StarTalk Radio - Things You Thought You Knew – Where the Sun Don’t Shine
Episode Date: July 25, 2023Does being in space mean there is no gravity? What does noon have to do with the Artemis Mission? Neil deGrasse Tyson and comedian Chuck Nice break down weightlessness, planetary alignments, and what ...is going on on the south pole of the moon. NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free.Thanks to our Patrons Tatiana Joine, Marcos Rodriguez, Peter Gordon, Leonard Leedy, RolandP, and Shimon Zig for supporting us this week.Photo Credit: NASA Apollo, Public domain, via Wikimedia Commons Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.
Transcript
Discussion (0)
You're in free fall.
Oh, wait, let me say something that makes me sound smart.
You will be falling to whatever pulls you, no matter where that is,
unless you happen to be in a Lagrange point.
Oh!
Oh!
Ah!
Oh!
Welcome to StarTalk,
your place in the universe where science and pop culture collide.
StarTalk begins right now.
This is StarTalk, Things You Thought You Knew Edition.
And of course, I'm doing this with my co-host, Chuck Nice.
So Chuck, I've done this experiment.
I ask people, where's the sun at 12 noon?
And invariably, more than half the cases, they point straight up.
Straight up.
High noon.
And what's odd is it means they've never looked.
Because for the entire continental United States, at no time of day and no day of the year is the sun ever directly overhead. You know why I think it's
difficult? Because it's hard to look at the sun. Yes, and you shouldn't look at the sun.
But you might notice maybe at noon, the shadows go away because it's pointing straight down.
True. But so it just means modern people just not observant. They'll repeat things they've heard.
True.
And puts the word high in front of noon,
leaves people thinking that it's directly overhead.
It's just not true.
It leaves some people thinking it's directly overhead.
It leaves other people thinking something totally different.
High noon, it's a very Western concept.
Yes.
It's where you kill a man in the middle of the day.
No, Chuck, no Western concept. Yes. It's where you kill a man in the middle of the day. No.
Chuck, no.
Stop.
No, it's where you have a shootout in the middle of the day.
Yes, that's true.
Whether or not anybody dies.
That's right.
True, true, true, true.
Right.
Meet you at high noon.
All right.
So there are places on Earth where the sun is occasionally directly overhead.
And it's between 23.5 degrees north latitude
and 23.5 degrees south latitude.
And 23.5 degrees is the tilt of Earth's axis in our orbit.
So that's where that number comes from.
If you go in that range, those are what we call the tropics.
And there are days of the year
where the sun is actually directly overhead.
Okay?
Cool.
If you're between those two zones.
Right.
And the Tropic of Cancer, which is the northern one, Tropic of Capricorn is the southern limit.
The Tropic of Cancer falls just below Key West.
Just below Key West.
Okay.
So that's why nobody in the continental United States
has ever...
Hawaii is about 15 degrees north latitude,
so Hawaii gets to experience this,
but not anybody else in the continental United States.
Okay.
The general trend here is
the farther away you are from the equator,
the closer you are to the poles,
the lower the noontime sun gets.
Gotcha.
Okay?
So, if in the tropics, it's occasionally directly overhead, as you inch your way out of the
tropics, the noontime sun gets lower and lower and lower in the sky.
Right. Right.
Okay.
Okay.
Now, that will change seasonally.
In New York City, where we live, where we record StarTalk,
the noon sun in the winter, on December 21st, first day of winter,
doesn't get more than 26 degrees above the horizon.
Ooh.
That's high noon, December 21st.
Wow.
Now you go to June 21st.
The high noon sun is higher, but still not directly overhead.
Gotcha.
All right, directly overhead would be 90 degrees up.
Right.
It's about, I got to look it up, 74 degrees, something like that.
Wow.
High.
That's high, but it's not still.
That's high, but that's a long way from directly overhead.
A long way from directly overhead. Wow. High. That's high, but it's not. It's high, but it's a long way from directly overhead. A long way from directly overhead. Okay. So, all I'm saying is that the highest the sun
gets on any day of the year is lower as you approach the pole. Okay? Gotcha. Okay. All right.
Okay.
All right.
So, you keep marching.
You get to the Arctic Circle.
Okay.
66.5 degrees of latitude.
There is a day where the sun never sets, and it stays that way throughout the summer.
And then it drops back down to the horizon, and then it goes below the horizon for the winter months.
