Around 1159 A.D., a mathematician called Bhaskara the Learned sketched a design for a wheel containing curved reservoirs of mercury.
He reasoned that as the wheels spun, the mercury would flow to the bottom of each reservoir, leaving one side of the wheel perpetually heavier than the other.
The imbalance would keep the wheel turning forever.
Bhaskara's drawing was one of the earliest designs for a perpetual motion machine, a device that can do work indefinitely without any external energy source.
Imagine a windmill that produced the breeze it needed to keep rotating.
Or a lightbulb whose glow provided its own electricity.
These devices have captured many inventors' imaginations because they could transform our relationship with energy.
For example, if you could build a perpetual motion machine that included humans as part of its perfectly efficient system, it could sustain life indefinitely.
There's just one problem.
They don't work.
Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that describes the relationship between different forms of energy.
The first law of thermodynamics says that energy can't be created or destroyed.
You can't get out more energy than you put in.
That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed.
There wouldn't be any left over to power a car or charge a phone.
But what if you just wanted the machine to keep itself moving?
Inventors have proposed plenty of ideas.
Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms.
None of them work.
The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle.
With a low center of mass, the wheel just swings back and forth like a pendulum, then stops.
What about a different approach?
In the 17th century, Robert Boyle came up with an idea for a self-watering pot.
He theorized that capillary action, the attraction between liquids and surfaces that pulls water through thin tubes, might keep the water cycling around the bowl.
But if the capillary action is strong enough to overcome gravity and draw the water up, it would also prevent it from falling back into the bowl.
Then there are versions with magnets, like this set of ramps.
The ball is supposed to be pulled upwards by the magnet at the top, fall back down through the hole, and repeat the cycle.
This one fails because like the self-watering pot, the magnet would simply hold the ball at the top.
Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working.
For each of these machines to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, breaking the first law of thermodynamics.
There are ones that seem to keep going, but in reality, they invariably turn out to be drawing energy from some external source.
Even if engineers could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law.
The second law of thermodynamics tells us that energy tends to spread out through processes like friction.
Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum.
That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine inevitably stopped.
So far, these two laws of thermodynamics have stymied every idea for perpetual motion and the dreams of perfectly efficient energy generation they imply.
Yet it's hard to conclusively say we'll never discover a perpetual motion machine because there's still so much we don't understand about the universe.
Perhaps we'll find new exotic forms of matter that'll force us to revisit the laws of thermodynamics.
Or maybe there's perpetual motion on tiny quantum scales.
What we can be reasonably sure about is that we'll never stop looking.
For now, the one thing that seems truly perpetual is our search.
I've always written primarily about architecture, about buildings, and writing about architecture is based on certain assumptions.
An architect designs a building, and it becomes a place, or many architects design many buildings, and it becomes a city, and regardless of this complicated mix of forces of politics and culture and economics that shapes these places, at the end of the day, you can go and you can visit them.
You can walk around them.
You can smell them.
You can get a feel for them.
You can experience their sense of place.
But what was striking to me over the last several years was that less and less was I going out into the world, and more and more, I was sitting in front of my computer screen.
And especially since about 2007, when I got an iPhone, I was not only sitting in front of my screen all day, but I was also getting up at the end of the day and looking at this little screen that I carried in my pocket.
And what was surprising to me was how quickly my relationship to the physical world had changed.
In this very short period of time, you know, whether you call it the last 15 years or so of being online, or the last, you know, four or five years of being online all the time, our relationship to our surroundings had changed in that our attention is constantly divided.
You know, we're both looking inside the screens and we're looking out in the world around us.
And what was even more striking to me, and what I really got hung up on, was that the world inside the screen seemed to have no physical reality of its own.
If you went and looked for images of the Internet, this was all that you found, this famous image by Opte of the Internet as the kind of Milky Way, this infinite expanse where we don't seem to be anywhere on it.
We can never seem to grasp it in its totality.
It's always reminded me of the Apollo image of the Earth, the blue marble picture, and it's similarly meant to suggest, I think, that we can't really understand it as a whole.
We're always sort of small in the face of its expanse.
