Everybody’s wired. If we’re not talking on the phone, we’re checking our e-mail. Everybody’s wireless too. We carry cell phones and pagers, and we browse the Internet while lounging on a park bench, connected to the farthest corners of the world through an untethered laptop computer.

No aspect of the industrial infrastructure has been changing more rapidly than communications technology. In North America it took a hundred years for the web of telegraph and telephone lines to spread over the whole of the continent and extend tentacles into every inhabited place. Then, starting in the 1950s, many of those long copper wires were ripped out and replaced by other kinds of communications channels, chiefly microwave and satellite links. And now the whole continent has been restrung yet again, this time with a filigree of glass fibers carrying digital signals. What took a century the first time was completed in little more than a decade.

The Telephone

In the Hollywood version of telephone history, Alexander Graham Bell is about to run next door to fetch his assistant when it suddenly dawns on him, Hey, I just invented the telephone! And so he speaks the fateful words into the brand-new instrument: “Mr. Watson, come here. I want you.” Maybe it really happened that way. In any case, sometime in March of 1876 Bell did have a working assemblage of batteries, wires, magnets, and other electrical doodads that could transmit the human voice from room to room.

Today the idea of getting sound from electricity no longer excites much wonder, but building a telephone system with the technology of the nineteenth century called for genius. Bell’s bright idea—which also occurred to his rival Elisha Gray—was a method for using sound as a kind of throttle valve to control the flow of an electric current. Parts of Bell’s basic scheme are still in use, and telephones that are 50 or 60 years old work perfectly well when you plug them into the modern network. On the other side of the plug, however, in the central offices and the long-distance networks, everything has changed.