And then it's not to be seen again.
Oh.
Until summertime.
Yeah.
So they basically just have day and night.
Yes, two seasons, day and night.
Exactly.
Day and night.
All right.
So now that makes an interesting fact.
Okay.
Let's go to the moon.
All right. Let's go to the moon and go to the moon. All right.
Let's go to the moon and go to the poles.
All right.
Okay.
Let's go to the South Pole.
No different.
We can go to the North Pole, but I got good stuff going on in the South Pole for this explainer.
Okay.
All right.
So, you go to the South Pole.
As you approach the pole, the sun, the height of the sun above the horizon doesn't get very high.
Right?
Just like I described
here on Earth.
Right.
Okay?
So, the noontime sun
in the south pole
of the moon
is very low
on the horizon.
Okay.
Are we there?
Okay.
I'm with you.
Now,
there are craters
on the moon.
Yes.
As you've surely seen.
Mm-hmm. Some craters on the moon. Yes. As you've surely seen. Mm-hmm.
Some craters are at the South Pole.
Okay.
There are craters everywhere, summer and the South.
Craters have rims.
Mm-hmm.
Okay.
Rims that stick up a little bit above the terrain.
Right.
All right.
Hmm.
Craters are deep. Right. All right. Hmm. Craters are deep.
Yes.
I got a deep crater and a rim, and I'm at the South Pole.
Oh, my gosh.
When the sun is up at the moon's South Pole,
it does not get high enough to peer above the rim of the crater.
So the base of some craters at the lunar south pole never, ever see sunlight.
Saw the sun.
Wow.
Okay.
So it is literally where the sun don't shine.
Okay.
Now.
There's another south pole where the sun don't shine. Okay. Now. There's another South Pole where the sun don't shine.
Just letting you know.
Okay.
Okay.
Okay.
So.
So.
Now, what's interesting on the moon is because there's no air
and there's no sky getting illuminated by sunlight.
Why do we have a blue sky?
Because light comes from the sun, scatters into the atmosphere.
So you say, oh, we have clear skies.
Actually, no.
You're looking at blue light scattered off of air molecules.
Right.
You're not actually looking at the universe.
Right.
The universe is cloaked by this scattered light.
And because the scattered light is everywhere,
if something is in a shadow, it's a little darker, but you can see it.
Because light's coming from everywhere other than the sun as well.
Right.
All right?
I mean, think about it.
If the sun were over to the left and there's a tree and the tree makes a shadow,
you shouldn't be able to see anything inside the shadow because the sun is not illuminating it.
It should be completely dark, but it's not.
Because light is coming from all the scattered light elsewhere in the atmosphere.
On the moon, where there is no atmosphere, there's no scattered light.
Shadows are pitch black.
Ooh.
All right.
That's actually kind of cool.
It is kind of cool.
It is kind of cool.
Unless you have something reflecting light into the shadow.
Right.
There's no scattered light from the atmosphere.
Oh, by the way, there are people who are sure we did not land on the moon.
And they looked at the photos of Neil Armstrong and Buzz Aldrin in daylight.
And they say, we know you're supposed to see stars in daylight.
And I don't see any stars in this photo.
Right.
Okay.
So, therefore, we didn't really go to the moon.
As though NASA wouldn't know to fake that if that were the case.
Oh, that's true.
Okay.
You think NASA are idiots?
That kind of makes a lot of sense.
If you know that, well, then we, the space people, definitely know it too.
Definitely know it too.
So why wouldn't we just throw little dots in the back and let them see some stars?
Okay, what the person doesn't know is how photography works.
The terrain is so bright from the sun, the aperture of the camera closes down
and cannot register the light of dim things such as the stars in the sky.
So that's why.
That's how that plays out.
There you go.
That's true.
That's absolutely the case.
All right, so let's get back to the South Pole.
So the sun not only doesn't shine there, you can't even see in it.
Right.
All right.
So now, what's making these craters?
Well, a meteor or something.
Something hit it.
Thank you.
I don't ask complicated questions.
Something hit it.
Something hit it.
Right.
Okay.
So meteors can be made of rock or they can be made of ice.
They're comet fragments that are out there.
So both can make these craters.
Right.
All right.
So now, if a comet hits the moon and the, so the material is now not rock.
It's like water and other ices like ammonia, ice, and things.
