Original image

The Quick 8: Eight Monetary Misprints

Original image

You may have heard that a batch of new $100 bills was recently misprinted (and if you haven’t, check out #1). It may be the latest monetary mishap, but it’s certainly not the only one - here are a pocketful of other misprints that may be lurking in your wallet, including a couple of stamps.

1. More than a billion of the new $100 bill are being recalled because the new security features tripped up the printing presses a bit, causing some of the bills to be creased and print incorrectly.

2. The Del Monte Note. Imagine the surprise of an Ohio college student when he made a routine stop at an ATM and received a $20 bill with a Del Monte banana sticker affixed to it… except it wasn’t actually just affixed, it was printed in the bill, as evidenced by the bill’s serial number partially stamped across the sticker. The student knew what he had his hands on, because he sold it on eBay for $10,100 in 2003. It was purchased by a collector named Daniel Wishnatsky, who in turn sold it for $25,300.

3. The Inverted Jenny stamp. The 1918 Inverted Jenny is probably the most famous stamp error ever made – and one of the most valuable. The plane on the stamp represented the Curtiss Jenny plane which was being used for the first-ever airmail services. A few sheets of the stamps were printed with the center image of the plane upside down, but only one that we know of made it past the Post Office. The sheet was later split up into blocks and singles. If you spot one, you’re definitely not going to want to put it on your water bill – a single easily goes for a half mil while a block of four took nearly $3 million at an auction in 2007.

4. Rush Hour 2 money. OK, it wasn’t real money, but that was kind of the problem. When the Jackie Chan and Chris Tucker movie was filming in Las Vegas, they shot a scene that involved an explosion of money. The bucks were bogus, of course, but that didn’t stop onlookers from grabbing up a souvenir when the money exploded in their direction. The fakes were so good that some people were able to go into nearby shops and spend them. The Secret Service ordered the studio that made the money to cease production of such authentic-looking currency.

5. Chilean 50-peso piece. It’s not just the U.S. that misprints money – in 2008, the mint in Chile produced thousands of 50-peso coins that deemed the country “Chiie.” It cost the mint director his job.
6. The Gronchi Rosa stamp. This Italian stamp was issued in 1961 to commemorate then-president Giovanni Gronchi’s trip to South America. It wasn’t until after the stamp had been issued that it was discovered that the artist had made a mistake on the boundaries between Peru and Ecuador. A new version was issued, but the error stamp is the one that’s in high demand, of course – it’s worth about $1,200 today.

7. Wisconsin quarter. If you’re one of those people who collect all 50 of the state quarters, check out your Wisconsin coin. There’s an ear of corn on the quarter that contains an extra leaf. That extra leaf is worth about $1,100 in mint condition.

8. Arrovo bill. A few years ago, the Central Bank of Philippines made a pretty embarrassing typo – it doesn’t get much worse than misspelling the name of your president. The 100-piso banknote should have spelled the name of the president as Gloria Macapagal Arroyo, but instead named her as “Arrovo.” Although the bill was recalled as soon as possible, there are a few thousand still estimated to be in circulation.

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

Original image
Stephen Missal
New Evidence Emerges in Norway’s Most Famous Unsolved Murder Case
May 22, 2017
Original image
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]