Imagine for a moment you're a HAM radio enthusiast, alone at night, idly working your way through the radio spectrum when you come across a broadcast on a disused shortwave channel, where usually there would be nothing but static.
The broadcast is a tune, or a buzz, or sometimes cartoon character Yosemite Sam saying "Varmint, I'm a-gonna b-b-b-bloooow ya ta'smithereenies" (yes, really) followed by a series of numbers read by a human or synthesized voice, on a bed of static for extra "I may never sleep again" vibes.
Have a listen to one of these broadcasts, and try to gauge on a scale of one to brown how hard you'd soil yourself if you'd heard it by chance.
For software engineer Chris Smolinski from Baltimore, this wasn't just a hypothetical. At 14-years-old, he had just got a shortwave radio and was trying it out when he hit upon the wrong broadcast.
"I was tuning in stations like the BBC and Radio Moscow, and then one day I just discovered someone reading off numbers," he told the Miami New Times. He began to document the numbers he heard on the station and others over the course of 20 years, before finally receiving an answer. The station he had heard – as is the prevailing theory of most numbers stations – broadcast coded messages, meant for people who had the cipher to decode them the other end.
These particular messages were sent by Cuba, meant for spies in the field. The advantage of sending the messages this way is that, though you may figure out where the signal is coming from, it's near impossible to discover who they are meant for and who is receiving them. The downside, as Cuba would discover, is that once someone – say, the FBI – has intercepted the cipher, they can continue to unravel your messages from thereon out.
Some of the messages, it would be revealed in a court case by the FBI, read "prioritize and continue to strengthen friendship with Joe and Dennis" and "Under no circumstances should [agents] German nor Castor fly with BTTR or another organization on days 24, 25, 26, and 27". Classic spy stuff, as well as "Congratulate all the female comrades for International Day of the Woman," which is just basic good manners.
The stations have been around since World War 1, though they were most prolific at the height of the Cold War. Sometimes broadcasting on a schedule, sometimes seemingly at random, they have creeped out people all around the world, not limiting themselves to the one language.
A particularly alarming theory about one number station – “MDZhB”, also known as "UVB-76" and "The Buzzer" – is that it is being used as a "Dead Hand" signal. The station broadcasts a constant monotonous tone, interrupted every few seconds by a foghorn-like sound, and occasionally by a Russian voice issuing messages such as "Ya UVB-76, Ya UVB-76. 180 08 BROMAL 74 27 99 14. Boris, Roman, Olga, Mikhail, Anna, Larisa. 7 4 2 7 9 9 1 4".
The "Dead Hand" theory suggests that what you really have to worry about is when the signal stops. If it's correct, the monotone is there as a sort of "everything is ok" alarm, a la The Simpsons. Should the signal cease for a certain amount of time because of a nuclear attack – according to this unverified theory – an automatic nuclear response would be triggered.
The station began broadcasting in the Soviet era, but didn't end with its fall. In the 1990s, mystery enthusiasts listened intently and realized that they could hear people in the background, having quiet conversations. The tone, which is still going today, isn't a recording, but a live sound produced by having a microphone placed near a speaker.
In November 2001, amateurs heard a person in the room speaking in Russian “I am 143. Not receiving the generator (oscillator)," to the reply "that stuff comes from hardware room.” In other deviations, perhaps designed to send speculation wild, the tone stopped in order to play a portion of Swan Lake.
Around 2010, conversations were heard more and more frequently, until one day they just... stopped. You may have noticed that a nuclear apocalypse did not follow thereafter (well spotted!), though the silence was short-lived. The station had been moved from the remote Russian village of Povarovo to another location, much more difficult to triangulate.
This gave a few brave investigators an opportunity to look around the station. One Russian explorer found a military logbook that appeared to confirm the station had been broadcasting messages from the Russian state, while others captured some fairly creepy images of a dilapidated and run-down military base, that looks like it could have been abandoned way back in the Cold War era.
After going deep into the base, they were forced to turn back.
"We sort of went underground under one of the buildings. As we descended into the basement of one of the buildings and ventured to a door that lead outside of the area of the building, when we opened it we were hit with a very vile chemical smell… it smelled very… acidic… I guess," the explorers wrote in a Reddit AMA.
"Not prepared to die of poisoning we turned back. In the room that was underground the building itself there was not much of interest. A few desks and filing cabinets filled with more useless papers. A few broken electronics and a bunch of other general crap."
Though mostly abandoned, it may still be watched. During their tour of the station, they were interrupted by a woman they describe as being in her mid-40s.
"At first I thought that she is a resident of the town out for a walk," the explorers said. "But as she walked past I saw that her stroller was empty. who goes to an [abandoned] military base [with] an empty stroller for a walk..?"