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Happy Anniversary, Lincoln Memorial!

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Today marks the anniversary of the dedication of the Lincoln Memorial in 1922. It's definitely one of the most distinguishable landmarks in Washington D.C., a place that certainly isn't lacking in memorable monuments. But how much do you really know about the famous tribute? I've tracked down some interesting tidbits for you to add to your arsenal of info.

1. It took 50 years to happen

Abraham Lincoln died on April 15, 1865. Just under two years later, in March 1867, the Lincoln Monument Association was incorporated by Congress to build an appropriate memorial to our 16th president. Apparently that was the easy part. It took the next 34 years to choose a location, and when one was finally chosen in 1901, the area was all swampland. It was another 10 years before the monument was authorized by Congress, and on February 12, 1914 (Lincoln's birthday) the first stone was officially put into place. Eight years later, the dedication ceremony took place and was attended by Lincoln's son, Robert Todd. The monument was dedicated by William Howard Taft.

2. The symbolism of the columns

There are 36 columns featured on the Lincoln Memorial. It wasn't planned this way, but the columns were eventually said to represent the 25 U.S. states at the time of Lincoln's death, plus the 11 seceded states. The names of the 48 states at the time of the monument's completion were written around the top; a plaque recognizes the later additions of Alaska and Hawaii in 1959.

3. It's been the site of some interesting events


Most people probably know that Martin Luther King, Jr.'s famous "I Have a Dream" speech took place at the Lincoln Memorial to honor Lincoln for issuing the Emancipation Proclamation.
But it was also where Richard Nixon tried to appeal to Vietnam War protestors a few days after the Kent State shootings. About 30 students were holding a vigil at the monument in the wee hours of the morning. At about 4:15 a.m., Nixon showed up to have a little chat with them. Neither side could be swayed from their opinions.
Also, for President Bush's 2001 inauguration, the Rockettes danced down the steps while performing their famous leg kicks. Not sure how I feel about that one.

4. The inscriptions

Stop squinting at the pictures "“ here's what the inscription over Lincoln's head says:
You'll also find the text of two of Lincoln's most famous speeches "“ the Gettysburg address, of course, and his second inaugural address. On this one, the word "future" was accidentally carved with an "E" instead of an "F" and had to be fixed. To this day, you can see where the error happened.

5. The stats

Lincoln himself is 19 feet, nine inches tall "“ but keep in mind that he's sitting down. The stone for the building is Indiana limestone and Yule marble; Lincoln is made of 28 blocks of Georgian marble. There are 98 steps that go from Lincoln to the reflecting pool, but the number has no significance. The Memorial is on the "tails" side of the penny, and if you look really close you can see a little figure of Lincoln etched in his proper place in the monument. The Memorial is also on the five dollar bill (although I'm sure you already knew that).

6. Is Lincoln using sign language?


If you look close at Lincoln's hands, his left hand looks like an "A" in American Sign Language and his right hand looks like an "L". Although the National Park Service denies that the positioning was intended, there might be some truth to this story. Sculptor David Chester French was quite familiar with ASL "“ his son was deaf. Furthermore, Lincoln signed federal legislation giving Gallaudet University, a college for the deaf, the right to give out "official" college degrees. So it's very possible that French snuck the reference in as a way to recognize Lincoln's contributions to the deaf.

7. The Lincoln Memorial goes high-tech

If you're headed to D.C. and didn't have time to do your research beforehand, no worries "“ your cell phone will provide all of the information you need. You can dial (202) 747-3420 to hear park rangers talk about 10 different themes, including "Debunking the Myths of the Lincoln Memorial" and "The Life and Times of Lincoln the Man". Although I suppose you don't have to be at the monument to hear the rangers talk "“ you can dial in from your couch if you really want to.

8. Are Robert E. Lee and Abraham Lincoln the same man?

You know in Harry Potter and the Sorcerer's Stone where Voldemort appears on the back of the head of poor Professor Quirrell? Apparently there's been a rumor circulating for years that the same thing is true of Lincoln and Lee. Supposedly, there's an outline of Confederate Army General Robert E. Lee's face carved on the back of the Lincoln statue. This has been repeatedly refuted, but the rumor still lurks.

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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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Stephen Missal
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]