January 1, 2026 • 46 mins
Daniel and Kelly answer questions about tornadoes, water purification, and massive moons in the sky.
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Speaker 1 (00:07):
Tornadoes always touched down on the plains. Is that because
hills block all the rains?
Speaker 2 (00:13):
When we treat water, we rotate, filtrate, and aerrate. Tell
me more, but be careful how you pronounce floculate?
Speaker 1 (00:22):
How large can a moon appear in our sky without
being shredded by gravity's tides?
Speaker 2 (00:28):
Whatever questions keep you up at night, Daniel and Kelly's
answers will make it right.
Speaker 1 (00:32):
Welcome to Daniel and Kelly's Extraordinary Universe.
Speaker 2 (00:49):
Hello. I'm Kelly Windersmith. I study parasites and space, and
I am afraid of tornadoes.
Speaker 1 (00:56):
Hi. I'm Daniel. I'm a particle physicist, and I'm afraid
of Zach's comments on our poetic introductions.
Speaker 2 (01:02):
Oh? Are we going to let the listeners know that
Zach skips the introductions for the listener question episodes because
he is actually really good at poetry and finds our
poetry sort of nauseating.
Speaker 1 (01:14):
It's not what we're famous for. Let's just put it
that way.
Speaker 2 (01:17):
We're having fun.
Speaker 1 (01:18):
But let me put it this way. At least your
spouse listens to our podcast.
Speaker 2 (01:22):
Oh, Katrina dozen Oh no, Oh, I'm mortified. Oh do
we really want to keep having her on our show.
The answer is yes, we absolutely do.
Speaker 1 (01:33):
This is my secret plan to pull her in to
hook her on the podcast.
Speaker 2 (01:36):
Oh fantastic, this is we're talking about tornadoes today. Let's
share our scariest tornado story. Do you have any tornado stories?
Speaker 1 (01:46):
Ooh, I do have a tornado story, though I wasn't
very scared. I was in my dorm room at Rice
in Houston and studying really hard for a test, and
I heard a bunch of shouting in the hallways and
I ignored it because I was busy. And then later
I just got there was a tornado that went right
through Houston and within about a mile of the campus.
And I didn't know anything about it. Yeah, and that's
(02:08):
not very typical for tornadoes to pass through cities, so
it was something of an event. How about you, what's
the closest you've been to a tornado?
Speaker 2 (02:15):
So Zach and I moved to Tuscaloosa, Alabama, right after
like the big tornado that like knocked out a bunch
of the city, and we were in a hotel before
we got our keys to our place, and there was
a tornado warning in the area, and I was like,
oh my gosh, another tornado is going to take out
half the city. And Zach was not worried at all,
and I was panicking. And Zach's like, all right, well,
(02:37):
you're obviously not going to sleep, so well you're panicking.
I'm going to take a shower. And I was looking
up what do you do if there's a tornado and
you're supposed to like get in a tub. Oh, And
so Zach finishes the shower, he comes out, and I'm
panicking and I was like, I think we should get
in the tub. And Zach is like almost asleep already.
And I go into the tub and like the tub
is filled with water, like something can happen with the drain,
(02:57):
and I was like, now we're gonna drown. And I
was more worried about, like Zach hampering our ability to
survive the tornado. And anyway, we were totally fine, and
I am kind of nuts.
Speaker 1 (03:08):
Is the point sounds like a swirling panic attack?
Speaker 2 (03:14):
I'm known for those.
Speaker 1 (03:15):
Actually yeah, yeah, well today you don't have to panic
because you are not going to experience a tornado. Instead,
you're going to experience an explanation of how tornadoes work
and where they form. Because we are answering questions from
listeners like you. People just like you who listen to
the podcast and want to know how things work out
there in the universe. They can't find answers online. They
(03:36):
ask JATGBT. They're not satisfied, so they write it to us,
and we are very happy to provide some answers.
Speaker 2 (03:42):
Daniel, how can you know for sure they're not going
to be experiencing a tornado. They could be listening to
this at any time. There could be a tornado when
they're listening.
Speaker 1 (03:50):
No, this is a tornado free podcast. I'm providing my guarantee.
Speaker 2 (03:53):
I think you are violating the rules of physics, and
I I'm going to write the physicist board and they're
gonna going to lose your job. Man.
Speaker 1 (04:01):
I'm going to hedge because everything is statistical in particle physics.
So I'm gonna give you my ninety five percent guarantee,
and that's my highest guarantee.
Speaker 2 (04:08):
All right, Well, that that's a pretty high guarantee. It
sounds to me like you just pulled that number out
of us swirling thin.
Speaker 1 (04:14):
Air all of statistics sounds like that, But really there's
a lot of rigorous calculations behind it. Trust me. All right, Well,
let's move on to more solid ground and answer some
questions from listeners. Here's a question from Patrick about tornadoes.
Speaker 3 (04:29):
Hi, Daniel, and Kelly. We had some tornadoes touched down
outside of Cincinnati recently, and I've noticed tornadoes seem to
hit the flatter, more open areas outside the city more
often than the city itself. I was thinking about why
this might be and wondering if I'm on the right track. So,
the weather system builds up enough power to form a
(04:49):
tornado over the unobstructed flat land, but in hilly areas
and populated areas, the power is attenuated by the hills
and buildings or alter the tornado's oscillation is damped by
the obstacles. So thanks for taking my question and let
me know if I'm on the right track.
Speaker 2 (05:09):
Whoa tornado's in Cincinnati. I grew up in Ohio, and
I don't feel like tornado should be allowed in Ohio.
I'm sorry you had to go through that. Patrick.
Speaker 1 (05:18):
Well, Cincinnati's like kinda on the border, isn't it's like
partly in Ohio, partly in Kentucky.
Speaker 2 (05:23):
Right, No, it's in Ohio.
Speaker 1 (05:25):
Isn't it a river that runs through it.
Speaker 2 (05:28):
Oh, maybe maybe I'm wrong. It might be a little
bit in Kentucky.
Speaker 1 (05:34):
What I think technically, you're right because the part of
the city that's north of the Ohio River is Cincinnati,
but there's definitely lots of city on the other side,
whether or not you officially call it Cincinnati.
Speaker 2 (05:48):
Daniel, I am gonna have to actually, I'm given this
point to you. I'm sorry I did not carefully study
Ohio geography because I was trying real hard to get
out of there.
Speaker 1 (05:58):
Sorry, Ohio, let me tell you about your home stance.
Speaker 2 (06:06):
All right, Kelly's betten oh for one? So far?
Speaker 1 (06:08):
All right?
Speaker 2 (06:09):
What is the tornado? Daniel? What am I so afraid of?
Speaker 1 (06:14):
So we've all seen tornadoes in movies, et cetera. They're
essentially rotating columns of air in contact with the cloud
and the ground. So you see this tube and it's
like twisting and flailing around, and they can be very
very powerful. The winds can be like up to four
hundred and eighty kilometers per hour, super incredible.
Speaker 2 (06:33):
What is that in freedom units?
Speaker 1 (06:38):
Fast? It's fast units? Okay, it's destructive. Yeah. And they
can be quite narrow or they can be really wide,
like big monster tornadoes up to three kilometers wide, and
for it to be class as a tornado has to
come from the cloud and make contact with the ground,
and that's where the destruction happens. These powerful winds, the
(06:58):
funnel touching the ground, and that funnel travels across the
ground and tear stuff up, and it can go for
like up to one hundred kilometers, tearing a path of
destruction across Kansas or Ohio or wherever Alabama.
Speaker 2 (07:11):
Man, do tornadoes always go from the clouds to the ground.
They never go from the ground to the clouds, that's
right there.
Speaker 1 (07:18):
Always start in the cloud and then descend to the ground.
There are other similar patterns like dust devils you might
have seen, which looks similar to tornadoes, but aren't officially tornadoes.
Those just are whirling patterns of wind on the ground
that touch only the ground and there's no cloud above them,
so they're not officially tornadoes. And if it's over water,
they can be called a water spout. So there's a
few variants of them.
Speaker 2 (07:38):
Okay, And are those things ever as damaging as tornadoes
or they're like tornadoes baby sisters and baby brothers.
Speaker 1 (07:46):
Well, they can be as powerful because the storms can
be powerful, but unless you're living on the water, and
they're not damaging houses, right, So the most damaging ones
are the ones that touch the ground, because that's where
the houses are.
Speaker 2 (07:56):
Got it, okay? All right? And where so we've noted
that they do sort of tend to be like aggregated
in certain geographic regions. Why is that.
Speaker 1 (08:06):
This is something that really America is best at. American
exceptionalism has data to back it up. In the case
of tornadoes, most of the tornadoes in the world are
in the United States. We have like eight hundred per year,
and most of them are in a slice of the
US in central and southeast corners of the country, which
we affectionately call tornado Alley. So there's like four times
(08:30):
as many tornadoes in the US as there are in
all of Europe. You have a few in like South Africa,
some in Europe, Australia, Eastern India, but primarily it's a
thing the US is best at.
Speaker 2 (08:41):
The wind really likes us, all right, So why are
we cursed with these tornadoes?
Speaker 1 (08:46):
Yes, So to understand why tornadoes happen here and less
often elsewhere, you have to understand how they form and
This is not something where the science is totally settled.
People are still working on this. It's a great example
of complex city. You're studying a system which has lots
of components which interact very strongly. Pulling a simple story
out of that is not always possible, but people are
(09:08):
working on it. We think that the ingredients are number one,
a huge thunderstorm, but not just like a normal thunderstorm,
one with like really powerful strong winds, hailstones, et cetera.
And in particular a thunderstorm called a super cell, which
is a set of tower and clouds up to fifteen
kilometers tall, so like a really massive cloud. So that's
(09:30):
ingredient number one. It's like a really powerful thunderstorm, a
very tall one. And then below that you need warm,
moist air on the ground, and we'll talk about how
these come together into a tornado in a minute. And
the third ingredient is sheer. You need strong changes in
the wind speed as you go up or down in altitude,
and so these things how they come together and make
(09:51):
a tornado. Again, it's not fully understood. There's a bunch
of different theories out there. One is that it starts
in the storm. You have these pockets of rotation in
the storm and then they somehow intensify and touch the ground.
And one way this might happen is that the warm
moist air on the ground is rising up and there's
already like pockets of rotation in the storm, and the
(10:14):
rising air connects with those and creates like a horizontal
rotation or as you have this rising pattern, sort of
like in a hurricane, you have like rising air in
the center, which then moves out to the edges, so
you get these horizontal rotation which then gets tilted into
a vertical column somehow. So that's sort of one cartoon explanation.
Speaker 2 (10:33):
But that kind of sounds like it's starting from the
bottom and like meeting the hurricane halfway, like it's coming
from the top and the bottom. So what am I
missing there?
Speaker 1 (10:40):
Yeah, you're right, And again simple stories are never going
to describe the complexity. What's happening there is that you
have this rising air which is coming up and contributing
and helping pull the cloud down. But still a cloud
is moving down towards the ground. It's not like there's
a tornado forming on the ground and reaching up to
the cloud. It's really the cloud coming down to meet
the ground. Yes, being pulled down and contributing by stuff
(11:02):
on the ground. Okay, there's another idea that maybe there's
a sudden down draft, a special kind of downdraft in
the cloud that reaches down and squeezes a column of
air which happens to be spinning. And now because you've
squeezed it, its spinning faster, and that instigates the tornado.
And this is a third theory that maybe there are
a lot of small vortices on the ground, like a
(11:24):
bunch of little random ones, which merge together and then
start spinning and pull the cloud down. And so there's
lots of different explanations. And one reason that we don't
have an answer is that it is a complex situation.
