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The World’s Strangest Radio Broadcasts

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We have only the vaguest idea where the broadcasts are coming from, and even less idea where they're going. The sounds are strange—the synthesized voices of women and children mixed with snatches of music, Morse code, or high-pitched buzzing. Sometimes the transmissions appear on a fixed schedule, other times in short random bursts. The only thing they have in common is the eerie recitation of numbers, beamed through shortwave radio signals bouncing across the globe.

These are the "number stations," which have mesmerized conspiracy theorists, radio enthusiasts, musicians and less obsessive members of the public for decades. They’ve been tracked with their own journal, recorded in an influential 4-CD set, and made appearances in lawsuits as well as a Cameron Crowe movie. No government agency has ever explained why they’ve taken over large portions of the shortwave radio dial, and why they’ve done so for years.

One of the most storied of the number stations is "The Lincolnshire Poacher," which began its transmissions with bars from the British folk song. Although it went off the air in 2008, number station detectives believe it was transmitting from a large military site in Cyprus. Another of the best-known stations, the Stasi-connected Swedish Rhapsody, started with a music box rendition of that tune before continuing with the voice of a little girl reciting numbers in German. A station known as the Magnetic Fields opened with the Jean-Michel Jarre's instrumental "Les Chants Magnétique" before broadcasting Arabic numerals and the English phrase "again, again."

The beginnings of the stations are unknown: by some accounts, the broadcasts first began during World War I, although better documentation exists for a beginning during the Cold War. While some suggest that they are the secret communications of drug smugglers, the more likely explanation involves espionage. Court cases, half-admissions, and the memoirs of ex-spies have brought the basics to light—the stations seem to be the broadcasts of intelligence agencies to their spies across the world. Messages are deciphered with a so-called one-time pad, in which a string of randomly generated numbers are mathematically added to text messages in order to encrypt, then subtracted to decrypt them. After each use, the pad is discarded.

While the use of number stations might seem startlingly low-tech for an espionage agency, their one-way nature has its advantages. Listening to the radio can’t be traced the way a telephone call can—because anyone can listen anywhere in the world, no one knows who the message is intended for. Listening to the radio isn’t a suspicious activity (the way carrying around expensive computer gadgetry might be) and doesn’t require much special equipment. Like the use of good old fashioned pen and paper, its simplicity is the key to its utility.

For years, public interest in the number stations was primarily limited to shortwave radio enthusiasts, who communicated with one another via online groups and magazines. A UK-based organization called ENIGMA (European Numbers Information Gathering and Monitoring Association), founded in 1993, tracked the transmissions with its own detailed newsletter for seven years. A radio hobbyist title called Monitoring Times Magazine also wrote about the stations, particularly through the activities of retired naval intelligence officer William Godby, alias Havana Moon. According to the Miami New Times, in the late 1980s Godby used signal-direction-finding equipment to pinpoint several number stations as coming from the "West Palm Beach airport, in nearby Tequesta, and at the Homestead Air Force Base. All were aimed at the Caribbean."

The name most often associated with the number stations today is Akin Fernandez and his Conet Project. In the early 1990s, the London-based Fernandez, who owns an indie music label, discovered the stations late one night while scrolling the dial with his new shortwave radio. When he discovered that no librarian or government agency could tell him what the number stations were doing, he became obsessed. The result, several years later, was a 4-CD set with samples of 150 different broadcasts, and an accompanying 74-page booklet. (Conet, a word Fernandez often heard on the broadcasts, is Czech for "end.") With the kind of treatment usually reserved for aging rock stars rather than secretive government broadcasts, the CDs became cult favorites—sampled by Wilco, who named its 2001 album Yankee Hotel Foxtrot after part of a numbers station broadcast, as well as other music groups, and appearing in the Cameron Crowe movie Vanilla Sky.

The Conet Project also prompted one of the first government admissions of the stations, when a UK government spokesperson told the Daily Telegraph in 1998: "These [numbers stations] are what you suppose they are. People shouldn't be mystified by them. They're not, shall we say, for public consumption."

