August 22, 2019 • 33 mins
The moon has just been deleted from the simulation. What will happen here on earth?
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:08):
Hey, Daniel, what's your favorite thing about looking at the
night Scott? You know, I should probably say something inspirational
about physics, etcetera. But honestly, being a family man, my
favorite thing is that it means my kids are probably asleep.
That's what the night sky means to you, that they're
safely touch dead exactly? Or do you mean actually asleep?
It's time for the adult portion of the day. That
(00:30):
sounds that's sounds kind of racing, trust me, in my
evening is not that exciting. But do you mean like
they're in bed or they're just sleep or what makes
it calm? Well, they're in bed and they're quiet. That's
all I really care about. Honestly, whether they're asleep or
not is their business now. But seriously, let's say, like
you're leaving the night Skuy, what does it make you
think of as a physicist, as an explorer, as a
(00:51):
as a thinker. You know, it makes me think about vastness,
the hugeeness of space, of course, you know, but also
like the vastness of time. I mean, you can see
time in the sky, know what. I love that when
you look at the sky it's basically the same sky
the people have been looking at and wondering about. For
as long as people have been looking and wondering, you know,
(01:12):
it hasn't changed that much. I have a question for you,
what if it wasn't? What if our night sky changed?
We Well, that'd be amazing. But as long as my
kids stay in bed and stay quiet, I'd be cool
with it. Hi am or Hammet cartoonists and the creator
(01:41):
of PhD comics. Hi. I'm Daniel. I'm a particle physicist,
a parent, and someone who likes to look up at
the night sky and enjoy the quiet, vastness of space.
And something we also share in comming is that we're
are the co authors of the book We Have No Idea,
a guide to the Unknown Universe. So if you are
wondering about it, we don't know what physicists I have
(02:02):
no idea about in our great, big universe. Please check
out that book. It's a lot of fun and it
features a lot of Jorges hilarious cartoons, so check it out.
It's what neither a physicist nor a cartoonist knows about
the universe. It also features a lot of Daniel's hilarious physics,
so if you're into both hilarities, please check it up.
(02:23):
But today, welcome to our podcast Daniel and Jorge Explain
the Universe, a production of I Heart Radio. That's right,
our podcast in which we think about all the things
that are surrounding us, all the things up in the
sky and down here on Earth, and try to explain
them to you in a way that makes you laugh
and hopefully illuminates your understanding of the world around us. Yeah,
and we also think about the big what if questions
(02:45):
in the universe, or if we can't use what if
because it's copyrighted by Random Monroe of XKCB, we also
tackle the what would happen is of the universe. We
consider ourselves sort of breeding ground for the next generation
of disaster movies by Michael Bay. You've done the Huge Shark,
You've done the Crazy Storm. What's next, the big Asteroid?
(03:08):
That's right, he's done that already, So we are just
generating ideas for the next summer blockbuster. I think it's
something a lot of people maybe wonder about out there.
You know, what could be the next huge thing that
could happen in this crazy, chaotic universe that might affect
my life? And you don't have to speculate. I know
the people out there wonder because they write to us
about it. We get emails people asking us. For example,
(03:31):
we did an episode recently about what would happen if
the Sun became a black hole? That's an honest question
that a bunch of people wrote in. People wonder about
these things. It's on people's minds. You know, things around
us seems stable, but what if something happened? And so
this might be another one in our series of what
would happen if and so to be on the podcast,
we are going to be answering the question what would
(03:58):
happen if the Earth lost its moon? Goodbye, mone, goodnight Moon.
That's right, although these days, you know you have to
say not to say good night to the moon. You
have to say good night to the moon. And it's
first colonizers by the Chinese. What do you mean there
are living things on the moon now because of us? Yes? Uh.
(04:19):
The Israeli's crash landed a probe on the moon, and
on that probe we're tarte grades, little water bears, and
so now we are just awaiting our lunar overlords, the
coming of the Tartar Grade civilization. Oh my god, what
(04:39):
a disaster, you know, I know, So be careful with
your science, folks, you may accidentally seed a new civilization
which destroys ours. Oh my good and Tarti grades are
super scary. Oh they're so cute. We're gonna do an
episode about Tartar grades in the next few weeks, so
tune in for that one. But to think about it,
as we talked about tonight, Remember the Moon is no
(05:00):
longer a lifeless rock. It is now home to about
a hundred little targegrades. Do you think they deserve their
own country? I think Donald Trump will probably try to
buy it. Yeah, Hey, if I can buy Greenland, why
can't I buy the Moon. They'll flash a signed they'll
make a formation on the surface of the Moon saying
we are not for We're not for sale exactly. But
(05:21):
it's an interesting question. You know, the moon is a
big fixture in our lives, in our skies, in mythology,
in romance. So what would happen sort to the human
psyche and to life on Earth if the Earth lost
its moons. It's a totally reasonable question. And you're saying
this was a listener question as well. Somebody some people
wrote this in yeah. Absolutely. People wrote this in and
(05:42):
and wanted to know, And as soon as I read it,
I thought that's a good question. I wonder how life
would change on the on the surface of the Earth
if we lost our moon. So I had to do
some research. It was a lot of fun actually, so
thank you folks for reading in this questions in aside, Daniel,
I think that's the title of our third book, what
would happen? What would happen? If? What would happen if
a physicist and a cartoonists got paid to make three books?
(06:05):
It would never happen. But I just wanted to get
a review of our book from one of the hard
grades on the moon. It's a life goal for me.
So that's what we will be talking about today, is
the question what would happen if the Earth lost its moon?
Like if it suddenly disappeared, Daniel, or if it, you know,
got knocked off and flew off or what do you
think they were thinking when they asked the question. I
(06:25):
don't know. I read a book recently by Neil Stevenson.
It's a great book. It's called Seven Eaves, in which
is the moon is demolished and all the rubble rains
down on Earth. That's pretty bad scenario. So it might
be that people are reading that book and wondering about it.
Um or you know, just if the moon was like
flung out in the space and got hit by an
aster and deflected. And there's lots of different scenarios, but
(06:46):
we'll dig into all of them. Wasn't that also a
plot point in Avengers in Finny War, like Thanos reaches
out and he grabs a moon and he brings it
down on the Avengers. I do watch these movies, but
they're like seventeen hours long, so I don't remember every
plot point. But that's a pretty interesting question. And I
imagine people think a lot of things would happen, or
maybe nothing would happen. Yeah. So, actually, before I didn't research,
(07:09):
before I even had an idea of my own, I
went out and I asked folks what they thought would
happen if the Earth lost its moon? And where were
you in the world when you ask these questions, or
even on the way you were as I was crash
landing on the Moon when I asked these questions. No, um,
here these questions were answered in some combination of Heathrow
Airport and random cities in Portugal. Cool. So think about
(07:31):
it for a second. What do you think would happen
if the Earth lost its moon? Here's what people had
to say. We wouldn't have moonlight. Well, I guess the
tides would be out of balance and we should have
floods coming. Yeah, because the whole stability of the whole
system will fail, and then the Earth will lose the
(07:53):
momentum and the oceans will I don't know what, but
it's not possible to life on Earth without the moon.
Life on Earth could theoretically survive. It is possible we
could survive without a moon. However, climates would be much
more unstable. I think it wouldn't be too bad for
(08:16):
life on Earth except for those title creatures. Does the
moon impact our seasonal change? No, I don't think so,
although at nighttime it does make the evening flowers blue.
All right, it seems like only bad things would happen.
That's what people guessed. But he said, like, great, I
(08:36):
hate the moon, Good riddance. Yeah, that's true. The moon
has a good good Um, it's pretty favorable. I guess.
I wonder if people ever do surveys like rate the
favorability or unfavorability of astronomical objects. What's the most popular
place to vote for this candidate or for the moon?