Even if you have all the data, even if you
take lots of measurements, answering the question of like well
why did this happen? Is complicated. It We touched on
(11:46):
this in our episode on causality, like is there a
single reason why it happens? One of the necessary ingredients.
Even thinking about like what an explanation would look like
is a little bit fuzzy because it's a really complicated environment.
It's not like a single Rube Goldberg machine where you say,
like A causes B, which causes C, which causes D. Right,
you have to have a lot of ingredients in place,
(12:07):
and maybe there's ranges of requirements. A lot of people
are doing simulation studies where they try to create tornadoes
in simulations to see like what ingredients are necessary and
how often does it happen. It's very expensive simulations because
you have to assimulate like all the rain drops and
all the different areas of wind here and there. So
it's something people are definitely working on, but not something
(12:28):
we fully understand.
Speaker 2 (12:29):
Well, I love that you've been covering the weather lately,
and so now I feel like I can ask you
any weather related questions. So this is great for me.
Speaker 1 (12:36):
So and I'll give you a ninety five percent confident
answer on anything.
Speaker 2 (12:39):
I don't feel great about that. But so, do we
understand why you get very strong thunderstorms in some area
since that's like ingredient number one that you need. Do
we understand that?
Speaker 1 (12:51):
Not fully weather? It's of course chaotic, but we can
model storms reasonably well, the formation of storms, like we
can predict when it's going to rain and when it's
going to hail. Check back to our episode about predicting
the weather we did recently to hear all about that.
So those ingredients are reasonably well understood. But why they
come together and make a tornado sometimes and not others.
It's a bit of a mystery. You have like storm
(13:11):
watchers on the ground and they'll be watching a storm like, oh,
it feels like it's going to come together, and then
it just like fizzles out and no tornado happens, And
we don't have a clear understanding of why that is. Sometimes,
but these rough ideas that you need a combination of
thunderstorms and then warm air on the ground and wind shear,
they can help us answer Patrick's question about why tornadoes
(13:32):
tend to form in the plains and your question about
why Tornado Alley exists.
Speaker 2 (13:36):
Well, those things that you said, those seem like there
are things that happen just about anywhere, right, severe storms,
warm moist air, and shear, Like you should be able
to get that anywhere, right, Yeah you.
Speaker 1 (13:48):
Can, and there are tornadoes all over the place. But
in lots of places there are mountains which block warm
moist air from coming in from the ocean, whereas in
the United States. For example, you got the Gulf of Mexico,
which is a lot of warm water, and there's a
lot of warm moist air that comes in from the
Gulf of Mexico, and there's no major mountain range there
to block it. Like Louisiana, no mountains there. That whole
(14:10):
state is totally flat, right, So that warm moist air
just rolls up into the center of the United States
and combines with Midwestern thunderstorms to give you tornadoes. And
the reason it doesn't extend like further west is we
have the Rocky Mountains like running through New Mexico and
Colorado and Wyoming and Idaho. The Rockies block a lot
of that warm moist air, and so you don't get
(14:31):
tornadoes in Utah, for example, as often as you do
in Missouri because they're blocked from the warm moist air
from the Gulf of Mexico.
Speaker 2 (14:40):
Yes, California's got something going for it.
Speaker 1 (14:44):
We got two lines that defense, the Rockies and then
the Sierras. So yeah, absolutely, I mean we got earthquakes
over here, but yeah, we don't have very often tornadoes.
Speaker 2 (14:53):
And I just realized we are maybe taking a political
stance by calling it the Gulf of Mexico, and I
support it on.
Speaker 1 (15:01):
We're taking a stance on facts.
Speaker 2 (15:02):
Yeah, well I just looked up Google maps and it
says Gulf of America. Now what, Oh my gosh.
Speaker 1 (15:09):
So the answer to Patrick's question is that we have
tornadoes on flat land because you need that warm moist
air and mountains blocket and so you need flat land
and you need like an open corridor to a warm
body of water that's going to provide that warm moist air.
So that's why we have Tornado Alley, and that's why
you have tornadoes in the city of Cincinnati in Kentucky.
Speaker 2 (15:31):
And I hope this is but I hope this is
the last tornado that hits Cincinnati, Ohio or Cincinnati, Kentucky.
(15:58):
And we're back. We're transitioning from tornadoes to biology. Yay. Biology,
And I get to talk about parasites a little bit,
so that's exciting.
Speaker 1 (16:07):
But we have a connection. Also, this is all about
flowing water, isn't it. Warmth and moist are going to
be relevant also for your question.
Speaker 2 (16:14):
Yeah, you're right, But also there's some chemistry and I
feel like this was kind of a trick chemistry question.
But I'm going to forgive John because parasites were tied
in and so that's okay, all right, So.
Speaker 1 (16:25):
Let's hear the question from John.
Speaker 4 (16:27):
This is John from New Mexico. A topic for biology
and a smattering of physics is how do you make
water safe to drink without OD and on chlorine? You
could compare Los Angeles Rural Virginia background through methods and
A word of the day in water treatment I understand
is floculation, and I bet Kelly Kent state it fast
(16:47):
enough without making the shows rating in R instead of
a G.
Speaker 2 (16:51):
All right, So I have practice saying floculation so that
this show can remain G instead of R or PG thirteen.
So when you're trying to clean water, you've got a
couple goals. So one, you want to remove debris like
sticks and rocks and rags and stuff like that because
you don't want to be drinking that. Of course, you
(17:12):
want to kill parasites, viruses and bacteria, and you want
to remove toxic stuff like pesticides.
Speaker 1 (17:19):
So where is this water coming from. We're drawing it
from like random rivers, or we're recycling water that's been used,
or we're gathering rain water or what.
Speaker 2 (17:28):
Yeah, so John wanted to know how you get water
for for example, a big city, a rural area and
if you're back country hiking and so, but I did
do a deep dive into how we treat our sewage.
So if Daniel wants to know about treating sewage, I'm
happy to tell you because I found that fascinating when
I got to that.
Speaker 1 (17:47):
Well, I happen to know that Orange County leads the
world with their toilet to tap system.
Speaker 2 (17:52):
Oh WHOA, that's excited.
Speaker 1 (17:55):
Katrina is a big fan. She's always visiting the Orange
County sewage treatment plant to get samples.
Speaker 2 (18:00):
Well that's because she wants the phages that are in there, right,
because yes, everyone should check out our episode with Katrina
on phage therapy. That was amazing. All right, well let's
start with Let's imagine that you are pulling water from
a lake or a river or something like that. Okay,
and so you've you've got this water. It might have dirt,
it might have sticks, it might have parasites, and so
(18:21):
the first thing you're gonna do is just like filter
out the big stuff. So if there's like a stick
in there, you just you get that stuff out. And
so now what you've got is water that has a
bunch of little tiny particles in there that you don't
really want in there anymore. And because they're so small,
they're going to take a really long time to settle out.
And so what you want to do is figure out
(18:43):
a way to get them to settle out faster. And
so the first step is called coagulation, because you're trying
to get all of these tiny particles to stick together
so they'll settle to the bottom. And so these tiny
little particles often have charges, and because they're charged, when
they get close to one another, they don't tend to
stick together because they might repel each other. And so
(19:03):
what they do, and this is where the chemistry comes in.
Speaker 1 (19:06):
H and so I know, gosh, bracing myself.
Speaker 2 (19:08):
Well, we're not going to get that detailed, so don't worry.
So anyway, so they tend to dump stuff in there,
like salts or kinds of aluminium or kinds of iron.
And essentially the goal is to binds to these charge
particles and make them neutral so that when these tiny
little particles bump into one another, they're more likely to
stick together and form bigger chunks.
Speaker 1 (19:31):
I see all right, so neutralize their charges, let them
happily clump up together so they're easier to filter out.
Speaker 2 (19:37):
Yes, exactly. Okay, so now you've got these clumps, but
you want to make those clumps even bigger actually, because
that would make it easier for them to fall down
to the bottom so that you can get them all
out of there. And so the next step is the
step that John mentioned, which is floculation. And essentially what.
Speaker 1 (19:54):
You're doing is it sounds like a punishment.
Speaker 2 (19:56):
It does flagellation or something like that, but but no
focus on flock. So flock is like a group of things.
And the goal here is that you are very gently
mixing the water so that the tiny clumps that you've
made start bumping into other clumps. And now they start
making much bigger clumps. You know. It's like a flock
(20:17):
of birds, you know, as they merge in the sky
together and all head to their migration site. But here
it's junk that you don't want to be drinking, and
so they bump into each other form big chunks, and
then you bring them to another area like another big pool.
And this is the sedimentation step. So you basically just
let the heavy stuff fall out by letting the water
(20:37):
sit for a while, and you draw the water off
the top.
Speaker 1 (20:40):
And so we've added salts and aluminum and iron in
order to help the stuff clump together. And what is
the stuff that we're gathering up? What is the stuff
that's clumping? Where does it come from? Why is it
there anyway?
Speaker 2 (20:51):
Well, I mean we're collecting from a natural system, and
so it could be little bits of poop or little
bits of sand, or you know, could it could be
just about anything. There's a lot of things in the river.
Speaker 1 (21:02):
The technical term I think is dirt.
Speaker 2 (21:04):
Does dirt also cover poop? And that's news to me.
Speaker 1 (21:08):
I think a big fraction of dirt is poop, isn't it.
Speaker 2 (21:10):
I don't know. Yeah, you should ask your what I.
Speaker 1 (21:12):
Think I will, okay, and then we'll ask your husband
to write a poem about it.
Speaker 2 (21:16):
Oh fantastic. Oh this is a family affair. I love
it all right. So you let the heavy stuff settle
to the bottom. You draw the water from the top
because all the heavy stuff is now down at the bottom,
and now you start running it through different kinds of filters.
So what you've done is you've removed like you know,
the poop, the dirt, whatever, the heavy stuff. But now
you want to make sure that there's no bacteria, parasites
(21:38):
or viruses in there anymore. These things are kind of tiny,
and so now you need to start passing the water
through different kinds of filters that are going to catch
these tiny things.
Speaker 1 (21:47):
Wow. So even for those super tiny stuff, you're still
using physical filters like super tiny meshes to block like viruses.
That's insane.
Speaker 2 (21:55):
Well, we're also going to get to a disinfection step
and so they get a little bit more serious eventually.
But here we're still trying to remove like the bigger stuff, like,
for example, parasites probably get stuck if you make it
go through like a big thing of sand, and the
water has to sort of like filter through the sand.
So you get some of that stuff out that way.
Speaker 1 (22:14):
But it's basically still the pasta strainer strategy.
Speaker 2 (22:17):
With a very very fine hole in the pasta strainer. Yeah.
So I mean think about like passing water over sand
or gravel and in some cases charcoal and charcoal is
using like Vanderwall's forces to capture stuff and then you
know it, whatever trickles out the bottom is probably pretty clean.
But viruses are really tiny, and so the viruses and
(22:40):
stuff probably got through there, and so the next step
is disinfection, where they usually add like chlorine, chlorine, chlorine dioxide,
chlorine stuff to try to kill whatever is left in
there that might be alive. They can also pass it
through like some UV light to try to like break
up the DNA in these organisms to kill them. But
(23:01):
most places, as far as I can tell, use some
version of like you know, bleach, some version of like chlorine.
And the other benefit of using chlorine is that it
continues to kill things as the water is passing through
your local like municipal pipes to get to your house well.
Speaker 1 (23:17):
At the Orange County Water Treatment plant, they walk you
through the whole process and at the end they have
a tap and they like pour you a glass of water,
and they're like here you go, and you've seen it
come from like raw sewage, oh man, and it's crystal clear,
beautiful water and you and you drink it. Oh yeah.
