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Strange Geographies: The First Ghetto

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Venice is a city known for its stunning art masterpieces and its architectural marvels, for its famous canals, for being the birthplace of Vivaldi and a haven for classical music and opera lovers. It is not widely known for its ghetto -- and yet the very word itself comes from Venice. Prior to the 16th century, the Jewish quarter of Venice was a foundry, or in Italian, a getto. To control the spread of fire should one break out, the foundry was on an island bordered on all sides by canals. But in 1516, when the city became crowded with refugees after a war with the Papal States, it was decreed that Venice's 1,000 Jews should all live together in one place -- the old foundry island, where they could be locked in at night, though free to roam the city during daylight hours.

The ghetto still stands today, and though it's obviously no longer mandatory, some 450 Jews live there and many more come to attend synagogues, study, and eat together at the ghetto's excellent kosher restaurants. Though officially-designated Jewish quarters existed in Spain and elsewhere hundreds of years before Venice had one, when I visited Venice several weeks ago, I was curious to see what the place where the word "ghetto" was born looked like today. This is what I found.

From one of the bridges leading to the gheto vecchio, you can see the main campo.

When Jews from Spain and Portugal flooded into Venice to escape the Inquisition in 1541, the ghetto welcomed them with open arms -- but soon ran out of space. The solution was to build higher, thus creating a neighborhood of medieval mini-skyscrapers.

The ghetto is tiny -- little more than a cluster of buildings and alleys surrounding a campo or two -- but people take full advantage of what open space is there.

There's a Jewish rest home right on the campo, as well as several synagogues and a Jewish Museum (the Museo Ebraico).

There's also a lot of good kosher food, including this fantastic pastry shop.

Did I mention it was tiny? Look at the shoulder room you get in this alley.

Ghetto residents could roam freely during the day but were locked in at night by walls and gates manned by Christian guards. Napoleon opened the gates and lifted all restrictions on Jews in 1797, and then Mussolini put them back in place in 1938. 1,670 Jewish Venetians were sent to concentration camps.

A section of the original wall remains, complete with Fascist-era barbed wire running atop it.

The scenes on the wall are somber reminders of what happened to many of the ghettos residents in WWII.

This was written on a wall not far away.

As was, somewhat more confusingly, this.

Like much of Venice, the first ghetto is both a fascinating piece of history and a still-living cultural center. If you have the chance to visit Venice, don't miss it!

You can check out more Strange Geographies here.

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iStock // Ekaterina Minaeva
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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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May 23, 2017
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