Who would you want to be as your president? But
what do you think is the most popular astronomical object?
(08:58):
But if you ask people like which object and this
guy would you delete if you had to delete one?
Because which is the least popular aspect of object? Least popular?
It's like those surveys online like what's your most popular
movie that you love or the most popular movie that
you hate? Yeah? Which all so writing folks, and let
us know which astronomical object do you love to hate? Pluto?
(09:21):
Probably poor Pluto? Um, but yeah, people people mostly said
negative things would happen, right, nobody would be happy if
the moon went away. And there's a big spectrum of
possible outcomes here, Like the person who said we wouldn't
have moonlight, like that's a disaster. You always like the
technical answers, the trivial technical answers, Right, Well, if we
(09:42):
didn't have a moon, we wouldn't have a moonlight. Technically true, yes,
but do you think he meant that more like romantically?
That like romance would be affected on Earth if there
was no moonlight. It probably would be. Yeah, they'd probably
be a different cycle of of conception and birth if
there wasn't a moonlight icon um. But yeah, that's a
great question. We'll be talking about what would happen physically, right,
(10:05):
not necessarily biologically or romantically, but kind of like, how
would the physics of our everyday life change if the
Moon suddenly disappeared? Well, Daniel, let's step through it first.
First of all, could it happen, Like, could our moon
just disappear or move away or float away? There are
lots of ways that we could lose our moon, right, um.
Number one, if something hits the Moon, you know, really
(10:27):
big asteroid or something. The Moon is an orbit around
the Earth, but that's a little bit delicate, right. It's stable,
but if it gets knocked out of orbit, it's pretty
tough to get back into orbit. So yeah, you could
get deflected. You mean, like an orbit is a very
delicate thing, right, Like it's something that you could easily
fly away or crashing into the planet if you disturb
the orbit. Yeah, exactly, of all the possible trajectories around
(10:49):
the planet, there's a very tiny fraction them that are
a stable orbit, right, And so you change your trajectory,
and you know, pretty sure soon you're sling shotting around
the planet and then off into space or something. But
you know, the Moon is hit all the time, that's
why it's covered in craters. Usually it's just hit by
a little rock and it doesn't change its motion significantly.
But there are bigger rocks out there, and if one
(11:09):
of them hit the Moon, then it could get deflected
into outer space. Sure, how big do you think it
would of a rock would it take to knock the
Moon out of orbit? I haven't done any calculations, but
you know, I think it has to be pretty substantial.
You know, you're talking something like, you know, hundreds of
meters wide are really a really pretty big solid rock.
And we're sort of I heard also we're kind of
(11:29):
losing the Moon anyways, Like the Moon doesn't want to
be around really, it's sort of edging slowly for another
planet in a way out of the party. They're like,
all right, you guys are kind of crazy. I am
gonna slowly move over to Mars because yeah, there's a
(11:51):
good party going on on Venus. So see you later.
Text you. Um, No, we're losing the Moon. It's not
actually in a totally stable orbit. It's getting further away
every year, but just by a tiny amount, just by
a few centimeters. I looked it up. It's about four
centimeters per year. And that's just the way it is.
It's it's like in an orbit that is not stable.
(12:12):
It's not in an orbit that self corrects or stays
in its lane the whole time. It's like in a
spiral outward away from the Earth. That's right. And you
have to remember that the Earth and the Moon are
a system, right. They're both orbiting the center of mass
of the Earth of the Moon. Like imagine if the
Moon and the Earth at the same mass, then their
center of mass would be between them, literally, and they
(12:34):
would both be moving around that point. But they're not
the same mass. The Earth is much much heavier than
the Moon, and so the center of mass of the
two is closer to the center of the Earth. So
but the two are really orbiting this point that's a
slightly offset from the center of the Earth. And they're
both spinning. So it's a big complicated system and energy
is moving from one part of it to another, and
(12:54):
so the Moon's rotation gets further out right. Um, But
that all so means it gets more angular momentum. So
the angle momentum has to come from somewhere. So as
the Moon get drifts away, the Earth actually slows down
a little bit. I mean the days get longer. Yeah,
it's complicated, it's complicated, and so this you know, this
(13:14):
whole system is not entirely stable, but it's a little
bit stable. It actually turns out it's more stable. You
get fewer fluctuations. We'll talk about it more in depth later,
but it plays a big role in keeping the Earth
in a sort of a stable rotation and and spin.
I have been feeling like that are my days are
are getting longer? You know, I just don't have the
same energy I had before when I was younger. I
(13:36):
don't know why you need more bananas. Most people feel
like as they get older, the days just fly by.
So that's one way the Moon could disappear. It could
literally get knocked off course and fly away, or it
is sort of slowly moving away. What are some other
ways of the moon we could lose the moon? Well,
the most catastrophic would be if it got hit by
a rock and it didn't get deflected into space, but
(13:57):
it got like broken up the Moon and is is
you know, not as like strong as the Earth is
size well held together. It's more of a pile of
rubble than the Earth is because it doesn't have like
inner magma and all that stuff, and so it could
get broken up. And that's exactly what happens in that
novel we were talking about earlier, seven Eves. Neil Stevenson
does like fantastic research for his novels. I've never found
(14:20):
a physics mistake in any of them, and I read
them very carefully. And in that people at first were like, wow, cool,
Look the Moon is exploding and there's all these shooting stars.
But then quickly they realized, oh, this is just a
bunch of rocks raining down on the Earth, and that's
not good. The Moon turned into shooting stars and all
that rained down on the Earth, it would heat of
the atmosphere and a lot of those pieces would land,
(14:41):
and you know, it's like getting hit by a by
a planet killer. Would it necessarily crash into Earth? Like
wouldn't like if the Moon cracked into two, wouldn't necessarily
crash down? Or would the two houses keep going around
the same orbit. It depends a lot on how the
cracking happens. If you like exactly cracking in place, then yeah,
they could keep orbiting just sort of cracked. But if
it's a big collision, then some of it's going to
(15:04):
get blown out into space, and some of it's gonna
turn into a ring around the Earth because some of
it will find a stable orbit, but a lot of
it will just fall into the gravity well of Earth
and land on Earth and kill a bunch of people.
So not a happy scenario. So don't shoot the moon.
Don't shoot the moon. That's right. Then shoot for the
moon or add the moon. Unless you're playing hard, you're
welcome to shoot the moon, but if you are in
(15:25):
possession of a moon busting rocket, please do not shoot
the moon. Alright, So it could maybe happen, And so
let's dig into what would happen if the Moon disappeared,
either by some physical process or just in our imaginations,
if somebody snapped their finger and their moon just disappeared.
What would happen to us here on Earth? But first
let's take a quick break, all right, Daniel, we're talking
(16:00):
about what would happened of the moon disappeared, and from
a physics point of view, what would happen to the
Earth if the Moon suddenly flew away or suddenly, um,
I don't know, collapse, if the masters of the simulation
just deleted it somehow. Yeah. Well, one of the most
immediate things the effects of the Moon on life on Earth,
(16:21):
of course, is it's gravity. Right. The Moon is a
big ball of stuff and it has gravity, and that
gravity pulls on the Earth, and it's a lot of
people probably know that Moon causes tides on the Earth
because it's pulling on the water that's on the Earth,
and it's literally lifting it up a little bit off
the surface, like sucking up the water up right. Yeah, exactly.
(16:43):
Remember how gravity works, It depends on the distance, right,
So the closer you are to the Moon, the stronger
the force of the Moon on you, and so on
the close side of the Earth, right, things are getting
pulled harder than on the far side of the Earth.
