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Happy Pi Day!

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Happy Pi Day, everyone! March 14 (3.14) at 1:59 (you get the idea) is the peak of Pi Day, a celebration of the Greek letter which represents the irrational number by which the diameter of a circle is multiple in order to obtain the circumference ... but you guys knew that, right?

The sixteenth letter of the Greek alphabet, p, was first used for the familiar value 3.1415"¦ in the publication, "Synopsis Palmariorium Mathesios," authored by William Jones in 1706, though the fact that "the ratio of the circumference to the diameter of a circle is the same for all circles, and that it is slightly more than 3, was known to ancient Egyptian, Babylonian, Indian and Greek geometers." 2006 was the 300th Anniversary of the introduction of the mathematical symbol pi. (Here's more on the history of Pi.)

Be prepared for 3.14.2009 by ordering a mental_floss "Simple as 3.141592..." shirt (men's or women's). Keep reading for more pi facts.

pi2.jpgWhen I was in high school, my math teacher, Ms. Coffield, encouraged us to celebrate Pi Day for extra credit, but it always turned out to be much more. Some students made necklaces, I wrote a poem, and others competed to see who could memorize the most digits. In this video, savant Daniel Tammet discusses with David Letterman how he recited 22,514 digits of pi from memory on Pi Day 2004.

From our Amazing Fact Generator: "In 1897, Indiana tried to pass a bill stating that pi is equal to 3.2 as opposed to its truly infinite value, but it never became law due to an intervention by a Purdue University professor."

Unfortunately, even in 2008, some people are confused about pi. Check out this picture below taken by a student at Georgia Southern (sent to me via my high school math teacher), where someone thought Pi Day was March 13, and that the digits were 3.13 ...
When I was asking for Weekend Links awhile back, Brian from San Francisco sent in this gem regarding pi that I saved until now:

"A work I am continually impressed by is "Poe, E.: Near a Raven," a constrained writing experiment that encodes 740 digits of Pi in a poem evoking Poe's 'The Raven.'" It's pretty cool, and helps illustrate that the concept of pi is all around us!

So today, try and have more fun with pi! Find out if your birthday is in the first 1254543 digits. And if you think you know all there is to know about 3.14, try your hand at this quiz. For those who are huge fans of pi, you can now smell irrational, too.

How many digits of pi do you know? This song may help. Does anyone else celebrate Pi Day? What are some of your activities or memories from it?

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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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Nick Briggs/Comic Relief
What Happened to Jamie and Aurelia From Love Actually?
May 26, 2017
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Nick Briggs/Comic Relief

Fans of the romantic-comedy Love Actually recently got a bonus reunion in the form of Red Nose Day Actually, a short charity special that gave audiences a peek at where their favorite characters ended up almost 15 years later.

One of the most improbable pairings from the original film was between Jamie (Colin Firth) and Aurelia (Lúcia Moniz), who fell in love despite almost no shared vocabulary. Jamie is English, and Aurelia is Portuguese, and they know just enough of each other’s native tongues for Jamie to propose and Aurelia to accept.

A decade and a half on, they have both improved their knowledge of each other’s languages—if not perfectly, in Jamie’s case. But apparently, their love is much stronger than his grasp on Portuguese grammar, because they’ve got three bilingual kids and another on the way. (And still enjoy having important romantic moments in the car.)

In 2015, Love Actually script editor Emma Freud revealed via Twitter what happened between Karen and Harry (Emma Thompson and Alan Rickman, who passed away last year). Most of the other couples get happy endings in the short—even if Hugh Grant's character hasn't gotten any better at dancing.

[h/t TV Guide]