StarTalk Radio - Cosmic Queries: The Sun and other Stars
Episode Date: September 8, 2013The Sun is the star of the show as astrophysicist Neil deGrasse Tyson and comic co-host Chuck Nice answer fan questions in this solar edition of Cosmic Queries. Subscribe to SiriusXM Podcasts+ on Appl...e Podcasts to listen to new episodes ad-free and a whole week early.
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Welcome to StarTalk, your place in the universe where science and pop culture collide.
StarTalk begins right now.
This is StarTalk.
This is StarTalk.
I'm your host, Neil deGrasse Tyson.
And I have with me in studio my co-host, Chuck Nice.
Hey, Neil.
Love it when you're here.
I love being here. I feel like we go way back, but we don't.
It just feels that way.
I don't know.
Yes, I have that effect on people.
I'm like a rash.
You feel very familiar.
So this is StarTalk, the Cosmic Queries edition.
And today we are themed.
We've solicited questions.
Yes.
Some come in unsolicited, and we pull those aside.
Right.
And then we call for others, and when they fit, we match them up.
Right.
And so today it's our sun and other stars.
Yes, and not like Tom Cruise or Meryl Streep, sun and other stars yes and not not like tom cruise or meryl street not those
other unless one of those slipped in but we had stars in the universe before there were stars in
hollywood ah just an fyi just to let people they took the name from us not according to people
magazine that's why on hollywood boulevard the shape is a star right that's what we got that's
correct that is borrowing our word shine bright like a diamond
you know what's borrowed our words pulsar watches borrowed our word that's right pulsar quasar
remember quasar television yes they borrowed that's we we got that first that's right that's
right i'm trying to think of any other cosmic branding well there's there's like start you
know star kiss oranges star kiss that goes on and don't get me started on that okay no no there's
like and there's sun kissed sun kiss star Kissed, Star Kissed, Moonglow Bath Beads.
Moon Pies.
Celestial Seasonings.
That's right.
Moon Pie.
Milkyway Candy Bar.
Mars.
You got me started.
Milkyway Candy Bar.
Mars Bar.
The Chevy Nova, except had they known that was a star that just blew up, they might not
have-
Right.
Not a good name for a car.
Please get into this.
So anyway.
All right.
So you got questions for me.
I haven't seen these.
You haven't seen any of these questions, nor do you know what they are going to say.
Called from the internet and other sources.
All from different sources.
Might even have a couple of callers.
That's good.
Oh, that's great.
So what do you got?
Let's jump right into it.
And let's kick it off at the beginning, okay?
And this is from Christopher Lloyd on Facebook.
He says, let's start-
Christopher Lloyd.
Christopher Lloyd.
As in an actor.
All right.
Christopher Lloyd wants to know, let's start at the beginning.
How does something like the sun even form or come into being the way that it is?
So in the current incarnation, how does that happen?
Yeah, cool.
Of course, this happens all the time.
Our galaxy has hundreds of billions of these things called stars.
So nature has no problem making these things.
And the star is made of gas,
100% of gas, and it comes from a gas cloud. Now, if we look through the galaxy and didn't find gas
clouds, we would wonder, where are these things born? But we find gas clouds. It's like looking
around society and never seeing a pregnant woman, but you see babies all over. You'd have to wonder,
where do babies come from? Do you know I feel the same way about pigeons?
But anyway.
Oh, because you don't see baby pigeons.
I've never seen baby pigeons.
Yeah, you're not alone.
It's one of the big mysteries of life.
Where's the little pigeon?
Where's the little pigeon?
They're just born whole.
Exactly.
Out of the egg, it's a big pigeon.
So either they're born quickly or, you know, so you have to ask these questions.
But society does have pregnant women, and you can judge how long they're pregnant if you take snapshots of the culture.
So that's what we do in the universe.
We take snapshots of the galaxy at different times, and we find out there are places where there are huge gas clouds.
Gravity is gathering the gas clouds into – it nucleates.
And if you get one part of a gas cloud that's slightly more dense than another,
it wins. It's got more
gravity than anywhere else, and then it attracts
more gas, then it has even more
gravity. So it's like Mexican food.
I can't, I don't follow the analogy.
I'm sorry.
Help me out on that one.
Well, you eat Mexican food, and
it causes gas, which leads to
more gas. Oh, I see. There you go. I missed that one. Sorry. That would be the bean part of eat Mexican food and it causes gas, which leads to more gas. Oh, I see.
There you go.
I missed that one.
Sorry.
That's okay.
That would be the bean part of the Mexican food.
