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4 Reasons the 4th is Strange

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I hope you all enjoyed the Fourth of July last weekend. I know I did -- copious amounts of grilled food were eaten, fireworks were observed, independence celebrated. But I was also in a reflective mood this year, and I got to thinking about the way we celebrate this holiday. Perhaps you'll agree with me: in some respects, it's downright strange.

Traditional fireworks release lots of nasty heavy metals

Yeah, they're pretty, and symbolic, and they make nice loud gut-rumbling bangs in the night. Unfortunately, they also release heavy metals like barium, copper and potassium perchlorate into the environment, which can linger in the the air for days and have been linked to various cancers. In fact, much of the toxic fallout of these patriotic bombs bursting in air (and eventually collecting in the water and soil) is in violation of federal Clean Air Act standards. So what's the alternative? Laser light shows are wowable, and don't cause any pollution -- but if you simply must blow things up, at least go green. Disney, which puts on hundreds of fireworks displays every year at its theme parks, is currently filing patents for "clean" fireworks technology; let's hope they don't keep it to themselves.

Fireworks can burn down your neighborhood

Most people don't need to be told that a cherry bomb can take off a finger and a poorly-aimed roman candle can celebrate your eyeball right out of its socket. But even more serious disasters can and do happen, like this 2006 fireworks factory explosion in Denmark. It damaged 350 buildings, left one firefighter dead and six injured, and the resulting explosions sent shockwaves as powerful as a magnitude-2 earthquake through surrounding neighborhoods. 2,000 people living near the factory were evacuated from their homes.

What does it mean to stage a pretend war when we're fighting two real ones?

I don't have an answer to that question, but it did occur to me. Let us know what you think! Meanwhile, I like what author and former Floss writer John Green has to say on the subject.

Even ten million firecrackers blowing up at once don't look that cool

It's all been done before, the Guinness records have been set -- so how do we top last year's fireworks display? Usually, the answer is volume -- both in terms of the number of fireworks set off and in decibels -- as in this display of 10,500,000 firecrackers being ignited on a vertical string, at the 2006 fireworks convention in Appleton, Wisconsin:

If you don't have quite that many fireworks at your disposal, however, there's always the indisputable novelty value of doing something like shooting a thousand bottle rockets out of a broken toilet:

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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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