♫ What in the world? ♫
♫ When? Why? Where? ♫
♫ Who's got the answers? ♫
♫ SKUNK BEAR! ♫
That's a good question
You probably know that pencil lead isn't actually lead
It's a mineral called graphite
A lattice of pure carbon atoms
To get to this graphite's origin
you can't just go back to a pencil factory
We have to go all the way back
to the start of the universe
Back then there wasn't any carbon
just a hot soup of high-energy particles
They cooled, forming hydrogen and helium
In the bellies of dying stars,
helium atoms were smashed together
Carbon was born!
When these stars exploded ...
the universe was seeded with this versatile new element
Here, on our planet, all living things are built with carbon atoms
That's why Carl Sagan was fond of saying, "We're made of star stuff"
So how did this carbon get into pencils?
Living things died, and some of them piled up in lake beds
Over millions of years their carbon atoms rearranged
Depending on pressure and temperature,
sometimes they became oil or coal
and sometimes they became graphite
A storm in the 16th century England revealed one of these deposits
and local shepherds used the stuff to mark their sheep
Graphite is a bunch of flat sheets of carbon atoms
stacked on top of each other
the bonds between those sheets are weak
so they slide apart really easily when
and when you drag a piece of graphite across a surface
like a piece of paper or a sheep
it leaves those sheets behind
Graphite looked and acted a lot like
lead so that's what people call it
In the 1800s a thoughtful young man
named Henry David Thoreau
found that mixing graphite with clay made it harder
Pencils with clayier graphite made lighter marks
And Thoreau's proud father introduced a numbering system
Soon pencils were being mass-produced in
factories like the General Pencil Company
They've been making pencils here for over a century
It all starts in the Lead Department
Graphite and clay are mixed in giant drums
This machine shapes the clay into rods
These are the cores of future pencils
They're baked to remove moisture
In the Grooving Department the cores are placed between wood panels
Two panels are glued together,
set to dry,
and then cut into individual pencils
In the Polishing Department the pencils get layer upon layer of paint
And the final touch?
And that's how pencil lead is made!
Send us more of your questions and please
subscribe to our channel
We'll answer new questions every other Tuesday