Samanth Subramanian

researching this book the best cables are the ones at the bottom of the ocean are just a hair thick just literally the thickness of a human hair they're made of highly purified glass and down that cable you send sort of little pulses of light lasers essentially and they kind of bounce around the inner walls of the glass and they come out at the other end and you can decode them

And what they do these days, there's a long name for it called wave division multiplexing, where they send different frequencies of light encoded with different streams of data.

And so that kind of bounces around the glass at various speeds.

And then it comes out of the other and you kind of suck it out and you...

code it all back together and you kind of read the information out that way.

And that has kind of exponentially increased the amount of data that a cable can carry.

You know, these cables are produced by just a handful of companies around the world.

So there's a little bottleneck over there in terms of technological capacity to produce these cables.

And then there's people who find the money for these cables.

So that used to include state-owned telecom companies.

Then it included private investors sort of raising money from a bunch of places.

Now, as we'll probably talk about, it's mostly big tech companies paying for it out of their own wallets because they can afford to.

And then they would fund a survey ship to go out and see what the best route for the cable would be from, say, London to Lisbon to Cape Town to the UAE.

And then the survey ship would come back and give you the best possible route.

And then a cable laying ship would go out, make multiple trips and just slowly, very slowly lay the cable along exactly that route.

And you have to do it that way because too fast and it might snap too slow and there's too much slack in the cable.

And so you really need to kind of find this optimum speed at which to travel.

And it's really funny.

There's one company in the entire world that makes the kind of software that all these cable ships use that determine the ship's path, the ship's speed, all of this stuff, just so the cable is laid just so.

That's basically it.