Welcome to Cosmos in a Pod's Space and Astronomy series.
Ever glance at your jewelry and wonder,
like, where the gold really came from?
Yeah, it's fascinating, right?
Totally.
Or realize that the calcium in your bones,
it has a pretty wild origin story.
Absolutely.
So today we're going deep, deep, deep
into how the universe creates the elements that, well,
make up everything.
You, me, this microphone.
That's right.
We're talking about stellar nucleosynthesis.
Stellar nucleo what now?
It sounds complex, but it's basically
how stars act like giant element factories.
OK, that makes more sense.
So they're forging the building blocks of, well, matter.
Yeah.
From the inside out.
Exactly.
So stars, they aren't just those pretty twinkling lights
up there.
They're like churning out ingredients for planets,
for people, even for this microphone.
Wild.
Precisely.
Think of a star as this massive gravity-powered furnace.
OK, I'm picturing it.
It all starts with hydrogen, the simplest
element, super abundant in the universe.
Hydrogen.
Deep inside the star's core, the pressure and heat,
they're so intense.
I bet.
Hydrogen atoms are forced to fuse together, forming helium.
OK, so two hydrogens become one helium.
Yeah, and this releases a tremendous amount
of energy in the process.
So that's the secret behind starlight.
It's a byproduct of this fusion process.
Whoa.
Exactly.
And that fusion energy, that's what
drives the whole element creation thing inside stars.
Wow.
As a star ages, it's like, imagine a cosmic pressure
cooker.
Uh-huh, OK.
But it's turning up the heat.
It starts fusing helium into heavier elements.
So what kinds of heavier elements?
Like carbon.
Carbon.
Now that's where things get relevant to us, right?
You got it.
Carbon.
That's one of the key ingredients for life, right?
At least life as we know it.
Absolutely.
The carbon in your DNA.
In my DNA.
Mine too.
It was once forged in the heart of a star.
No way.
And the process keeps going.
Stars can fuse even heavier elements,
creating oxygen, neon, magnesium.
It's like a cosmic assembly line building the periodic table.
Pretty much.
So if I'm getting this right, bigger stars,
they can create heavier elements.
Exactly.
Because they have more of that intense fusion power.
I'm seeing a pattern here.
You're right on track.
The more massive a star is, the hotter and denser it's core.
So it can fuse heavier and heavier elements.
OK, that makes sense.
So it's all about size.
But there's got to be a limit, right?
Like a cosmic speed bump or something.
There is.
And that speed bump is iron.
Iron.
Iron is like a wall in the fusion process.
To create elements heavier than iron, you need to add energy.
Wait, so you don't get energy out.
You have to put it in on.
Exactly.
So when a star's core starts filling up with iron,
it's heading towards a pretty dramatic finale.
OK, I can only imagine.
I bet this finale involves something spectacular.
What happens when a star runs out of fuel, hits that iron wall?
I mean, it can't just fizzle out, right?
Definitely not.
What happens is one of the most awe-inspiring events
in the universe.
Hit me with it.
A supernova.
I knew it.
When a massive star reaches this critical point, it collapses.
Collapses on itself.
Yeah.
And this triggers a colossal explosion, an explosion
that can outshine entire galaxies.
OK, I knew supernovae were bright.
But outshining galaxies?
That's not level.
It's truly mind-boggling.
And they're not only visually stunning.
I can imagine.
They're also crucial for creating those heavier elements,
the ones beyond iron on the periodic table.
So we're talking gold, platinum, uranium, the heavy hitters.
Exactly.
These heavyweights are forged in the intense chaos of a supernova.
So picture this.
Imagine a cosmic storm of neutrons.
OK.
Bombarding atomic nuclei, building them up
into heavier and heavier elements.
All in, like a fraction of a second.
Pretty much.
This process is called the R process, or rapid neutron capture
process.
The R process.
So the gold in my ring, or in a hypothetical Olympic gold
metal, that was created during a supernova explosion.
Ah, it's kind of poetic when you think about it.
It really is.
And supernovae don't just create these elements.
They scatter them across the universe.
It's like a cosmic seed spreader,
enriching interstellar space with the building
blocks for future stars, planets, and even life.
So it's destruction and creation all wrapped up
in one incredible package.
Yeah.
You could say that.
Supernovae sound pretty important.
But I'm guessing they aren't the only way
the universe gets creative with elements, right?
What other cosmic element factories are out there?
You're right.
Supernovae aren't the only players in this game.
There are other processes, even involving
stars that aren't as massive.
Oh.
So even smaller stars contribute to the element mix.
Cool.
What happens there?
One example is a white dwarf explosion, also known
as a type Ia supernova.
Type Ia.
OK.
Remind me, what's a white dwarf again?
A white dwarf is what's left over when a sun-like star uses
up all its fuel.
It's incredibly dense.
Dense like how?
Imagine packing the mass of the sun
into something the size of Earth.
Whoa.
Dense is an understatement.
Yeah, it's pretty wild.
So how do these white dwarfs get involved in creating elements?
They don't just sit around being super compact, right?
Yeah.
Not always.
Sometimes a white dwarf has a companion star,
and it can start pulling material from its neighbor.
If it pulls in enough material, it can reach a critical mass
and boom, it explodes in a type Ia supernova.
So even in their afterlife, these stars
can still pack a punch.
What kind of elements do these explosions create?
They're especially good at creating elements
like nickel and iron.
Iron, huh?
That rings a bell.
Remember, iron is that wall in the fusion process.
