This is 99% invisible. I'm Roman Mars.

Today's show is about something so tiny and unremarkable and ubiquitous

that I can't quite believe we're doing a whole episode about it.

It's sand, the tiny grains of eroded rock that we sculpted into castles at the beach.

Sand might not seem like a topic worthy of our attention,

but Vince Beiser wrote a whole book about sand.

It's called The World and Agrain

and I promise you, it is fascinating.

Here's my conversation with Vince, all about sand

and how it transformed our civilization.

You know, when you were spending a few years on this, I imagine, you told someone you were working on a book about

sand. What was the look on their face? and you

explain it to them to make them understand

how do you explain it to them to make them understand how cool and important this subject is?

So every single time I would get this look that was just like, huh? Like why am I trapped? You know, why am I trapped in a conversation with this person who's about to, you know, who's so obsessed with the most boring thing on earth and

basically my comeback was why would I write a book about what sounds like the most boring thing in the world

and the reason is because sand is actually the most important solid

substance on Earth. It's the literal foundation of modern civilization.

Yeah. And so how do we use sand in our daily lives? So basically if you

look around you right now, I don't know where you are, but chances are excellent

no matter what kind of building or office or room you're sitting in.

The floor underneath you, the walls around the ceiling overhead,

...