Let's focus on the water. The water molecules, there's a lot of energy there. It's like water and other ices like ammonia ice and things. Let's focus on the water.
The water molecules,
there's a lot of energy there.
It'll evaporate.
The water molecule flies up.
Okay?
And then falls back
to the moon's surface.
All right.
Right.
All right.
Well, if it falls
to a part of the surface
that's in sunlight,
it'll eventually evaporate
and escape.
Right.
But suppose it happens to fall where the sun don't shine.
It stays frozen.
It stays frozen.
Frozen is called a cold trap.
That's the official term for it.
Nice.
Cold trap.
And it falls in there and it stays there for billions of years.
Oh.
Let me say that right.
Billions of years. Billions of years. Oh. Let me say that right. Billions of years.
Billions of years.
And so the next mission to the moon,
Artemis, okay?
The one where we're going to land,
Artemis 3.
Right.
Okay, this is NASA's mission.
Artemis is the twin sister of Apollo.
And Artemis was the goddess of the moon and other related things.
So they're targeting the South Pole to land to check and verify that there's water there inside those craters.
We not only think there is theoretically, we have some measurements that there's likely water there.
And now we're going to go and verify for sure.
Because if there is, you don't need to bring water to the moon to drink.
Oh, look at that.
It's what's called ISRU, in situ resource utilization, which is a NASA thing.
And so.
Why bring sand to the beach?
Why bring water to the moon?
You ain't got to bring water to the moon. Right, right, right. I like that. Why bring sand to the beach? Why bring water to the moon? You ain't got to bring water to the moon.
Right, right, right.
I like that.
Why bring sand to the beach?
Very good.
There you go.
Unless your beach ain't got no sand.
It's a rocky beach.
It's a rocky beach.
Right, right.
So, all of this is related to the fact that the sun doesn't get very high in the sky at the poles.
That's all.
That's true.
That's why I started on Earth and I landed
on the moon for this explainer. That's very cool. That I love. I love it. That's why NASA,
we're checking out the South Pole. It'll be a geologically, chemically interesting
next place to visit. Wow. So we go to the moon to look for water in a cold trap.
In a cold trap. And they'll need their own lights to see their way around. Plus, it's not this way because it's like molecule deposits,
but you'd have to mine the water through the material.
You bring the lunar material through and sift out the water molecules,
and then you have a puddle of water.
What they could do is sprinkle the water back in and then go ice skating, maybe.
Oh, that'd be good.
That's kind of cool.
Unless it's too cold to ice skate. That could happen.
Hi, I'm Chris Cohen from Haworth, New Jersey, and I support StarTalk on Patreon.
Please enjoy this episode of StarTalk Radio with your and my favorite personal astrophysicist,
Neil deGrasse Tyson.
Every time you see a space movie or something and people are in space,
they're always weightless.
You ever notice that?
That's true.
And you know that because they're, well, if you're Sandra Bullock,
your hair is like an afro.
You got a little space afro going on.
Except she didn't.
Exactly.
In the movie Gravity, her bangs always seemed to know which way down was.
That's funny.
Even when everything else was floating in the capsule.
So it leaves people thinking that space equals no gravity.
Right.
It leaves people thinking that.
Like, you just go up into space, and all of a sudden, you're weightless.
Right.
And weightlessness is a very special condition for which you do not have to be in space to
achieve.
So I just want to just tease this out of people's misunderstandings.
I'm not going to push back on you.
I'm just going to say that maybe your people have something to do with this.
Here's why.
Whenever you see people, you know, in space, in the space station, whatever, they always say they're in zero G.
Well, we think zero G means zero gravity.
That's what we're going to think.
Correct.
It is zero G because there's no net gravitational force acting on them.
Okay?
No net.
There's an important distinction here, and I don't want to be too pedantic semantic about it.
Yeah.
But, but, okay?
If you are in orbit around Earth,
you are falling towards Earth.
We did a whole explainer on this.
Yes, we did.
How do you achieve orbit?
All right.
Talk about Newton and shooting the cannonball off.
Oh, the cannonball and your duck and all of that.
So here's my point.
Let's say you are en route towards the moon.
Okay. Okay. Do you know how we do that?
How does NASA do that? Well, they go into orbit. The subway? Then they do a TLI, trans lunar
injection, where they leave earth orbit and aim towards where the moon will be when they get there.