Around the same time, Cuba’s "Atención" station became the world's first station publicly accused of broadcasting to spies. During a federal espionage trial following the 1998 arrest of the "Cuban Five," U.S. prosecutors claimed the spies were using hand-held shortwave receivers to listen to Atención broadcasts, entering the numbers into their laptops to decode the transmissions. The FBI testified that they'd broken into one spy's apartment and copied the decryption program, which they used to decode several messages. Three of the messages were revealed in court:

  • "Prioritize and continue to strengthen friendship with Joe and Dennis,"
  • "Under no circumstances should German nor Castor fly with BTTR or another organization on days 24, 25, 26 and 27,"
  • "Congratulate all the female comrades for International Day of the Woman."

And while some of the broadcasts might be just as banal as that last one, as Fernandez notes in the Conet Project booklet, part of the thrill of listening (the stations are still going strong) is that you have no idea what messages are being transmitted, or who else might be listening. "How many corporations are being compromised by mailmen who pretend to be listening to football results as they rifle through mail? And is the bus conductor on the no. 22 listening to the radio and writing down the results of the horses, or is he being told who his next murder victim is to be? Are all commuters really commuters? What is that buzzing?"

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iStock // Ekaterina Minaeva
technology
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Stephen Missal
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New Evidence Emerges in Norway’s Most Famous Unsolved Murder Case
May 22, 2017
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A 2016 sketch by a forensic artist of the Isdal Woman
Stephen Missal

For almost 50 years, Norwegian investigators have been baffled by the case of the “Isdal Woman,” whose burned corpse was found in a valley outside the city of Bergen in 1970. Most of her face and hair had been burned off and the labels in her clothes had been removed. The police investigation eventually led to a pair of suitcases stuffed with wigs and the discovery that the woman had stayed at numerous hotels around Norway under different aliases. Still, the police eventually ruled it a suicide.

Almost five decades later, the Norwegian public broadcaster NRK has launched a new investigation into the case, working with police to help track down her identity. And it is already yielding results. The BBC reports that forensic analysis of the woman’s teeth show that she was from a region along the French-German border.

In 1970, hikers discovered the Isdal Woman’s body, burned and lying on a remote slope surrounded by an umbrella, melted plastic bottles, what may have been a passport cover, and more. Her clothes and possessions were scraped clean of any kind of identifying marks or labels. Later, the police found that she left two suitcases at the Bergen train station, containing sunglasses with her fingerprints on the lenses, a hairbrush, a prescription bottle of eczema cream, several wigs, and glasses with clear lenses. Again, all labels and other identifying marks had been removed, even from the prescription cream. A notepad found inside was filled with handwritten letters that looked like a code. A shopping bag led police to a shoe store, where, finally, an employee remembered selling rubber boots just like the ones found on the woman’s body.

Eventually, the police discovered that she had stayed in different hotels all over the country under different names, which would have required passports under several different aliases. This strongly suggests that she was a spy. Though she was both burned alive and had a stomach full of undigested sleeping pills, the police eventually ruled the death a suicide, unable to track down any evidence that they could tie to her murder.

But some of the forensic data that can help solve her case still exists. The Isdal Woman’s jaw was preserved in a forensic archive, allowing researchers from the University of Canberra in Australia to use isotopic analysis to figure out where she came from, based on the chemical traces left on her teeth while she was growing up. It’s the first time this technique has been used in a Norwegian criminal investigation.

The isotopic analysis was so effective that the researchers can tell that she probably grew up in eastern or central Europe, then moved west toward France during her adolescence, possibly just before or during World War II. Previous studies of her handwriting have indicated that she learned to write in France or in another French-speaking country.

Narrowing down the woman’s origins to such a specific region could help find someone who knew her, or reports of missing women who matched her description. The case is still a long way from solved, but the search is now much narrower than it had been in the mystery's long history.

[h/t BBC]

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