The Internet is used for pretty much everything. There's Twitter, Facebook, Reddit, Instagram, TikTok, Wikipedia, and I guess the world's economy does some other stuff with it or something. Anyway, it's really important. Billions of people are walking around with easy access to the Internet in their pockets. But, like, how does it work? Let us skip right past WiFi and mobile networks. Assume your amazingly clever tweet magically gets to a nearby cell tower. What happens then? Does it wirelessly connect to another cell tower until it gets to some Twitter server sitting in a room somewhere? Does it go to space and come back? Does it travel through a trans-dimensional wormhole? Does it get attached to a South African Swallow and sent away with love? Nope.

The vast majority of Internet traffic uses fiber optic cables. Fiber optic cables are tiny, hair-sized strands of glass. Why is “optic” in the name? Well, just as electric wires carry electric current, fiber optic cables carry light and the light generator of choice for these cables are lasers! Yep, the modern internet is literally a bunch of lasers shooting pulses light everywhere.

Picture showing a cable with silly lables

There are millions of miles of fiber optic cables that connect every major city in the world together. The path of these cables will typically follow highways and railroads to go from city to city. Within cities fiber optic cable is buried under sidewalks, streets and sometimes strung along power lines.

Remember when I mentioned that the world is connected by fiber optic cables?... Now you're probably saying “But, sudorandom, there's absolutely no way these cables can span across the OCEANS. That'd be crazy!”. I would respond by saying “they are under the oceans! And IT IS INCREDIBLY CRAZY”. It takes a lot of money and engineering effort to lay these down. There are specialized ships for laying submarine cables. When breaks happen (from boat anchors, nation-state sabotage and sharks) there are different kind of ship that can locate and pull this cable from the bottom of the ocean to make repairs. There's even an organization that provides a map that shows every operating underwater cable and it's nuts.

Submarine Cable Map > Image Source: TeleGeography

Let's recap a bit. The Internet is a large global network of hair-sized glass strands that we shoot laser beams into... and is sometimes attacked by sharks. Sometimes knowing how things work makes it much more awesome. Note that I'm glossing over many, many details. In later updates I will dive deeper into the backbone of the Internet. Hopefully you learned a bit more behind what's happening behind the blinking lights on your home router.

Shark Attacking Submarine Cable > Image Source: YouTube snapshot

#internet #backbone #fiber #shark

Do you have questions, suggestions, comments, insults? Send an email to