Okay. Nice. All right. So at that point, they shut off their engines. If you're in space and your engines are shut off, you are falling towards whatever is pulling you wherever it is.
That's right.
You're in free fall.
Oh, wait, let me say something that makes me sound smart.
And I learned this from an explainer that we did.
This is why you need to listen to the explainers, people. You will be falling
to whatever pulls you,
no matter where that is,
unless you happen to be
in a Lagrange point.
Oh.
Oh.
Ah!
Look at that!
Ah!
This is what I love this job,
because I didn't know that,
like, however,
whenever I didn't know it, I didn't know it.
Okay.
So there are five of them.
And so we don't have to get into that just now.
But all I'm saying is if you are coasting, then you are falling towards whatever is pulling you at that point.
Right.
Okay?
You will be weightless as long as you are coasting.
Right.
Okay.
No matter what. Okay okay and so here's what
will happen they have transluder injection which is enough speed to make it to the one of the
lagrange points between earth and the moon that's called l1 that point, the Earth's pull towards Earth equals the moon pull towards the moon.
That's a balance point.
It's a balance point.
Okay.
So now, if I have enough energy to cross that point, now I will guarantee to fall towards the moon.
Towards the moon.
Exactly.
Now, if I don't have enough speed to reach that point, guess what happens?
Earth says,
where you going?
Come on back. What the hell do you think
you're doing?
You trying to sneak out on me?
Get your ass back to Earth.
So if you don't make it to
that first Lagrangian point, you will
fall back to Earth. Exactly.
Okay? But that entire time,
you're still just falling. Okay? But that entire time, you're still just falling.
Okay?
As you're leaving Earth, you are falling.
Earth's gravity is pulling back on you, slowing you down, but you're in free fall.
Right.
Even though you're leaving Earth, and you're free fall when you turn around, and you're
free fall when you come back, you're weightless that entire time.
Okay?
If you cross the boundary point, you're weightless crossing it. You're weightless that entire time. Okay? If you cross the boundary point, you're weightless crossing it.
You're weightless the whole time.
Okay? You are weightless until
you hit the
moon.
Then you are
one-sixth Earth's gravity.
Okay? On the moon.
After you collide. Alright?
Or, if you
turn on your engines. Okay Or if you turn on your engines.
Okay.
If you turn on your rocket engines anywhere in space.
Okay.
When you were otherwise just coasting.
Right.
You will have what is effectively a gravitational field inside your rocket.
All right.
Because the rockets will be accelerating the spaceship.
Gotcha. Okay? It will be accelerating the spaceship. Gotcha.
Okay?
It'll be accelerating.
Right.
So, what's a good way to show that?
All right.
So, how about this?
So, we're in a rocket sort of headed towards Mars, let's say.
Okay.
We're standing on the bottom of the rocket.
Okay.
Okay?
So, the bottom, the trail end of this thing headed towards Mars. But we're weightless. We're weightless. But we're glued on the bottom of the rocket. Okay. Okay? So the bottom, the trail end of this thing headed towards Mars.
But we're weightless.
We're weightless.
But we're glued to the bottom.
And I toss you something, it'll just go straight towards you.
Right.
Okay?
Because everything is weightless.
Everything, nothing's falling.
It'll just go straight towards you.
Okay?
Now watch.
I now ignite the rockets.
The moment I toss the object,
the rocket is going at a particular speed
the instant I let go of the object,
and the rocket is going faster in the next instant
and still faster in the instant after that,
so the object will look like it'll fall
towards the floor of the rocket.
Towards the back, which is our floor.
Correct.
It'll look like it's falling towards the rocket, towards the bottom of the rocket. Towards the back, which is our floor. Correct. It'll look like it's
falling towards the rocket, towards the bottom
of the rocket. Whereas it's
the bottom of the rocket accelerating
towards the object.
Right.
Einstein figured out
that if you're in a rocket,
you cannot
know the difference
between the rocket accelerating through space and whether the rocket is sitting there on Earth.
Right.
Because the rocket is creating an artificial gravity.
Correct.
By having the acceleration.
Now, I managed to catch in a couple of episodes of The Expanse.
I love that show.
Anyway, The Expanse is like there's the folks from Mars,
and then there's the asteroid belt, then the Earth Federation,
and of course there's wars and things and fighting and bad people.
All right, point is, when they put on their rockets,
there's acceleration inside the rocket.
