Our modern media spring from a common source, an invention that is rarely mentioned today but that had as decisive a role in shaping society as the internal combustion engine or the incandescent lightbulb. The invention was called the Audion.
It was the first electronic audio amplifier, and the man who created it was Lee de Forest.
Even when judged by the high standards set by America's mad-genius inventors, de Forest was an oddball. Nasty, ill-favoured and generally despised-in high school, he was voted "homeliest boy" in his class - he was propelled by an enormous ego and an equally outsized inferiority complex. When he wasn't marrying or divorcing a wife, alienating a colleague or leading a business to ruin, he was usually in court defending himself against charges of fraud or patent infringement - or pressing his own suit against one of his many enemies.
De Forest grew up in Alabama, the son of a schoolmaster. After earning a doctorate in engineering from Yale in 1896, he spent a decade fiddling with the latest radio and telegraph technology, desperately seeking the breakthrough that would make his name and fortune. In 1906, his moment arrived. Without quite knowing what he was doing, he took a standard two-pole vacuum tube, which sent an electric current from one wire (the filament) to a second (the plate), and he added a third wire to it, turning the diode into a triode. He found that when he sent a small electric charge into the third wire - the grid - it boosted the strength of the current running between the filament and the plate. The device, he explained in a patent application, could be adapted "for amplifying feeble electric currents".
De Forest's seemingly modest invention turned out to be a world changer. Because it could be used to amplify an electrical signal, it could also be used to amplify audio transmissions sent and received as radio waves. Up to then, radios had been of limited use because their signals faded so quickly. With the Audion to boost the signals, long-distance wireless transmissions became possible, setting the stage for radio broadcasting. The Audion became, as well, a critical component of the new telephone system, enabling people on opposite sides of the country, or the world, to hear each other talk.
De Forest couldn't have known it at the time, but he had inaugurated the age of electronics. Electric currents are, simply put, streams of electrons, and the Audion was the first device that allowed the intensity of those streams to be controlled with precision. As the 20th century progressed, triode tubes came to form the technological heart of the modern communications, entertainment and media industries. They could be found in radio transmitters and receivers, in hi-fi sets, in public address systems, in guitar amps. Arrays of tubes also served as the processing units and data storage systems in many early digital computers. The first mainframes often had tens of thousands of them. When, around 1950, vacuum tubes began to be replaced by smaller, cheaper and more reliable solid-state transistors, the popularity of electronic appliances exploded. In the miniaturised form of the triode transistor, Lee de Forest's invention became the workhorse of our information age.
In the end, de Forest wasn't quite sure whether to be pleased or dismayed by the world he had helped bring into being. In "Dawn of the Electronic Age", a 1952 article he wrote for Popular Mechanics, he crowed about his creation of the Audion, referring to it as "this small acorn from which has sprung the gigantic oak that is today world-embracing". At the same time, he lamented the "moral depravity" of commercial broadcast media. "A melancholy view of our national mental level is obtained from a survey of the moronic quality of the majority of today's radio programs," he wrote.
Looking ahead to future applications of electronics, he grew even gloomier. He believed that "electron physiologists" would eventually be able to monitor and analyse "thought or brain waves", allowing "joy and grief [to]be measured in definite, quantitative units". Ultimately, he concluded, "a professor may be able to implant knowledge into the reluctant brains of his 22nd-century pupils. What terrifying political possibilities may be lurking there! Let us be thankful that such things are only for posterity, not for us."
From The Shallows: What the Internet Is Doing to Our Brains, copyright © 2010 Nicholas Carr; to be published by W.W. Norton and Company in June.