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The Quick 10: 10 U.S. Coins You Won't Find in Your Pockets

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The change pocket of my billfold is full of pennies. Just pennies. I pilfer dimes, quarters and nickels for the vending machines at work, or sometimes parking meters. But pennies? I never use them. Half pennies would be even worse, so I'm really glad those went out of production more than 150 years ago. Here are a few more coins you're unlikely to find jingling in your pockets... and if you do, I'd definitely avoid using them in Vendoland, no matter how strong your Diet Coke craving is.

1. Large cent. Unlike the currency of most countries, our coins don't get larger with a larger denomination. That pesky dime just screws everything up. But it was even more out of order from 1793-1857, when the cent piece was about an inch in diameter. That made it slightly bigger than a quarter.

2. The half-cent. Production of this coin of little value was during the same time frame as the large cent - 1793-1857. It was made of pure copper and was just slightly smaller than the large cent. The 1797 variety had "Two hundred for a dollar" etched into it, which really puts it into perspective.

3. The two-cent piece. The two-cent piece had a run of less than 10 years "“ 1864-1873. Its design contributed to the coins we use today: it was the first piece of U.S. coinage to have "In God We Trust" on it. There was some talk of bringing the two-cent coin back during the 1970s, but it obviously went nowhere.

4. The three-cent piece. When there was a rare postage decrease in 1851, taking the price of a stamp from five cents to three, people demanded a three-cent coin. I guess they really believed in super-precise change. There were two three-cent coins, actually - one was called a three-cent silver, which was the lightest coin ever made by the U.S. It was even smaller than a dime and, in fact, was given the nickname "trime."

5. The half-dime. I know what you're thinking: "Um, you mean the nickel?" But no "“ the half dime was totally different. Made of silver, it was smaller than the dime and was doing just fine as our five-cent piece until people with investments in the nickel industry lobbied for coins to be created with their metal of choice instead. Their arguments were successful and the first nickel five-cent piece was minted in 1866. Since the half-dime wasn't phased out until 1873, that meant U.S. citizens had a couple of five-cent coin options for a few years. By the way, should you ever come across an 1870-S half dime, don't let that thing out of your sight. The "S" stands for San Francisco, and up until the late 1970s it was unknown that any of these coins were minted in San Francisco. They're extremely rare "“ selling one would net you at least $425,000, which is what the one discovered in 1978 sold for.

6. The 20-cent piece. If you find yourself in possession of a 20-cent piece, you're in luck. This particular coin was minted for an extremely short period "“ one of the shortest in American history "“ and was not very widely circulated. On top of that, it was minted in the Carson City Mint, which was only open from 1870-1893. So what does all of that mean for you? It means if you have one, your measly 20-cent piece could be worth a cool $460,000, which is what an 1876-CC piece went for just last year.

7. The three-dollar piece. There was a method to the madness of the three-dollar coin. You see, at the time, a stamp was a mere three cents. So with a three-dollar piece, people could easily buy a sheet of 100 stamps just by forking over one of these heavy gold beauties. It didn't prove to be very popular, though, and it was discontinued in 1889. Today, one is worth at least four hundred dollars and possibly up to $4,000,000 for an extremely rare 1870-S version of the coin. How rare? So far, only one is known to exist.

8. Stella. Then there's the four dollar coin, AKA the Stella. It was made when the U.S. was thinking about joining the Latin Monetary Union, a movement that was kind of like the creation of the Euro in modern times. All currency would contain a certain amount of silver or gold so it could be spent in any country and still have the same value. As you've probably noticed, the LMU fell apart after WWI and was never implemented. The Stella went with it. What I find most amusing about Stella's story is that when the whole plan went kablooey, the unused coins were sold to Congressmen as collector's items. You can imagine what a scandal it was when the coins showed up as jewelry on some of the most famous bordello madams in Washington.

9. Fractional currency. When times get rough, people hoard precious metals. We're experiencing that to a certain extent now. But during the Civil War, people refused to spend coins, believing the value of the metal might be worth more than the actual coin sometime in the near future. To try to counteract this, the government issued paper money in tiny amounts - three, five, 10, 15, 25 and 50-cent notes.

10. The Eagle. I think it's a good thing the eagle never really took flight "“ imagine how mad you would be when you discovered that a hole in your pocket caused you to lose $40. The eagle was a 10 dollar gold piece that was in circulation until 1933; there were also quarter eagles and double eagles. And if you think losing one of those would be bad, imagine if a denomination called the Union had been put into circulation "“ it would have been worth 10 eagles.

