When I plug an Ethernet cable into my computer, is my computer directly connected to every server on the Internet?

Solution 1:

The Internet is a system of interconnected smaller networks that can reach each other through routing. You could essentially "follow the path" to any server you're directed to, but there are basically endless paths to any destination. If you were to start from your Ethernet connection, you would first hit your home router, then hit your ISP's routers. The ISP routers have HUGE routing tables that know how to direct you to the destination you're trying to get to, and will direct your traffic accordingly. This is why in many diagrams you see of the Internet, there is a big cloud. The cloud means that there is no definite path that it will travel each time, but in one way or another your traffic will be routed through the Internet until you hit your destination.

Essentially, you are not directly connected to every domain on the Internet. It is simply the routers that are able to direct your traffic you generate to the correct destination.

With the metaphor type of idea you used, you could say the same thing about your mailbox at home. You obviously aren't directly connected to everyone's mailbox. However, if you put something in the mail (you could think of this as your home router) it will then end up in the postman's hand, who brings it to the post office (you could think of this as your ISP). Once it hits the post office, it's sorted and sent on its way to the next destination (you could think of this as a router). Your mail will then be sent to another larger post office (you could think of this as yet another router) that is closer to the mail's destination. It will be sorted and keep getting passed to other postal services (more routers) until it gets to a local post office near its destination. A different postman will then deliver your mail to the correct address you sent it to.

The Internet is a complex world, but hopefully this helped you have a brief understanding of basics :).

For more of a visual:

• a map of the Internet. It probably isn't 100% accurate but you can see how everyone is connected and how there is a plethora of paths you could take.
• a map of fiber optics
• an interactive map of fiber optics, showing the lines that are under the ocean which connect all of us together. These fiber optic lines are packed with a ton of fiber connections, at very very high speeds.

Solution 2:

This is a good example of when superuser tries too hard -_-;

The answer is simply yes. Yes, you could follow cables from your computer all the way to the ESPN server, following the same path as a HTTP GET packet would take. You would probably have to go underwater at some point depending on your location, and almost certainly have to break in to a high-security hosting center only to leave again, but yes - because your web traffic is very unlikely to take any wireless routes (like satellites, long-range IR or wifi) you could do a “ghetto traceroute” of sorts.

How unlikely are wireless routes? Well it depends on where you live - some countries (like Korea) modernized extremely rapidly after WWII and many people needed an internet connection faster than cable companies could dig up the roads. Even though most of Korea is now on fibre, satellite companies still do good business. In other locations, the terrain makes it economically unfeasible to lay wire, so you see satellites and line-of-sight wireless bridges more often than copper. Island continents of Asia and very remote farms in Australia generally use line-of-sight WiMAX connections, whilst mountainous countries like Kazakhstan have some of the highest-throughput satellites of anywhere in the world.

However, as you can probably imagine, these wireless bridges are only ever used in the last leg of the connection from server to client. Wireless connections are never used on the core internet backbone as they suffer from serious latency (over a second for many geo-synchronous orbit satellites), are significantly slower than fiber, and their reliability depends on surrounding wireless interference, as well as the weather (commonly known as “rain fade”). For all these reasons, if you have a wireless connection to the internet, you would certainly know about it.

A small qualifier to all this however is that very few electrical devices are ever in 'direct contact' with each other. A lot of power modulation is done using electromagnetic induction (https://www.youtube.com/watch?v=hajIIGHPeuU), and there’s obviously optic which blurs the definition of “physically connected” depending on whether you believe a photon is a particle or a wave :P

If you were to redefine the question as "if every computer on the internet suddenly went silent, and i sent 50,000 Giggawatts down my internet cable - assuming nothing could fuse out, would a signal be detectable on an ESPN server?" To which the answer would be no, because routing information is required and data has to be processed, repackaged, and sent down physically different circuits via induction with a fresh source of energy required to do so. Simply sending energy down your wire wouldn't be enough.

Solution 3:

It is 2015 AD, and the whole globe has been wired up. The whole globe? No, one small village ...

But seriously: Internet technology fundamentally relies on the principle that the Internet is not a single physical network and that Internet networking can operate on pretty much any conceivable type of physical network. That underlying network doesn't need to use cables, it may use radio communication or satellite communication (these are used in practice) or even a carrier pigeon service (if you really insist).

So you don't need a physical cable to be connected to the Internet, and many places with internet connections, such as remote islands, ships and space stations, are not in fact attached with cables.

And of course there are plenty of mobile devices and WiFi-connected computers these days.

Solution 4:

Your computer is connected to every other computer on the internet in the same way that your telephone is connected to every other telephone in the world.

There is no one piece of wire, but one thing is connected to another, and yes, eventually all computers on the internet are connected.