Exactly.
So, yeah.
So, if you have slightly more mass, slightly more density in your region of a gas cloud
than another, you are more likely to condense first and then you win that contest and all
the matter comes to you.
Eventually, in the center center as the matter accumulates
it gets hotter and hotter and hotter it's under pressure gas clouds under pressure get hotter
and eventually it triggers thermonuclear fusion and a star is born look at that thermonuclear
fusion there you got so it just gets hot it bursts into flames like i am so hot i'm just
gonna bust into flames yeah and it's thermonuclear,
it's fusion energy.
It's not like fire energy.
Exactly.
It's another kind of energy
that you derive
from the nucleus of an atom
rather than from
sort of molecules
breaking apart.
Normal fire
is just molecules
breaking apart
that have stored energy
that releases it as fire.
Right,
this is different.
We say stars burn,
but we don't mean burn.
Right.
We mean that-
They're not on fire. They're thermonucleating. Exactly. Yo, that's fascinating. Yeah. This is different. We say stars burn, but we don't mean burn. Right. We mean- They're not on fire.
They're thermonucleating.
Exactly.
Yo, that's fascinating.
Yeah.
All right, man.
Way to go.
And that was Christopher Lloyd?
That was Christopher Lloyd.
Was that their actor, Christopher Lloyd?
You know it doesn't say, but let's just say it is.
You know my favorite acting role of his?
Most adults don't know this.
Is?
He was the hacker on Cyberchase on PBS.
That's right.
But he had to have kids to know that. Christopher Lloyd is
hacker and let's see, Gilbert
Gottfried is the parrot. Yes!
No, no, he's the little duck.
Yeah, the little bird. Yes, exactly.
Of course Gilbert Gottfried would be the duck.
Yes.
So, yeah, so it's
a show that teaches mathematics
and science to kids. To children.
That's how I know it. Because I'm a child who needs to know about mathematics.
Hey, let's move on.
All right, what do you got?
Jason Clow.
This is also from Facebook.
This is Jason from Facebook.
Do they say where they're from?
I like knowing the city.
Yeah, they do.
What city?
Oh, no.
He did not say where he is from.
Just from Facebook.
The city of Facebook, yes.
Yes, exactly.
Okay, this is what he wants to know.
What technological advances would be needed
to prevent our sun from expanding?
And how close are we to obtaining that technology?
And he has an example.
Dude, we're still pulling oil out of the ground.
Oh, snap.
Dude.
Oh, snap.
Dude, give that hope up.
Yeah, you better, like, think.
Was it a follow-up?
No, no, no.
That hope up.
Yeah, you better like think.
Was it a follow-up?
No, no, no.
He was like, okay, like the gravity satellite in Doctor Who episode SO1EO2, end of the world.
That one.
Yes.
I'm going to say that this guy's a real ladies' man.
Just saying.
He knows episode numbers from Doctor Who.
You know he is slaying the ladies.
All right.
There is a way to prolong the life of a star. And if we were ever to do that for the sun, because our civilization would somehow outlive the life expectancy of most mammals, the mammal life expectancy is about three
million years. And on average, and we're a mammal, so unless we figure out a way to beat those odds,
we're toast for one reason or another after, on average, three million years.
That's why I love talking to you. You're always so uplifting.
The sun's got another five billion years left. So we'd have to prolong our lives
until the sun is ready to die and then prolong the life of the sun. So one way to do that is
it's got hydrogen in the center converting it to helium. That's the thermonuclear fusion.
There's a lot of hydrogen in the outer layers that never makes it to the center.
So when the sun runs out of helium, it only runs out of helium in the center.
And so what you need is a way to channel helium from the outer layers deep down into the center
to give it fresh supply. You do that, the sun could live 100 billion years.
Oh my God.
No question about it.
So you would basically just have to funnel helium back to the center of the sun.
No, no, sorry. Did I say helium? I meant hydrogen.
Oh, hydrogen.
Hydrogen in the outer layers.
Okay.
Because it's converting hydrogen into helium.
All these outer layers, you bring it back in, you prolong the life of the sun.
Fascinating.
More after this break.
You're listening to Cosmic Queries.
Star Talk.
We'll see you StarTalk Radio.
I'm your host, Neil deGrasse Tyson.
I'm an astrophysicist with the American Museum of Natural History right here in New York City.
I got with me in studio Chuck Nice Comic.
That's right.
At Chuck Nice Comic on Twitter.
That's me.
I'm supposed to plug you.
All right.
Just before the break, we talked about prolonging the life of the sun.
