Wait. That's the cable?

I was expecting something so much bigger.

That's the internet.

To get across the ocean, nearly all internet traffic

has to use a cable like that one.

- It's tiny. I'm so surprised. - You're actually surprised.

I know, I could tell. Love it.

All right, let's go get some hard hats.

Cleo: If you're watching this YouTube video

anywhere outside of the United State,

this is probably how it's getting to you.

For most of us, the internet is virtual.

It's made of Instagram posts and e-mails and YouTube videos.

But it's also a physical thing,

and what it's made of and where it goes matters

for how we use the internet now

and who will be benefit in the future.

So I want to know how does our internet really work

and what comes next?

( music playing )

( music playing )

The decade I was born, people were still learning about the internet,

and they didn't exactly consider it crucial.

But, you know, I think about this.

What about this internet thing?

What the hell is that exactly?

And they call it the World Wide Web.

You can e-mail anyone.

What the hell is e-mail?

Man: Can you believe what's possible these days?

Conversations through your computer.

Cleo: But now it seems we can't even function without it.

Jobs require online applications.

Parents around the country know

that their kids can't get an adequate education

without internet access.

I mean, people tweeting that they needed

to be rescued and a boat came in.

It's truly been life saving.

The internet has become essential to us,

but a lot of us still don't know how it works.

Okay, I need you to close your eyes.

- All of us? - Just trust me. Just close your eyes.

Yeah, for real. I'm serious. Close your eyes.

What's the craziest thing she could show us

- when we open our eyes? - ( laughs )

- I hope it's kittens. - Okay, now you can open them.

( screams )

- Joss: Tiny people! - Alex: They're us.

Christophe: It's tiny us.

So I know that there are three major parts of the internet.

We are on this outer ring. They call it the last mile,

but really it's the first and last mile.

So it's the texts we send,

the notifications we receive, the apps we use.

Everything we do to connect or receive information from the internet

happens in this first and last mile.

And we are inside...

the Vox office.

Also out in this outer ring are houses.

- You guys wanna help me put these down? - Yes.

- Trees. - So all of the--

all of the trees and all of the houses,

all Wi-Fi, which uses routers

somewhere in our office or somewhere in your home,

and all cell service,

which means that you're paying a cell tower

a little bit further away,

but still pretty close by.

All this wireless technology uses radio waves

to send signals into and out of the internet.

I'm gonna show you how this works.

But first, I'm gonna take a selfie.

Perfect. Okay.

So this is our selfie. I-- ( laughs )

- Joss, you've nailed that face. - Yeah, it's my go-to.

So I'm just gonna send this to you via e-mail.

- Typical e-mail. - Typical e-mail.

- There it is. - Boom.

- Ta-da. - So my goal is to figure out

how my e-mail got from my phone to yours.

In order for my e-mail to get from here to here,

my phone takes that photo

and cuts it up

- into more manageable packets. - No!

- We've been decapitated. - Just--

- Christophe: Just me. - Just you.

- So, imagine each packet like a letter in an envelope. - Uh-huh.

So, each envelope gets a header,

which is a little bit more information that includes--

- Christophe: Where it's from. - Where it's from and where it's going to,

and a bunch of other things that we're not going to talk about.

So the format of each header follows a set of rules,

and you can think about these rules

like the rules of the online postal system.

How everything is packaged and sent and received on the internet.

So you've probably heard people say that everything that happens

in our computer is ones and zeros.

- Right? Binary. - I have. Yeah.

Cleo: Which we can think of

as a kind of Morse code your computer understands.

And everything that you send over the internet

- is also binary. - Mm-hmm.

Christophe: ( gasps ) What?

- Ta-da! - When did this happen?

- What? - I do magic now.

- Okay. - Incredible.

So, each one or zero is a bit

and eight bits is a byte.

So, if this photo was 1.1 megabytes

that's 8,800,000 ones and zeros.

So, somehow these binary ones and zeros

have to get onto radio waves to be transported

- to the router, right? - Exactly. Yes.

- Okay. - And that's where I got stuck.

So, I called up Sundeep Rangan,

who specializes in computer engineering at NYU.

How does a wave carry binary information?

Ah, that is a very good question.

So, the simplest thing you could do

is every time you want to transmit, say, a zero,

you could transmit one frequency.

And every time you want to transmit a one,

you transmit a different frequency.