What happens is that every object ends up becoming sort
of not spherical, but look more like an ellipse al, right,
where the stuff that's on the closer side gets pulled up,
(17:05):
you know, to be closer, and the stuff that's on
the farther side isn't getting pulled as hard, and so
it stretches out sort of long ways that way, so
the Earth, instead of being a sphere, becomes a little obloid,
both closer to the Moon and away from the Moon.
That's where tides. That's where tides come from. Right, it's
not it's not the because the moon is going around
(17:26):
the Earth or both both things are. And the reason
the tides change is because the Moon is going around
the Earth and the tides follow it. Right, And uh,
you know the reason it's the water is just because
water is easier to move than rock. Right. It does
also slightly squeeze the Earth and change the shape of
the Earth, but that's a much smaller effect than just
changing the levels of the ocean, because obviously water is
(17:48):
much easier to squeeze than rock. I always wonder what
sort of actually happening when the tides go up and down,
you know, like it's it's the moon pulling on the
water and so the water becomes less dense or you
know what I mean, Like how does it go up?
It's more about where the water is on Earth. Right,
the you have you have the huge ocean, and all
(18:09):
the oceans are basically connected and sea level is not
a constant all the way around the Earth. Right, Sea
level is not the same distance from the center of
the Earth everywhere around the Earth. Because of the tides.
Some of the water is getting gathered together into a bigger,
deeper pile on some places, and it's getting slurped up
from other places. So you get less water in the
(18:30):
oceans on the sides and more water in the oceans
on the moon side and on the opposite side. It's
like it's recruiting water to where the Moon is. Yeah, exactly,
Like say you took all the water and you put
it in the Pacific Ocean, all the water from all
the other oceans, and put it in the Pacific Ocean.
Obviously that ocean would be deeper and the other ones
would be shallower. It's basically that on a much smaller scale.
(18:51):
So it's not a density thing, no, like there's less
gravity or more. Yeah, but the water it's kind of cool,
like the Moon is lifting the water, right, it's like
gathering the water together into a pile. Um. That's it's
a real size, you know. It sort of blows my mind.
The moon is big enough, given how far away it
is to actually like make piles of stuff on Earth
just due to its gravity. Yeah, that's true. I mean
(19:13):
it's a little circle in the sky and yet it's
pulling a bunch of water into space. Yeah, it's a
it's a big effect. And you know, people, um, some
biologists give tides a big role in the development of life. Yeah,
because one theory goes that, you know, in the sort
of primordial soup rehabl these organic materials float around in oceans,
(19:34):
that the tidal regions are the best place for life
to start because the water is sort of mixing a lot, right,
you get the tides coming in and out, and you're
getting a lot of waves and splashing, and you get
like periods, Yeah, a lot of churn exactly. And so
I mean I think it's just speculation. I think people
think that tides play a role in the development of life.
You know, we can't go back and do the other
(19:55):
experiment like delete the moon, run the Earth simulation and
see if life takes long reach developed. But it's a
cool idea, right, I mean, like life wouldn't just develop
in a lake or a pond. Yeah, they sort of
you need that sort of like motion to get things going.
And also they noticed that these brackish ecosystems where you
mix fresh and salt water and those get mixed due
(20:15):
to tides, those that have the most diversity. And so
I think that's another argument that the origin of life
on Earth was affected by tides. All right, So if
we didn't have the Moon, we wouldn't have ties, not quite.
That's the fascinating thing is that you delete the Moon,
tides are not gone. They're just smaller. And the reason
is that we also have tides because of the Sun. What, Yeah,
(20:38):
the Sun. It makes perfect sense, right. The Sun is
much further away but much much huger than the Moon,
and it also pulls on the Earth, obviously, and so
it pulls stuff closer to it more strongly and stuff
on the opposite side less strongly, and so it does
the same thing to the Earth's oceans that the Moon does,
but of course in a slightly different angle. Right, So
(21:00):
you have the tides on Earth are complicated because you've
got the little tides from the Sun and you've got
the big tides from the Moon. And you know, that's
why the tides sometimes are smaller than others. Wow, I
had no idea, and we thought about it before it's
I guess, you know, I guess the sun. It seems
so far away and so little in the sky, but
it's really swinging the earth around like a slingshot, and
(21:22):
so some of them must affect the water on the surface.
Absolutely does. So we would still have tides without the moon.
We just wouldn't have as strong a tide, and the
tides will be more regular because we have this complicated
two body effects where you have two different things with
two different periods, sometimes adding up to each other, sometimes
contradicting each other. Right, so we have more complicated tides
(21:42):
and larger tides because we have the moon and the sun.
So we would have smaller tides or like half as
much or like a tent. What do you think. I
think it's about a quarter. Yeah, I think the moon
is the majority of the tides, but the sun is
a is a non negligible effect. So maybe we wouldn't
miss it in that way, or maybe life could have
still developed without the moon. Yeah, probably probably. And the
(22:04):
moon and the tides have a lot of effect on
the atmosphere as well, right, not just the water, but
it affects the tides and and the just the gravitational
pull of the Moon. It squeezes the atmosphere and affects
things like global currents and uh, and so you get
a lot more mixing just in general in the atmosphere
because you have the Moon. And so people speculate that
(22:25):
if you didn't have the Moon, not only would you
not have tides, you have different patterns of global currents
and you have stronger regional weather patterns because it wouldn't
be as much sort of global mixing and evening out
of stuff, all right, so it would affect the tides,
but maybe not completely. And what else would happen if
the moon disappeared, Well, obviously we wouldn't have eclipses, right,
Like you know, without the moon, you can't get the
(22:46):
Moon's shadow on the Earth either kind of eclipse, like
a lunar eclipse. That's true, you need the moon for both.
And you might scoff at that, but you know, eclipses
are they're they're kind of amazing events. I had the
opportunity to be in the full eclipse region for the
last one, and I was shocked at how how sort
(23:07):
of deeply spiritual event it was for me, somebody who's
not really very spiritual at all. And I think that
eclipses in history have also inspired a lot of thinkers
and and astronomers, early astronomers, and so I think, um,
without having eclipses, we would have a bit of a
different culture. Do you think it would have affected our
scientific development? You know, like with having the moon there,
(23:28):
God is thinking about planets and orbits and you know,
bodies and mass and motion, right, because didn't Newton sort
of used the moon in his thinking about gravity. Absolutely,
I think it's vital because there's this incredible step in
human history and physics that that Newton accomplished, connecting motion
(23:49):
of stuff on Earth to motion of stuff in the sky, right,
to say, maybe the same rules that apply here on
Earth also apply to stuff in the sky. And that's
a much easier leap to make if you can see
stuff in the sky that seems concrete, right, The stars
and all that stuff, they're just tiny dots. You have
no idea that they're really things, or they're just lights
up in some some ceiling. But the moon looks like
(24:10):
a thing, right, it looks like a big rock. It's immediate,
it's there, And so I think it's very helpful for
early thinkers to understand that the stuff out there in
the sky was just more like the stuff here on earth.
Maybe God's thinking that maybe this guy is not just
a big canvas with pinpoints on them, right, Like, maybe
there are there are things out there and we and
(24:30):
we can understand them, right, they follow the rules that
we can figure out. That's an incredible moment in the
history of like human intellectual thought, right, that we could
understand the cosmos all right, So no eclipses smaller tides.
What else would happen if we said good night, Yeah,
well we would have darker nights. Right. The moon is
basically a big mirror for the sun, and so when
(24:52):
the sun is on the other side of the planet,
the moon provides a little bit of reflection of the
Sun's light. And so you know, we've all been out
on a on the night when you have a full
moon and it's much easier to see. And there's a
lot of animals that rely on the moon. But it
affects some animals in a good way and some in
a bad way. Right. Yeah. For example, some animals like owls, right,
(25:13):
they hunt at night, right, and they use the moonlight.