A lot of our water comes from toilets, which is
actually the connection with our first question, because you know,
(23:39):
how does that water get to the seward treatment plant
will flush it down the toilet. We create a little
toilet tornado.
Speaker 2 (23:45):
Okay, I didn't see where that was going until you
got there.
Speaker 1 (23:48):
But it's a bit of a reach, ye, all right.
So does that mean that the water that's coming out
of our tap has chlorine and these chemicals in it
and also like destroyed carcasses of bacteria and by because
they can't actually remove it, right, it's still in there.
Speaker 2 (24:03):
Yeah, that's right. And according to the Center for Disease
Control or the CDC, low levels of disinfectants like chlorine
in your water don't make people sick, but some people
are more sensitive to this kind of stuff than other people.
If you're worried, you should talk to your physician. But
we have been treating water like this for about one
hundred years and for most people it's not a problem.
Speaker 1 (24:24):
And are these strategies different from what you might do
in a rural region or if you're like in the
back country.
Speaker 2 (24:30):
Super different?
Speaker 1 (24:31):
Really?
Speaker 2 (24:31):
Yeah? So for example, I live in a very rural region.
I say that I live in Charlottesville, but I actually
live on a farm, you know, a bit away from Charlottesville,
and what we use is groundwater. So we talked about
how in a city you'd go through a bunch of
different kinds of filtration methods, but here the filtration method
that we use is nature. You know, rain water falls
(24:54):
on the ground and it has to trickle through loads
of dirt and sand and stuff, and a bunch of
the stuff that you don't want to be drinking sort
of gets stopped by the sand on the way down
to become part of the groundwater. So the groundwater is like,
you know, there's like a hard rock underneath groundwater accumulates
on top of it, and then you can dig a
well that goes into the area where water is stored
(25:15):
underground and you can pump that up into your house.
Does that make sense?
Speaker 1 (25:19):
It's sort of amazing. I mean, you're talking about using
nature to filter out nature.
Speaker 2 (25:24):
Yes, but it doesn't always work fantastically. So if you
live in a city, then your water has to pass
a bunch of tests before it gets to you, or
like the facility needs to regularly do monitoring to make
sure that like the levels that it has to hit
are being achieved, whereas me I have to collect water
samples every year and pay somebody to test our water
(25:47):
to make sure that, for example, our septic system isn't
leaking bacteria into the groundwater or you know, I live
around a lot of farms. If they were using a
bunch of pesticides, maybe some of them could seep down
into the groundwater and end up in our drinking water.
Speaker 1 (26:00):
So your groundwater has no filters other than this natural system,
like you just pump it up and drink it.
Speaker 2 (26:06):
Yeah, wow, yeah it does. It goes through like a
sedimentation step just to make sure that any dirt has
fallen out of it. But we don't do anything after that.
Speaker 1 (26:14):
And when people visit your farm, you don't ask them
to like sign a waiver or anything. I mean, I've
drunk this water.
Speaker 2 (26:19):
I was gonna say, I didn't ask you to sign
a Katrina.
Speaker 1 (26:22):
I wish i'd heard this podcast episode before I visited.
Speaker 2 (26:25):
But like I said, we get our water tested, and
our water always has pristine levels of everything. So country living.
Speaker 1 (26:33):
It was delicious.
Speaker 2 (26:34):
Yeah, thank you, country living at its best.
Speaker 1 (26:39):
Wow. All right, button up your overalls and have a
glassy It always sounds good.
Speaker 2 (26:44):
Well I don't know why I had to go to
the overalls, but anyway, all.
Speaker 1 (26:47):
Right, country living, No, you don't wear overalls around the farm.
Speaker 2 (26:50):
Not yet, not yet. I'll get there. I'll get there,
But so maybe next year when I start with my dairy.
Speaker 1 (26:54):
Goats and don't misinterpret me. Overalls was a positive comment.
I'm not anti overalls.
Speaker 2 (26:58):
No, they do look very comfy, all right.
Speaker 1 (27:02):
So what about if you're hiking in the back country
and you don't have access to any of these things?
What do you do?
Speaker 2 (27:07):
Okay, Well, first all, note that not everybody is as
lucky as I am. They don't always live in an
area where the groundwater is clean, and which case they
do have to use extra filters or disinfectants and stuff
like that. So we're lucky we don't have to add
extra steps, but depending on where you are, you might
have to. If you are in the back country, maybe
what you're doing is you pull up to a river
and you pull some water out, and that is the
(27:28):
only water you have to drink. So what are you
going to do? The first thing you're going to do
for all the methods we're going to talk about is
strain the big junk out of it. Yeah, take out
the rocks, take out the leaves, maybe pass it through
a handkerchief or something. And then I check the CDC
website and actually have pretty good, pretty detailed instructions for
what you're supposed to do, and the best thing to do,
if you're able, is to boil it. Boiling will kill
(27:50):
the bacteria, it'll kill the viruses, it'll kill the parasites.
And if you bring it up to boiling for just
one minute, that's usually all it takes. But if you're
at high elevation, like above sixty five hundred feet, you
need to boil it for three times as long. And
that is because of chemistry. So you can blame chemistry.
Speaker 1 (28:08):
Because water boils at lower temperatures at high.
Speaker 2 (28:11):
Yes, exactly, so you need to do it for longer.
Speaker 1 (28:13):
And I love how thorough they are in their warnings.
They say, to avoid burns, allow the water to cool
before using it, don't drink boiling water people.
Speaker 2 (28:22):
Yeah, that's right, that's right. Remember to breathe while you're
doing this process, and do.
Speaker 1 (28:27):
Not take a shower in boiling water, thank you, CDC.
Speaker 2 (28:30):
Right, don't stick knives in your eye. Yeah, but you
know they're covering their tails.
Speaker 1 (28:36):
Anytime you read one of these, I imagine that there
was some instance where somebody needed that warning, you know,
and they're responding to them. They're like, all right, we
didn't think we had to say this, but apparently here.
Speaker 2 (28:45):
We are exactly.
Speaker 5 (28:47):
Yeah.
Speaker 2 (28:48):
I do feel like anytime there's a tenus like that,
there's a story that you probably would want to hear.
But anyway, all right, so what if for whatever reason,
you can't boil you are hiking and it's raining and
you can't startifire or something. In that case, you can
hope that you thought ahead to bring a couple different
kinds of filters with you. And the problem with filters,
(29:09):
or the difficulty with filters, is something we talked about earlier,
which is that viruses are really really small, so getting
a filter that can filter out viruses is really difficult,
very teeny diny little holes that stuff needs to pass through.
You can use a reverse osmosis system, where essentially they're
like pushing water through a very very very very very
(29:32):
fine mesh and just about anything that isn't water doesn't
make it through to the other side, and so you
end up with like one side that has all the
gross stuff mixed with some water, and one side that
has clean water. I feel like I got mixed answers
on whether or not this will remove parasites. This might
work if you're like really in a pinch, but you know,
I think you pretty much always want to boil it
or maybe use one of these filters followed by a
(29:54):
disinfectant that's more likely to kill the viruses, and so
disinfectants is another option. This doesn't work as well against parasites.
Parasites are like bigger and a little bit harder to kill,
so like chlorine or iodine is maybe less likely to
kill them, although it might kill some of them. But
you can add chlorine or iodine, but if you're pregnant
or have some other issues with iodine, you might want
(30:15):
to skip iodine. Check the CDC website. But basically you
can add some chemicals to also kill parasites. Finally, if
you're really in a pinch and all you have is
a plastic bottle with no filters, no disinfectants, you can
still try to filter it to get the big stuff out,
and you want that water to be as clear as
possible because you're going to be trying to use the
(30:37):
sun's UV radiation to kill stuff that's in there.
Speaker 1 (30:40):
Particle physics is our last line of defense.
Speaker 2 (30:42):
Oh this counts as particle physics.
Speaker 1 (30:45):
Mm hmm.
Speaker 2 (30:46):
All right, I'll give it to you.
Speaker 1 (30:47):
These are high energy photons exactly zapping those viruses.
Speaker 2 (30:51):
I was wondering why you looked like you were getting
excited about something, and I realized, now you were getting
excited because we were about to get to particle physics.
But I'm learning to read you. I should have known
particle physics was coming.
Speaker 1 (31:04):
That's how you know.
Speaker 2 (31:05):
That's how you know, all right, So anything that makes
the water cloudy you want to get out because any
suspended particle in there is going to stop UV radiation
from hitting the bacteria and viruses that you're trying to kill.
If it's a super sunny day and your water super clear,
then you can leave a plastic bottle filled with water
under the sun for about six hours and that will
probably kill everything hopefully.
Speaker 1 (31:26):
Amazing.
Speaker 2 (31:26):
Yeah, amazing, totally. And if it's cloudy, you might want
to wait, like as much as two days. I think
I'd still feel better if I did some other additional
treatments to it.
Speaker 1 (31:34):
What if you launched your water into space so it's
exposed to radiation in space? Would that make it safer?
How did you not prepare for that question? You're an
expert on space.
Speaker 2 (31:45):
So what I'm wondering is so okay. So we talked
about how space can even kill tartar grades, which are,
like I supposably indestructible. But what I'm wondering is if
you launched it to space, would that, like if there
were pesticides in the water, would solve the problem of
the chemicals? And so I do think that would kill
bacteria and viruses and parasites, But I don't know if
(32:08):
it would remove pesticides the same way as like a
charcoal filter would. And so I think for any of
these things, it's important to keep in mind, like what
are my goals? You know, if you're drinking from a
waterway and there's a bunch of farms upriver, you might
want to worry about pesticides, and maybe you want something
like a charcoal filter. But if you're just worried about
you don't want to get giardia beaver fever, then maybe
(32:30):
disinfecting is the way to go beaver fever.
Speaker 1 (32:32):
I've never heard of that.
Speaker 2 (32:34):
Oh no. I think Giardia became famous when some people
were camping downstream of a beaver dam and the beavers
gave them giardia, which gives them massive diarrhea and had
a friend who got giardia once. She called it muddy
butthole disease.
Speaker 1 (32:50):
But the good news is, if you're an astronaut and
you're in space, your water is probably not going to
give you beaver disease.
Speaker 2 (32:57):
That's probably true, but you are probably drinking yesterday's coffee.
You're drinking recycled urine and sweats.
Speaker 1 (33:04):
All right, well, let's hear if we have muddied the
waters or clarified everything. For John, Oh, that.
Speaker 2 (33:09):
Was bravo, Daniel, bravo.
Speaker 4 (33:11):
Thank you Kelly for the insightful answer. You floculated all
the little bits and pieces into really understandable podcast. Thank
you again.
Speaker 2 (33:41):
So we've established that you can probably get clean water
in space by just exposing it to how horrible space is.
Another horrible thing that could happen in space would be
if your moon broke into many pieces.
Speaker 1 (33:53):
But one of the amazing things about space is that
it exposes us to other kinds of environment and other
kinds of vistas. And we've all seen movies where you
have like two stars in the sky or huge moons.
And one of our favorite listeners, Joe, has a question
about what extremes are possible.
Speaker 5 (34:12):
Hi, Daniel and Kelly, this is Joe from Florida. Loving
the show, but even more really appreciate your willingness to
answer random questions from any one of us. To that point,
I'm playing games and other imagery of sci fi planets
and worlds. It's really common to see a massive planetary
body taking much of the sky, kind of like a
(34:34):
moon of a gas giant, where it's just the whole
thing creates a very alien appearance. So I got to
thinking after the Parker solar probe quote touched the Sun,
I ran those numbers, and even at closest approach, I
think it was only about a twelve degree of the
sky field of view, so it'd be big, but not
completely taking up your vision big. So my question is,
(34:57):
is based on Roch limits and assumptions of standard planetary compositions,
what's the largest a body can appear in the sky. Well,
your own world is still kind of in a stable
orbit and you're not being torn apart or coming into
any of those majora's mass kind of situations. Thanks a lot,
guys love the show.