So these explosions provide a way to get more of it
out into the universe.
So we've got massive stars going supernova,
white dwarfs getting in on the action, anything else.
It seems like the universe has a lot of ways to create elements.
Oh, absolutely.
There's another incredible phenomenon that we've
been learning a lot more about, neutron star mergers.
Neutron star mergers.
I've heard of those.
They sound intense.
Imagine two neutron stars, the super dense remnants
of supernovae spiraling towards each other and colliding.
It's a mind blowing event.
OK, two super dense objects smashing together.
That sounds intense as an understatement,
but I'm guessing it produces more than just
like a cosmic light show.
You bet.
Neutron star mergers are now thought
to be one of the main sources of the heaviest elements
in the universe, especially gold.
Gold comes from neutron star mergers.
Seriously.
These mergers release an immense amount of energy
and a flood of neutrons, triggering the R
process on a colossal scale.
It's like a cosmic gold factory.
Wow.
OK, so to sum up, we've got regular stars fusing lighter
elements, giant stars going supernova,
white dwarf explosions, Andean neutron star mergers,
all contributing to this amazing element creating sympathy.
That's the picture.
It's this intricate dance of stellar processes
that has enriched the universe with the elements
we see today.
Wow.
OK.
And it all ties back to that amazing chart
we all learned about in school, the periodic table.
Oh, yeah, the periodic table.
I remember memorizing all those elements and their symbols.
But you're saying there's more to it than just
like a list of ingredients.
The periodic table is actually a cosmic history book.
It's not just a random arrangement of elements.
It tells a story about where each element came from
and the incredible events that created them.
Hold on.
You're saying I can read the history of the universe
just by looking at the periodic table?
It's blowing my mind a little.
It really is.
Think about it.
The lattice elements, hydrogen and helium,
were created way back at the beginning during the Big Bang.
Oh, right, the Big Bang.
Then as stars formed and began their fusion processes,
they created heavier elements like carbon, oxygen,
and silicon.
So those elements, the ones that are most common and important
for us, they're products of stellar fusion.
I never realized there was such a deep connection.
It's a fundamental connection.
And then you have the heavier elements, like iron and nickel,
formed in the cores of massive stars
before they go supernova.
And of course, the heaviest of them all,
like gold, platinum, and uranium,
are primarily forged in those powerful supernovae and neutron
star mergers.
Wow.
So the periodic table isn't just a chart.
It's a timeline showing the progression of element
creation from the Big Bang to the most extreme events
the universe has to offer.
That's a great way to think about it.
It shows us that the elements that make up our world,
and even us, have this incredibly long and fascinating
history, stretching back billions of years.
And it leads us to a pretty profound realization.
We are literally made of star stuff.
OK, that phrase, we are star stuff.
I've heard it before, but it never really sunk in until now.
It's mind-blowing to think that the atoms in our bodies
were once part of these distant stars
and these incredible cosmic events.
It really does change your perspective, doesn't it?
It connects us to the vastness of space and time
and reminds us that we're part of this grand cosmic story,
a story that's still unfolding.
Really?
With all that we've learned, there's still mysteries out
there.
What are scientists still puzzling over?
It seems like we've uncovered this whole cosmic recipe
for how elements are made, but what's still missing.
Like, what are the big questions scientists are still
grappling with?
Well, one of the puzzles is figuring out the exact roles
of different cosmic events.
We know supernovae and neutron star mergers both
create heavy elements, but we're still working out
the precise proportions.
It's like trying to figure out the exact recipe
for a complex dish.
We know the main ingredients, but the exact amounts
are still kind of mystery.
So it's like a cosmic cooking show
where we're still figuring out the measurements.
What else is on the scientific to-do list
when it comes to elements?
Another area of active research is
understanding rare processes, like the slow neutron
capture process or S-process.
S-process.
OK.
This happens in certain types of stars,
and it contributes to the creation
of some heavy elements, but the details
are still being worked out.
It's like finding a hidden ingredient that
adds a subtle flavor to the cosmic mix.
Oh, I like that.
A hidden ingredient.
And I imagine with new telescopes like the James Webb,
we're probably going to uncover even more mysteries, maybe
even processes we haven't even imagined yet.
Absolutely.
The universe is full of surprises.
And as we develop new tools to observe it,
we're constantly making new discoveries, discoveries
that challenge our understanding.
Makes sense.
It's an exciting time to be studying the cosmos.
It really is.
This whole idea that we're made of star stuff,
that our very existence is tied to these incredible cosmic
events, it's humbling and inspiring.
It definitely makes me appreciate the night sky
in a whole new way.
I feel the same way.
It underscores the interconnectedness
of everything in the universe.
We're not just observers.
We're active participants in this grand cosmic story.
A story that's still unfolding.
Exactly.
Well, this has been an incredible journey from stars
as element factories to supernovae, neutron star
mergers, and the periodic table as a cosmic history book.
It's been a mind-expanding deep dive
into the origins of, well, everything.
Ha ha.
It really has.
It's been a pleasure sharing this journey with you
and hopefully with our listeners as well.
And remember, this is just the beginning.
There's so much more to explore, to discover
about the fascinating world of astronomy.
Absolutely.
So to all our listeners out there,
if you want to continue this cosmic adventure with us,
be sure to follow and subscribe to our podcast
and our YouTube channel.
We've got plenty more deep dives to come exploring mysteries
of the universe and beyond.
Until next time, keep looking up and never stop wondering.