They have very powerful eyes. But they need some light,
and so owls have to hunt by only starlight, then
you know they're not going to find as many rats.
And so conversely, getting rid of the moon would be
good for rats because they've mostly come out at night
to find their food and their main predator is owls,
(25:36):
and so if it's darker than it's easier to scurry
along and you know, find that pizza on the on
the New York subway or whatever. So if you are
a pro rat, this would be a good thing. If
your pro owls. You make that sound like pro rat
is impossible, I am pro rat, because no I am.
You may not be aware, but we actually have rats
as pets at home. Yeah, yeah, I think I remember.
(25:58):
So rats are very sweet, very purpose We got them
on purpose. Yes, um, they're very sweet, very intelligent, very loving,
very smart little creatures. Actually, all right, so you're in
the pro And also because while the moon played some
role in, you know, helping us think about the cosmos,
it's actually kind of annoying from an astronomical point of
(26:20):
view because you can ruin a nice dark night, which
is you couldn't You can't see the stars very well. Yeah,
like I've gone camping sometimes, and one of my favorite
things by camping, he's getting to look up at the
night sky and seeing a really dark night, because it's
incredible how many stars are out there, right, And most
people who live in big cities, they have no idea
how many stars are visible in the night sky. But
(26:41):
when you go out in the middle of nowhere and
you're far from everything and you can finally see the
Milky Way in all of its beautiful glory. But then
there's the moon and all you can see is the
moon and nothing else, you know, watching it exactly, and
so us for romantic physicists, it's beautiful. No, you're right.
I was just a cat thing the other day, and
(27:01):
you know, I remember looking up and seeing the milk
away and it was amazing, and my kids were super impressed.
I hadn't thought about it back then, but you're right.
I think it was a moonless night, and if the
moon happened out, we we wouldn't have seen these things.
All right. Let's get into what else would happen if
we lost the moon, And this one is a little
bit more serious. I have to say it would actually
(27:23):
affect you on a daily basis. But first let's take
a quick break, all right. We're talking about what would
happen if the moon disappeared, and we've talked about smaller tides,
(27:45):
no eclipses, which would be a bummer for poets and
um ancient civilizations perhaps, and darker nights. But there is
sort of a serious consequence to having no moon, right, yeah, exactly.
This is a bit of speculation based on modeling people
have done, But it seems like having a moon plays
(28:05):
a big role in the Earth's rotation and in its tilt. Right,
So the Earth spins around once a day, but it's
also tilted off of its axis, right, which is why
we have seasons. Like sometimes you're tilted a little bit
closer to the sun, sometimes you tilt a little further
from the Sun. And so the Earth's rotation controls the
length of the day, and it's tilt controls the the
(28:26):
magnitude of our seasons. And as we were talking about before,
the Earth and the moon are part of a complicated
system of anglar momentum, and and it seems like having
a moon makes the Earth's situation a little bit more stable.
Like planets without a moon, it's easier for their tilt
to change, like we could the way we're spinning around
(28:48):
in place, not just around the Sun, could change, like
we could tilt more towards the Sun or away from this. Yeah, exactly.
We're more susceptible, for example, being struck by rocks or
this kind of stuff. And the only way we could
absorb the angular momentum of some like impact or something
would be by the Earth changing its tilt or changing
its rotation speed. But if you have a moon, you
(29:09):
have a more complicated system that can absorb it in
other ways. And so you know, if it's some big buffer,
it's like a gravitational buffer. Yeah exactly, it's like a
gravitational buffer, and you can dump some of that stuff
into the moon, like well, make the moon spin faster
or make the Moon go around a little faster or whatever,
and so without affecting that. Yeah, And so it seems
like having a moon makes the whole system a little
(29:31):
bit more stable for the Earth. So you know, we
could end up like if we lost our moon, we
could end up in a situation where we have no tilt, right,
which means we have like no seasons, right, because the
tilt is what gives you seasons, right, yeah, exactly. The
tilt of the Earth relative to the Sun means sometimes
the people in the north are closer to the Sun,
and sometimes means they're further away from the Sun. Right, Yeah,
(29:54):
So if we lost our moon, we'd lose a bit
of our gravitational angle momentum buffer, and we'd be more
susceptible to some of these big changes, which could have
like obviously huge effects on the climate and survivability of
the Earth, well beyond whether rats can get gobbled up
by owls or whether or not Jorge can see the
Milky Way on his camping trip. There will be no seasons,
(30:14):
or there could be crazy extreme seasons, which and maybe
that those kinds of things wouldn't support light, right, it
would be Um, it would be a big deal. Yeah,
all right, Daniel, So, um, those are all pretty cool. Um,
but I'm a little bit worried now should I be worried?
Is the moon going to be going away anytime soon?
All these things are fun to think about, you know,
(30:35):
interesting to sort of probe the physics of the situation,
But none of these things are very likely to happen. Right,
We've been watching the skies for a long time. We're
pretty sure that there are no big rocks headed for
us that are likely to obliterate the Moon. It would
be pretty surprising if that happened. As long as we
are friendly to the programmers who run the stimulation and
(30:55):
they don't just decide to delete the Moon from our existence,
then I think we can on having the Moon for
you know, a lot longer. In fact, I was thinking
it would be kind of a best case scenario. Actually,
if like an asteroid hits the Moon and knocks it
out of orbit, that's like a good thing because it
means that then it hit hit up exactly exactly. We
sort of use up our buffer on that one asteroid
(31:16):
and we'd be totally vulnerable to the next one. Be
like those movies where the bullet it is headed is
headed towards you, but then somebody runs in and inters,
that's right exactly, and you lose that person, but at
least you didn't get shot the target. Greats are like,
we'll save you, that's right. So maybe thanks to the
Israelis for founding the lunar colony. Cool. But I'd imagine
(31:43):
also that even if we lost the Moon through whatever reason,
it doesn't sound like immediate death for us. You know,
it would mean changes in patterns and tides and seasons,
but maybe not immediate like we're dead in the war. Yeah,
it would not be immediate death. We have some time
to adjust and you know, even if the earth seasons
(32:03):
get more dramatic, we'll figure it out. You know. Think
about the careful, considered way that we're dealing with climate
change right now. Doesn't that give you confidence that we'll
be able to handle something like that? Sarcasm, sarcasm, sarcasm,
that's what a sarcastic physicistm There you go. No, but
this is definitely solidly in the fun to think about
(32:23):
but not actually worry about category. All right, Well, so
if you're a rat lover you can rest at ease.
Then all those rats out there are no, wait, you
should be worried. You don't need to worry about. Sorry.
If you're a rat lover, then uh, I'm sorry. We
can can't get me any time. You know what, rats
are going to survive longer than we are, I think.
(32:44):
All right, thanks for tuning in, and thank you for
sending these fascinating questions. If you have a question about
a crazy hypothetical situation, you'd like us to work out
in details, send it to us at questions at Daniel
and Jorge dot com. So in the meantime, go out
there and look at the moon and appreciate its beauty
or its absence if you want to be at the stars.
And that's right and the Milky Way. Moons are something
(33:08):
you never appreciate until you lose them. I hope you
enjoyed it, See you next time. If you still have
a question after listening to all these explanations, please drop
us a line. We'd love to hear from you. You
can find us at Facebook, Twitter, and Instagram at Daniel
(33:28):
and Jorge that's one word, or email us at Feedback
at Daniel and Jorge dot com. Thanks for listening and
remember that Daniel and Jorge Explain the Universe is a
production of I Heart Radio. For more podcast from my
Heart Radio, visit the I Heart Radio app, Apple Podcasts,
or wherever you listen to your favorite shows. Yeah
Hey, Daniel, what's your favorite thing about looking at the
night Scott? You know, I should probably say something inspirational
about physics, etcetera. But honestly, being a family man, my
favorite thing is that it means my kids are probably asleep.