Speaker 1 (35:16):
All right, So this is a super fun hypothetical question.
He's essentially asking how close can we get to science fiction?
How big in the sky can something appear and still
obey the laws of physics?
Speaker 2 (35:29):
Love it? And so did this require you to do
some actual math or was this answer available somewhere.
Speaker 1 (35:34):
No, I had to do a little bit of calculations here.
This is very cool. I liked thinking about this because
it's super awesome to have big features in the sky.
There's something really powerful about that because you're connected to them.
You're like seeing the scale of the Solar System and
the universe in the sky. And you know, we're lucky
that our moon is so big and so close, and
(35:55):
a lot of people aren't aware, but there are bigger
things in the sky than the moon. For example, Androma
the galaxy is bigger in the night sky than the moon.
We think of it as super distant, and it is,
but it's also incredibly big. The reason that's a surprise
is that most of the time you can't see it
because it's dim. But if you train a camera on
(36:16):
it and follow it and accumulate light, you can see
Andromeda in the sky. So not with your eyes, unfortunately,
but it's there, dominating the night sky.
Speaker 2 (36:24):
Still kind of feels like cheating to compare an entire
galaxy to a moon.
Speaker 1 (36:29):
Well, I mean, we're just talking about angular sizes, right,
It's just for a reference. Obviously, the Moon is much
smaller than Andromeda, but so much closer, and that's really
the trade off here. What we're talking about is the
size in the sky, which is what we call angular distance.
And the way you calculate this is there's a formula,
but essentially it depends on the radius of the object
(36:51):
and on the distance from the object. So the bigger
the object, the bigger it is in the night sky.
The further away it is, the smaller it is in
the night sky. So to be big in the night sky,
you can be pretty small but very very close, or
you can be far away but absolutely enormous. And so
that's how you calculate it.
Speaker 2 (37:07):
Okay, So I haven't stared at the Sun for very
long because I've been told not to. Yes, but if
I were to stare at the Sun, would the Sun
in the moon? Would they be about the same size?
How different in size would they be if I stared?
Speaker 1 (37:19):
Well we know this because we have eclipses. Right, the
Moon is almost exactly the same size as the Sun
in the sky. They're both about half a degree, which
is the unit we use, and that's just an incredible coincidence.
Often in science, when we see coincidences, we're like, hmm,
what does that mean? Is that a clue? Why is that?
But sometimes they're just coincidences, like there's no reason that
(37:41):
the Moon and the Sun have to take up almost
exactly the same amount of sky. But it does lead
to very spectacular eclipses. So we're very grateful for this coincidence.
Speaker 2 (37:51):
Maybe the aliens knew we would really enjoy eclipses, so they,
you know, they work some stuff out for us.
Speaker 1 (37:56):
Yeah, that or the programmers of the simulation. Oh, I
don't know, but it works out.
Speaker 2 (38:00):
Pretty well, all right, thanks whoever.
Speaker 1 (38:02):
So, the biggest easily visible thing in our night sky
are the Sun and the moon about half a degree,
and Joe's wondering about how big things can get. And
the physics we have to understand here are the physics
of tidal forces. That is, the Earth pulls on the
Moon with its gravity, and we tend to think about
the Earth as a point and the Moon is a
point and forces between those two points, but they're not
(38:23):
really points. The Moon has a side that's closer and
a side that's further away. It has an extent to it,
and the side of the Moon that's closer feels the
Earth's gravity more powerfully than the side of the Moon
that's further away, because gravity depends on distance, and so
because there's a difference in those forces, effectively, it's like
the Earth is trying to pull the Moon apart. It
is and actually squeezes the Moon and makes it a
(38:45):
little bit like a football.
Speaker 2 (38:46):
And this reminds me of the book Seven Eves.
Speaker 1 (38:50):
Yes exactly, Neil Stevenson's really fun novel about what would
happen if the Moon was destroyed. And in that novel,
it's not really much of a spoiler to say it's
destroyed by some like alien impactor, But in reality, the
Moon would be destroyed if it got too close to
the Earth, because the closer you get to the Earth,
the greater the difference between the forces on your edges,
and so effectively, the greater the force trying to pull
(39:12):
you apart, and eventually you approach what we call the
Roche limit, which is the closest you can get without
being pulled into little bits, and essentially form a ring,
and for two objects of equal density of a planet
and a moon, that radius is about two and a
half times the radius of the planet, which is actually
quite close. That would be like eighteen thousand kilometers from
(39:33):
the center of our planet, but the moon currently is
like three hundred and eighty thousand kilometers away, So the
Moon could get a lot closer and be a lot
bigger in our sky without being torn into rings.
Speaker 2 (39:46):
I am feeling like I'll sleep better tonight knowing that
it's not close to the roach limit.
Speaker 1 (39:51):
That's good, not at all. And so if you somehow
engineered the moon, you put a rocket on it, and
you brought it in closer to the Earth and all
the way to the roach limit, it would be about
twenty times bigger in the sky than it is currently. Wow, right,
about ten angular degrees, about the size of one or
two outstretched hands. It would be pretty big. It would
(40:11):
be awesome.
Speaker 2 (40:12):
Would that really mess up astronomy because it would be
all right, so Daniel and I both have our hands
out stretched right now and we're looking at that. Yeah,
So how bad would that be for astronomy?
Speaker 1 (40:20):
That would be pretty bad because it would make moonlit
nights much brighter, right, you'd have much more powerful moonshadows.
And already moonlit nights are bad for astronomy because that's
light pollution. Right, It's like having a big light in
the sky. It's like a second sun. You are reflecting
the sun, a mini version of it. So this would
be twenty times as powerful, So it would be bad
(40:41):
for astronomy.
Speaker 2 (40:42):
I thought you were going to say moonlit nights are
bad for astronomers because they're not very romantic or something
like that, because the rest of us love moonlit nights.
Speaker 1 (40:51):
Well, a moonlit night is romantic because the light is dim, right,
It's like why you turn down the lights to make
them romantic. And so at some point cranking that thing
up by factor twenty no longer as romantic.
Speaker 2 (41:01):
Okay, yeah, I could see that. You're gonna need much
better curtains.
Speaker 1 (41:05):
Yeah, but let's do a little bit more engineering to
try to make this bigger. What if we didn't just
use our moon. What if we took a bigger object,
Like what if we somehow pulled Mars into our orbit,
then we used it as a second moon, and we
brought it in just outside Mars's roach limit. Well, that
would be about twice as big in the sky as
the Moon at the roach limit, because Mars is bigger
(41:27):
than the moon, so it'd be about forty times the
size our moon currently is in the sky, an angular
distance of about twenty degrees.
Speaker 2 (41:34):
Maybe it's just that I grew up with the Moon
being so far away, but I'd feel like a little crowded,
you know, like you need to give me some space. Mars.
You're getting too close. You're kind of freaking me out.
Speaker 1 (41:44):
All right, Well, then you're not gonna like the next scenario.
I did a calculation to try to think about how
close you could bring any object, forget the Moon, forget Mars.
What if we're engineering something that we want to fill
our sky and you could make it out of some
natural material. Roach limit depends on density, because something that's
denser holds itself together better. So if you make it,
(42:05):
for example, out of iron, you can get it closer.
But then iron is also denser, and so the object
becomes smaller, so it doesn't take up as much in
the sky. So I imagined, what if we had a
object the mass of the Earth, And my calculation suggests
that if you make it about three times as dense
as the Earth, so use like pure iron. Then its
(42:26):
roch limit would be about one and a half times
the Earth's radius. And this new moon we build because
it's denser than the Earth but it still has the
same mass, would have a radius of about one half
of the Earth's radius. So this thing would be orbiting
just above the ground.
Speaker 2 (42:42):
What just above the Earth?
Speaker 1 (42:45):
Just above the ground on Earth, you'd have to like
duck as this thing goes by.
Speaker 2 (42:49):
Oh yeah, that's no way to live.
Speaker 1 (42:53):
But you know, and these are simplified calculations that we're
really pushing to the extreme. We're assuming that the Roch
limit formula applies here, and I'm not sure it really does.
And of course, you know you've got any mountains, those
are gonna get rubbed right off. But about your answer. Sure,
So if you're out there and you have an earth
mass worth of iron, and you're thinking about building this
(43:17):
moon and having an orbit just above the surface, you
should know that I only give you my ninety five
percent guarantee, which is my highest guarantee, by the way,
But if you did this, it would fill half the sky.
Speaker 2 (43:28):
Please don't listen to Daniel. Everyone look at he would
sell us all out to the aliens if it would
explain gravity, like, absolutely, we can't depend on Daniel for
our safety, everyone.
Speaker 1 (43:40):
Ninety five percent, you can't. Now you can also imagine
the opposite scenario. What if you're on the Moon, right,
and you're not on the planet. So in our Solar system,
if you were to land on Io and look up
at Jupiter in the sky, it already fills twenty angular degrees, right,
that's the size we're talking about of having like Mars
(44:00):
in our sky. So that's already the case. Jupiter is
huge in the sky above Io, and in comparison, like
if you're on Titus, Saturn is only like five and
a half degrees, which is still big, right, a lot
bigger than the Moon is in our sky, but not
as dramatic. But I calculated what would happen if you
brought Io close to its roch limit with Jupiter, and
(44:20):
then it would be like sixty degrees in the sky,
So that would be like, wow, what of you a Jupiter? Right?
And then if you made Io out of like something
incredibly tough like diamond, it could get much closer without
being torn apart. So the roach limit depends on what
the object is made out of. And then you could
get Jupiter to be ninety five degrees across in the
(44:41):
sky before it's going to tear apart your diamond.
Speaker 2 (44:44):
Moon hotly cow. I mean, you'd be dead long before that,
but wow.
Speaker 1 (44:50):
What a way to go, right way to go. You'd
be sitting on your diamond Moon, sipping super clean water
from your waste water treatment facility, watching torn play out
on the surface of Jupiter.
Speaker 2 (45:02):
You know what that sounds. If you've got to go,
that's high up there on my list of ways to go.
Speaker 1 (45:08):
And this episode will have prepared you to understand the
science of each of those elements.
Speaker 2 (45:12):
That's right, You're welcome.
Speaker 1 (45:13):
All right, Well, let's hear if Joe is satisfied with
our answer to his science fiction inspired question.
Speaker 5 (45:19):
Thank you so much Daniel and Kelly for that answer.
It will please you and other listeners to know that
I do not have an Earth's massive iron ready to
put in dangerously close orbit. While giant objects in the
sky may look pretty epic, sounds like for all our
survival better, they remain comfortably distant. I guess the first
human on Aisle will have quite the view. But for
(45:39):
those of us remaining earthbound. I'm so eager for that
binary sunset portrait, so alien engineers, when you have a moment,
that'd be great. Thank you again and keep looking up.
Speaker 2 (45:56):
All right. Well, thank you everyone who submitted questions. If
you'd like to ask ask us a question, you can
write us at questions at Daniel and Kelly dot org,
or you can join us on our discord channel. You
can find an invitation to our discord channel at danielant
Kelly dot org, or you could send us a message
to our social media pages. Although answers there are slightly
less reliable, so I suggest email or discord.
Speaker 1 (46:19):
We really do reply to every email. People continue to
be shocked when we actually replied. We will write back
to you with an answer to your question. Try it.
Speaker 2 (46:28):
Yep. We love hearing from y'all.
