Author Interviews
11:59 am
Thu May 31, 2012

The Internet: A Series Of 'Tubes' (And Then Some)

Originally published on Thu May 31, 2012 2:08 pm

Increasingly, Internet users are working "in the cloud" — creating and sending data that isn't stored on local hard drives. It's easy to imagine our emails and photos swirling around in cyberspace without a physical home — but that's not really how it works. Those files are still stored somewhere, but you can only find them if you know where to look.

In Tubes, journalist Andrew Blum goes on a journey inside the Internet's physical infrastructure to uncover the buildings and compounds where our data is stored and transmitted. Along the way, he documents the spaces where the Internet first started, and the people who've been working to make the Web what it is today.

Blum tells Fresh Air's Terry Gross that the Internet can be thought of as three separate entities: data centers that store information, Internet exchange points where networks meet to exchange data with each other, and fiber-optic cables that connect all of the information traveling between cities and continents.

Blum calls these fiber-optic cables, many of which traverse the ocean bottom, the "most poetic places of the Internet."

"They're about the thickness of a garden hose, and they're filled with a handful of strands of fiber-optic cable," he says. "And light goes in one end of the ocean and out the other end of the ocean. And that light is accelerated along its journey by repeaters that look like bluefin tuna underwater."

The repeaters and the fiber-optic cables extend for thousands of miles below the ocean's surface, along the same routes where other telecommunication cables have been placed for decades. Blum, who watched one of the fiber-optic cables emerge from the sea in Lisbon, says the process hasn't changed much over the decades.

"I saw pictures from [a telegraph] museum in England where the pictures from 100 years earlier looked exactly the same," he says. "The Englishmen in their hats were watching the laborers digging in the wet trench, pulling the cables up. So the technology has changed but the culture hasn't changed, and the points being connected haven't changed much."

In the States, many of the trans-Atlantic cables coming from Europe terminate in an art deco-style office building at 60 Hudson St. in New York City. More than 100 telecommunications companies have offices in the building, which contains more than 70 million feet of cable wire.

"It's essentially a building-sized jumble of wires," says Blum. "It's been [a very important building] for the telephone as well. So there's this mix of very high-tech, high-capacity, brand-new machines, and then these old banks of copper wires and switches. ... And the contrast is incredible. It's amazing that we think of the Internet as a high-tech, sterile place, and this place is the complete opposite."

In fact, Manhattan is full of buildings containing key parts of the Internet, says Blum. In 2010, Google acquired 111 8th Ave., a block-long building in Chelsea that sits almost directly on top of large bundles of fiber-optic cables. The building is designed to allow tenants to connect to these fiber-optic lines directly.

"It's that autonomy to connect — to do whatever they want and to make their own decisions about how they're connecting to other networks that allows the Internet to be both robust and cheap," says Blum.

Even though there's some potential risk involved, Blum believes the locations of these data centers will never become secret.

"The Internet is all about one network connecting to another network. It's the space in between that makes it come alive," he says. "And if you're secret — if you try to hide where you are — then you essentially can't function as a network on the Internet because nobody knows where you are. And if you're in the business of selling your connection, then you have no business at all if you won't tell anyone where it is."


Interview Highlights

On the late Alaska Sen. Ted Stevens saying the Internet is made up of "a series of tubes."

"He's not wrong. The Internet is absolutely made of tubes. What else could it be made of? It's many other things — these protocols and languages and machines and a whole set of fantastically complex layers and layers of computing power that feeds the Internet every day. But if you think of the world in physical terms, and you're trying to be as reductive as possible and try to understand what this is, there's no way around it — these are tubes. And from the very first moment, from the basement of a building in Milwaukee to Facebook's high-tech, brand-new data center, and along the ceiling and the walls, are these steel conduits. But I know a tube when I see one."

On the makeup of the Internet

"The Internet has parts and pieces. We think of it as this singular whole, and we use the word 'cloud' as a crutch to avoid thinking about the specific parts; but, in fact, it is as singular as anything else."

On visiting Facebook's data center, located in central Oregon

"It was an interesting place to be because I realized that this was a place that was connected to some of the most important moments of my friends' lives. This was the place from which announcements of weddings and family members' deaths and new jobs and new babies came from, so there was a real disconnect between the sense of it being a building full of machines and the emotional importance that it had on my life."