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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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Sponsor Content: BarkBox
8 Common Dog Behaviors, Decoded
May 25, 2017
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Dogs are a lot more complicated than we give them credit for. As a result, sometimes things get lost in translation. We’ve yet to invent a dog-to-English translator, but there are certain behaviors you can learn to read in order to better understand what your dog is trying to tell you. The more tuned-in you are to your dog’s emotions, the better you’ll be able to respond—whether that means giving her some space or welcoming a wet, slobbery kiss. 

1. What you’ll see: Your dog is standing with his legs and body relaxed and tail low. His ears are up, but not pointed forward. His mouth is slightly open, he’s panting lightly, and his tongue is loose. His eyes? Soft or maybe slightly squinty from getting his smile on.

What it means: “Hey there, friend!” Your pup is in a calm, relaxed state. He’s open to mingling, which means you can feel comfortable letting friends say hi.

2. What you’ll see: Your dog is standing with her body leaning forward. Her ears are erect and angled forward—or have at least perked up if they’re floppy—and her mouth is closed. Her tail might be sticking out horizontally or sticking straight up and wagging slightly.

What it means: “Hark! Who goes there?!” Something caught your pup’s attention and now she’s on high alert, trying to discern whether or not the person, animal, or situation is a threat. She’ll likely stay on guard until she feels safe or becomes distracted.

3. What you’ll see: Your dog is standing, leaning slightly forward. His body and legs are tense, and his hackles—those hairs along his back and neck—are raised. His tail is stiff and twitching, not swooping playfully. His mouth is open, teeth are exposed, and he may be snarling, snapping, or barking excessively.

What it means: “Don’t mess with me!” This dog is asserting his social dominance and letting others know that he might attack if they don’t defer accordingly. A dog in this stance could be either offensively aggressive or defensively aggressive. If you encounter a dog in this state, play it safe and back away slowly without making eye contact.

4. What you’ll see: As another dog approaches, your dog lies down on his back with his tail tucked in between his legs. His paws are tucked in too, his ears are flat, and he isn’t making direct eye contact with the other dog standing over him.

What it means: “I come in peace!” Your pooch is displaying signs of submission to a more dominant dog, conveying total surrender to avoid physical confrontation. Other, less obvious, signs of submission include ears that are flattened back against the head, an avoidance of eye contact, a tongue flick, and bared teeth. Yup—a dog might bare his teeth while still being submissive, but they’ll likely be clenched together, the lips opened horizontally rather than curled up to show the front canines. A submissive dog will also slink backward or inward rather than forward, which would indicate more aggressive behavior.

5. What you’ll see: Your dog is crouching with her back hunched, tail tucked, and the corner of her mouth pulled back with lips slightly curled. Her shoulders, or hackles, are raised and her ears are flattened. She’s avoiding eye contact.

What it means: “I’m scared, but will fight you if I have to.” This dog’s fight or flight instincts have been activated. It’s best to keep your distance from a dog in this emotional state because she could attack if she feels cornered.

6. What you’ll see: You’re staring at your dog, holding eye contact. Your dog looks away from you, tentatively looks back, then looks away again. After some time, he licks his chops and yawns.

What it means: “I don’t know what’s going on and it’s weirding me out.” Your dog doesn’t know what to make of the situation, but rather than nipping or barking, he’ll stick to behaviors he knows are OK, like yawning, licking his chops, or shaking as if he’s wet. You’ll want to intervene by removing whatever it is causing him discomfort—such as an overly grabby child—and giving him some space to relax.

7. What you’ll see: Your dog has her front paws bent and lowered onto the ground with her rear in the air. Her body is relaxed, loose, and wiggly, and her tail is up and wagging from side to side. She might also let out a high-pitched or impatient bark.

What it means: “What’s the hold up? Let’s play!” This classic stance, known to dog trainers and behaviorists as “the play bow,” is a sign she’s ready to let the good times roll. Get ready for a round of fetch or tug of war, or for a good long outing at the dog park.

8. What you’ll see: You’ve just gotten home from work and your dog rushes over. He can’t stop wiggling his backside, and he may even lower himself into a giant stretch, like he’s doing yoga.

What it means: “OhmygoshImsohappytoseeyou I love you so much you’re my best friend foreverandeverandever!!!!” This one’s easy: Your pup is overjoyed his BFF is back. That big stretch is something dogs don’t pull out for just anyone; they save that for the people they truly love. Show him you feel the same way with a good belly rub and a handful of his favorite treats.

The best way to say “I love you” in dog? A monthly subscription to BarkBox. Your favorite pup will get a package filled with treats, toys, and other good stuff (and in return, you’ll probably get lots of sloppy kisses). Visit BarkBox to learn more.