Right.
And all you have to do is churn fresh fuel, which lives in the outer layers down into the center.
Right.
And we know this works because there are stars that collide with one another.
And when you collide, you mix your materials.
And stars have a fresh birth simply because all the helium that it collected in the center
as leftover byproduct all gets mixed back into the star and fresh hydrogen shows up in the middle.
And then you have a new life to the star.
Now, it just seems to me if we have the power to prolong the life of the sun by churning
its contents, we have the power to just move to another damn solar system.
If we can do that, move to Mars or to Jupiter's moons.
You know what I mean?
So there might be other options available than messing with the sun.
Like making the Earth a spaceship and just actually leaving.
Yeah, keep the whole Earth intact.
Great.
I hadn't thought about that.
And just take it someplace else.
Cool.
I mean, hey, if we can manipulate the sun, we can do that, right?
You can do that, but you need an energy source en route.
So we've got to get cozy until you get to another solar system.
True that.
I don't think that far ahead in life.
So we've got another question.
Yeah, let's go to the phones, actually.
And we have on the phone with us Jared, who is a 16-year-old student.
Jared, how are you?
Jared on the line? Jared's on the line. Oh, with us Jared, who is a 16-year-old student. Jared, how are you? Jared on the line?
Jared's on the line.
Oh, yeah.
Jared, hello.
Chuck introduced you as a student, but at age 16, I would assume you're a student somewhere.
Otherwise, you're a truant dropout.
Sure, yeah.
Okay, good.
Well, I'm a student at North Gwinnett High School in Sewanee, Georgia.
Okay, cool.
Well, welcome to StarTalk.
Yeah, so what do you got? So my question is,
in five billion years,
when our sun begins to run out of hydrogen
to fuse into helium,
do you think that we will be able to prolong its life
by somehow adding the planet Jupiter
or any of the gas giants, for that matter,
into the sun?
Okay, yes.
That's an excellent question.
So, like in the previous segment,
we talked about churning the sun,
giving it a fresh supply of fuel.
Of course, Jupiter and or Saturn
are mostly hydrogen and helium.
They have a similar composition to the sun itself.
Really?
So, if you had a way to cram Jupiter
down into the core,
yes, you could prolong the sun even further.
So, Jared, what do you have against Jupiter, man, if you want to sacrifice it to the sun?
Yeah, it would be a sacrifice, wouldn't it?
No, no, I like Jupiter, especially its moons and their potential for life.
Yeah, the moons are where the action is.
Like Europa and Io, all of these are kept warm by the stress of Jupiter's gravity.
Its tidal forces are keeping those moons warm well outside of the habitable zone.
You know, there's that zone where it's just the right temperature for your liquid water to stay liquid.
Yeah, not too close.
You freeze not too far away.
Jupiter's far enough to freeze, but it's got another energy source not dependent on the sun.
So, Jared, I'm glad you recognize Jupiter's moons in this.
But so the general solution to prolonging the sun is try to get some fuel down into
the center.
And you wouldn't have to bring a whole planet there because most of the sun's mass never
participates in the thermonuclear fusion going on in the core.
So Jupiter itself could work, but I'm betting that if we're really powerful at solar and
geoengineering, that it would be easier to sort of churn the sun's outer layers down
into the middle than it would be to readjust Jupiter's orbit, lose a nighttime planet,
lose the beautiful moons around it, just to prolong the sun a
little longer.
There you go.
So we're going to keep the neighborhood the same.
Keep the hood.
We're going to keep the hood the same, Jared.
That's what we're going to do.
Okay.
All right.
Hey, thanks for calling, buddy.
All right.
Thanks, Jared.
All right.
And remember, nerds rule, okay?
All right.
All right, buddy.
Take care.
All right.
No, good.
So there's some hope.
There is hope.
I love that.
We've got high schoolers asking questions like that.
We've got hope for the world.
Without a doubt.
That makes me happy.
What else you got there?
Okay.
Hey, let's go to Twitter right now.
And this comes from at Vincenzo.
These are people who tweeted at StarTalk Radio.
They tweeted at StarTalk Radio and asked a question.
And this is at-
Vincenzo.
Vincenzo, 1023, at Vincenzo.
I bet he's born October 23rd.
That's my guess.
You know, I would never think that.
See, I would say there are 1,022 other Vincenzos.
Okay.
All right, here we go.
How, or could you describe how big the sun would look in the skies
of mercury so the way we see the sun how would it look from another planet yeah i don't have
that off the top of my head but i can calculate it okay so we are uh the earth sun distance is
one unit let's call it one unit one unit we call it one unit. Call it one unit. We call it one astronomical unit.