That's right.
There's basically, they have a way to attach to the surfaces
when they are in zero G,
and they make sure you know that,
so they're not playing loosey-goosey with the laws of physics.
Yeah, they wear gravity boots.
Gravity boots.
But in other conditions and other circumstances,
and I haven't seen all seasons,
but the few I've seen, they're thinking about this.
They play it straight, yeah.
They play it straight, and when it's accelerating,
there is an effective field of gravity in the ship.
And the higher that acceleration is, the higher that gravity will feel.
Okay?
Unlike the film, what's the one where they had moon pirates?
Don't get me started.
Oh, it had Tommy Lee Jones in it.
Oh, yes, you do.
Ad Astra.
Oh, yes, you do. Ad Astra. Oh, yes.
Ad Astra.
In Ad Astra,
they're in rockets
accelerating to the moon,
so it takes faster
than three days
to get there.
Right.
And in the accelerating rockets,
everybody's weightless.
Yes.
That's correct.
No.
That's not how that works.
So great.
If you want to get to the moon
in a few hours,
everybody's sitting in their chair feeling this gravity.
You might as well be on a 737 to New York City.
Thank you.
Because it's the same thing.
Same thing.
What a great catch, because I now remember that,
but I didn't even catch that.
I didn't even make that connection.
They all float around weightless,
and you see the rockets firing in the back.
That's not how that works.
Wow.
No, the difference with a 737 is, in the 737, you still feel Earth's gravity down because
you're not in orbit and you're not in free fall.
Right.
That's why balloons, if you're floating, but you still have, if you put a scale under your
feet, you're going to still weigh as much as you do on Earth.
Right.
It's not in free fall.
Right.
Okay?
Right.
It's all in free fall. Right. Okay? Right. It's all about free fall.
Now, if I put you in an elevator, cut the cable, you're in free fall.
Right.
So you're going to fall, and the chalk that you're holding is falling, or the ball, and everything's falling, and it looks like it's floating in front of your face.
So you could let go of your drink, your little soda can, while you're falling in the elevator, and it would just stay right there, right with you.
Correct.
Correct.
And you want to know a really cool experiment?
Okay.
You could do this at home,
but we'll do it in the elevator first.
Because these are experiments you do in the elevator
before you die at the bottom.
Okay, so this is, but it's for science.
Well, we might as well get those experiments out of the way.
I mean.
If you're going to die, let it not be in vain.
Exactly.
When the elevator hits the bottom.
So, if you have one of these big gulps, okay?
So, it's a huge container.
And you're sitting there.
And the elevator's on the, you know, 100th floor.
And you puncture a hole in the side of your big gulp vessel.
Okay?
So, what's going to happen?
Well, it should start, you know, sprinkling out.
Well, it's a sprinkle.
It's a nice hole.
It's a stream.
It'll stream out.
It'll have a nice arc as it goes down.
Okay?
It's coming out because it feels pressure
from the weight of the water above the hole.
Above the hole, right.
Go back to our water tower.
Water towers, yeah. If you want to know about the hole, right. Go back to our water tower. Water towers, yeah.
If you want to know about
the weight of water.
So, and by the way,
if you put multiple holes,
the one at the bottom
will make a longer stream
than the ones that are above it
because it's under higher pressure.
Right.
Okay?
So, you have a long stream,
a middle stream,
and a little stream.
If you can punch
the three holes in it simultaneously.
Right.
That's the weight of the water
putting pressure to have the water exit the hole.
So now, cut the cable.
Okay.
You fall.
The cup falls.
The soda falls.
Everything is falling and everything is in free fall and everything is weightless.
You are in zero G. If you are in zero G, the water is no longer under pressure
because the water above it doesn't weigh anything.
Right.
And if the water above it doesn't weigh anything,
there is no pressure for the water to come out the hole.
The water does not know to exit the hole
and all three of those spillages cuts off instantly.
Nice.
For the entire journey until you die at the bottom.
Right.
In which case, you just got a bigger mess on the floor
than you have to worry about with the big gulp.
You know, believe me.
Okay, so now, the way to do this is go get a big gulp.
Right?
Ready?
Here's what you do. Puncture three holes in it,
three vertical holes, and then put tape, one piece of tape over it, okay? Now fill it up
with some liquid that doesn't make a mess. Now stand up on some ladder, all right? Or above
some stairs or something, right? Now hold it up high and film this. Film
this, okay? Okay.