Speaker 1 (46:29):
Thanks everyone, have a great day and stay curious.
Tornadoes always touched down on the plains. Is that because
hills block all the rains?
Speaker 2 (00:13):
When we treat water, we rotate, filtrate, and aerrate. Tell
me more, but be careful how you pronounce floculate?
Speaker 1 (00:22):
How large can a moon appear in our sky without
being shredded by gravity's tides?
Speaker 2 (00:28):
Whatever questions keep you up at night, Daniel and Kelly's
answers will make it right.
Speaker 1 (00:32):
Welcome to Daniel and Kelly's Extraordinary Universe.
Speaker 2 (00:49):
Hello. I'm Kelly Windersmith. I study parasites and space, and
I am afraid of tornadoes.
Speaker 1 (00:56):
Hi. I'm Daniel. I'm a particle physicist, and I'm afraid
of Zach's comments on our poetic introductions.
Speaker 2 (01:02):
Oh? Are we going to let the listeners know that
Zach skips the introductions for the listener question episodes because
he is actually really good at poetry and finds our
poetry sort of nauseating.
Speaker 1 (01:14):
It's not what we're famous for. Let's just put it
that way.
Speaker 2 (01:17):
We're having fun.
Speaker 1 (01:18):
But let me put it this way. At least your
spouse listens to our podcast.
Speaker 2 (01:22):
Oh, Katrina dozen Oh no, Oh, I'm mortified. Oh do
we really want to keep having her on our show.
The answer is yes, we absolutely do.
Speaker 1 (01:33):
This is my secret plan to pull her in to
hook her on the podcast.
Speaker 2 (01:36):
Oh fantastic, this is we're talking about tornadoes today. Let's
share our scariest tornado story. Do you have any tornado stories?
Speaker 1 (01:46):
Ooh, I do have a tornado story, though I wasn't
very scared. I was in my dorm room at Rice
in Houston and studying really hard for a test, and
I heard a bunch of shouting in the hallways and
I ignored it because I was busy. And then later
I just got there was a tornado that went right
through Houston and within about a mile of the campus.
And I didn't know anything about it. Yeah, and that's
(02:08):
not very typical for tornadoes to pass through cities, so
it was something of an event. How about you, what's
the closest you've been to a tornado?
Speaker 2 (02:15):
So Zach and I moved to Tuscaloosa, Alabama, right after
like the big tornado that like knocked out a bunch
of the city, and we were in a hotel before
we got our keys to our place, and there was
a tornado warning in the area, and I was like,
oh my gosh, another tornado is going to take out
half the city. And Zach was not worried at all,
and I was panicking. And Zach's like, all right, well,
(02:37):
you're obviously not going to sleep, so well you're panicking.
I'm going to take a shower. And I was looking
up what do you do if there's a tornado and
you're supposed to like get in a tub. Oh, And
so Zach finishes the shower, he comes out, and I'm
panicking and I was like, I think we should get
in the tub. And Zach is like almost asleep already.
And I go into the tub and like the tub
is filled with water, like something can happen with the drain,
(02:57):
and I was like, now we're gonna drown. And I
was more worried about, like Zach hampering our ability to
survive the tornado. And anyway, we were totally fine, and
I am kind of nuts.
Speaker 1 (03:08):
Is the point sounds like a swirling panic attack?
Speaker 2 (03:14):
I'm known for those.
Speaker 1 (03:15):
Actually yeah, yeah, well today you don't have to panic
because you are not going to experience a tornado. Instead,
you're going to experience an explanation of how tornadoes work
and where they form. Because we are answering questions from
listeners like you. People just like you who listen to
the podcast and want to know how things work out
there in the universe. They can't find answers online. They
(03:36):
ask JATGBT. They're not satisfied, so they write it to us,
and we are very happy to provide some answers.
Speaker 2 (03:42):
Daniel, how can you know for sure they're not going
to be experiencing a tornado. They could be listening to
this at any time. There could be a tornado when
they're listening.
Speaker 1 (03:50):
No, this is a tornado free podcast. I'm providing my guarantee.
Speaker 2 (03:53):
I think you are violating the rules of physics, and
I I'm going to write the physicist board and they're
gonna going to lose your job. Man.
Speaker 1 (04:01):
I'm going to hedge because everything is statistical in particle physics.
So I'm gonna give you my ninety five percent guarantee,
and that's my highest guarantee.
Speaker 2 (04:08):
All right, Well, that that's a pretty high guarantee. It
sounds to me like you just pulled that number out
of us swirling thin.
Speaker 1 (04:14):
Air all of statistics sounds like that, But really there's
a lot of rigorous calculations behind it. Trust me. All right, Well,
let's move on to more solid ground and answer some
questions from listeners. Here's a question from Patrick about tornadoes.
Speaker 3 (04:29):
Hi, Daniel, and Kelly. We had some tornadoes touched down
outside of Cincinnati recently, and I've noticed tornadoes seem to
hit the flatter, more open areas outside the city more
often than the city itself. I was thinking about why
this might be and wondering if I'm on the right track. So,
the weather system builds up enough power to form a
(04:49):
tornado over the unobstructed flat land, but in hilly areas
and populated areas, the power is attenuated by the hills
and buildings or alter the tornado's oscillation is damped by
the obstacles. So thanks for taking my question and let
me know if I'm on the right track.
Speaker 2 (05:09):
Whoa tornado's in Cincinnati. I grew up in Ohio, and
I don't feel like tornado should be allowed in Ohio.
I'm sorry you had to go through that. Patrick.
Speaker 1 (05:18):
Well, Cincinnati's like kinda on the border, isn't it's like
partly in Ohio, partly in Kentucky.
Speaker 2 (05:23):
Right, No, it's in Ohio.
Speaker 1 (05:25):
Isn't it a river that runs through it.
Speaker 2 (05:28):
Oh, maybe maybe I'm wrong. It might be a little
bit in Kentucky.
Speaker 1 (05:34):
What I think technically, you're right because the part of
the city that's north of the Ohio River is Cincinnati,
but there's definitely lots of city on the other side,
whether or not you officially call it Cincinnati.
Speaker 2 (05:48):
Daniel, I am gonna have to actually, I'm given this
point to you. I'm sorry I did not carefully study
Ohio geography because I was trying real hard to get
out of there.
Speaker 1 (05:58):
Sorry, Ohio, let me tell you about your home stance.
Speaker 2 (06:06):
All right, Kelly's betten oh for one? So far?
Speaker 1 (06:08):
All right?
Speaker 2 (06:09):
What is the tornado? Daniel? What am I so afraid of?
Speaker 1 (06:14):
So we've all seen tornadoes in movies, et cetera. They're
essentially rotating columns of air in contact with the cloud
and the ground. So you see this tube and it's
like twisting and flailing around, and they can be very
very powerful. The winds can be like up to four
hundred and eighty kilometers per hour, super incredible.
Speaker 2 (06:33):
What is that in freedom units?
Speaker 1 (06:38):
Fast? It's fast units? Okay, it's destructive. Yeah. And they
can be quite narrow or they can be really wide,
like big monster tornadoes up to three kilometers wide, and
for it to be class as a tornado has to
come from the cloud and make contact with the ground,
and that's where the destruction happens. These powerful winds, the
(06:58):
funnel touching the ground, and that funnel travels across the
ground and tear stuff up, and it can go for
like up to one hundred kilometers, tearing a path of
destruction across Kansas or Ohio or wherever Alabama.
Speaker 2 (07:11):
Man, do tornadoes always go from the clouds to the ground.
They never go from the ground to the clouds, that's
right there.
Speaker 1 (07:18):
Always start in the cloud and then descend to the ground.
There are other similar patterns like dust devils you might
have seen, which looks similar to tornadoes, but aren't officially tornadoes.
Those just are whirling patterns of wind on the ground
that touch only the ground and there's no cloud above them,
so they're not officially tornadoes. And if it's over water,
they can be called a water spout. So there's a
few variants of them.
Speaker 2 (07:38):
Okay, And are those things ever as damaging as tornadoes
or they're like tornadoes baby sisters and baby brothers.
Speaker 1 (07:46):
Well, they can be as powerful because the storms can
be powerful, but unless you're living on the water, and
they're not damaging houses, right, So the most damaging ones
are the ones that touch the ground, because that's where
the houses are.
Speaker 2 (07:56):
Got it, okay? All right? And where so we've noted
that they do sort of tend to be like aggregated
in certain geographic regions. Why is that.
Speaker 1 (08:06):
This is something that really America is best at. American
exceptionalism has data to back it up. In the case
of tornadoes, most of the tornadoes in the world are
in the United States. We have like eight hundred per year,
and most of them are in a slice of the
US in central and southeast corners of the country, which
we affectionately call tornado Alley. So there's like four times
(08:30):
as many tornadoes in the US as there are in
all of Europe. You have a few in like South Africa,
some in Europe, Australia, Eastern India, but primarily it's a
thing the US is best at.
Speaker 2 (08:41):
The wind really likes us, all right, So why are
we cursed with these tornadoes?
Speaker 1 (08:46):
Yes, So to understand why tornadoes happen here and less
often elsewhere, you have to understand how they form and
This is not something where the science is totally settled.
People are still working on this. It's a great example
of complex city. You're studying a system which has lots
of components which interact very strongly. Pulling a simple story
out of that is not always possible, but people are
(09:08):
working on it. We think that the ingredients are number one,
a huge thunderstorm, but not just like a normal thunderstorm,
one with like really powerful strong winds, hailstones, et cetera.
And in particular a thunderstorm called a super cell, which
is a set of tower and clouds up to fifteen
kilometers tall, so like a really massive cloud. So that's
(09:30):
ingredient number one. It's like a really powerful thunderstorm, a
very tall one. And then below that you need warm,
moist air on the ground, and we'll talk about how
these come together into a tornado in a minute. And
the third ingredient is sheer. You need strong changes in
the wind speed as you go up or down in altitude,
and so these things how they come together and make
(09:51):
a tornado. Again, it's not fully understood. There's a bunch
of different theories out there. One is that it starts
in the storm. You have these pockets of rotation in
the storm and then they somehow intensify and touch the ground.
And one way this might happen is that the warm
moist air on the ground is rising up and there's
already like pockets of rotation in the storm, and the
(10:14):
rising air connects with those and creates like a horizontal
rotation or as you have this rising pattern, sort of
like in a hurricane, you have like rising air in
the center, which then moves out to the edges, so
you get these horizontal rotation which then gets tilted into
a vertical column somehow. So that's sort of one cartoon explanation.
Speaker 2 (10:33):
But that kind of sounds like it's starting from the
bottom and like meeting the hurricane halfway, like it's coming
from the top and the bottom. So what am I
missing there?
Speaker 1 (10:40):
Yeah, you're right, And again simple stories are never going
to describe the complexity. What's happening there is that you
have this rising air which is coming up and contributing
and helping pull the cloud down. But still a cloud
is moving down towards the ground. It's not like there's
a tornado forming on the ground and reaching up to
the cloud. It's really the cloud coming down to meet
the ground. Yes, being pulled down and contributing by stuff
(11:02):
on the ground. Okay, there's another idea that maybe there's
a sudden down draft, a special kind of downdraft in
the cloud that reaches down and squeezes a column of
air which happens to be spinning. And now because you've
squeezed it, its spinning faster, and that instigates the tornado.
And this is a third theory that maybe there are
a lot of small vortices on the ground, like a
(11:24):
bunch of little random ones, which merge together and then
start spinning and pull the cloud down. And so there's
lots of different explanations. And one reason that we don't
have an answer is that it is a complex situation.
