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Armchair Field Trip: The Grassy Knoll

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Whether you believe that Lee Harvey Oswald acted alone or think that John F. Kennedy's assassination in 1963 was the result of a huge government conspiracy, there's no question that Dallas is the place where it all went down. Since that's where I was last week, of course I had to check out the Grassy Knoll.

As a side note, when we were consulting the GPS system in our rental car, we weren't totally sure how to look up the site of JFK's assassination. We didn't know it had taken place at Dealey Plaza and didn't know what the name of the museum was (or, in fact, that there even was a museum). We jokingly wondered if it would be listed under "Grassy Knoll" in the GPS Yellow Pages. Guess what? It was.


Anyway, when we got to Dealey Plaza, we discovered the Sixth Floor Museum, a museum dedicated to JFK's life, death and legacy. The museum is, as its name implies, on the sixth floor of what used to be known at the Texas School Book Depository where Lee Harvey Oswald fired the shots that killed Kennedy (or didn't fire the shots, depending on your theory). Maybe it's just me, but I found it rather morbid that the museum was housed in the very place JFK's (possible) killer holed up to shoot him.

At the museum, I learned some interesting facts about the events surrounding that fateful day.

BookDepository2.jpg"¢ Lee Harvey Oswald was an employee at the Book Depository at the time.

"¢ There were concerns about the President's safety in Dallas because United Nations Ambassador Adlai Stevenson has been hit with a protest sign and spat on in the city less than a month earlier.

"¢ Minutes before JFK was shot, a local T.V. station announced that it was clear that any worries about anti-Kennedy activists in Dallas were completely unfounded.

"¢ A Presidential car with a bulletproof top didn't exist then, although plans for one were in the works.

Zapruder.jpg"¢ The only video known to exist of the entire event is the Abraham Zapruder video, which he sold to Life magazine for $150,000. He also turned a copy of the film over to the Secret Service.

"¢ Vice President Lyndon B. Johnson was sworn in as President an hour and 38 minutes after President Kennedy was pronounced dead. First Lady Jacqueline Kennedy stood next to him wearing the same clothes she was wearing when her husband was shot approximately two hours earlier.

"¢ JFK's funeral took place on November 25th, 1963 "“ his son's third birthday.

"¢ Lee Harvey Oswald was pronounced dead two days and seven minutes after President Kennedy was pronounced dead.

"¢ The plaza is named for George Bannerman Dealey who published the Dallas Morning News for a number of years. He also was a key player in helping to revitalize the Dealey Plaza area.

"¢ Buildings in Dealey Plaza have not been changed since 1963, which is really noticeable when looking at the extremely modern Dallas skyline behind it.

And, oddly, available in the gift shop were action figures of not just of JFK, but also Abraham Lincoln, Uncle Sam, and"¦. Laura Bush?? (Is it just me, or is that a strange combo?)

Well, I'm hesitant to ask, but what do you think? Single shooter? Government conspiracy? JFK is actually still alive and hanging out in a bar somewhere with Elvis and Tupac??

Previous Armchair Field Trips:

The Corn Palace
The International Spy Museum
Intercourse, Pennsylvania
Ogunquit, Maine
Aquinnah, Massachusetts

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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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Opening Ceremony
These $425 Jeans Can Turn Into Jorts
May 19, 2017
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Opening Ceremony

Modular clothing used to consist of something simple, like a reversible jacket. Today, it’s a $425 pair of detachable jeans.

Apparel retailer Opening Ceremony recently debuted a pair of “2 in 1 Y/Project” trousers that look fairly peculiar. The legs are held to the crotch by a pair of loops, creating a disjointed C-3PO effect. Undo the loops and you can now remove the legs entirely, leaving a pair of jean shorts in their wake. The result goes from this:


Opening Ceremony

To this:


Opening Ceremony

The company also offers a slightly different cut with button tabs in black for $460. If these aren’t audacious enough for you, the Y/Project line includes jumpsuits with removable legs and garter-equipped jeans.

[h/t Mashable]