Take the tape,
quickly remove it. Rip it off.
You'll see the three streams
and then let it go.
And all three streams will just
stop, like they were just cut off.
Because while the cup is
falling, it is weightless. And it'll
continue that way until it hits the ground.
Very cool.
If you are accelerating, this is what happens.
And by the way, NASA calls it microgravity.
To this day, I do not understand why.
Or rather, I'll make a stronger statement.
They have misnamed it by calling it microgravity.
Gravity is identically zero on an orbiting spacecraft.
They're worried because we're
still in Earth's gravitational field.
Okay? So I think they're worried
that that might confuse people.
So that's why you say zero-g.
Because that's a force.
Zero-g force.
It is a zero-g.
And world to Cronkite.
In the 1960s, when we went, when Apollo was eight,
Apollo eight or 10, when we first went to the moon before the astronauts landed,
this, one of his broadcasts said, as of 445 this afternoon,
the astronauts have left the gravitational pull of the earth.
It's like.
And then he had to say,
this just in, I'm an idiot.
I've just been told that I'm a complete dumbass
because that's not true.
Because they're en route to the moon,
which last we checked,
is held to Earth by Earth's gravity, right?
So what he meant there was
that it crossed from Earth's influence to the moon's influence. It crossed one of the Lagrange points. Right. So what he meant there was that it crossed from Earth's influence to the moon's influence.
It crossed one of the Lagrange points.
Right.
So he lost a learning opportunity for the audience.
And so, yeah, there's no micro nothing.
Okay.
It is zero freaking G, period.
There you go.
Zero G.
This was fun.
This was great.
All right. And this thing with the acceleration and Earth's gravity, that's called, to Einstein, the equivalence principle.
And it's one of the deepest, most brilliant ideas ever advanced in the history of physics.
The equivalence principle.
Right. gravitational acceleration is not only equivalent, it is indistinguishable from acceleration by rockets or anything else
that would move you through space.
If you did that in a box with no windows,
you would not be able to tell that.
Correct.
Look at that.
Am I on Earth or am I accelerating through space at 1G?
You would not know.
Science.
You got to love it.
I love it. And one last thing,
the units of acceleration,
that's why they have this weird construct, okay?
So, the acceleration of gravity
is 32
feet per second
per second.
Those are units.
What does that mean? Per second per second? What does that mean?
And it's actually per second squared if you did it out.
What that means is? Per second, per second. What does that mean? And it's actually per second squared if you did it out. What that means is for every second,
you increase your speed by 32 feet per second.
Right.
So how fast are you going after two seconds?
64 feet per second.
How fast are you going after three seconds?
128 per second.
No, 96.
I'm sorry, 96 feet.
Oh, no, it's 32, not 64.
It's 32, right, right, okay.
It's another 32.
Another 32.
So every second,
Every second, it's another 32.
And it will never stop.
Right.
Never stop.
Well, it'll stop until you hit.
Oh, wait.
Now you just made me think of the Expanse again.
I just got something that they do in that show.
What do they do?
What do they do?
When they're approaching a planet,
even though they're really far away
from the planet,
the rockets are firing
in the opposite direction.
Yes.
Yes.
Yes.
That's right.
Otherwise, they'll just free fall down.
They'll free fall down.
And they'll crash land.
So you have to,
so you turn around,
the rockets slow you down.
That will give you an acceleration,
by the way.
Okay? It'll give you so
all of a sudden they'll have some kind of g-forces operating on them and they can take that all the
way in if they want yeah yeah but it it looks weird because they're like nowhere near the planet
but yet they're still firing retro rockets well yeah because they've been speeding up so fast
that whole way it's falling towards them. Falling towards the planet.
They have to do that in order to put on the brakes. In fact, one of the ideas of how to get to Mars
without being zero G for nine months
is you accelerate at one G halfway to Mars.
Right.
Then you turn around and decelerate at 1G to Mars.
And so you're in Earth's gravity, 1G, the entire trip.
That's how you do that.
And then you don't need the medical examiner looking at you or whoever they are.
Something's happened to his bone density.
We're not actually sure what it is.
There's no bone density issue.
That's right.
Yeah. you've looked up at the night sky before i have indeed all right and and you've been perhaps
prompted from time to time to notice what the press would bill as a planetary alignment of note.
