Old-fashioned radios produced sound by boiling liquid lightning. The distinctive drone that emerged, of churning static and leaping foam, came to be known as “white noise.” This term is said by some to be arbitrary in origin, though others believe it was derived from the color of the electric vapor that churned through the innards of these devices.
The fluid in question did not actually power these radios (which still needed to be plugged into a wall). Rather, it provided them with a signal. Direct transmitter to receiver communication proved to be impossible for several decades, forcing operators to rely upon an intermediary channel. Fortunately, nature was able to provide such a medium: recorded sound was projected upward into the sky as electromagnetic radiation, and was then carried from place to place by clouds in the upper atmosphere.
Eventually, these signals returned to the earth as lightning, but not as a liquid. As such, transforming them into something that could be poured into a radio’s intake valve required some unusual engineering. Typically, lightning causes the air that surrounds it to rapidly expand with a wave of sudden pressure, a phenomenon more commonly known as “thunder.” When lightning was made to strike a rod, however, if the air surrounding the rod already proved to be more dense than the metal from which it was composed, no thunder would occur, and instead, raw electricity would drip from the metal like sweat. Through this process, lightning could be bottled, and with all of the information that it contained intact.
There was, of course, no way to know what signals were contained in each bolt. Some proved to be empty, though most contained at least a song, or a newscast, or if the listener was lucky, an episode of Mercury Theatre. The primary thrill came from pouring them into the machine, turning up the temperature, and finding out what sounds had fallen from heaven. They weren’t always in a language that could be understood by the listener, or even always something meant for human ears, but this didn’t dissuade enthusiasts. Once boiled away, the bolt was gone forever- and its contents became a memory shared only by those gathered around the speakers. Back then, no matter what gurgled out of the radio, it felt special.
Over time, the lightning rod gave way to the antenna, and the path between transmitter and receiver came to be traversable through air alone. The last few phials of liquid lightning are rumored to have been acquired by Ernest Hemingway, who allegedly used them to make cocktails during the liberation of Paris. Some believe that there are a handful of old signals still out there, wandering from cloud to cloud; if so, it is likely that nobody will be there to listen when they finally tumble back to Earth.