Even if you have all the data, even if you
take lots of measurements, answering the question of like well
why did this happen? Is complicated. It We touched on
(11:46):
this in our episode on causality, like is there a
single reason why it happens? One of the necessary ingredients.
Even thinking about like what an explanation would look like
is a little bit fuzzy because it's a really complicated environment.
It's not like a single Rube Goldberg machine where you say,
like A causes B, which causes C, which causes D. Right,
you have to have a lot of ingredients in place,
(12:07):
and maybe there's ranges of requirements. A lot of people
are doing simulation studies where they try to create tornadoes
in simulations to see like what ingredients are necessary and
how often does it happen. It's very expensive simulations because
you have to assimulate like all the rain drops and
all the different areas of wind here and there. So
it's something people are definitely working on, but not something
(12:28):
we fully understand.
Speaker 2 (12:29):
Well, I love that you've been covering the weather lately,
and so now I feel like I can ask you
any weather related questions. So this is great for me.
Speaker 1 (12:36):
So and I'll give you a ninety five percent confident
answer on anything.
Speaker 2 (12:39):
I don't feel great about that. But so, do we
understand why you get very strong thunderstorms in some area
since that's like ingredient number one that you need. Do
we understand that?
Speaker 1 (12:51):
Not fully weather? It's of course chaotic, but we can
model storms reasonably well, the formation of storms, like we
can predict when it's going to rain and when it's
going to hail. Check back to our episode about predicting
the weather we did recently to hear all about that.
So those ingredients are reasonably well understood. But why they
come together and make a tornado sometimes and not others.
It's a bit of a mystery. You have like storm
(13:11):
watchers on the ground and they'll be watching a storm like, oh,
it feels like it's going to come together, and then
it just like fizzles out and no tornado happens, And
we don't have a clear understanding of why that is. Sometimes,
but these rough ideas that you need a combination of
thunderstorms and then warm air on the ground and wind shear,
they can help us answer Patrick's question about why tornadoes
(13:32):
tend to form in the plains and your question about
why Tornado Alley exists.
Speaker 2 (13:36):
Well, those things that you said, those seem like there
are things that happen just about anywhere, right, severe storms,
warm moist air, and shear, Like you should be able
to get that anywhere, right, Yeah you.
Speaker 1 (13:48):
Can, and there are tornadoes all over the place. But
in lots of places there are mountains which block warm
moist air from coming in from the ocean, whereas in
the United States. For example, you got the Gulf of Mexico,
which is a lot of warm water, and there's a
lot of warm moist air that comes in from the
Gulf of Mexico, and there's no major mountain range there
to block it. Like Louisiana, no mountains there. That whole
(14:10):
state is totally flat, right, So that warm moist air
just rolls up into the center of the United States
and combines with Midwestern thunderstorms to give you tornadoes. And
the reason it doesn't extend like further west is we
have the Rocky Mountains like running through New Mexico and
Colorado and Wyoming and Idaho. The Rockies block a lot
of that warm moist air, and so you don't get
(14:31):
tornadoes in Utah, for example, as often as you do
in Missouri because they're blocked from the warm moist air
from the Gulf of Mexico.
Speaker 2 (14:40):
Yes, California's got something going for it.
Speaker 1 (14:44):
We got two lines that defense, the Rockies and then
the Sierras. So yeah, absolutely, I mean we got earthquakes
over here, but yeah, we don't have very often tornadoes.
Speaker 2 (14:53):
And I just realized we are maybe taking a political
stance by calling it the Gulf of Mexico, and I
support it on.
Speaker 1 (15:01):
We're taking a stance on facts.
Speaker 2 (15:02):
Yeah, well I just looked up Google maps and it
says Gulf of America. Now what, Oh my gosh.
Speaker 1 (15:09):
So the answer to Patrick's question is that we have
tornadoes on flat land because you need that warm moist
air and mountains blocket and so you need flat land
and you need like an open corridor to a warm
body of water that's going to provide that warm moist air.
So that's why we have Tornado Alley, and that's why
you have tornadoes in the city of Cincinnati in Kentucky.
Speaker 2 (15:31):
And I hope this is but I hope this is
the last tornado that hits Cincinnati, Ohio or Cincinnati, Kentucky.
(15:58):
And we're back. We're transitioning from tornadoes to biology. Yay. Biology,
And I get to talk about parasites a little bit,
so that's exciting.
Speaker 1 (16:07):
But we have a connection. Also, this is all about
flowing water, isn't it. Warmth and moist are going to
be relevant also for your question.
Speaker 2 (16:14):
Yeah, you're right, But also there's some chemistry and I
feel like this was kind of a trick chemistry question.
But I'm going to forgive John because parasites were tied
in and so that's okay, all right, So.
Speaker 1 (16:25):
Let's hear the question from John.
Speaker 4 (16:27):
This is John from New Mexico. A topic for biology
and a smattering of physics is how do you make
water safe to drink without OD and on chlorine? You
could compare Los Angeles Rural Virginia background through methods and
A word of the day in water treatment I understand
is floculation, and I bet Kelly Kent state it fast
(16:47):
enough without making the shows rating in R instead of
a G.
Speaker 2 (16:51):
All right, So I have practice saying floculation so that
this show can remain G instead of R or PG thirteen.
So when you're trying to clean water, you've got a
couple goals. So one, you want to remove debris like
sticks and rocks and rags and stuff like that because
you don't want to be drinking that. Of course, you
(17:12):
want to kill parasites, viruses and bacteria, and you want
to remove toxic stuff like pesticides.
Speaker 1 (17:19):
So where is this water coming from. We're drawing it
from like random rivers, or we're recycling water that's been used,
or we're gathering rain water or what.
Speaker 2 (17:28):
Yeah, so John wanted to know how you get water
for for example, a big city, a rural area and
if you're back country hiking and so, but I did
do a deep dive into how we treat our sewage.
So if Daniel wants to know about treating sewage, I'm
happy to tell you because I found that fascinating when
I got to that.
Speaker 1 (17:47):
Well, I happen to know that Orange County leads the
world with their toilet to tap system.
Speaker 2 (17:52):
Oh WHOA, that's excited.
Speaker 1 (17:55):
Katrina is a big fan. She's always visiting the Orange
County sewage treatment plant to get samples.
Speaker 2 (18:00):
Well that's because she wants the phages that are in there, right,
because yes, everyone should check out our episode with Katrina
on phage therapy. That was amazing. All right, well let's
start with Let's imagine that you are pulling water from
a lake or a river or something like that. Okay,
and so you've you've got this water. It might have dirt,
it might have sticks, it might have parasites, and so
(18:21):
the first thing you're gonna do is just like filter
out the big stuff. So if there's like a stick
in there, you just you get that stuff out. And
so now what you've got is water that has a
bunch of little tiny particles in there that you don't
really want in there anymore. And because they're so small,
they're going to take a really long time to settle out.
And so what you want to do is figure out
(18:43):
a way to get them to settle out faster. And
so the first step is called coagulation, because you're trying
to get all of these tiny particles to stick together
so they'll settle to the bottom. And so these tiny
little particles often have charges, and because they're charged, when
they get close to one another, they don't tend to
stick together because they might repel each other. And so
(19:03):
what they do, and this is where the chemistry comes in.
Speaker 1 (19:06):
H and so I know, gosh, bracing myself.
Speaker 2 (19:08):
Well, we're not going to get that detailed, so don't worry.
So anyway, so they tend to dump stuff in there,
like salts or kinds of aluminium or kinds of iron.
And essentially the goal is to binds to these charge
particles and make them neutral so that when these tiny
little particles bump into one another, they're more likely to
stick together and form bigger chunks.
Speaker 1 (19:31):
I see all right, so neutralize their charges, let them
happily clump up together so they're easier to filter out.
Speaker 2 (19:37):
Yes, exactly. Okay, so now you've got these clumps, but
you want to make those clumps even bigger actually, because
that would make it easier for them to fall down
to the bottom so that you can get them all
out of there. And so the next step is the
step that John mentioned, which is floculation. And essentially what.
Speaker 1 (19:54):
You're doing is it sounds like a punishment.
Speaker 2 (19:56):
It does flagellation or something like that, but but no
focus on flock. So flock is like a group of things.
And the goal here is that you are very gently
mixing the water so that the tiny clumps that you've
made start bumping into other clumps. And now they start
making much bigger clumps. You know. It's like a flock
(20:17):
of birds, you know, as they merge in the sky
together and all head to their migration site. But here
it's junk that you don't want to be drinking, and
so they bump into each other form big chunks, and
then you bring them to another area like another big pool.
And this is the sedimentation step. So you basically just
let the heavy stuff fall out by letting the water
(20:37):
sit for a while, and you draw the water off
the top.
Speaker 1 (20:40):
And so we've added salts and aluminum and iron in
order to help the stuff clump together. And what is
the stuff that we're gathering up? What is the stuff
that's clumping? Where does it come from? Why is it
there anyway?
Speaker 2 (20:51):
Well, I mean we're collecting from a natural system, and
so it could be little bits of poop or little
bits of sand, or you know, could it could be
just about anything. There's a lot of things in the river.
Speaker 1 (21:02):
The technical term I think is dirt.
Speaker 2 (21:04):
Does dirt also cover poop? And that's news to me.
Speaker 1 (21:08):
I think a big fraction of dirt is poop, isn't it.
Speaker 2 (21:10):
I don't know. Yeah, you should ask your what I.
Speaker 1 (21:12):
Think I will, okay, and then we'll ask your husband
to write a poem about it.
Speaker 2 (21:16):
Oh fantastic. Oh this is a family affair. I love
it all right. So you let the heavy stuff settle
to the bottom. You draw the water from the top
because all the heavy stuff is now down at the bottom,
and now you start running it through different kinds of filters.
So what you've done is you've removed like you know,
the poop, the dirt, whatever, the heavy stuff. But now
you want to make sure that there's no bacteria, parasites
(21:38):
or viruses in there anymore. These things are kind of tiny,
and so now you need to start passing the water
through different kinds of filters that are going to catch
these tiny things.
Speaker 1 (21:47):
Wow. So even for those super tiny stuff, you're still
using physical filters like super tiny meshes to block like viruses.
That's insane.
Speaker 2 (21:55):
Well, we're also going to get to a disinfection step
and so they get a little bit more serious eventually.
But here we're still trying to remove like the bigger stuff, like,
for example, parasites probably get stuck if you make it
go through like a big thing of sand, and the
water has to sort of like filter through the sand.
So you get some of that stuff out that way.
Speaker 1 (22:14):
But it's basically still the pasta strainer strategy.
Speaker 2 (22:17):
With a very very fine hole in the pasta strainer. Yeah.
So I mean think about like passing water over sand
or gravel and in some cases charcoal and charcoal is
using like Vanderwall's forces to capture stuff and then you
know it, whatever trickles out the bottom is probably pretty clean.
But viruses are really tiny, and so the viruses and
(22:40):
stuff probably got through there, and so the next step
is disinfection, where they usually add like chlorine, chlorine, chlorine dioxide,
chlorine stuff to try to kill whatever is left in
there that might be alive. They can also pass it
through like some UV light to try to like break
up the DNA in these organisms to kill them. But
(23:01):
most places, as far as I can tell, use some
version of like you know, bleach, some version of like chlorine.
And the other benefit of using chlorine is that it
continues to kill things as the water is passing through
your local like municipal pipes to get to your house well.
Speaker 1 (23:17):
At the Orange County Water Treatment plant, they walk you
through the whole process and at the end they have
a tap and they like pour you a glass of water,
and they're like here you go, and you've seen it
come from like raw sewage, oh man, and it's crystal clear,
beautiful water and you and you drink it. Oh yeah.