There was a big one that happened that was on the news some time ago last year.
That's what I'm saying.
It was huge.
Everybody was talking about it.
Everybody was talking about it.
Did you see it?
No, I didn't, to be honest.
Okay, of course you didn't.
Okay.
I'm going to be honest.
I did not see it.
You did not see it.
They made a giant deal out of it, and I was like, okay.
Okay, so if I say the planets are aligned, what would that mean to you?
What do you think that means?
Well, for me, like, just the intuitive thought would be that you go out, look up, and you see a line of dots in the sky, like they're in, you know, in queue to come, you know, get some ice cream or something. In a line. In a line of dots in the sky like they're in queue to come get some ice cream or something like that.
In a line.
In a line.
Planetary alignment.
Okay.
So put a pin in there and consider the following.
Okay.
Okay?
We have the sun in the middle of its own star system, the solar system.
And first out, we have Mercury.
Right. Okay? Orbits the first out, we have Mercury. Right.
Okay?
Orbits the sun.
Then you have Venus.
Then you have Earth.
Then you have Mars.
Then you have Jupiter.
Then you have Saturn.
And then you have Uranus and Neptune.
Okay?
Right.
You realize that all of those planets orbit the sun in about the same plane right okay so we're like one giant pizza pie
with the sun in the middle okay okay so far so good oh by the way pluto orbits 30 degrees out
of that plane one of the many reasons why it does not belong among us. Well, you know, because Pluto was just like,
look, I've marched to the beat of my own drum.
Okay.
So therefore, you are your own damn...
Pluto has its own rhythms, for sure.
Right.
All right.
So everybody is orbiting in the same plane,
geometric plane, flattened plane around the solar system. And by the way, everybody's moving in the same plane, geometric plane, flattened plane around the solar system.
And by the way, everybody's moving in the same direction, which was a deep hint for
us to tell us how the solar system formed.
Okay?
Like, do these planets fly in randomly?
Well, if they did, then they'd have random orbits around the sun.
Right.
And then some going forward, some going, quote, backwards.
So they're all going in the same direction and then some going forward some going quote backwards so they all go in the
same direction and all in the same plane and so it was concluded this is now thinking that's been
250 years ago that maybe we started from a big gas cloud that collapsed into this pancake and
in that pancake the planets formed with the sun in the middle.
That gets you everybody orbiting in the same direction
and in the same plane.
Okay, so now let's go down to Earth
and look up into the sky.
Where are you going to find all the planets?
Are they going to be everywhere in the sky?
No.
No.
They're going to be on the same plane as you are.
On the same plane as we are.
Okay.
So, not only that, at any given moment, at night,
you're looking at half the sky.
Right.
So, on average, half the stuff is going to be in the sky when you're looking up.
On average.
Right.
Half the stuff.
Okay.
Because we are on a ball.
And so.
You look at one side.
You look at one side of the ball and you see half of what's out there.
You're seeing half the sky.
Because the other side of the ball is looking at the other half of what's out there.
You're seeing half the sky, okay?
And you got to wait until it's nighttime for them, but they see the other half, okay?
All right.
Half the sky.
So, point is, of the planets, including the moon, okay, which is also tilted a little out of the plane, but not enough to be important for this example.
And the sun is in the plane, almost by definition, because we're orbiting the sun.
Okay?
So, the classical planets of antiquity,
which were all the objects that moved against the background stars,
that wandered.
The Greek word for wanderer is planetes,
which is where we get the word planet.
And there were seven planets.
The sun, the moon, Mercury, Venus, Mars, Jupiter, and Saturn, and the seven days of the week, the names we give to the seven days of the week are traceable to the gods that oversaw those
days, dating back to Greek and Roman mythologies. We've also touched with Norse mythologies.
So the Norse counterpart gods
to the Greek and Roman gods share the same day.
Okay.
So Thursday is whose day?
Thor.
Thor.
Thor wields the lightning bolt.
Who in Roman legend wields lightning bolt?
Zeus.
Well, Zeus is Greek. Well, Zeus is Greek. Jupiter is Roman. lightning bolt who in roman legend reels lightning bolt uh zeus zeus well zeus is the greek jupiter
is roman so so if you look at the romance languages the word for thursday is named for jupiter okay
and what is it uh in in spanish no spanish umaculous, Hueves. Hueves, that's Jupiter.