That's what the night sky means to you, that they're
safely touch dead exactly? Or do you mean actually asleep?
It's time for the adult portion of the day. That
(00:30):
sounds that's sounds kind of racing, trust me, in my
evening is not that exciting. But do you mean like
they're in bed or they're just sleep or what makes
it calm? Well, they're in bed and they're quiet. That's
all I really care about. Honestly, whether they're asleep or
not is their business now. But seriously, let's say, like
you're leaving the night Skuy, what does it make you
think of as a physicist, as an explorer, as a
(00:51):
as a thinker. You know, it makes me think about vastness,
the hugeeness of space, of course, you know, but also
like the vastness of time. I mean, you can see
time in the sky, know what. I love that when
you look at the sky it's basically the same sky
the people have been looking at and wondering about. For
as long as people have been looking and wondering, you know,
(01:12):
it hasn't changed that much. I have a question for you,
what if it wasn't? What if our night sky changed?
We Well, that'd be amazing. But as long as my
kids stay in bed and stay quiet, I'd be cool
with it. Hi am or Hammet cartoonists and the creator
(01:41):
of PhD comics. Hi. I'm Daniel. I'm a particle physicist,
a parent, and someone who likes to look up at
the night sky and enjoy the quiet, vastness of space.
And something we also share in comming is that we're
are the co authors of the book We Have No Idea,
a guide to the Unknown Universe. So if you are
wondering about it, we don't know what physicists I have
(02:02):
no idea about in our great, big universe. Please check
out that book. It's a lot of fun and it
features a lot of Jorges hilarious cartoons, so check it out.
It's what neither a physicist nor a cartoonist knows about
the universe. It also features a lot of Daniel's hilarious physics,
so if you're into both hilarities, please check it up.
(02:23):
But today, welcome to our podcast Daniel and Jorge Explain
the Universe, a production of I Heart Radio. That's right,
our podcast in which we think about all the things
that are surrounding us, all the things up in the
sky and down here on Earth, and try to explain
them to you in a way that makes you laugh
and hopefully illuminates your understanding of the world around us. Yeah,
and we also think about the big what if questions
(02:45):
in the universe, or if we can't use what if
because it's copyrighted by Random Monroe of XKCB, we also
tackle the what would happen is of the universe. We
consider ourselves sort of breeding ground for the next generation
of disaster movies by Michael Bay. You've done the Huge Shark,
You've done the Crazy Storm. What's next, the big Asteroid?
(03:08):
That's right, he's done that already, So we are just
generating ideas for the next summer blockbuster. I think it's
something a lot of people maybe wonder about out there.
You know, what could be the next huge thing that
could happen in this crazy, chaotic universe that might affect
my life? And you don't have to speculate. I know
the people out there wonder because they write to us
about it. We get emails people asking us. For example,
(03:31):
we did an episode recently about what would happen if
the Sun became a black hole? That's an honest question
that a bunch of people wrote in. People wonder about
these things. It's on people's minds. You know, things around
us seems stable, but what if something happened? And so
this might be another one in our series of what
would happen if and so to be on the podcast,
we are going to be answering the question what would
(03:58):
happen if the Earth lost its moon? Goodbye, mone, goodnight Moon.
That's right, although these days, you know you have to
say not to say good night to the moon. You
have to say good night to the moon. And it's
first colonizers by the Chinese. What do you mean there
are living things on the moon now because of us? Yes? Uh.
(04:19):
The Israeli's crash landed a probe on the moon, and
on that probe we're tarte grades, little water bears, and
so now we are just awaiting our lunar overlords, the
coming of the Tartar Grade civilization. Oh my god, what
(04:39):
a disaster, you know, I know, So be careful with
your science, folks, you may accidentally seed a new civilization
which destroys ours. Oh my good and Tarti grades are
super scary. Oh they're so cute. We're gonna do an
episode about Tartar grades in the next few weeks, so
tune in for that one. But to think about it,
as we talked about tonight, Remember the Moon is no
(05:00):
longer a lifeless rock. It is now home to about
a hundred little targegrades. Do you think they deserve their
own country? I think Donald Trump will probably try to
buy it. Yeah, Hey, if I can buy Greenland, why
can't I buy the Moon. They'll flash a signed they'll
make a formation on the surface of the Moon saying
we are not for We're not for sale exactly. But
(05:21):
it's an interesting question. You know, the moon is a
big fixture in our lives, in our skies, in mythology,
in romance. So what would happen sort to the human
psyche and to life on Earth if the Earth lost
its moons. It's a totally reasonable question. And you're saying
this was a listener question as well. Somebody some people
wrote this in yeah. Absolutely. People wrote this in and
(05:42):
and wanted to know, And as soon as I read it,
I thought that's a good question. I wonder how life
would change on the on the surface of the Earth
if we lost our moon. So I had to do
some research. It was a lot of fun actually, so
thank you folks for reading in this questions in aside, Daniel,
I think that's the title of our third book, what
would happen? What would happen? If? What would happen if
a physicist and a cartoonists got paid to make three books?
(06:05):
It would never happen. But I just wanted to get
a review of our book from one of the hard
grades on the moon. It's a life goal for me.
So that's what we will be talking about today, is
the question what would happen if the Earth lost its moon?
Like if it suddenly disappeared, Daniel, or if it, you know,
got knocked off and flew off or what do you
think they were thinking when they asked the question. I
(06:25):
don't know. I read a book recently by Neil Stevenson.
It's a great book. It's called Seven Eaves, in which
is the moon is demolished and all the rubble rains
down on Earth. That's pretty bad scenario. So it might
be that people are reading that book and wondering about it.
Um or you know, just if the moon was like
flung out in the space and got hit by an
aster and deflected. And there's lots of different scenarios, but
(06:46):
we'll dig into all of them. Wasn't that also a
plot point in Avengers in Finny War, like Thanos reaches
out and he grabs a moon and he brings it
down on the Avengers. I do watch these movies, but
they're like seventeen hours long, so I don't remember every
plot point. But that's a pretty interesting question. And I
imagine people think a lot of things would happen, or
maybe nothing would happen. Yeah. So, actually, before I didn't research,
(07:09):
before I even had an idea of my own, I
went out and I asked folks what they thought would
happen if the Earth lost its moon? And where were
you in the world when you ask these questions, or
even on the way you were as I was crash
landing on the Moon when I asked these questions. No, um,
here these questions were answered in some combination of Heathrow
Airport and random cities in Portugal. Cool. So think about
(07:31):
it for a second. What do you think would happen
if the Earth lost its moon? Here's what people had
to say. We wouldn't have moonlight. Well, I guess the
tides would be out of balance and we should have
floods coming. Yeah, because the whole stability of the whole
system will fail, and then the Earth will lose the
(07:53):
momentum and the oceans will I don't know what, but
it's not possible to life on Earth without the moon.
Life on Earth could theoretically survive. It is possible we
could survive without a moon. However, climates would be much
more unstable. I think it wouldn't be too bad for
(08:16):
life on Earth except for those title creatures. Does the
moon impact our seasonal change? No, I don't think so,
although at nighttime it does make the evening flowers blue.
All right, it seems like only bad things would happen.
That's what people guessed. But he said, like, great, I
(08:36):
hate the moon, Good riddance. Yeah, that's true. The moon
has a good good Um, it's pretty favorable. I guess.
I wonder if people ever do surveys like rate the
favorability or unfavorability of astronomical objects. What's the most popular
place to vote for this candidate or for the moon?
Who would you want to be as your president? But
what do you think is the most popular astronomical object?
(08:58):
But if you ask people like which object and this
guy would you delete if you had to delete one?
Because which is the least popular aspect of object? Least popular?