So if there was this world and this screen, and if there was the physical world around me, I couldn't ever get them together in the same place.
And then this happened.
My Internet broke one day, as it occasionally does, and the cable guy came to fix it, and he started with the dusty clump of cables behind the couch, and he followed it to the front of my building and into the basement and out to the back yard, and there was this big jumble of cables against the wall.
And then he saw a squirrel running along the wire, and he said, "There's your problem.
A squirrel is chewing on your Internet."
(Laughter) And this seemed astounding.
The Internet is a transcendent idea.
It's a set of protocols that has changed everything from shopping to dating to revolutions.
It was unequivocally not something a squirrel could chew on.
(Laughter) But that in fact seemed to be the case.
A squirrel had in fact chewed on my Internet.
(Laughter) And then I got this image in my head of what would happen if you yanked the wire from the wall and if you started to follow it.
Where would it go?
Was the Internet actually a place that you could visit?
Could I go there?
Who would I meet?
You know, was there something actually out there?
And the answer, by all accounts, was no.
This was the Internet, this black box with a red light on it, as represented in the sitcom "The IT Crowd."
Normally it lives on the top of Big Ben, because that's where you get the best reception, but they had negotiated that their colleague could borrow it for the afternoon to use in an office presentation.
The elders of the Internet were willing to part with it for a short while, and she looks at it and she says, "This is the Internet?
The whole Internet?
Is it heavy?"
They say, "Of course not, the Internet doesn't weigh anything."
And I was embarrassed.
I was looking for this thing that only fools seem to look for.
The Internet was that amorphous blob, or it was a silly black box with a blinking red light on it.
It wasn't a real world out there.
But, in fact, it is.
There is a real world of the Internet out there, and that's what I spent about two years visiting, these places of the Internet.
I was in large data centers that use as much power as the cities in which they sit, and I visited places like this, 60 Hudson Street in New York, which is one of the buildings in the world, one of a very short list of buildings, about a dozen buildings, where more networks of the Internet connect to each other than anywhere else.
And that connection is an unequivocally physical process.
It's about the router of one network, a Facebook or a Google or a B.T. or a Comcast or a Time Warner, whatever it is, connecting with usually a yellow fiber optic cable up into the ceiling and down into the router of another network, and that's unequivocally physical, and it's surprisingly intimate.
A building like 60 Hudson, and a dozen or so others, has 10 times more networks connecting within it than the next tier of buildings.
There's a very short list of these places.
And 60 Hudson in particular is interesting because it's home to about a half a dozen very important networks, which are the networks which serve the undersea cables that travel underneath the ocean that connect Europe and America and connect all of us.
And it's those cables in particular that I want to focus on.
If the Internet is a global phenomenon, if we live in a global village, it's because there are cables underneath the ocean, cables like this.
And in this dimension, they are incredibly small.
You can you hold them in your hand.
They're like a garden hose.
But in the other dimension they are incredibly expansive, as expansive as you can imagine.
They stretch across the ocean.
They're three or five or eight thousand miles in length, and if the material science and the computational technology is incredibly complicated, the basic physical process is shockingly simple.
Light goes in on one end of the ocean and comes out on the other, and it usually comes from a building called a landing station that's often tucked away inconspicuously in a little seaside neighborhood, and there are amplifiers that sit on the ocean floor that look kind of like bluefin tuna, and every 50 miles they amplify the signal, and since the rate of transmission is incredibly fast, the basic unit is a 10-gigabit-per-second wavelength of light, maybe a thousand times your own connection, or capable of carrying 10,000 video streams, but not only that, but you'll put not just one wavelength of light through one of the fibers, but you'll put maybe 50 or 60 or 70 different wavelengths or colors of light through a single fiber, and then you'll have maybe eight fibers in a cable, four going in each direction.
And they're tiny.
They're the thickness of a hair.
And then they connect to the continent somewhere.
They connect in a manhole like this.
Literally, this is where the 5,000-mile cable plugs in.
This is in Halifax, a cable that stretches from Halifax to Ireland.
And the landscape is changing.
Three years ago, when I started thinking about this, there was one cable down the Western coast of Africa, represented in this map by Steve Song as that thin black line.
