Hi there, Nidge here.
This bonus episode of Imagine This is a little different to usual.
In our last step, we journeyed into space to learn about the life of a star.
I reckon you should check out that episode first and then listen to this one.
Hope you enjoy it.
And remember, keep questioning.
Hello?
Niche, can you hear me?
It's Kirsten Banks.
Dr. Banks, the astronomer superstar.
What's up?
Well, me.
I'm up in space and there's something you have to see.
What is it?
One of the most powerful and mysterious things in the whole universe.
Get up here.
Hurry.
Did you hear that?
Dr Kirsten Banks, who has one of the coolest jobs in the whole cosmos, wants to show us something powerful and mysterious.
What do you think she's talking about?
Planets, stars, moons, galaxies.
Maybe even a black hole.
They're super dangerous.
Yeah, I think you're right.
We've had some questions about black holes.
My name is Maisie.
I am six years old.
I would like to know what is a black hole in space and how does it exist?
Hi, I'm Rohan and I'm five years old and I want to know what's inside a black hole.
Hi, my name is Bernie and I'm eight.
And I want to know, will our sun turn into a black hole?
Hmm, the closest black hole is really far away.
We're going to have to do some pretty good imagining to get to Kirsten.
Ready!
Let's start with a spaceship.
Engage.
Imaginarium.
Turbocharge.
Times infinity.
Space jump.
Hyperdrive.
Aye aye Captain.
We can get to Kirsten at light speed.
The speed of light is so fast.
We'll have to go faster.
Even at light speed.
It'd still take over a thousand years to get there.
What's faster than light speed?
It's almost impossible to imagine.
Never!
You're right.
Nothing's impossible to imagine.
Are we ready?
Yep!
Let's go!
Woohoo!
We're back in space!
Look out the window.
I can see a comet whizzing past.
It's so amazing.
I can see space now.
There's stars.
There's planets.
Ah, there's Kirsten.
Hello.
She's in a space suit floating outside the ship.
Can you let me in?
It's cold out here.
Quick, let her in.
Phew.
Hi, everyone.
Hey, Kirsten.
Hello.
Hi, Kirsten.
Thanks for meeting me.
I have something amazing to show you.
Remember when we were here last time?
Yeah.
You showed us how a star is made and what happens when it dies.
Yeah, we saw a red super giant collapse.
Wait, what's a super giant?
Uh, it's a red giant.
A giant doing a pop-off.
Supergiants are extremely large stars.
They can be hundreds, even thousands of times bigger than our sun.
And we call the red ones red because, well, they are.
Because it's like really hot.
Actually, it's red because the star is cooling down.
The hotter stars look blue.
What?
Blue?
You'd think it'd be the other way around.
Yeah, like opposite.
Stars are born from big clouds of a gas called hydrogen floating in space.
Yeah, the big gas clouds are called... Nebulas.
Yeah.
All the dust joins together and makes a star.
Hydrogen turns into helium.
Yes.
Over millions of years.
Gravity pushes that gas together into a ball so tight that the tiny bits of hydrogen gas they smash together and they turn into helium.
It makes it so hot and so bright.
That's when a star is all grown up and shining bright until it runs out of gas and it starts to cool down.
Small stars just fizzle out, but supergiant stars are the real showstoppers.
They go supernova.
Like a volcano, like explosion.
That's because gravity is pushing down on the star so hard that when it runs out of power, gravity makes it collapse in on itself.
And then it goes...
But gravity doesn't stop there.
It keeps pushing on the space where the star used to be, and this is what it creates.
What's that?
It just looks all black.
You can't even see it.
It looks like space is empty there.
Very spooky.
Oh my gosh, I think it's a black hole.
Yep, the densest object in the universe.
What does dense mean?
I think it means the stuff that you can squeeze inside something.
Yes.
Density is all about how much stuff you can squeeze into a space.
Dense things are heavier than things that are less dense.
So the denser something is, the heavier it is, and the more gravity it feels.
Gravity makes things feel heavy?
Yep.
An example is how a bucket is lighter when it's full of air and heavier when it's full of water.
Because the bucket's empty.
It may look empty, but it's still got air in it.
And air is full of stuff.
You just can't see it.
Air is lighter than water.
That means water is more dense than air.
And what if that bucket was full of, let's say, rocks?
The rock bucket would be heavier.
Because it's more dense.
Yes!
Now imagine squeezing the entire planet Earth into that bucket.
That'd be a very dense bucket.
Definitely.
More than rocks.
That'd be pretty heavy.
That's not possible.
It is in a black hole.
A black hole is infinitely dense.
Infinitely dense means there's no limit to its density.
Wow.
Its gravity can squish an entire super giant star down into something smaller than a grain of sand.
The gravity is so strong.
Yep, and if things get too close, it pulls it all in.
Including us.
We're going in.
Get ready for spaghettification.
Spaghetta for what?
What's that?
Everyone comes and puts spaghetti in the black hole.
Bolognese?
Spaghetti?
As things get close to a black hole they get sucked in.
But because they kind of get sucked in infinitely, things stretch and basically become space noodles.
What?
I don't want to be a space noodle.
Can I eat them with tomato sauce?
No way.
I don't think so.
That's spaghetti.
What's on the other side?
What would happen when you went inside a black hole?
We can honestly only imagine.
That's why a black hole is called a black hole.
Its gravity is so powerful, not even light can shine out of it if it gets too close.
Not even wide.
I don't want my buddy to get stretched.
I don't want to be space spaghetti.
We're safe here for now.
But if you get too close and go past a certain line called the event horizon, nothing can get out.
I'm glad we're not going to get sucked in, but I still don't want to be this close.
Yeah, come on.
Let's get out of here.
Great imagining, everyone.
Feel like never going in space again.
I feel happy and sad.
Because I'm happy, I'm not going to get sucked in, but I do want to try space noodles.
We won't be sucked into a black hole for real, will we?
Are there any black holes near us?
No, there are no black holes anywhere near Earth.
And there are no supergiant stars near Earth that could go supernova either.
So we will never be at risk of being sucked into a black hole.
I promise.
What about the sun?
That's a star.
What if it sucks up Earth?
Our sun is a much smaller star than a supergiant.
Small stars never go supernova or turn into a black hole.
Our sun's going to burn hot and bright for billions of years.
Oh, that's lucky.
I love our sun.
Thanks for taking us into space, Kirsten.
Again.
Anytime.
Thanks, Kirsten.
Thanks, Kirsten.
Thanks.
Hey, Nish, can we go up in that space hyperdrive again?
Again?
We just got home oh, all right, but no one is allowed to imagine me becoming space spaghetti.
We promise not me.