Okay.
It's named for Jupiter.
Point is,
all of these objects in any given night
are always in a line.
Period.
So it's,
I don't know how else to bring the news to you.
We are in the plane of the solar system,
and we're looking out,
and we see other objects in the plane of the solar system.
And if you take a circle, put it on its side, it's a line.
There you go.
So it's a news story that happens every single night
today in the news planetary alignment once again once again so the way they try to bump it up is
if some planets are a little closer to each other in our sight line than at other months.
Okay?
So if they're a little closer, then you don't have to sort of turn your head along the line to see them.
You might catch them in one glimpse.
Okay.
Fine.
Generally, that is what they want to call planetary alignments, but it leaves people
thinking that planets are not aligned at any other time, whereas they are always aligned.
Right.
Period.
Period.
Yes.
Period.
That's just it.
And the moon is among them.
And the moon too.
The moon is among them.
So, in any given night, if you see the moon over here on the right and Venus over there
on the left, make an arc between them and complete that arc across the sky.
Look for other planets on that arc.
And you'll find them.
You'll find them.
You'll find Jupiter, Saturn.
And if not that half of the night, wait till the other half of the night.
Right.
Okay?
Our top story tonight, once again, the planets decided to line up.
Film at 11.
Now, here's something else they do.
They'll say the planets are aligned and this lineup will not repeat for another 150,000 years.
That's the one that happened last year that everybody was going crazy.
So you want to put that on your calendar.
That's not going to repeat for another 150 000 years well by the way every night will not repeat for another 150 000 years whatever
i mean you can calculate what the it's the point is it's possible for something to be rare
and completely uninteresting. Right.
Because every night is equally as rare.
Exactly.
Hey, if we're all special, nobody's special.
Then nobody's special.
Right.
We knew that.
We learned that from The Incredibles.
Right.
So I just try to put, people say, oh, you're such a downer.
I put it on social media. Why are you such a downer?
I like looking up.
There are other reasons to look up.
Right.
Okay?
I don't have to fake a reason for you to look up.
You know, the asteroid might be coming.
Why don't you look up for that?
All right?
No, no, don't look up.
Really?
I saw that documentary.
That's a documentary.
Don't look up.
That's funny.
That was funny.
So that's all I got to say about...
The planetary alignment.
Planetary alignments.
Yeah, just chill.
Yeah, there you go, guys.
So it's BS, basically.
And because we're orbiting the sun,
we're always getting new angles on how everybody's aligned.
And it's always new,
and it's not going to repeat for hundreds of thousands of years,
but every single day is that.
So, you know, there it is.
By the way, there is something called a conjunction.
Oh.
Which sounds like you need ointment for it.
What's a function?
Yeah, conjunction.
I got some ointment to fix your conjunction.
All right. Make sure you wash your hands if you get a conjunction. I got some ointment to fix your conjunction. Right. Make sure you wash
your hands if you get a conjunction.
Okay. Conjunction is you get
like three
planets, and I'll include
the moon among them as a classical
planet that wanders against the...
By the way, they call them wanderers because they didn't
understand the physics of gravity.
Right. Right. After Newton,
they're not wandering at all.
They know exactly what they're doing.
Exactly.
We actually know where they're going.
And so do they, right?
Right.
So nobody's wandering.
So a conjunction is when you have at least three objects
that are in the same part of the sky
where you can, like, you know, look through binoculars and all of them are in one
field of view we call those conjunctions those are worth coming out to check out okay cool but
this notion that of alignment no and it's even made it into our language oh uh things are going
so well the planets must have aligned right it's it's it's worked its way into our culture. And so you say, yeah, things work out for me all the time
because, in fact, the planets are always aligned.
Exactly.
Also, I'm the master of my own fate, you know.
I would like to thank me.
No, no, you get the boxer who wins and says,
I thank God for the ability to pummel your other person.
So they should go to the other person and they're saying,
I blame God.
Exactly.
Just to thank God. God hates me.
Somebody else ought to get to blame God.
I lost because God hates me, okay?
It's that simple.
If God liked me, I wouldn't be here right now.
All right.
We got to call it quits there on Star Talks,
Things You Thought You Knew Edition.
Chuck, always good to have you.
I'm Neil deGrasse Tyson, your personal astrophysicist.
As always, I bid you to keep looking up.