It's like those surveys online like what's your most popular
movie that you love or the most popular movie that
you hate? Yeah? Which all so writing folks, and let
us know which astronomical object do you love to hate? Pluto?
(09:21):
Probably poor Pluto? Um, but yeah, people people mostly said
negative things would happen, right, nobody would be happy if
the moon went away. And there's a big spectrum of
possible outcomes here, Like the person who said we wouldn't
have moonlight, like that's a disaster. You always like the
technical answers, the trivial technical answers, Right, Well, if we
(09:42):
didn't have a moon, we wouldn't have a moonlight. Technically true, yes,
but do you think he meant that more like romantically?
That like romance would be affected on Earth if there
was no moonlight. It probably would be. Yeah, they'd probably
be a different cycle of of conception and birth if
there wasn't a moonlight icon um. But yeah, that's a
great question. We'll be talking about what would happen physically, right,
(10:05):
not necessarily biologically or romantically, but kind of like, how
would the physics of our everyday life change if the
Moon suddenly disappeared? Well, Daniel, let's step through it first.
First of all, could it happen, Like, could our moon
just disappear or move away or float away? There are
lots of ways that we could lose our moon, right, um.
Number one, if something hits the Moon, you know, really
(10:27):
big asteroid or something. The Moon is an orbit around
the Earth, but that's a little bit delicate, right. It's stable,
but if it gets knocked out of orbit, it's pretty
tough to get back into orbit. So yeah, you could
get deflected. You mean, like an orbit is a very
delicate thing, right, Like it's something that you could easily
fly away or crashing into the planet if you disturb
the orbit. Yeah, exactly, of all the possible trajectories around
(10:49):
the planet, there's a very tiny fraction them that are
a stable orbit, right, And so you change your trajectory,
and you know, pretty sure soon you're sling shotting around
the planet and then off into space or something. But
you know, the Moon is hit all the time, that's
why it's covered in craters. Usually it's just hit by
a little rock and it doesn't change its motion significantly.
But there are bigger rocks out there, and if one
(11:09):
of them hit the Moon, then it could get deflected
into outer space. Sure, how big do you think it
would of a rock would it take to knock the
Moon out of orbit? I haven't done any calculations, but
you know, I think it has to be pretty substantial.
You know, you're talking something like, you know, hundreds of
meters wide are really a really pretty big solid rock.
And we're sort of I heard also we're kind of
(11:29):
losing the Moon anyways, Like the Moon doesn't want to
be around really, it's sort of edging slowly for another
planet in a way out of the party. They're like,
all right, you guys are kind of crazy. I am
gonna slowly move over to Mars because yeah, there's a
(11:51):
good party going on on Venus. So see you later.
Text you. Um, No, we're losing the Moon. It's not
actually in a totally stable orbit. It's getting further away
every year, but just by a tiny amount, just by
a few centimeters. I looked it up. It's about four
centimeters per year. And that's just the way it is.
It's it's like in an orbit that is not stable.
(12:12):
It's not in an orbit that self corrects or stays
in its lane the whole time. It's like in a
spiral outward away from the Earth. That's right. And you
have to remember that the Earth and the Moon are
a system, right. They're both orbiting the center of mass
of the Earth of the Moon. Like imagine if the
Moon and the Earth at the same mass, then their
center of mass would be between them, literally, and they
(12:34):
would both be moving around that point. But they're not
the same mass. The Earth is much much heavier than
the Moon, and so the center of mass of the
two is closer to the center of the Earth. So
but the two are really orbiting this point that's a
slightly offset from the center of the Earth. And they're
both spinning. So it's a big complicated system and energy
is moving from one part of it to another, and
(12:54):
so the Moon's rotation gets further out right. Um, But
that all so means it gets more angular momentum. So
the angle momentum has to come from somewhere. So as
the Moon get drifts away, the Earth actually slows down
a little bit. I mean the days get longer. Yeah,
it's complicated, it's complicated, and so this you know, this
(13:14):
whole system is not entirely stable, but it's a little
bit stable. It actually turns out it's more stable. You
get fewer fluctuations. We'll talk about it more in depth later,
but it plays a big role in keeping the Earth
in a sort of a stable rotation and and spin.
I have been feeling like that are my days are
are getting longer? You know, I just don't have the
same energy I had before when I was younger. I
(13:36):
don't know why you need more bananas. Most people feel
like as they get older, the days just fly by.
So that's one way the Moon could disappear. It could
literally get knocked off course and fly away, or it
is sort of slowly moving away. What are some other
ways of the moon we could lose the moon? Well,
the most catastrophic would be if it got hit by
a rock and it didn't get deflected into space, but
(13:57):
it got like broken up the Moon and is is
you know, not as like strong as the Earth is
size well held together. It's more of a pile of
rubble than the Earth is because it doesn't have like
inner magma and all that stuff, and so it could
get broken up. And that's exactly what happens in that
novel we were talking about earlier, seven Eves. Neil Stevenson
does like fantastic research for his novels. I've never found
(14:20):
a physics mistake in any of them, and I read
them very carefully. And in that people at first were like, wow, cool,
Look the Moon is exploding and there's all these shooting stars.
But then quickly they realized, oh, this is just a
bunch of rocks raining down on the Earth, and that's
not good. The Moon turned into shooting stars and all
that rained down on the Earth, it would heat of
the atmosphere and a lot of those pieces would land,
(14:41):
and you know, it's like getting hit by a by
a planet killer. Would it necessarily crash into Earth? Like
wouldn't like if the Moon cracked into two, wouldn't necessarily
crash down? Or would the two houses keep going around
the same orbit. It depends a lot on how the
cracking happens. If you like exactly cracking in place, then yeah,
they could keep orbiting just sort of cracked. But if
it's a big collision, then some of it's going to
(15:04):
get blown out into space, and some of it's gonna
turn into a ring around the Earth because some of
it will find a stable orbit, but a lot of
it will just fall into the gravity well of Earth
and land on Earth and kill a bunch of people.
So not a happy scenario. So don't shoot the moon.
Don't shoot the moon. That's right. Then shoot for the
moon or add the moon. Unless you're playing hard, you're
welcome to shoot the moon, but if you are in
(15:25):
possession of a moon busting rocket, please do not shoot
the moon. Alright, So it could maybe happen, And so
let's dig into what would happen if the Moon disappeared,
either by some physical process or just in our imaginations,
if somebody snapped their finger and their moon just disappeared.
What would happen to us here on Earth? But first
let's take a quick break, all right, Daniel, we're talking
(16:00):
about what would happened of the moon disappeared, and from
a physics point of view, what would happen to the
Earth if the Moon suddenly flew away or suddenly, um,
I don't know, collapse, if the masters of the simulation
just deleted it somehow. Yeah. Well, one of the most
immediate things the effects of the Moon on life on Earth,
(16:21):
of course, is it's gravity. Right. The Moon is a
big ball of stuff and it has gravity, and that
gravity pulls on the Earth, and it's a lot of
people probably know that Moon causes tides on the Earth
because it's pulling on the water that's on the Earth,
and it's literally lifting it up a little bit off
the surface, like sucking up the water up right. Yeah, exactly.
(16:43):
Remember how gravity works, It depends on the distance, right,
So the closer you are to the Moon, the stronger
the force of the Moon on you, and so on
the close side of the Earth, right, things are getting
pulled harder than on the far side of the Earth.
What happens is that every object ends up becoming sort
of not spherical, but look more like an ellipse al, right,
where the stuff that's on the closer side gets pulled up,
(17:05):
you know, to be closer, and the stuff that's on
the farther side isn't getting pulled as hard, and so
it stretches out sort of long ways that way, so
the Earth, instead of being a sphere, becomes a little obloid,
both closer to the Moon and away from the Moon.