On replacing existing infrastructure

"Because fiber-optics cables are essentially glass tubes, you can replace the flashlight on the end with a newer model, and that will transmit more data. So you can keep the same actual fiber, replace the equipment on either end, and suddenly you've increased the capacity by an order or even two orders of magnitude. So that's a start. That will get us a few years down the road. But then it's a constant gardening process. It's replacing the old ones and putting in new ones."

On researching Google and Facebook

"Out of all of the companies I spoke with, Google was the one that shared the least. Facebook, in contrast, was the opposite. They believed that this was your data. You, the public, had a right to understand where it was and what they did with it."

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross. You know what makes your wireless Internet connection possible? Wires, cables, zillions of them - underground cables, undersea cables, buildings that have layers and layers of wires, interconnecting networks. Your wireless connection and the cloud, they have a physical infrastructure; it's just out of our sight. And that physical infrastructure is the subject of the new book "Tubes: A Journey to the Center of the Internet" by my guest Andrew Blum. He's a correspondent for Wired.

The title of the book "Tubes" is a reference to former Alaska Senator Ted Stevens' remark that the Internet was a series of tubes, a remark that was widely mocked, but Blum discovered the infrastructure of the Internet does have a lot of tubes.

Andrew Blum, welcome to FRESH AIR. So before we get into a more detailed description of the physical structure of the Internet, just give us like an aerial view, you know, like an overview of what the Internet physically is.

ANDREW BLUM: Well, the Internet is a network of networks, and so those networks, some begin at your house, and they sort of travel across the country, and Facebook will run a global network, or Google will run a global network, and then those networks have to connect to each other.

And where they often connect to each other are in places called Internet exchange points, where there's a refrigerator-sized router belonging to one network, and it's plugged into a refrigerator-sized router belonging to another network, usually through a yellow fiber-optic cable.

GROSS: And then?

BLUM: Essentially any time you do anything online, you're essentially asking, it's like a self-addressed, stamped envelope. You're saying: Please, send me this Web page, you know, from where it is. And oh, by the way, I'm over here. This is my address on the Internet. And that command goes off, passes almost decidedly through these very specific list of Internet exchange points, and then sends that sort of larger trove of data back to you.

GROSS: So let me ask you about the cloud. We think of the cloud, you know, the image of it is like - a cloud. It's something in space, you know, it's not physical, it's just like your data, instead of being on your hard drive, which could crash, or which your device could get stolen, you could lose it, it's like stored in this cloud in cyberspace someplace where it's going to be safe.

But the cloud isn't really a cloud. It's like a lot of machines. When you store something on the, quote, "cloud," where is it really being stored?

BLUM: Well, it depends whose cloud. It's interesting. I mean, the Internet is made of so many parts. I know my cloud happens to be stored in suburban Virginia. That's where the service that I use for backup has a data center not far from Dulles Airport. But your cloud might be in Oregon or in Minneapolis or anywhere else.

And I think it's a really key point that the Internet has parts and pieces. We think of it this singular whole, and we use the word "cloud" as a crutch to kind of avoid thinking about the specific parts. But in fact, you know, it is as singular as anything else.

GROSS: So if you're storing your email or your data on your hard drive on a cloud, are you basically just storing it on somebody else's hard drive?

BLUM: You are. I mean, that's really what it means. You're exchanging the hard drive on your desk for a much larger hard drive run by a company far away. And it's interesting, you can very rarely find out where your cloud is. If you look at these, you know, companies like Dropbox or SugarSync or even iTunes, it's not transparent at all. There's no sense that we want to know where this is. There's no sense that we should be allowed to know where it is, and we're increasingly disconnected from it, although disconnected is funny because obviously we're so connected to it.

GROSS: How well are the cloud hard drives backed up?

BLUM: Well, it depends again on sort of which cloud, right. So - but hopefully they're backed up at least twice, ideally in two different locations on different parts of the world or different parts of the country. And, you know, hopefully the network engineers and the systems engineers who built your cloud did it well enough that there's very little chance that all of those would disappear at once.

GROSS: Are they vulnerable to things like earthquakes, floods, terrorism, crashes?

BLUM: To a certain extent. They're most vulnerable to mechanical failure. I mean, hard drives fail all the time, as some of us unfortunately know, and, you know, earthquakes and floods are - the cloud itself isn't as vulnerable to that. The cables that connect the Internet on a global scale are much more vulnerable, particularly to underwater earthquakes. And terrorism is a sort of different case. Most of the conversation about cybersecurity is about virtual hacking, it's about people sort of, you know, logging in through their keyboards to a computer and doing some harm to it. There's very little discussion about physical harm to the network.

