How the Universe Works
Season 3
TV Series | How the Universe Works | Contents page
How the Universe Works S03E01
Part 1
Dec. 22, 2021, 6:44 p.m.
The sun, our nuclear powerhouse
Our star, its light powers our world and us
Without light, we would not be alive
Starting deep inside the sun
We follow the brutal journey
Of a single, tiny package of light -- A photon
The ride that any photon takes to get to my eyes
When i look up at the sun is an amazing one
From its ancient birth in the sun's core
To its escape from the surface
The light reaching me from the sun
Was produced before there was even human civilization
It's an incredible idea
Join our photon
On its incredible million-Year journey
Through the most hostile environment in the solar system
To bring light and life to earth
The universe, home to billions of galaxies
each made of billions of stars
And, in an unremarkable corner of our galaxy, the milky way
Lies the sun, our closest star
a dazzling sphere of intense light, too bright for the naked eye
But strip away that glare, and the sun transforms Into a giant ball
Of super heated gas dominating our cosmic stage
The sun is really the star of the show
The sun is the parent of the whole solar system
It provides its children, the planets
With everything they need
We depend on the sun for energy, for light, for warmth
We would not exist without the sun
The sun generates heat and light
The energy source for all life on earth
All of the energy that my body uses
Literally what i'm doing to talk to you right now
Came from the sun
The sun truly is the creator of all of the life around us
The sun is a constantly exploding
Nuclear bomb, violent and essential
Our entire existence is powered by the energy
Emitted in those nuclear reactions in the sun
We are here because of the light from the sun
We are here because of those nuclear reactions
And no aspect of our existence could persist
If it wasn't there
Light is one of the basic building blocks of the universe
I find light to be probably
The most amazing thing in the universe.
It's so important in everything.
I mean, it's everything. It's everywhere.
So, it's such a fundamental part of everything that exists.
Fundamental and fast.
The fastest thing in the cosmos
traveling at 186,000 miles per second
The sun is about 93 million miles away from us
So, going at 186,000 miles per second,
That's about eight minutes
But those eight minutes
Are just the brief last leg of its incredible journey
It may have taken the light as much as a million years
To escape from the sun's raging interior
which means the light we're seeing right now
Was created long before
Our ancestors left the plains of africa
When i first learned this fact,
I was already a practicing scientist
I had never really thought about that,
And on first glance, it just blew me away
Right now the light reaching me from the sun
Was produced before there was even human civilization
And yet, the minute it gets to the surface of the sun,
It races away and is here eight minutes after that
It's an incredible idea
The ride that any photon takes to get to my eyes
When i look up at the sun is an amazing one
That ride starts deep in the belly of our star
If we could open up the sun
We'd see layers of dense hydrogen gas
Hundreds of thousands of miles deep
And at its center, the core, the sun gives birth to light
forged in one of the most violent reactions In the universe, nuclear fusion
The specific nuclear reaction that powers the sun is fusion
Fusion of hydrogen into helium
You take two hydrogen atoms, you ram them together
And what's left over is a helium atom
It sounds simple enough
But it's not
It's actually hard to get two atoms to fuse
Two photons have the same charge
They're both positively charged. they want to repel each other
Protons don't like to get close together
They have to come together with a huge amount Of energy or velocity
To get close enough to begin to fuse
And that's very, very rare
To force protons together
Takes immense amounts of heat and pressure
generated by the invisible hand of gravity
The sun contains 99.8% of all the matter In the solar system
That's a lot of mass
All that mass pulls the sun together
With unimaginable gravitational force
With gravity crushing things down
Things get close enough together and nuclear fusion happens
In this nuclear compactor
Hydrogen atoms slam together
100 million quadrillion quadrillion times each second
Some of these collisions are so powerful that atoms fuse
Releasing energy
When the protons come together to bind together
They lose a little bit of mass
And that mass gets converted into energy
And every second of every day
About five million tons of stuff is being converted to energy
It's amazing
Each collision creates a tiny burst of energy
A packet of light impossibly small and incredibly powerful
Somehow, our photon will deliver its energy to earth
Where it will power the planet and make life possible
But right now it's nothing like the light we see
It has massive amounts of energy, and it's deadly
The light we see from our star is old
much older than the eight minutes it takes to get from the sun to earth
That short leap across space is the end of a long, hard journey
That starts deep inside our sun
When we look at the sun
We say, "how beautiful, how elegant, and how simple"
Light is formed in the sun
And it shines and lights up our world
Well, not so fast
How the Universe Works
Season 3
TV Series | How the Universe Works | Contents page