During all the speculation about the possible effects of Hurricane Sandy, not much was said about its effect on the Internet.
There is a reason for that. The Internet was conceived as a distributed network. There is no one "command center," a physical place where the network as a whole is vulnerable. It is a network of networks, designed to route data around any part of it that fails.
Conventional wisdom holds that because the Internet began as a military project, it was constructed so that it couldn't be taken out by a nuclear strike. Although those involved with the birth of the Internet have said that was never a stated objective, it obviously occurred to those funding its construction.
Thus the Internet as a whole is not susceptible to a natural disaster like Sandy that strikes one part of the country.
But despite the popular term "cloud," used to describe services available on the Internet as though they hang above us somewhere in the sky, the Internet does have places where it exists physically.
In a fascinating book titled "Tubes: A Journey to the Center of the Internet," Wired correspondent Andrew Blum sets out to find where the Internet exists physically.
At its beginnings, the Internet was made of pulses of electricity flowing over phone lines that connected less than two dozen university sites, such as Carnegie Mellon University. Now it is made of pulses of light flowing through whisker-thin glass wires bundled together into fiber optic cables. These glass strands have to connect to each other and one of the main pieces of Internet infrastructure are Internet exchanges, or IXes, where networks meet. They usually are featureless, warehouselike buildings stuffed to the gills with computer servers.
Although there are many small IXes, the three largest are in Europe -- Frankfurt, Germany, Amsterdam and London. If one major exchange went down, traffic could switch to another.
Because the Internet is worldwide, data have to make their way across, or rather under, the oceans. This is done with communications cables that lie on the ocean floor. These underwater cables are protected, but they have been severed by underwater landslides triggered by earthquakes. Then ships have to pull them up and graft them back together.
There are numerous places where these cables come ashore, and many of them are along the East Coast where Sandy hit. A map of these cable landfalls is at submarinecablemap.com. and includes places like Manasquan, N.J., and Bellport, N.Y., on Long Island.
The cables emerge from the ocean at these places and run underground to a nearby shore station. Shore stations are bunkerlike buildings where the transoceanic cables connect to the terrestrial networks. From the shore stations, the fiber optics cable continues underground to an IX or another connection point. These terrestrial cables are often laid in railroad right-of-ways or even in unused gas pipelines.
But websites have to have computers that hold their content, and those servers are often "hosted" by a service.
This is where Sandy managed to wreak some havoc.
Datagram -- which hosted Huffington Post, for example -- lost power to its facility in lower Manhattan and lost its backup generators in the flooding. And its backup location in Newark, N.J., also went offline because of Sandy.
So although New York is a communications nexus, the essence of the Internet does not reside there. The essence of the Internet is nowhere and everywhere.