That's where tides. That's where tides come from. Right, it's
not it's not the because the moon is going around
(17:26):
the Earth or both both things are. And the reason
the tides change is because the Moon is going around
the Earth and the tides follow it. Right, And uh,
you know the reason it's the water is just because
water is easier to move than rock. Right. It does
also slightly squeeze the Earth and change the shape of
the Earth, but that's a much smaller effect than just
changing the levels of the ocean, because obviously water is
(17:48):
much easier to squeeze than rock. I always wonder what
sort of actually happening when the tides go up and down,
you know, like it's it's the moon pulling on the
water and so the water becomes less dense or you
know what I mean, Like how does it go up?
It's more about where the water is on Earth. Right,
the you have you have the huge ocean, and all
(18:09):
the oceans are basically connected and sea level is not
a constant all the way around the Earth. Right, Sea
level is not the same distance from the center of
the Earth everywhere around the Earth. Because of the tides.
Some of the water is getting gathered together into a bigger,
deeper pile on some places, and it's getting slurped up
from other places. So you get less water in the
(18:30):
oceans on the sides and more water in the oceans
on the moon side and on the opposite side. It's
like it's recruiting water to where the Moon is. Yeah, exactly,
Like say you took all the water and you put
it in the Pacific Ocean, all the water from all
the other oceans, and put it in the Pacific Ocean.
Obviously that ocean would be deeper and the other ones
would be shallower. It's basically that on a much smaller scale.
(18:51):
So it's not a density thing, no, like there's less
gravity or more. Yeah, but the water it's kind of cool,
like the Moon is lifting the water, right, it's like
gathering the water together into a pile. Um. That's it's
a real size, you know. It sort of blows my mind.
The moon is big enough, given how far away it
is to actually like make piles of stuff on Earth
just due to its gravity. Yeah, that's true. I mean
(19:13):
it's a little circle in the sky and yet it's
pulling a bunch of water into space. Yeah, it's a
it's a big effect. And you know, people, um, some
biologists give tides a big role in the development of life. Yeah,
because one theory goes that, you know, in the sort
of primordial soup rehabl these organic materials float around in oceans,
(19:34):
that the tidal regions are the best place for life
to start because the water is sort of mixing a lot, right,
you get the tides coming in and out, and you're
getting a lot of waves and splashing, and you get
like periods, Yeah, a lot of churn exactly. And so
I mean I think it's just speculation. I think people
think that tides play a role in the development of life.
You know, we can't go back and do the other
(19:55):
experiment like delete the moon, run the Earth simulation and
see if life takes long reach developed. But it's a
cool idea, right, I mean, like life wouldn't just develop
in a lake or a pond. Yeah, they sort of
you need that sort of like motion to get things going.
And also they noticed that these brackish ecosystems where you
mix fresh and salt water and those get mixed due
(20:15):
to tides, those that have the most diversity. And so
I think that's another argument that the origin of life
on Earth was affected by tides. All right, So if
we didn't have the Moon, we wouldn't have ties, not quite.
That's the fascinating thing is that you delete the Moon,
tides are not gone. They're just smaller. And the reason
is that we also have tides because of the Sun. What, Yeah,
(20:38):
the Sun. It makes perfect sense, right. The Sun is
much further away but much much huger than the Moon,
and it also pulls on the Earth, obviously, and so
it pulls stuff closer to it more strongly and stuff
on the opposite side less strongly, and so it does
the same thing to the Earth's oceans that the Moon does,
but of course in a slightly different angle. Right, So
(21:00):
you have the tides on Earth are complicated because you've
got the little tides from the Sun and you've got
the big tides from the Moon. And you know, that's
why the tides sometimes are smaller than others. Wow, I
had no idea, and we thought about it before it's
I guess, you know, I guess the sun. It seems
so far away and so little in the sky, but
it's really swinging the earth around like a slingshot, and
(21:22):
so some of them must affect the water on the surface.
Absolutely does. So we would still have tides without the moon.
We just wouldn't have as strong a tide, and the
tides will be more regular because we have this complicated
two body effects where you have two different things with
two different periods, sometimes adding up to each other, sometimes
contradicting each other. Right, so we have more complicated tides
(21:42):
and larger tides because we have the moon and the sun.
So we would have smaller tides or like half as
much or like a tent. What do you think. I
think it's about a quarter. Yeah, I think the moon
is the majority of the tides, but the sun is
a is a non negligible effect. So maybe we wouldn't
miss it in that way, or maybe life could have
still developed without the moon. Yeah, probably probably. And the
(22:04):
moon and the tides have a lot of effect on
the atmosphere as well, right, not just the water, but
it affects the tides and and the just the gravitational
pull of the Moon. It squeezes the atmosphere and affects
things like global currents and uh, and so you get
a lot more mixing just in general in the atmosphere
because you have the Moon. And so people speculate that
(22:25):
if you didn't have the Moon, not only would you
not have tides, you have different patterns of global currents
and you have stronger regional weather patterns because it wouldn't
be as much sort of global mixing and evening out
of stuff, all right, so it would affect the tides,
but maybe not completely. And what else would happen if
the moon disappeared, Well, obviously we wouldn't have eclipses, right,
Like you know, without the moon, you can't get the
(22:46):
Moon's shadow on the Earth either kind of eclipse, like
a lunar eclipse. That's true, you need the moon for both.
And you might scoff at that, but you know, eclipses
are they're they're kind of amazing events. I had the
opportunity to be in the full eclipse region for the
last one, and I was shocked at how how sort
(23:07):
of deeply spiritual event it was for me, somebody who's
not really very spiritual at all. And I think that
eclipses in history have also inspired a lot of thinkers
and and astronomers, early astronomers, and so I think, um,
without having eclipses, we would have a bit of a
different culture. Do you think it would have affected our
scientific development? You know, like with having the moon there,
(23:28):
God is thinking about planets and orbits and you know,
bodies and mass and motion, right, because didn't Newton sort
of used the moon in his thinking about gravity. Absolutely,
I think it's vital because there's this incredible step in
human history and physics that that Newton accomplished, connecting motion
(23:49):
of stuff on Earth to motion of stuff in the sky, right,
to say, maybe the same rules that apply here on
Earth also apply to stuff in the sky. And that's
a much easier leap to make if you can see
stuff in the sky that seems concrete, right, The stars
and all that stuff, they're just tiny dots. You have
no idea that they're really things, or they're just lights
up in some some ceiling. But the moon looks like
(24:10):
a thing, right, it looks like a big rock. It's immediate,
it's there, And so I think it's very helpful for
early thinkers to understand that the stuff out there in
the sky was just more like the stuff here on earth.
Maybe God's thinking that maybe this guy is not just
a big canvas with pinpoints on them, right, Like, maybe
there are there are things out there and we and
(24:30):
we can understand them, right, they follow the rules that
we can figure out. That's an incredible moment in the
history of like human intellectual thought, right, that we could
understand the cosmos all right, So no eclipses smaller tides.
What else would happen if we said good night, Yeah,
well we would have darker nights. Right. The moon is
basically a big mirror for the sun, and so when
(24:52):
the sun is on the other side of the planet,
the moon provides a little bit of reflection of the
Sun's light. And so you know, we've all been out
on a on the night when you have a full
moon and it's much easier to see. And there's a
lot of animals that rely on the moon. But it
affects some animals in a good way and some in
a bad way. Right. Yeah. For example, some animals like owls, right,
(25:13):
they hunt at night, right, and they use the moonlight.
They have very powerful eyes. But they need some light,
and so owls have to hunt by only starlight, then
you know they're not going to find as many rats.