That's how you get your way around the solar system, right? Okay.
So Earth is by definition one astronomical unit.
Venus is 0.7 astronomical units.
Mercury is 0.4 astronomical units.
Okay.
So Mercury is like half is, you know, basically half the distance.
If you're half the distance to something, the thing is twice as big.
Twice as big.
Yes, it's basically twice.
So the Vandans point would be a huge yellow ball.
Well, huge, twice as big.
Right.
When we can quantify it, you don't need adjectives.
Okay.
It's twice as big.
I'm just saying.
Thanks for making me feel smart.
We got adjectives because we can't quantify, right? This is true. Okay. It's twice as big. I'm just saying. Thanks for making me feel smart.
We got adjectives because we can't quantify, right? This is true.
I felt awesomely huge about that.
Well, numerically, what was it?
Right.
I can't go there.
So it would literally be twice as big.
Yeah, a little bit more than twice as big.
But here's what's devastating.
Light, the intensity of light goes up not as the factor closer, but as the factor closer squared.
So if you're twice as close, then the intensity of sunlight will be four times as great.
Two squared is four.
So the sun would be twice as big in the sky, but you'd never be able to see it.
It'll be four times.
Yeah, I mean, you'd be vaporized in the heat.
Yeah, you'd have other issues than just wondering how big the sun is in the sky.
Gosh. Yeah. That is fascinating. Well, there you go, Vincenzo. There's your heat. Yeah. You'd have other issues than just wondering how big the sun is in the sky. Gosh.
Yeah.
That is fascinating.
Well, there you go, Vincenzo.
There's your answer.
Yeah.
That is, the answer is don't look at the sun when you're on Mercury.
Another issue is you can ask how far away do you have to be for the daytime sky to be
so dim that you can see the stars of night in the daytime?
Okay.
That question wasn't asked, but this reminds me of that.
I've thought about this.
All right.
And if you get to like around Neptune, that's far enough away.
So that if Earth were at Neptune, you'd see stars in the daytime.
Oh, really?
Yeah.
That's kind of cool.
Because the sun would be so dim and so far away.
Is that the same premise as the moon being visible by day?
Like sometimes by day you see like a full moon or a half moon in the sky.
Okay, so two things, Chuck.
Go ahead.
You've never seen the full moon in the daytime?
I have.
No.
My vision is that good, Neil.
Seriously.
You may have seen moon.
I've had LASIK surgery, sir.
You may have been mooned in the daytime.
It wasn't like the orb.
All right.
So here's the thing.
But apart from the full moon, which only comes out at night, every other phase of the moon appears at some time during the day.
The moon is out in the day as often as it's out at night, basically.
Okay.
So contrary to what many people think is what's going on.
But, yeah, you'd be able to see.
The moon comes out in the day, but it's not nighttime.
Neptune is 30 times as far away from the sun as Earth is, 30 AUs, astronomical units.
So the sun would be 1 30th the size and 1 900th as bright.
What?
30 squared.
So basically 1 1000th is bright.
Yeah, and it's just a dim light.
It's a blip.
It's a pinhole in the sky.
Blip.
So now let me ask you a piece of trivia,
and you say this full moon never comes out during the day.
Never.
Ever.
Not on Earth.
So how about a solar eclipse?
Would that be the-
A total solar eclipse is new moon.
That's a new moon.
Okay.
You're looking at the backside of the moon,
which is completely dark,
because it's the other side that's lit up
that's coming between you and the sun.
You always have an answer, don't you?
No.
Just because my answers sound like they need a snap at the end.
All right, go.
We got like 90 seconds.
We got 90 seconds.
Here we go.
You got another one.
You know what?
Let me find a quick one.
Are we just incredibly lucky to have a sun 400 times bigger than our moon and 400 times
farther away?
What are the odds of another star planet moon system out there having the same exact setup?
It's luck.
Oh, my God.
Yeah.
What he's asking is, during a total solar eclipse, the size of the moon is basically
exactly the same.
Same size.
So it makes for a beautiful eclipse watching.
Right.
But it has very little other meaning or value.
Early in the history of the Earth, the moon was closer.
Do you know the moon is spiraling away from Earth at about two inches per year?
You told me that before.
That's the only reason I know it.
Okay.
So in the past, the moon was closer and bigger.
So for most of Earth's history, the moon was much larger than the sun.
Right.
You still get eclipses, but you wouldn't get that beautiful sort of corona edge atmosphere of the sun glowing around the outback.