A lot of our water comes from toilets, which is
actually the connection with our first question, because you know,
(23:39):
how does that water get to the seward treatment plant
will flush it down the toilet. We create a little
toilet tornado.
Speaker 2 (23:45):
Okay, I didn't see where that was going until you
got there.
Speaker 1 (23:48):
But it's a bit of a reach, ye, all right.
So does that mean that the water that's coming out
of our tap has chlorine and these chemicals in it
and also like destroyed carcasses of bacteria and by because
they can't actually remove it, right, it's still in there.
Speaker 2 (24:03):
Yeah, that's right. And according to the Center for Disease
Control or the CDC, low levels of disinfectants like chlorine
in your water don't make people sick, but some people
are more sensitive to this kind of stuff than other people.
If you're worried, you should talk to your physician. But
we have been treating water like this for about one
hundred years and for most people it's not a problem.
Speaker 1 (24:24):
And are these strategies different from what you might do
in a rural region or if you're like in the
back country.
Speaker 2 (24:30):
Super different?
Speaker 1 (24:31):
Really?
Speaker 2 (24:31):
Yeah? So for example, I live in a very rural region.
I say that I live in Charlottesville, but I actually
live on a farm, you know, a bit away from Charlottesville,
and what we use is groundwater. So we talked about
how in a city you'd go through a bunch of
different kinds of filtration methods, but here the filtration method
that we use is nature. You know, rain water falls
(24:54):
on the ground and it has to trickle through loads
of dirt and sand and stuff, and a bunch of
the stuff that you don't want to be drinking sort
of gets stopped by the sand on the way down
to become part of the groundwater. So the groundwater is like,
you know, there's like a hard rock underneath groundwater accumulates
on top of it, and then you can dig a
well that goes into the area where water is stored
(25:15):
underground and you can pump that up into your house.
Does that make sense?
Speaker 1 (25:19):
It's sort of amazing. I mean, you're talking about using
nature to filter out nature.
Speaker 2 (25:24):
Yes, but it doesn't always work fantastically. So if you
live in a city, then your water has to pass
a bunch of tests before it gets to you, or
like the facility needs to regularly do monitoring to make
sure that like the levels that it has to hit
are being achieved, whereas me I have to collect water
samples every year and pay somebody to test our water
(25:47):
to make sure that, for example, our septic system isn't
leaking bacteria into the groundwater or you know, I live
around a lot of farms. If they were using a
bunch of pesticides, maybe some of them could seep down
into the groundwater and end up in our drinking water.
Speaker 1 (26:00):
So your groundwater has no filters other than this natural system,
like you just pump it up and drink it.
Speaker 2 (26:06):
Yeah, wow, yeah it does. It goes through like a
sedimentation step just to make sure that any dirt has
fallen out of it. But we don't do anything after that.
Speaker 1 (26:14):
And when people visit your farm, you don't ask them
to like sign a waiver or anything. I mean, I've
drunk this water.
Speaker 2 (26:19):
I was gonna say, I didn't ask you to sign
a Katrina.
Speaker 1 (26:22):
I wish i'd heard this podcast episode before I visited.
Speaker 2 (26:25):
But like I said, we get our water tested, and
our water always has pristine levels of everything. So country living.
Speaker 1 (26:33):
It was delicious.
Speaker 2 (26:34):
Yeah, thank you, country living at its best.
Speaker 1 (26:39):
Wow. All right, button up your overalls and have a
glassy It always sounds good.
Speaker 2 (26:44):
Well I don't know why I had to go to
the overalls, but anyway, all.
Speaker 1 (26:47):
Right, country living, No, you don't wear overalls around the farm.
Speaker 2 (26:50):
Not yet, not yet. I'll get there. I'll get there,
But so maybe next year when I start with my dairy.
Speaker 1 (26:54):
Goats and don't misinterpret me. Overalls was a positive comment.
I'm not anti overalls.
Speaker 2 (26:58):
No, they do look very comfy, all right.
Speaker 1 (27:02):
So what about if you're hiking in the back country
and you don't have access to any of these things?
What do you do?
Speaker 2 (27:07):
Okay, Well, first all, note that not everybody is as
lucky as I am. They don't always live in an
area where the groundwater is clean, and which case they
do have to use extra filters or disinfectants and stuff
like that. So we're lucky we don't have to add
extra steps, but depending on where you are, you might
have to. If you are in the back country, maybe
what you're doing is you pull up to a river
and you pull some water out, and that is the
(27:28):
only water you have to drink. So what are you
going to do? The first thing you're going to do
for all the methods we're going to talk about is
strain the big junk out of it. Yeah, take out
the rocks, take out the leaves, maybe pass it through
a handkerchief or something. And then I check the CDC
website and actually have pretty good, pretty detailed instructions for
what you're supposed to do, and the best thing to do,
if you're able, is to boil it. Boiling will kill
(27:50):
the bacteria, it'll kill the viruses, it'll kill the parasites.
And if you bring it up to boiling for just
one minute, that's usually all it takes. But if you're
at high elevation, like above sixty five hundred feet, you
need to boil it for three times as long. And
that is because of chemistry. So you can blame chemistry.
Speaker 1 (28:08):
Because water boils at lower temperatures at high.
Speaker 2 (28:11):
Yes, exactly, so you need to do it for longer.
Speaker 1 (28:13):
And I love how thorough they are in their warnings.
They say, to avoid burns, allow the water to cool
before using it, don't drink boiling water people.
Speaker 2 (28:22):
Yeah, that's right, that's right. Remember to breathe while you're
doing this process, and do.
Speaker 1 (28:27):
Not take a shower in boiling water, thank you, CDC.
Speaker 2 (28:30):
Right, don't stick knives in your eye. Yeah, but you
know they're covering their tails.
Speaker 1 (28:36):
Anytime you read one of these, I imagine that there
was some instance where somebody needed that warning, you know,
and they're responding to them. They're like, all right, we
didn't think we had to say this, but apparently here.
Speaker 2 (28:45):
We are exactly.
Speaker 5 (28:47):
Yeah.
Speaker 2 (28:48):
I do feel like anytime there's a tenus like that,
there's a story that you probably would want to hear.
But anyway, all right, so what if for whatever reason,
you can't boil you are hiking and it's raining and
you can't startifire or something. In that case, you can
hope that you thought ahead to bring a couple different
kinds of filters with you. And the problem with filters,
(29:09):
or the difficulty with filters, is something we talked about earlier,
which is that viruses are really really small, so getting
a filter that can filter out viruses is really difficult,
very teeny diny little holes that stuff needs to pass through.
You can use a reverse osmosis system, where essentially they're
like pushing water through a very very very very very
(29:32):
fine mesh and just about anything that isn't water doesn't
make it through to the other side, and so you
end up with like one side that has all the
gross stuff mixed with some water, and one side that
has clean water. I feel like I got mixed answers
on whether or not this will remove parasites. This might
work if you're like really in a pinch, but you know,
I think you pretty much always want to boil it
or maybe use one of these filters followed by a
(29:54):
disinfectant that's more likely to kill the viruses, and so
disinfectants is another option. This doesn't work as well against parasites.
Parasites are like bigger and a little bit harder to kill,
so like chlorine or iodine is maybe less likely to
kill them, although it might kill some of them. But
you can add chlorine or iodine, but if you're pregnant
or have some other issues with iodine, you might want
(30:15):
to skip iodine. Check the CDC website. But basically you
can add some chemicals to also kill parasites. Finally, if
you're really in a pinch and all you have is
a plastic bottle with no filters, no disinfectants, you can
still try to filter it to get the big stuff out,
and you want that water to be as clear as
possible because you're going to be trying to use the
(30:37):
sun's UV radiation to kill stuff that's in there.
Speaker 1 (30:40):
Particle physics is our last line of defense.
Speaker 2 (30:42):
Oh this counts as particle physics.
Speaker 1 (30:45):
Mm hmm.
Speaker 2 (30:46):
All right, I'll give it to you.
Speaker 1 (30:47):
These are high energy photons exactly zapping those viruses.
Speaker 2 (30:51):
I was wondering why you looked like you were getting
excited about something, and I realized, now you were getting
excited because we were about to get to particle physics.
But I'm learning to read you. I should have known
particle physics was coming.
Speaker 1 (31:04):
That's how you know.
Speaker 2 (31:05):
That's how you know, all right, So anything that makes
the water cloudy you want to get out because any
suspended particle in there is going to stop UV radiation
from hitting the bacteria and viruses that you're trying to kill.
If it's a super sunny day and your water super clear,
then you can leave a plastic bottle filled with water
under the sun for about six hours and that will
probably kill everything hopefully.
Speaker 1 (31:26):
Amazing.
Speaker 2 (31:26):
Yeah, amazing, totally. And if it's cloudy, you might want
to wait, like as much as two days. I think
I'd still feel better if I did some other additional
treatments to it.
Speaker 1 (31:34):
What if you launched your water into space so it's
exposed to radiation in space? Would that make it safer?
How did you not prepare for that question? You're an
expert on space.
Speaker 2 (31:45):
So what I'm wondering is so okay. So we talked
about how space can even kill tartar grades, which are,
like I supposably indestructible. But what I'm wondering is if
you launched it to space, would that, like if there
were pesticides in the water, would solve the problem of
the chemicals? And so I do think that would kill
bacteria and viruses and parasites, But I don't know if
(32:08):
it would remove pesticides the same way as like a
charcoal filter would. And so I think for any of
these things, it's important to keep in mind, like what
are my goals? You know, if you're drinking from a
waterway and there's a bunch of farms upriver, you might
want to worry about pesticides, and maybe you want something
like a charcoal filter. But if you're just worried about
you don't want to get giardia beaver fever, then maybe
(32:30):
disinfecting is the way to go beaver fever.
Speaker 1 (32:32):
I've never heard of that.
Speaker 2 (32:34):
Oh no. I think Giardia became famous when some people
were camping downstream of a beaver dam and the beavers
gave them giardia, which gives them massive diarrhea and had
a friend who got giardia once. She called it muddy
butthole disease.
Speaker 1 (32:50):
But the good news is, if you're an astronaut and
you're in space, your water is probably not going to
give you beaver disease.
Speaker 2 (32:57):
That's probably true, but you are probably drinking yesterday's coffee.
You're drinking recycled urine and sweats.
Speaker 1 (33:04):
All right, well, let's hear if we have muddied the
waters or clarified everything. For John, Oh, that.
Speaker 2 (33:09):
Was bravo, Daniel, bravo.
Speaker 4 (33:11):
Thank you Kelly for the insightful answer. You floculated all
the little bits and pieces into really understandable podcast. Thank
you again.
Speaker 2 (33:41):
So we've established that you can probably get clean water
in space by just exposing it to how horrible space is.
Another horrible thing that could happen in space would be
if your moon broke into many pieces.
Speaker 1 (33:53):
But one of the amazing things about space is that
it exposes us to other kinds of environment and other
kinds of vistas. And we've all seen movies where you
have like two stars in the sky or huge moons.
And one of our favorite listeners, Joe, has a question
about what extremes are possible.
Speaker 5 (34:12):
Hi, Daniel and Kelly, this is Joe from Florida. Loving
the show, but even more really appreciate your willingness to
answer random questions from any one of us. To that point,
I'm playing games and other imagery of sci fi planets
and worlds. It's really common to see a massive planetary
body taking much of the sky, kind of like a
(34:34):
moon of a gas giant, where it's just the whole
thing creates a very alien appearance. So I got to
thinking after the Parker solar probe quote touched the Sun,
I ran those numbers, and even at closest approach, I
think it was only about a twelve degree of the
sky field of view, so it'd be big, but not
completely taking up your vision big. So my question is,
(34:57):
is based on Roch limits and assumptions of standard planetary compositions,
what's the largest a body can appear in the sky. Well,
your own world is still kind of in a stable
orbit and you're not being torn apart or coming into
any of those majora's mass kind of situations. Thanks a lot,
guys love the show.