GROSS: Maybe there should be discussion of that.

BLUM: I think there should be definitely. I think - I mean, most of these places are well-secured but not perfectly secured. And at the same time, though, it would be a strange terrorist attack. You would be going after a place that people don't realize exist. You would - most likely there would be a backup. So your impact would be negligible.

The worst-case scenario is a sort of simultaneous destruction of these places at a scale that's almost impossible to imagine being pulled off. It's almost like saying, you know, we're going to take away all the airports in the U.S. They're just - they're too big, there are too many of them, they are as single pieces too broad.

GROSS: Let's talk about the tubes under the sea, which is - the Internet has a huge physical presence under the sea. Tell us about what's there.

BLUM: The undersea cables are the most - I feel are the most poetic pieces of the Internet. They're about - usually about the thickness of a garden hose, and they're filled with strands of fiber-optic cable. And light goes in one end and comes out the other, goes in one end of the ocean and comes out the other end of the ocean. And that light is accelerated along its very long journey, thousands of miles by these repeaters that look kind of like bluefin tuna, underwater.

And there's a system in there that essentially accelerates the photons, almost like a water wheel, sort of goosing them along on their journey across the ocean, not at the speed of light, at about two-thirds the speed of light. And what amazes me about them is that you can sort of - you can - when you look at one, you can conceive of it very easily.

It's this - you know, it's two inches thick, it looks like a garden hose, it's easy to think about, and then you think about the other dimension. You think about the fact that this goes on for thousands of miles. You sort of think about looking out into the ocean and imagining that it crosses and goes all the way across, and that part is incredibly expansive and incredibly difficult to understand.

But then you think of it - you think of the sort of ease with which we talk, you know, talk on the phone across, you know, across oceans, or we send an email to Europe or someplace, and you realize that we sort of touch these things constantly.

GROSS: Maybe you can explain a little bit more about how fiber-optic lines work, because it just seems like magic to me. Maybe it's too technically complex to explain, but how light can convey data through these tubes in the ocean and not get all the data scrambled, just all that. I can't begin to comprehend it.

BLUM: It's difficult to comprehend, and I confess I can't comprehend it fully myself. There is a - I do understand the basics of it, and the most interesting part is that you have many frequencies of light passing through a single strand of fiber. Frequencies are colors of light.

So in a single strand of fiber, you might have a 10-gigabit-per-second wave, a wave of light, that will transmit through pulses 10 gigabits per second of data, you know, essentially 1,000 times more than your home Internet connection might be, through a single wave of light.

But then on top of that, through that same strand of fiber, there'll be dozens, if not a hundred, other wavelengths of light, other colors of light passing through that same fiber. So you have incredible, incredible capacity through a single strand of fiber, and that's, particularly for the undersea cables across the ocean, that's what allows them to carry stupendous amounts of data through a single strand of fiber. Then the cables will have perhaps four strands of fiber going in each direction because each strand is - the light is only traveling one way across the ocean, and there's a matching pair, where the light is traveling the other way.

GROSS: Even though these are really high-tech, you know, tubes or cables, whatever you want to call them, they still seem so old-fashioned in a way. I mean, I always think, oh, in the Internet era, everything is done through, like satellites and just, like, through the air, and that's not true. Can you just talk a little bit about the old-fashioned-ness of cables under the sea in a satellite era?

BLUM: So with the cables, one of the most amazing things is that they still connect the places that have always been port cities: Mombasa, Mumbai, Singapore, Hong Kong, New York. And so that geography hasn't changed even though the technology has changed.

And the way that they're laid hasn't changed very much at all. There's still a ship that steams across the water laying, you know, laying one of these cables off its stern. What's inside the cable has changed: It's gone from copper to strands of fiber-optic cable. But the process of it is still the same.

And even more remarkably, when it lands on the beach, it's exactly the same, and even culturally it's exactly the same. Almost always there's an English engineer ready to sort of receive it and directing the show, and almost always there are sort of local, often immigrant, laborers who are sort of doing the heavy lifting.

And I watched one of these cables come up on the shore in Lisbon, and that was exactly what it was. And then I saw pictures in the archive of the Porthcurno Telegraph Museum in England, which is sort of the granddaddy of all cable landing sites, and the pictures from 100 years earlier looked exactly the same, these Englishmen in their hats, you know, watching these laborers sort of digging in the wet trench, you know, pulling the cable up.

GROSS: Are the cables laid basically in the same places that the copper wires were laid?