Setting that mood lighting for the Earth.
It's so mood lighting for four minutes at a time.
So it is complete coincidence that that's the case.
And it won't forever be that way.
As the moon continues to spiral away, one day it'll become smaller than the sun in all cases.
So you'll get what's called an annular eclipse.
An annular eclipse.
Yes, which is, Latin is it for ring?
An annulus is a ring.
And so what happens is the moon doesn't completely cover the sun, and it leaves a ring of sunlight around the edge.
It's also a beautiful thing to behold.
Awesome.
But you need filters and things to watch it.
Awesome.
There you go.
We'll be back on StarTalk Radio, the Cosmic Queries edition.
This is StarTalk Radio radio we're back i'm neil degrasse tyson with chuck nice hey i just heard you just co-hosted the view yeah does this give you like women credit like
what do you you know i gotta tell you neil i don't believe anything will ever give me women cred, to be honest.
Gloria Steinem could actually breastfeed me, and I wouldn't have women cred.
I know they allowed men to co-host.
Is this a special thing?
Well, they do it on Fridays.
Friday.
So they had a Guy Day Friday, and I was the co-host for that.
Guy Day Friday.
For that particular Guy Day Friday.
I'll look for you.
Yeah.
Yeah.
It's fun.
All right.
So these are Cosmic Queries.
Yes.
Edition of StarTalk.
So the whole hour is given totally unto questions from our fan base and the listener audience. Correct. Yeah, it's fun. All right, so these are Cosmic Queries edition of Star Talk.
So the whole hour is given totally unto questions from our fan base and the listener audience.
Correct.
And it comes through Facebook and all our social media outlets.
And the theme today is our star, the sun, and other stars. And other stars.
Yeah, so let's do it.
I haven't seen these questions.
You have not seen them.
That's my favorite part of this is that this is the first time you get to hear the questions.
So it's like the people are actually asking you the questions.
On the spot.
On the spot.
Go for it.
Just using me as a conduit.
So here we are.
And if I don't have an answer, I'm going to tell you.
All right, go.
So this is Arlen Cundert.
Arlen Cundert from Facebook wants to know, are there solar systems of stars?
What I mean by this is, is there a system with an upper or a super massive parent star with orbiting smaller stars, but with smaller stars having planets serving as moons?
So each star in the parent system would have its own subsolar system.
And no, Dr. Tyson, you can't just say yes, we call them galaxies.
And no, Dr. Tyson, you can't just say yes.
We call them galaxies.
Oh, and because you always want to know where we're from,
I'm from Reynoldsburg, Columbus, which is in Ohio.
Which, first of all, thanks for coming to Wright State in Dayton, Ohio, back in March.
It was awesome to hear you speak in person.
Please answer my question.
There's a whole... Oh, my gosh.
So you knew I want to know where people
come from. I'm always asking you. I don't know.
It's just Facebook.
It's Twitter. Oh, it's hilarious.
So man, he's like covering your ass.
Yes, he is. Got me covered.
Thanks, and I did give a talk
in Ohio.
That was a fun day that I spent there.
So,
they even took me to one of the local pubs.
That's always a thing to do in a college town.
Absolutely.
But that was at like 3 in the afternoon.
I hear they got a lot of drinking problems in Ohio.
All right.
So the way it works is if you look at the night sky, half of the stars you see aren't solo stars at all.
They're double, multiple, triple, quadruple star systems.
Really?
Yeah.
Even, for example, the nearest star to the sun, Alpha Centauri.
Yes.
That's a multiple star system.
Okay.
The nearest star in that star system is called Proxima Centauri.
That's right.
Right.
So you can have multiple star systems.
If they are far enough away from one another then each one could then have its
own planetary system not a problem gotcha but if they are too close to one another
as the planet comes around the backstretch right its gravitational allegiance can be compromised
ah so it just doesn't know which one do I belong to. It's like, who's your daddy? Exactly.
I want to go with Proxima, but I can't help myself.
Alpha is just so sexy.
So you want a system that's far enough away so that the orbits are stable.
And gravitationally stable, it means you're not perturbed by somebody else tugging on you.
So yeah, you can have these.
We haven't discovered them yet.
Right.
And in any big, large scale.
But yeah.
But it can happen.
It definitely can happen.
Oh, fascinating.
You got it.
That is awesome.
Okay, thanks for that.
I just love the fact
that we're going to have
a solar system soap opera.
I love that. It's a solar system of solar systems. It's a solar system of solar system soap opera. I love it.