Speaker 1 (35:16):
All right, So this is a super fun hypothetical question.
He's essentially asking how close can we get to science fiction?
How big in the sky can something appear and still
obey the laws of physics?
Speaker 2 (35:29):
Love it? And so did this require you to do
some actual math or was this answer available somewhere.
Speaker 1 (35:34):
No, I had to do a little bit of calculations here.
This is very cool. I liked thinking about this because
it's super awesome to have big features in the sky.
There's something really powerful about that because you're connected to them.
You're like seeing the scale of the Solar System and
the universe in the sky. And you know, we're lucky
that our moon is so big and so close, and
(35:55):
a lot of people aren't aware, but there are bigger
things in the sky than the moon. For example, Androma
the galaxy is bigger in the night sky than the moon.
We think of it as super distant, and it is,
but it's also incredibly big. The reason that's a surprise
is that most of the time you can't see it
because it's dim. But if you train a camera on
(36:16):
it and follow it and accumulate light, you can see
Andromeda in the sky. So not with your eyes, unfortunately,
but it's there, dominating the night sky.
Speaker 2 (36:24):
Still kind of feels like cheating to compare an entire
galaxy to a moon.
Speaker 1 (36:29):
Well, I mean, we're just talking about angular sizes, right,
It's just for a reference. Obviously, the Moon is much
smaller than Andromeda, but so much closer, and that's really
the trade off here. What we're talking about is the
size in the sky, which is what we call angular distance.
And the way you calculate this is there's a formula,
but essentially it depends on the radius of the object
(36:51):
and on the distance from the object. So the bigger
the object, the bigger it is in the night sky.
The further away it is, the smaller it is in
the night sky. So to be big in the night sky,
you can be pretty small but very very close, or
you can be far away but absolutely enormous. And so
that's how you calculate it.
Speaker 2 (37:07):
Okay, So I haven't stared at the Sun for very
long because I've been told not to. Yes, but if
I were to stare at the Sun, would the Sun
in the moon? Would they be about the same size?
How different in size would they be if I stared?
Speaker 1 (37:19):
Well we know this because we have eclipses. Right, the
Moon is almost exactly the same size as the Sun
in the sky. They're both about half a degree, which
is the unit we use, and that's just an incredible coincidence.
Often in science, when we see coincidences, we're like, hmm,
what does that mean? Is that a clue? Why is that?
But sometimes they're just coincidences, like there's no reason that
(37:41):
the Moon and the Sun have to take up almost
exactly the same amount of sky. But it does lead
to very spectacular eclipses. So we're very grateful for this coincidence.
Speaker 2 (37:51):
Maybe the aliens knew we would really enjoy eclipses, so they,
you know, they work some stuff out for us.
Speaker 1 (37:56):
Yeah, that or the programmers of the simulation. Oh, I
don't know, but it works out.
Speaker 2 (38:00):
Pretty well, all right, thanks whoever.
Speaker 1 (38:02):
So, the biggest easily visible thing in our night sky
are the Sun and the moon about half a degree,
and Joe's wondering about how big things can get. And
the physics we have to understand here are the physics
of tidal forces. That is, the Earth pulls on the
Moon with its gravity, and we tend to think about
the Earth as a point and the Moon is a
point and forces between those two points, but they're not
(38:23):
really points. The Moon has a side that's closer and
a side that's further away. It has an extent to it,
and the side of the Moon that's closer feels the
Earth's gravity more powerfully than the side of the Moon
that's further away, because gravity depends on distance, and so
because there's a difference in those forces, effectively, it's like
the Earth is trying to pull the Moon apart. It
is and actually squeezes the Moon and makes it a
(38:45):
little bit like a football.
Speaker 2 (38:46):
And this reminds me of the book Seven Eves.
Speaker 1 (38:50):
Yes exactly, Neil Stevenson's really fun novel about what would
happen if the Moon was destroyed. And in that novel,
it's not really much of a spoiler to say it's
destroyed by some like alien impactor, But in reality, the
Moon would be destroyed if it got too close to
the Earth, because the closer you get to the Earth,
the greater the difference between the forces on your edges,
and so effectively, the greater the force trying to pull
(39:12):
you apart, and eventually you approach what we call the
Roche limit, which is the closest you can get without
being pulled into little bits, and essentially form a ring,
and for two objects of equal density of a planet
and a moon, that radius is about two and a
half times the radius of the planet, which is actually
quite close. That would be like eighteen thousand kilometers from
(39:33):
the center of our planet, but the moon currently is
like three hundred and eighty thousand kilometers away, So the
Moon could get a lot closer and be a lot
bigger in our sky without being torn into rings.
Speaker 2 (39:46):
I am feeling like I'll sleep better tonight knowing that
it's not close to the roach limit.
Speaker 1 (39:51):
That's good, not at all. And so if you somehow
engineered the moon, you put a rocket on it, and
you brought it in closer to the Earth and all
the way to the roach limit, it would be about
twenty times bigger in the sky than it is currently. Wow, right,
about ten angular degrees, about the size of one or
two outstretched hands. It would be pretty big. It would
(40:11):
be awesome.
Speaker 2 (40:12):
Would that really mess up astronomy because it would be
all right, so Daniel and I both have our hands
out stretched right now and we're looking at that. Yeah,
So how bad would that be for astronomy?
Speaker 1 (40:20):
That would be pretty bad because it would make moonlit
nights much brighter, right, you'd have much more powerful moonshadows.
And already moonlit nights are bad for astronomy because that's
light pollution. Right, It's like having a big light in
the sky. It's like a second sun. You are reflecting
the sun, a mini version of it. So this would
be twenty times as powerful, So it would be bad
(40:41):
for astronomy.
Speaker 2 (40:42):
I thought you were going to say moonlit nights are
bad for astronomers because they're not very romantic or something
like that, because the rest of us love moonlit nights.
Speaker 1 (40:51):
Well, a moonlit night is romantic because the light is dim, right,
It's like why you turn down the lights to make
them romantic. And so at some point cranking that thing
up by factor twenty no longer as romantic.
Speaker 2 (41:01):
Okay, yeah, I could see that. You're gonna need much
better curtains.
Speaker 1 (41:05):
Yeah, but let's do a little bit more engineering to
try to make this bigger. What if we didn't just
use our moon. What if we took a bigger object,
Like what if we somehow pulled Mars into our orbit,
then we used it as a second moon, and we
brought it in just outside Mars's roach limit. Well, that
would be about twice as big in the sky as
the Moon at the roach limit, because Mars is bigger
(41:27):
than the moon, so it'd be about forty times the
size our moon currently is in the sky, an angular
distance of about twenty degrees.
Speaker 2 (41:34):
Maybe it's just that I grew up with the Moon
being so far away, but I'd feel like a little crowded,
you know, like you need to give me some space. Mars.
You're getting too close. You're kind of freaking me out.
Speaker 1 (41:44):
All right, Well, then you're not gonna like the next scenario.
I did a calculation to try to think about how
close you could bring any object, forget the Moon, forget Mars.
What if we're engineering something that we want to fill
our sky and you could make it out of some
natural material. Roach limit depends on density, because something that's
denser holds itself together better. So if you make it,
(42:05):
for example, out of iron, you can get it closer.
But then iron is also denser, and so the object
becomes smaller, so it doesn't take up as much in
the sky. So I imagined, what if we had a
object the mass of the Earth, And my calculation suggests
that if you make it about three times as dense
as the Earth, so use like pure iron. Then its
(42:26):
roch limit would be about one and a half times
the Earth's radius. And this new moon we build because
it's denser than the Earth but it still has the
same mass, would have a radius of about one half
of the Earth's radius. So this thing would be orbiting
just above the ground.
Speaker 2 (42:42):
What just above the Earth?
Speaker 1 (42:45):
Just above the ground on Earth, you'd have to like
duck as this thing goes by.
Speaker 2 (42:49):
Oh yeah, that's no way to live.
Speaker 1 (42:53):
But you know, and these are simplified calculations that we're
really pushing to the extreme. We're assuming that the Roch
limit formula applies here, and I'm not sure it really does.
And of course, you know you've got any mountains, those
are gonna get rubbed right off. But about your answer. Sure,
So if you're out there and you have an earth
mass worth of iron, and you're thinking about building this
(43:17):
moon and having an orbit just above the surface, you
should know that I only give you my ninety five
percent guarantee, which is my highest guarantee, by the way,
But if you did this, it would fill half the sky.
Speaker 2 (43:28):
Please don't listen to Daniel. Everyone look at he would
sell us all out to the aliens if it would
explain gravity, like, absolutely, we can't depend on Daniel for
our safety, everyone.
Speaker 1 (43:40):
Ninety five percent, you can't. Now you can also imagine
the opposite scenario. What if you're on the Moon, right,
and you're not on the planet. So in our Solar system,
if you were to land on Io and look up
at Jupiter in the sky, it already fills twenty angular degrees, right,
that's the size we're talking about of having like Mars
(44:00):
in our sky. So that's already the case. Jupiter is
huge in the sky above Io, and in comparison, like
if you're on Titus, Saturn is only like five and
a half degrees, which is still big, right, a lot
bigger than the Moon is in our sky, but not
as dramatic. But I calculated what would happen if you
brought Io close to its roch limit with Jupiter, and
(44:20):
then it would be like sixty degrees in the sky,
So that would be like, wow, what of you a Jupiter? Right?
And then if you made Io out of like something
incredibly tough like diamond, it could get much closer without
being torn apart. So the roach limit depends on what
the object is made out of. And then you could
get Jupiter to be ninety five degrees across in the
(44:41):
sky before it's going to tear apart your diamond.
Speaker 2 (44:44):
Moon hotly cow. I mean, you'd be dead long before that,
but wow.
Speaker 1 (44:50):
What a way to go, right way to go. You'd
be sitting on your diamond Moon, sipping super clean water
from your waste water treatment facility, watching torn play out
on the surface of Jupiter.
Speaker 2 (45:02):
You know what that sounds. If you've got to go,
that's high up there on my list of ways to go.
Speaker 1 (45:08):
And this episode will have prepared you to understand the
science of each of those elements.
Speaker 2 (45:12):
That's right, You're welcome.
Speaker 1 (45:13):
All right, Well, let's hear if Joe is satisfied with
our answer to his science fiction inspired question.
Speaker 5 (45:19):
Thank you so much Daniel and Kelly for that answer.
It will please you and other listeners to know that
I do not have an Earth's massive iron ready to
put in dangerously close orbit. While giant objects in the
sky may look pretty epic, sounds like for all our
survival better, they remain comfortably distant. I guess the first
human on Aisle will have quite the view. But for
(45:39):
those of us remaining earthbound. I'm so eager for that
binary sunset portrait, so alien engineers, when you have a moment,
that'd be great. Thank you again and keep looking up.
Speaker 2 (45:56):
All right. Well, thank you everyone who submitted questions. If
you'd like to ask ask us a question, you can
write us at questions at Daniel and Kelly dot org,
or you can join us on our discord channel. You
can find an invitation to our discord channel at danielant
Kelly dot org, or you could send us a message
to our social media pages. Although answers there are slightly
less reliable, so I suggest email or discord.
Speaker 1 (46:19):
We really do reply to every email. People continue to
be shocked when we actually replied. We will write back
to you with an answer to your question. Try it.
Speaker 2 (46:28):
Yep. We love hearing from y'all.
Speaker 1 (46:29):
Thanks everyone, have a great day and stay curious.
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
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