BLUM: They are, they are. I mean, for the most part they definitely are. I mean across the Atlantic or around from Cornwall, from the sort of Land's End, the western tip of England, around to Gibraltar, through the Mediterranean, through the Suez. You know, these are the sort of classic trade routes, and they haven't changed with the Internet. The Internet has only traced them.

GROSS: So the fiber-optic cables that are at the bottom of the ocean, what are they susceptible to? Like, there's fish there, there's possible earthquakes. Like what are some of the problems cables could face?

BLUM: I think the things that usually get them are anchors being dragged by ships and earthquakes. There's a famous case from 2006 in Lausanne, off the coast of Taiwan, wherein a very powerful earthquake essentially severed, you know, six out of the eight cables connecting, connecting essentially north Asia and south Asia, and the Internet stopped. You know, there was essentially no - you know, everything ground to a halt until they were able to sort of route around it. And traditionally we think about that happening sort of automatically, but in that case it was a - you know, it was so dramatic that it was a matter of people unplugging the connections on one of the end of the cable into a different cable.

And then of course the repair takes weeks because in order to repair these underwater cables, you have to go out of the ship, throw a grappling hook over the side, lift the cable off the ocean floor, find the other end of the cable, the broken side, stitch them back together and then drop them over. And that's a very physical, a very sort of hand process that took weeks in that case.

GROSS: If you're just joining us, my guest is Andrew Blum. He's the author of the new book "Tubes: A Journey to the Center of the Internet." And he writes for Wired and several other publications. Let's take a short break here, and then we'll talk some more. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: If you're just joining us, my guest is Andrew Blum, and his new book is called "Tubes: A Journey to the Center of the Internet." One of the places that you visited in trying to understand the Internet, the physicality of the Internet, was a data center in Milwaukee that's the central data center for Milwaukee Internet communication. And it's in an office building built in 1901. It was the former home of the Milwaukee Athletic Club, and just one of those great paradoxes that, like, the high-tech Internet center in Milwaukee is in this, like, old building. What's in it?

BLUM: Well, in the basement, the basement is filled with wires. You can't see the ceiling because there are so many wires attached to the ceiling. And those wires sort of attach to these steel boxes that sort of look like coffins, that are kind of up-up, you know, up in the corner, where the wires come in from underneath the street.

And then they travel up to this variety of offices upstairs that these companies have colonized. And I was visiting with a guy who's an engineer for an ISP, an Internet service provider, called Netwurx, a sort of small one in southeastern Wisconsin. And this was the place that his 10,000 customers got their Internet from.

And if you think of a company like Verizon or Comcast as having this huge breadth and complexity, this was the opposite. He had a single machine in his sort of dusty office with the windows thrown open to the Wisconsin winter to keep the machines cool. And coming out of the machine were primarily two yellow cables.

And one cable went to Cogent, which is a wholesale Internet provider, a sort of global network that he gets his - that he connects his network to, and the other cable went to Time Warner, their business division. But you can think of it very simply as when - all of his customers connected to the Internet through these two cables. One went one way; one went the other.

And I said: Then where does it go? And he said: It doesn't matter to me. Once Cogent's got it, they're going to worry about it on a global scale. But it really revealed to me that at every single - every single moment we spend online is made of these forks in the road. And in aggregate, they're almost impossible to conceive, but when you look at them individually, they're incredibly simple: There's a yellow cable connecting one router to another router.

GROSS: So there's another building I want to ask you to describe, and this is one that's in New York. It's a former Western Union building that opened in 1930 and once carried high-gauge copper wire for telegraphs. What's the building being used for now?

BLUM: That building is 60 Hudson Street, downtown in Tribeca, and that is the building where the majority of transatlantic cables terminate. They land on the beach, usually in Long Island or New Jersey, but then they connect right back to 60 Hudson, and that's where they then connect to everybody else. So it's essentially, it's a big - you know, the building is a sort of building-size jumble of wires, you know, one network connecting to another network.

GROSS: And you went there?

BLUM: I did go there, yeah. It's a - it's a - there's a lot of history, and it's been very important for the telephone, as well. And so there's this mix of these, you know, incredibly high-tech, brand new, very high-capacity machines and then these old sort of huge banks of copper wires and switches, you know, where - you know, that say like Deutsche Telecom, you know, that are - you know, that's the place where Deutsche Telecom connected all of its calls to the U.S.

And the contrast is incredible. It's amazing that, you know, we think of it as this - the Internet, we expect it to be a sort of high-tech, sterile place and some of its places are, but this place is the complete opposite. It's this great sort of old art deco palace.