It's a solar system of solar systems.
It's a solar system of solar systems.
Yeah, you got it.
I love it.
All right, here's something from Jared Connor, also writing to us on Facebook.
Dr. Tyson, can solar systems form in the intergalactic medium?
If so, could there be planets in those solar systems with intelligent life?
Ooh.
So this person has vocabulary.
Yes.
Intergalactic medium.
All right.
So what we have is between the planets, we call that interplanetary medium.
Between the stars, interstellar medium.
And then every collection of stars that we find is part of a galaxy.
Then there's this void between the galaxies.
Could we have stars there?
Yes.
But our best understanding of all this tells us that these are stars that may have been
flung out of a galaxy, typically in a galaxy collision.
They're really train wrecks when they happen.
And when they do, stars fly hither and yonder.
So they just escape the train wreck and then they're on their own way
escape the train and they're on their own so they're rogue stars basically that's the word
they're rogue stars just the same way you can have planets wandering between the stars right
we call them rogue planets okay you can have rogue stars cast asunder after a galactic collision and
we have galactic collisions all the time and so there's no reason why you couldn't.
Yes.
And these are stars that are basically homeless in a way.
Oh.
I know.
Do they have signs that say we'll shine for food?
They're homeless.
Homeless stars?
Homeless, galactic homeless stars.
Yeah.
So there's no reason.
But it would be very hard to see them because stars are not dim.
Stars are too dim to give us enough light across intergalactic space for us to tell that they're there.
Okay.
So they're not staying still long enough for us to see?
No, you can stay still, but you're one damn star in the middle of a void.
Think about it.
When you look out of our galaxy, you need awesome telescopes to see only the brightest stars in other galaxies.
Otherwise, it's the merged puddle of light from the 100 billion stars themselves.
I got you.
You're not picking them out one at a time.
No, you are not.
You're listening to StarTalk Cosmic Queries Edition on our star, the sun, and the solar system.
We'll be right back.
We're back on StarTalk Radio.
I'm Neil deGrasse Tyson in studio with Chuck Nice.
Hey.
Chuck.
It's good to be here, Neil.
Love you, man.
Love you too, man.
All right.
This is the StarTalk Cosmic Queries edition.
Right.
And the topic is our sun and other solar systems.
Absolutely.
And we have a phone call. A phone call.
Once again, another phoner.
Okay.
And on the line is Kat from the Boston area.
Kat.
Boston area. That's very on the line is Kat from the Boston area. Kat. Boston area.
That's very nebulous, Kat.
All the cities around Boston have women's names.
So are you from Beverly or Lynn?
Where are you from?
I'm from Somerville, and I've never heard a woman named Somerville before.
Yeah, neither have I.
Okay.
So you got me on that.
Somerville, that's the original home of, what's the ice cream maker?
Ben & Jerry?
The other one.
Steve's Ice Cream.
Steve's Ice Cream.
Steve's Ice Cream.
The flagship store was in Somerville, and I ate a lot.
I gained 30 pounds.
You've been at Steve's Ice Cream.
So, Kat, what do you have?
Somerville is Boston's stripper name, by the way, Kat.
Okay.
So, what do you have, Kat?
My question is, basically, recently on Facebook someone had posted asking why
are the effects of gravity
shown as a funnel if there's no up or
down? And you had mentioned that
that's a 2D illustration of a
four-dimensional phenomenon. So you read my
Facebook page?
I stalk it a little bit.
I'm not going to lie to you. No one
stalks anything a little bit.
But I just answered that like yesterday or something.
So thanks for checking it out.
Okay, yeah, go on.
So my question is just why then are galaxies and solar systems disc-shaped or on their own planes?
Excellent question.
And that plagued philosophers for centuries until the mid-1800s.
Immanuel Kant.
Immanuel Kant. Immanuel Kant.
That doesn't sound good at all.
Actually, one of Siri's replies on the iPhone, if you ask her, Siri, what is the meaning
of life?
She says, I'm sorry, I can't answer that.
Ah, what a joke.
Very existential of her.
Totally existential.
Very existential of her.
Of the iPhone, yes. So, Immanuel Kant and a few others tried to ask the question and answer the question,
how is it that the entire solar system, the planets and the moons, all orbit in a plane
and they orbit in the same direction?
Like, what are the odds?
What are the odds?
Yeah, all right.
So, what they hypothesized was something called literally the nebular hypothesis,
which has borne out in the centuries of observations and data that we've taken since then.
And basically you start out with a massive gas cloud.
It collapses.
As you collapse, you begin to spin faster.