And so conversely, getting rid of the moon would be
good for rats because they've mostly come out at night
to find their food and their main predator is owls,
(25:36):
and so if it's darker than it's easier to scurry
along and you know, find that pizza on the on
the New York subway or whatever. So if you are
a pro rat, this would be a good thing. If
your pro owls. You make that sound like pro rat
is impossible, I am pro rat, because no I am.
You may not be aware, but we actually have rats
as pets at home. Yeah, yeah, I think I remember.
(25:58):
So rats are very sweet, very purpose We got them
on purpose. Yes, um, they're very sweet, very intelligent, very loving,
very smart little creatures. Actually, all right, so you're in
the pro And also because while the moon played some
role in, you know, helping us think about the cosmos,
it's actually kind of annoying from an astronomical point of
(26:20):
view because you can ruin a nice dark night, which
is you couldn't You can't see the stars very well. Yeah,
like I've gone camping sometimes, and one of my favorite
things by camping, he's getting to look up at the
night sky and seeing a really dark night, because it's
incredible how many stars are out there, right, And most
people who live in big cities, they have no idea
how many stars are visible in the night sky. But
(26:41):
when you go out in the middle of nowhere and
you're far from everything and you can finally see the
Milky Way in all of its beautiful glory. But then
there's the moon and all you can see is the
moon and nothing else, you know, watching it exactly, and
so us for romantic physicists, it's beautiful. No, you're right.
I was just a cat thing the other day, and
(27:01):
you know, I remember looking up and seeing the milk
away and it was amazing, and my kids were super impressed.
I hadn't thought about it back then, but you're right.
I think it was a moonless night, and if the
moon happened out, we we wouldn't have seen these things.
All right. Let's get into what else would happen if
we lost the moon, And this one is a little
bit more serious. I have to say it would actually
(27:23):
affect you on a daily basis. But first let's take
a quick break, all right. We're talking about what would
happen if the moon disappeared, and we've talked about smaller tides,
(27:45):
no eclipses, which would be a bummer for poets and
um ancient civilizations perhaps, and darker nights. But there is
sort of a serious consequence to having no moon, right, yeah, exactly.
This is a bit of speculation based on modeling people
have done, But it seems like having a moon plays
(28:05):
a big role in the Earth's rotation and in its tilt. Right,
So the Earth spins around once a day, but it's
also tilted off of its axis, right, which is why
we have seasons. Like sometimes you're tilted a little bit
closer to the sun, sometimes you tilt a little further
from the Sun. And so the Earth's rotation controls the
length of the day, and it's tilt controls the the
(28:26):
magnitude of our seasons. And as we were talking about before,
the Earth and the moon are part of a complicated
system of anglar momentum, and and it seems like having
a moon makes the Earth's situation a little bit more stable.
Like planets without a moon, it's easier for their tilt
to change, like we could the way we're spinning around
(28:48):
in place, not just around the Sun, could change, like
we could tilt more towards the Sun or away from this. Yeah, exactly.
We're more susceptible, for example, being struck by rocks or
this kind of stuff. And the only way we could
absorb the angular momentum of some like impact or something
would be by the Earth changing its tilt or changing
its rotation speed. But if you have a moon, you
(29:09):
have a more complicated system that can absorb it in
other ways. And so you know, if it's some big buffer,
it's like a gravitational buffer. Yeah exactly, it's like a
gravitational buffer, and you can dump some of that stuff
into the moon, like well, make the moon spin faster
or make the Moon go around a little faster or whatever,
and so without affecting that. Yeah, And so it seems
like having a moon makes the whole system a little
(29:31):
bit more stable for the Earth. So you know, we
could end up like if we lost our moon, we
could end up in a situation where we have no tilt, right,
which means we have like no seasons, right, because the
tilt is what gives you seasons, right, yeah, exactly. The
tilt of the Earth relative to the Sun means sometimes
the people in the north are closer to the Sun,
and sometimes means they're further away from the Sun. Right, Yeah,
(29:54):
So if we lost our moon, we'd lose a bit
of our gravitational angle momentum buffer, and we'd be more
susceptible to some of these big changes, which could have
like obviously huge effects on the climate and survivability of
the Earth, well beyond whether rats can get gobbled up
by owls or whether or not Jorge can see the
Milky Way on his camping trip. There will be no seasons,
(30:14):
or there could be crazy extreme seasons, which and maybe
that those kinds of things wouldn't support light, right, it
would be Um, it would be a big deal. Yeah,
all right, Daniel, So, um, those are all pretty cool. Um,
but I'm a little bit worried now should I be worried?
Is the moon going to be going away anytime soon?
All these things are fun to think about, you know,
(30:35):
interesting to sort of probe the physics of the situation,
But none of these things are very likely to happen. Right,
We've been watching the skies for a long time. We're
pretty sure that there are no big rocks headed for
us that are likely to obliterate the Moon. It would
be pretty surprising if that happened. As long as we
are friendly to the programmers who run the stimulation and
(30:55):
they don't just decide to delete the Moon from our existence,
then I think we can on having the Moon for
you know, a lot longer. In fact, I was thinking
it would be kind of a best case scenario. Actually,
if like an asteroid hits the Moon and knocks it
out of orbit, that's like a good thing because it
means that then it hit hit up exactly exactly. We
sort of use up our buffer on that one asteroid
(31:16):
and we'd be totally vulnerable to the next one. Be
like those movies where the bullet it is headed is
headed towards you, but then somebody runs in and inters,
that's right exactly, and you lose that person, but at
least you didn't get shot the target. Greats are like,
we'll save you, that's right. So maybe thanks to the
Israelis for founding the lunar colony. Cool. But I'd imagine
(31:43):
also that even if we lost the Moon through whatever reason,
it doesn't sound like immediate death for us. You know,
it would mean changes in patterns and tides and seasons,
but maybe not immediate like we're dead in the war. Yeah,
it would not be immediate death. We have some time
to adjust and you know, even if the earth seasons
(32:03):
get more dramatic, we'll figure it out. You know. Think
about the careful, considered way that we're dealing with climate
change right now. Doesn't that give you confidence that we'll
be able to handle something like that? Sarcasm, sarcasm, sarcasm,
that's what a sarcastic physicistm There you go. No, but
this is definitely solidly in the fun to think about
(32:23):
but not actually worry about category. All right, Well, so
if you're a rat lover you can rest at ease.
Then all those rats out there are no, wait, you
should be worried. You don't need to worry about. Sorry.
If you're a rat lover, then uh, I'm sorry. We
can can't get me any time. You know what, rats
are going to survive longer than we are, I think.
(32:44):
All right, thanks for tuning in, and thank you for
sending these fascinating questions. If you have a question about
a crazy hypothetical situation, you'd like us to work out
in details, send it to us at questions at Daniel
and Jorge dot com. So in the meantime, go out
there and look at the moon and appreciate its beauty
or its absence if you want to be at the stars.
And that's right and the Milky Way. Moons are something
(33:08):
you never appreciate until you lose them. I hope you
enjoyed it, See you next time. If you still have
a question after listening to all these explanations, please drop
us a line. We'd love to hear from you. You
can find us at Facebook, Twitter, and Instagram at Daniel
(33:28):
and Jorge that's one word, or email us at Feedback
at Daniel and Jorge dot com. Thanks for listening and
remember that Daniel and Jorge Explain the Universe is a
production of I Heart Radio. For more podcast from my
Heart Radio, visit the I Heart Radio app, Apple Podcasts,
or wherever you listen to your favorite shows. Yeah
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
Las Culturistas with Matt Rogers and Bowen Yang
Ding dong! Join your culture consultants, Matt Rogers and Bowen Yang, on an unforgettable journey into the beating heart of CULTURE. Alongside sizzling special guests, they GET INTO the hottest pop-culture moments of the day and the formative cultural experiences that turned them into Culturistas. Produced by the Big Money Players Network and iHeartRadio.