Now there are six cables and more coming, three down each coast.
Because once a country gets plugged in by one cable, they realize that it's not enough.
If they're going to build an industry around it, they need to know that their connection isn't tenuous but permanent, because if a cable breaks, you have to send a ship out into the water, throw a grappling hook over the side, pick it up, find the other end, and then fuse the two ends back together and then dump it over.
It's an intensely, intensely physical process.
So this is my friend Simon Cooper, who until very recently worked for Tata Communications, the communications wing of Tata, the big Indian industrial conglomerate.
And I've never met him.
We've only communicated via this telepresence system, which always makes me think of him as the man inside the Internet.
(Laughter) And he is English.
The undersea cable industry is dominated by Englishmen, and they all seem to be 42.
(Laughter) Because they all started at the same time with the boom about 20 years ago.
And Tata had gotten its start as a communications business when they bought two cables, one across the Atlantic and one across the Pacific, and proceeded to add pieces onto them, until they had built a belt around the world, which means they will send your bits to the East or the West.
They have -- this is literally a beam of light around the world, and if a cable breaks in the Pacific, it'll send it around the other direction.
And then having done that, they started to look for places to wire next.
They looked for the unwired places, and that's meant North and South, primarily these cables to Africa.
But what amazes me is Simon's incredible geographic imagination.
He thinks about the world with this incredible expansiveness.
And I was particularly interested because I wanted to see one of these cables being built.
See, you know, all the time online we experience these fleeting moments of connection, these sort of brief adjacencies, a tweet or a Facebook post or an email, and it seemed like there was a physical corollary to that.
It seemed like there was a moment when the continent was being plugged in, and I wanted to see that.
And Simon was working on a new cable, WACS, the West Africa Cable System, that stretched from Lisbon down the west coast of Africa, to Cote d'Ivoire, to Ghana, to Nigeria, to Cameroon.
And he said there was coming soon, depending on the weather, but he'd let me know when, and so with about four days notice, he said to go to this beach south of Lisbon, and a little after 9, this guy will walk out of the water.
(Laughter) And he'll be carrying a green nylon line, a lightweight line, called a messenger line, and that was the first link between sea and land, this link that would then be leveraged into this 9,000-mile path of light.
Then a bulldozer began to pull the cable in from this specialized cable landing ship, and it was floated on these buoys until it was in the right place.
Then you can see the English engineers looking on.
And then, once it was in the right place, he got back in the water holding a big knife, and he cut each buoy off, and the buoy popped up into the air, and the cable dropped to the sea floor, and he did that all the way out to the ship, and when he got there, they gave him a glass of juice and a cookie, and then he jumped back in, and he swam back to shore, and then he lit a cigarette.
(Laughter) And then once that cable was on shore, they began to prepare to connect it to the other side, for the cable that had been brought down from the landing station.
And first they got it with a hacksaw, and then they start sort of shaving away at this plastic interior with a -- sort of working like chefs, and then finally they're working like jewelers to get these hair-thin fibers to line up with the cable that had come down, and with this hole-punch machine they fuse it together.
And when you see these guys going at this cable with a hacksaw, you stop thinking about the Internet as a cloud.
It starts to seem like an incredibly physical thing.
And what surprised me as well was that as much as this is based on the most sophisticated technology, as much as this is an incredibly new thing, the physical process itself has been around for a long time, and the culture is the same.
You see the local laborers.
You see the English engineer giving directions in the background.
And more importantly, the places are the same.
These cables still connect these classic port cities, places like Lisbon, Mombasa, Mumbai, Singapore, New York.
And then the process on shore takes around three or four days, and then, when it's done, they put the manhole cover back on top, and they push the sand over that, and we all forget about it.
And it seems to me that we talk a lot about the cloud, but every time we put something on the cloud, we give up some responsibility for it.
We are less connected to it.
We let other people worry about it.
And that doesn't seem right.
There's a great Neal Stephenson line where he says that wired people should know something about wires.
And we should know, I think, we should know where our Internet comes from, and we should know what it is that physically, physically connects us all.
Thank you.
(Applause) (Applause) Thanks.
(Applause)