This is like what happens with a skater draws in his or her arms.
What happens when that happens?
They spin faster. Spin faster. That's what happens with a skater draws in his or her arms. What happens when that happens? They spin faster.
Spin faster.
That's what happens.
So as you spin faster, in the plane of that spinning, the material can't fall in because the centrifugal forces prevent that.
Right.
Okay?
Technically, they're centripetal forces.
Centripetal, yes.
Yeah, but centrifugal is colloquial.
Correct. But centripetal is colloquial. Correct, right. So in the axis, in sort of the equator of the spinning, it can't come in because of these centripetal forces.
Correct.
But top to bottom, it can collapse without hesitation.
So what you get is a flattened disk where everything is orbiting in the same direction.
Oh, my God.
That makes perfect sense.
Exactly.
That is awesome.
All right.
And so this dude figured this out in the middle 1800s,
and it's been working ever since.
Now, suppose you are moving very slowly in this,
and you're not collapsing quickly.
You can actually form stars that don't actually collapse into a disk.
If you form stars, the reason why it sticks to a disk, it's because it's made of mostly gas at the beginning.
And gas can't pass through itself.
Any more than one hot marshmallow can pass through another hot marshmallow.
What happens when two hot marshmallows hit?
You get a bigger hot marshmallow, that's all.
Well, they stick.
They stick to each other.
Yes, they stick and become a bigger one. So when you have a gas cloud collapsing, it sticks to itself in the plane, and it doesn't collapse within the plane.
It stays flat.
Everything else collapses pancake-style to it.
Do you know our galaxy is flatter than a pancake?
It's as flat as a crepe, actually.
A crepe?
A crepe.
We have a delicious galaxy.
We are 100,000 light years across
and about 100 light years thick.
So we are a thousand
to one ratio thickness to
diameter. Wow.
And that's basically a crepe. Yeah, it's a little
pancake. It's not a pancake. Yeah, it's a crepe.
So Kat, you okay? Are we
square? Oh yeah, my mind is blown.
Yeah, that was a great answer, man.
Everyone's mind should be blown daily.
Yes.
So have some galaxy for breakfast tomorrow.
Every time I eat a crepe, I think of our galaxy.
That's awesome.
You got it.
Thanks, Kat.
Thank you.
All right.
Chuck, we got like 20 seconds left.
You got a quick one there?
Let me see.
Here's a very quick one.
Before our last segment.
Go.
What would happen if a cubic centimeter of matter was instantly transported from the center of the sun
to the Earth's surface?
Bang.
Oh, there's some
misinformation out there
that somehow
we would all vaporize.
No, we'd just mix
with the atmosphere,
cool down,
and it'd be slightly hotter
in that area.
The answer is nothing.
Nothing?
Yeah, a cubic centimeter
of the sun
is not actually
that much material.
Remember, it's made of gas.
When we come back,
the final segment of Cosmic Queries, StarTalk.
We're back for our final segment of StarTalk Radio's Cosmic Queries edition.
I still like to think of it as StarTalk after hours.
Yeah.
So, these are questions called from the internet.
In the last segment, someone asked about a cubic centimeter of the center of the sun brought to Earth.
Yes. I think they're worried like Earth will explode or something.
Right.
Turns out that cubic centimeter will be 10 million degrees.
That's hot.
That is hot.
No bow to doubt it, okay?
But here's, and in the sun, it was undergoing fusion.
If you bring it to Earth, it's no longer under pressure.
That pressure is what contains it, what sustains it, what feeds it.
You bring it to Earth, it'll heat up the surrounding atmosphere,
but it's not going to bring fusion to it. You bring it to Earth, it'll heat up the surrounding atmosphere, but it's not going to bring fusion
to it. You lost the pressure. It'll come into
equilibrium with the atmosphere.
It'll be hot in that area
briefly. It'll radiate away. And that'll be it.
Not even a thang.
There you go. Not even a thang.
So Chuck, a new tradition we
have in the final segment is
the lightning round. That's what it is. And we have a
bell for it. You have the bell.. That's what it is. And we have a bell for it.
You have the bell.
There it goes, okay?
I will answer every question as a sound bite.
Correct.
So we can cram,
because I take so long on all the other segments,
try to pack in as many questions as we have.
Okay.
Are you ready?
I am ready, sir.
Go for it.
Okay, here we go.
This is from Louis Moses on Facebook. Do dust clouds around stars cause electrical storms?
Electrical storms around the star, I don't know.
So here's what happens. The sun, stars, the sun in particular in this case, gives off what we call a solar wind, which are charged particles.