GROSS: And how did it become an Internet center?

BLUM: The stories about how these places become what they are always seem to combine a sort of fact of geography - you know, Lower Manhattan is an important place for communications, it always has been - and then often a sort of charismatic salesman, you know, often somebody who convinced the first network or the first two networks to come in and say hey, you guys should both come, and when you get here, you should connect, and then other people will come, too, and they'll connect.

And that was - you know, that was the case at 60 Hudson. The legend is that the, you know, the reason the - with the deregulation of the telecommunications industry, everybody needed to connect to AT&T, to Ma Bell. And Ma Bell is just two blocks away. But the - in order to connect, they had to get inside the building, and AT&T said no, we won't let you inside the building, we're not obligated to.

And then an entrepreneur sort of realized that Western Union had maintained control of their quote-unquote "network," which actually meant the clay conduits underneath the street that connected the old AT&T building with the old Western Union building. And he used that underground path, that, you know, that actual, you know, this physical space to connect - to essentially tether in 60 Hudson to 32 Avenue of the Americas.

And that allowed all of these new upstart telecommunications companies to connect to the old AT&T, and over time, 60 Hudson, the upstarts, became bigger or at least more important for the Internet and for international telecommunications than the old AT&T building.

GROSS: So you live in New York. Is any of your data routed through this 60 Hudson Street building?

BLUM: Most certainly, yeah. No, I connect to the Internet through a cable company called Cablevision, and there's a certain amount that they'll tell you, and there's a certain amount you can see by sort of using different programs that analyze the path of the data, and that's always public. It has to be public because the bits have to know where to go.

You know, so I know, I can sort of read the tea leaves that Cablevision connects to other networks at 60 Hudson Street, at another building a little bit farther uptown called 111 Eighth Avenue that happens to be owned, as of recently, by Google. And I can sort of very clearly imagine that when I send an email to a colleague in London, that transmission is passing through 60 Hudson Street, going out to Long Island under the ocean, going through an equivalent building in London called Telehouse and arriving at his desk.

GROSS: Now you mentioned Google recently bought a building in New York, and you say it's one of the most important buildings on the Internet: Why?

BLUM: It is one of these buildings where more networks connect than anywhere else. It's a sort of - it's an absolute key hub for the networks of the Internet. And it also happened to be where Google began to put their New York employees. And then a couple years ago, they bought the building outright for $1.9 billion, the largest real estate transaction of the year in the U.S.

And this raised some eyebrows in the networking community because it was sort of like American Airlines buying LaGuardia Airport. And - but the strange thing was that Google said, well, you know, we just need it for the office space. So I suppose it was sort of like American Airlines buying LaGuardia Airport and saying, you know, actually we just need a place to park our trucks.

But this is a key nodal point. This is a spot where networks need the sort of ability to connect without any interference. And it's that sort of autonomy to connect, that ability to do whatever they want, to sort of make their own decisions about how they're connecting to other networks, that allows the Internet to be both robust and to a certain extent cheap.

GROSS: So what function does this building serve in terms of Internet traffic?

BLUM: It's another one of this very short list of the most important places where networks meet. New York is rare that it has two or you might say three of a list of perhaps a dozen buildings around the world that are the most important meeting places for networks.

GROSS: Andrew Blum will be back in the second half of the show. His new book is called "Tubes: A Journey to the Center of the Internet." I'm Terry Gross, and this is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: This is FRESH AIR. I'm Terry Gross, back with Andrew Blum. His new book "Tubes" is about the physical infrastructure of the Internet - all the wires and cables that make wireless Internet and the cloud possible. Earlier in our interview, we talked about some of the buildings that housed the wires connecting networks to other networks, serving as central hubs for the Internet. And he described the location of some of these places.

Are we giving away secrets here by naming, you know, buildings, giving out addresses that are central to the Internet? I mean, are they supposed to be secret so that they're not going to be disrupted, there won't be terrorist attacks on them, vandalism?

BLUM: No. It's interesting. They can't be secret, because if they were secret, then the networks wouldn't know where to connect to each other.

GROSS: So people who you spoke to who run or own some of these Internet centers, where the wires are, they were happy to give you information about their location and what they do and how they do it...

BLUM: Yeah...

GROSS: ...knowing that you were writing a book?

