what of you a Jupiter? Right?
• 44:26
  Speaker 1: And then if you made Io out of like something
• 44:29
  Speaker 1: incredibly tough like diamond, it could get much closer without
• 44:33
  Speaker 1: being torn apart. So the roach limit depends on what
• 44:36
  Speaker 1: the object is made out of. And then you could
• 44:38
  Speaker 1: get Jupiter to be ninety five degrees across in the
• 44:41
  Speaker 1: sky before it's going to tear apart your diamond.
• 44:44
  Speaker 2: Moon hotly cow. I mean, you'd be dead long before that,
• 44:47
  Speaker 2: but wow.
• 44:50
  Speaker 1: What a way to go, right way to go. You'd
• 44:53
  Speaker 1: be sitting on your diamond Moon, sipping super clean water
• 44:57
  Speaker 1: from your waste water treatment facility, watching torn play out
• 45:00
  Speaker 1: on the surface of Jupiter.
• 45:02
  Speaker 2: You know what that sounds. If you've got to go,
• 45:05
  Speaker 2: that's high up there on my list of ways to go.
• 45:08
  Speaker 1: And this episode will have prepared you to understand the
• 45:10
  Speaker 1: science of each of those elements.
• 45:12
  Speaker 2: That's right, You're welcome.
• 45:13
  Speaker 1: All right, Well, let's hear if Joe is satisfied with
• 45:16
  Speaker 1: our answer to his science fiction inspired question.
• 45:19
  Speaker 5: Thank you so much Daniel and Kelly for that answer.
• 45:21
  Speaker 5: It will please you and other listeners to know that
• 45:24
  Speaker 5: I do not have an Earth's massive iron ready to
• 45:27
  Speaker 5: put in dangerously close orbit. While giant objects in the
• 45:30
  Speaker 5: sky may look pretty epic, sounds like for all our
• 45:32
  Speaker 5: survival better, they remain comfortably distant. I guess the first
• 45:36
  Speaker 5: human on Aisle will have quite the view. But for
• 45:39
  Speaker 5: those of us remaining earthbound. I'm so eager for that
• 45:41
  Speaker 5: binary sunset portrait, so alien engineers, when you have a moment,
• 45:46
  Speaker 5: that'd be great. Thank you again and keep looking up.
• 45:56
  Speaker 2: All right. Well, thank you everyone who submitted questions. If
• 45:59
  Speaker 2: you'd like to ask ask us a question, you can
• 46:01
  Speaker 2: write us at questions at Daniel and Kelly dot org,
• 46:04
  Speaker 2: or you can join us on our discord channel. You
• 46:06
  Speaker 2: can find an invitation to our discord channel at danielant
• 46:10
  Speaker 2: Kelly dot org, or you could send us a message
• 46:13
  Speaker 2: to our social media pages. Although answers there are slightly
• 46:16
  Speaker 2: less reliable, so I suggest email or discord.
• 46:19
  Speaker 1: We really do reply to every email. People continue to
• 46:22
  Speaker 1: be shocked when we actually replied. We will write back
• 46:25
  Speaker 1: to you with an answer to your question. Try it.
• 46:28
  Speaker 2: Yep. We love hearing from y'all.
• 46:29
  Speaker 1: Thanks everyone, have a great day and stay curious.