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Wikimedia Commons

Harry Houdini

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Wikimedia Commons

For years, every time we so much as touch a toe out of state, I’ve put cemeteries on our travel itinerary. From garden-like cemeteries to boot hills, whether they’re the final resting places of the well-known but not that important or the important but not that well-known, I love them all. After realizing that there are a lot of taphophiles (cemetery and/or tombstone enthusiasts) out there, I’m finally putting my photo library of interesting tombstones to good use.

OK, I’m cheating a little bit for today’s Grave Sightings. I haven’t actually visited this grave, but it’s too timely to let this one pass.

Ehrich Weiss, better known to most as world-famous illusionist Harry Houdini, died on October 31, 1926. On October 22, Houdini was in his dressing room at a theater in Montreal when a few college kids dropped in. One of them mentioned that he had heard that one of the great mysteries of Houdini was his iron stomach—that no punch could harm him. Though he had broken his ankle a few days earlier and was really in no condition to withstand a beating, Houdini, perhaps eager to perpetuate the aura of intrigue surrounding his persona, agreed to let one of the students deliver a few blows to his gut.

The student certainly didn’t go easy on the 52-year-old Houdini, and the punishing punches may have been the illusionist’s undoing. After his show that night, Houdini was in such pain that he needed help undressing. By October 24, his temperature was up to 104 degrees Fahrenheit; he collapsed in the middle of a show. After recovering and powering through the performance, he passed out again shortly thereafter. Houdini was finally admitted to a hospital the next day, where doctors diagnosed appendicitis. When they got inside, surgeons discovered that the appendix had already ruptured, resulting in what would end up being a fatal case of peritonitis. Whether the ruptured appendix was caused by the punches or had already been festering is something that’s still debated to this day.

On October 31, 1926, the great Houdini performed his very last vanishing act. But before he went, the skeptic promised his wife that if the dead could communicate with the living—a feat he didn't believe was possible, and one he worked to debunk—he would find his way back to her, and they established a coded message that would prove it.

Though she held seances annually on the anniversary of his death for 10 years, Bess Houdini never heard the code word. Sadly, the two weren’t reunited in death—at least not on earth. Though Houdini’s grave can be found at Machpelah Cemetery in Queens, N.Y., the marker there bearing Bess’ name is just a cenotaph. Because she was raised Catholic and Machpelah is a Jewish cemetery, her remains rest at Gate of Heaven Cemetery in Hawthorne, N.Y.

See all entries in our Grave Sightings series here.

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iStock // Ekaterina Minaeva
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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Name the Author Based on the Character
May 23, 2017
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