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

There are symbols all around us that we take for granted.

Like the lightning strike icon to indicate that something is high voltage,

or a little campfire to indicate that something is flammable.

Those icons, they might have some fascinating origin story,

but their symbolism is pretty obvious.

But other abstract icons are not so straightforward.

Like, why does one vertical line and two angled lines inside of a circle indicate peace?

Where does the smiley face come from? Or the power button?

Today, we sent out the 99pi team to dig into the backstory behind some of those images you see every day.

You might know what they mean, but you don't know why they mean what they mean.

We're calling this episode ubiquitous icons.

So, Emmett is here to bring the story of the peace symbol.

Here I am.

We're not talking about the peace symbol.

Like two fingers out when someone takes a picture.

Right, no.

The drawing of a circle with a little stick.

Yeah, the one that looks kind of like the Mercedes-Benz logo that you see everywhere.

I mean, it's kind of hard to think of a more ubiquitous icon than the peace symbol.

Yeah, right. It's like truly, truly everywhere.

And I think what interested me about it was that despite it's sort of totally ubiquitous,

...