BLUM: I mean, for the most part, that was because all of the networks and all of these buildings are privately owned. They're all for-profit companies. And so one that I focus in particular, called Equinix, has a competitor called TELEX. And as soon as Equinix heard that I was talking to TELEX, and TELEX heard that I was talking to Equinix, they wanted to make sure that I knew and everybody knew that, in fact, their building was more important. And if you asked them, you know, what's the most important building on the Internet, they'll say oh, no. Our building is the most important building on the Internet. That's why you should come and connect your network to other networks inside our building. So, in some ways, it was the opposite. Everybody had something to sell. Everybody was eager to talk about, you know, how their place was the most important.

GROSS: So the two companies that you just mentioned, Equinix and TELEX, who think that they're - that they each are the most important centers on the Internet, what they do is connect networks to each other?

BLUM: What they do is, essentially, provide the space. They provide the building, the physical place where you can rent a little piece of real estate - usually a cage, actually a cage, like, you know, with steel walls - and they'll sell you some power. And they'll make sure the building is secure. And then they'll charge you to run a cable from your cage to someone else's cage, called a cross-connect. So there will be a monthly rent on that cable. And that's, so they make the money on the connection, and then they make the money on the power. They make the money on the rent. And there's a real premium to be in these most important places.

But if you're a network, you know, that premium might be worth it, because you want to be able to connect to as many people as easily as possible, as efficiently as possible, you know, by not having to lease a long-distance communications line, like we're talking on now, but just being able to string a single cable across the room or across the building.

GROSS: So the Internet works, like, magically right now. I mean, it works like so well most of the time, assuming your cable company is in good shape.

(LAUGHTER)

BLUM: Mm-hmm.

GROSS: But, you know, I can't help but wonder: What happens in 10 years, 20 years, 30 years when these cables get old and maybe need to be replaced, or the technology gets improved and they need to be upgraded? There's just, like, so many wires around the world now, so many cables under the ocean. I mean, how do you deal with that? It seems like it's much more complex than, say, telephone connections used to be.

BLUM: Yeah. Well, one of the amazing things about the fiber optic cables is that because they're essentially these glass tubes, you can replace the flashlight on the end with a newer model, and that will transmit more data. So you can keep the same actual fiber, replace the equipment on either end, and suddenly you've increased the capacity, you know, by an order or even two orders of magnitude. So that's a start. That will get us a few years down the road. But then it's a sort of constant gardening process. You know, it's constantly, you know, replacing the old ones and putting in new ones.

And these old buildings, you know, now that they've been active for a decade or so, one guy described it as being like an ice core. You know, if you drill down, you see, you know, networks from 10 years ago. The new ones are just layered on top. The new connections are on top, and the old ones are deep beneath, and there's no way to remove them.

There's a joke that the building in London called Telehouse, that there's a fortune to be made in copper mining, you know, because if somebody could figure out how to get all these old copper cables out of this old building, then they would be rich. You know, there's all this detritus of the last generation of networks only, you know, 10-12 years ago.

GROSS: So your book is called "Tubes," and it's about, like, the physical part of the Internet, the wires, the cables, the - and you use the word tubes a lot, you know, in the book.

BLUM: Yeah.

GROSS: For instance, the cables under the ocean, you describe as tubes. So in 2006, Senator Ted Stevens of Alaska described the Internet as a series of tubes, and he got mocked so badly for that. And it really seemed like, the way he described it, he had no idea what he was talking about. He had no idea what the Internet is. Would you go so far as to defend him?

BLUM: I would. Absolutely.

(LAUGHTER)

BLUM: I mean we - it was a - he's certainly not wrong. You know, the Internet is absolutely made of tubes. You know, what else could it be made of? It's many other things. There's, you know, there's these protocols and, you know, languages and, you know, machines. You know, there's a whole sort of fantastically complex, you know, layers and layers and layers of computing power that obviously feeds the Internet every day.

But if you think of the world in physical terms, you know, if you try to be as reductive as possible and trying to understand what, you know, what this is, there's no way around it. You know, these are, you know, these are tubes. And from the very first moment, from the time that I, you know, from the basement in that building in Milwaukee, you know, through Facebook's sort of high-tech brand-new data center, you walk through these buildings, and in the ceilings and along the walls are these steel conduits. We call them conduits, but I know a tube when I see one.

(LAUGHTER)

GROSS: OK. Well, Andrew Blum, thank you so much for explaining a lot about the Internet. I appreciate it.

BLUM: Thanks for having me.

GROSS: Andrew Blum is the author of "Tubes: A Journey to the Center of the Internet." Transcript provided by NPR, Copyright NPR.