And then as long as the receiver can detect

which frequency it is, it can know it's a one or zero.

That's actually called frequency modulation.

Is it also fair then to say

that at its most basic, a cell phone is a radio?

Sundeep: It is a radio.

It is absolutely a radio.

Okay, so waves with binary information

have to get from my phone to the router.

But then at the router, they have to be turned into something else

that can go out the back of that device

along cables to get to their next location.

Depending on what the wire is made of,

it's either gonna be pulses of electricity

if the wire is copper, or pulses of laser light.

Sundeep: So, it's a laser and it just turns on

when there's a one, it turns off when it's zero.

So, faster than this.

- A little bit faster than that. - Faster than this?

So our photo went from binary to radio waves

- to little flashes of laser light, right? - Yes.

Where does it go after that?

We're about to find out,

but I'm gonna take Alex.

- You're not taking me? - No.

It's his turn. I gotta go.

Ooh.

So, the wires out of the back of our router

connect to other wires inside out office,

which are owned by our internet service provider

- or ISP. - Alex: Okay.

And they're responsible for looking at the header

of each of those envelopes

and figuring out the most efficient route

to get to its next location, which is an internet hub.

- Alex: And where would that be? - Cleo: Right there.

That's an internet hub.

- Alex: This old building? - Cleo: Yeah.

- All right, let's go. - It looks just like every other

office building I've ever seen.

Greg Sisk: Well, it started as Western Union's headquarters.

So, it supported telegraph operators back in the day,

and it's migrated to today

where it's supporting the internet

- here in lower Manhattan. - That's poetic.

So all those wires all need to come to a place like this

to connect between networks.

So, for our example, our ISP in the office has a network.

And AT&T, which is Christophe's cell provider, has a network.

And in order for my e-mail to get from my phone

into Christophe's phone,

all of those networks have to send those ones and zeros

across those wire pathways.

There's so much that happens

in that split second that you connect.

So there's really no such thing as a cloud

or any type of magnanimous--

- The cloud is a marketing term. - Yeah.

Cleo: The thing that I find really amazing is that,

like, my e-mail is one of the millions of messages

flowing through these cables.

That feels really abstract, but it's actually--

there's a message to somebody's mom

and there's a college application

and there's a job offer.

And there's a dank meme in here somewhere.

( music playing )

Okay, so my e-mail became a series of waves of light

that travels over the tubes of the internet.

But what if I wanted to send it somewhere really far away?

Somewhere on the other side of the world?

We're in Newington, New Hampshire, to go to a factory

that's gonna show us how the internet works at long distances.

We're headed into the third layer, the internet backbone.

Oh, that's the cable highway.

What's the cable highway?

Cleo: That's where the cables go

from the factory down to the dock.

The company we're gonna go see,

SubCom, is one of the top four submarine cable providers

in the world.

There's the ship.

- All right. - Hi.

- Hi. I'm Alysia. - Hi. I'm Cleo.

- So nice to meet you. - Nice to meet you.

Alysia: This is the SubCom Decisive.

She is a custom-built cable installation

and maintenance vessel.

She's 139 meters long,

which is about 450 feet.

- Wow. - Yeah.

Cleo: The engineering and material science at work here

are incredibly complex.

But the basic process is actually really simple.

Light goes in on one side of the ocean

and comes out on the other.

So, as the Decisive moves across the ocean,

the internet cable is gonna come out the back

and be laid down behind it.

And sometimes it's gonna be buried in the ocean floor

by that machine right there.

But most of the time it's just gonna lay there

on the bottom of the ocean.

So, these are the two types of cable that we have, the two basic types.

So this one, this is called lightweight cable.

So that's the one that we would use in the middle of the ocean.

And then this piece is the stuff that we use

the plow to install and actually bury.

And the cable is engineered to be super strong in a lot of ways,

but it is also very delicate in a lot of other ways.

Cleo: The wires that carry the light waves themselves

are typically made of fiberglass,

literally just a continuous strand of glass

about the size of a human hair.

Why is it that there are so few fibers?

We're working on trying to put more fibers inside the cable

to get more data into each fiber to make it

so that we can send more information than what we already have.

( music playing )

Whoa!

- So that's the cable tank. - Whoa.

Slow, slow. We got the pipe. We got the pipe.

Alysia: Work it over. Work it over.

What we're doing is we're loading it into the tank

in a continuous spool, right?