And those particles can enter a dust cloud and ionize the dust cloud or excite it and possibly have it trigger a phenomenon similar to what we have on Earth, like our aurora.
So maybe there's aurora in nearby dust clouds to stars.
I haven't thought it through, but it's certainly possible.
There you go.
You got it.
Next.
This is from Marta Secreca.
Marta.
Marta.
What do we know of the star
that exploded to give material
to form our solar system?
Nice.
I would love to name it.
Oh, do you name something that's dead?
Yes.
Long gone and dead
that we can't find anywhere.
Yeah, it's dead and gone.
Right.
Actually, my great-grandmother had a name. Oh, no, I have to yeah it's dead and gone right actually my great
grandmother has a name oh no i have to go great great because i actually knew my great grandmother
so well it's not so five billion years ago there was a star that exploded created enrichment iron
nickel you know um nitrogen oxygen a lot of the things we find on earth and in our bodies
were forged in a star that came right before us.
Yes, it gave its life for us, and that's a good thing.
Sure, go ahead and name it, but we have no idea where the remains are.
Most of it is just completely gone.
Some of it is in us ourselves.
Okay, well, it died for us.
Let's call it Jesus Star.
There you go.
The Jesus Star.
The Jesus Star. All right. Here we go. The Jesus Star. The Jesus Star.
All right.
Here we go.
All right, let's move on.
This is from Sarah Ashley Colding.
Will the sun burn out before or after we collide with Andromeda?
Ooh, this is a cool one.
So the sun will burn out in like five billion years.
And now the collision with Andromeda is not an overnight thing we are two huge systems
and we'll start falling towards one another distort that'll happen between five and seven
billion years from now so the death of the sun should be our highest priority not the collision
not the collision with Andromeda bang nicely done all right okay um this is from Dennis B via email
oh by the way people might not have known that we're on a collision course with another galaxy.
Yeah, I was going to say that's...
Sorry, I forgot to say, holy...
And you're saying that it's going to happen.
Oh, yeah, but we have other issues before then.
All right, go.
Okay, okay.
Go.
Gentlemen, it's been a pleasure playing with you.
It's like the Titanic.
All right, here we go from Dennis B via email.
If the sun were to disappear in an instant,
how quickly will we on Earth know about its gravity-wise?
Eight minutes and 20 seconds.
Next.
If the sun disappeared, we would not know about it at all.
We would still orbit.
We would still feel its gravity.
We would still feel its heat and warmth and light for 8 minutes and 20 seconds.
Then all hell breaks loose.
What a great movie!
We fly off, and there's no way you could have known about it,
because that information is moving at the speed of light.
From the absence of a sun to the radius of our orbit.
Oh, that is fantastic.
You got it.
Okay.
Next. This is that is fantastic. You got it. Okay. Next.
This is from Kelly Smith.
By the way, if you can do the math, the speed of light divided into the distance from the
sun to the earth, you get eight minutes and 20 seconds.
And the answer is, I can't do the math.
Yes, you can.
Yes, you can.
Yes, you can.
Yes.
Go.
Here we go.
Kelly Smith from Facebook wants to know, wow, okay, I don't know if we could do this in
a soundbite, but I'm going to give it to you.
How are neutron stars formed?
What is their life cycle?
Ooh, so a white dwarf star, which is sort of the first stage of the death of a star,
our sun will become a white dwarf, is held up by what's called electron pressure.
Electrons can't get it too close to one another.
They'll separate.
Right.
All right?
It's called electron pressure, electron degeneracy pressure.
But you can overcome that
But you can't be an electron
If you overcome it
You can overcome the electron pressure
By cramming the electrons
Into the protons
That are in the nucleus
Gotcha
You cram a negative charge
In a positive charge
What do you get?
Beautiful fireworks
You get a neutron
The charges cancel
And that's how you make a neutron star
Cramming electrons
Up the butt of a proton And so how you make a neutron star, cramming electrons up the butt of a proton.
And so then you get a neutron star far more dense than a white dwarf ever was.
In fact, one cubic centimeter would weigh as much as a herd of 30 billion elephants.
You had me at cramming up the butt.
We got to run.
This has been Cosmic Queries edition of StarTalk Radio.
I'm Neil deGrasse Tyson, your host.
Thanks, Chuck.
Nice for being here.
Funded in part by a grant from the National Science Foundation.
Keeping us going.
Nice.
Thanks to all the listeners for believing in what we're doing.
We'll see you next time, StarTalk Radio.
As always, keep looking up.