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Making Snow with Hot Water and Other Frozen Phenomena

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Much of North America is experiencing the coldest temperatures in twenty years. They call this a polar vortex, in which Arctic air currents sweep further south than usual. Today is supposed to be the coldest day of the vortex. For now. Temperatures fell so fast that reports came in across Canada of frostquakes, which occur when groundwater freezes so fast that it cracks the frozen ground. They make a lot of noise, but don't cause much damage. Other strange things occur when the temperature falls this far and this fast.

Last year, Yan at Geeks Are Sexy made a video demonstrating what happens when you throw boiling water into the air when it's very cold outside. At the time, in Ontario, the temperature was -13°F (-25°C). He explained,

Oh, and for those who are wondering why you need to use hot water, well, hot water evaporates more quickly than cold water since it’s already closer to the point of evaporation, so when it hits cold air in the form of tiny droplets of liquid, it just turns into snow and water vapor.

He also added a warning to be careful throwing, lest the hot water fall on you. The transformation may seem instantaneous, but it does take a little time. There are other such videos, like a demonstration from Yellowknife, Northwest Territories, where the temperature was -30°C (-22°F), and another from Alaska at -40° (C&F). They even try this stunt at -52°C in Oymyakon, Russia.

In fact, the trick had become so common that this year, chrisgsauce had to step up the game a bit to go viral. When the temperature dipped to -41° in South Porcupine, Ontario, last week, he loaded the hot water into a Super Soaker!

You can see almost the same type of reaction on a larger scale when a hot springs geyser erupts in the recent extremely cold temperatures in Iceland.

Eruption, water vapor, snowfall, and no water. Cool, huh?

The problem with stunts like this is that people try to recreate it without taking the proper precautions. Suddenly, the latest deep freeze has given that opportunity to Americans who have never dealt with temperatures this low. In their excitement, many actually burned themselves with the hot water. At least 50 Tweets related the same story.

Unlike Canadians, few of the new experimenters used a pair of weatherproof gloves -and they probably haven't ever played with boiling water before. Couple that with the fact that it isn't quite -40 degrees in most of the United States, and throwing boiling water into the air doesn't seem so safe anymore.

In Chicago, Micah Uetricht tried the experiment because the wind chill was 30 below, but that isn't the same as the real air temperature. And stepping out on the balcony without proper outdoor clothing is asking for trouble. Video contains some NSFW language.

A much safer experiment for those of us in the lower 48 would be to blow soap bubbles and see how fast they freeze. As thin as that soap membrane is, it doesn't take long in cold air!

In the weird case of the "ice serpents" emerging from this pipe, a lot of rain fell, which filled the pipe, then the temperature dropped quickly. As the water froze, it was pushed out of a hole in the pipe, creating the weirdly beautiful structures. Photograph by Ninja Viking

This is what happens when a building catches on fire during a deep freeze. This warehouse in Chicago burned last January, and required plenty of water from the Chicago Fire Department to extinguish it. However, with the temperature at around 10°F, the water froze as soon as it did its job. See more pictures here. Photograph by Robert R Gigliotti of RPGPhotography.

So if you're going to go out and have fun in the snow, dress warmly, and take the necessary precautions before you experiment!

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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]