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What Is El Niño, and Why Does It Have Such a Big Impact?

Sea surface temperature anomalies, in °C, January 24–31, 2016

A snowstorm in the Midwest this week has its roots in a weather pattern influenced by El Niño—a disturbance that dropped several inches of rain in California, traversed the Rocky Mountains, and spun-up a formidable blizzard that threatens to produce up to a foot of snow across the central United States. El Niño has taken on an almost legendary quality in the United States, entering the collective mind of the public in the late 1990s as an epic weather pattern that drenches California in an unending deluge of tropical moisture.

An El Niño is the abnormal warming of sea surface temperatures in the eastern equatorial Pacific Ocean. The event occurs when winds over the Pacific Ocean near the equator slow down or reverse direction, allowing unusually warm water to accumulate around the eastern part of the equatorial Pacific. When sea surface temperatures in this portion of the Pacific climb 0.5°C above average for seven consecutive months, it’s officially considered an El Niño. Now, an upward shift of one-half of one degree doesn’t sound like much—it’s not!—but, in a similar way to a fever in the human body, it doesn’t take much abnormal heat to make a huge impact both on the ocean and the atmosphere above it.

How can warm water in the Pacific Ocean affect the weather thousands of miles away? Everything is connected. One of the most heavily advertised effects of El Niño is that it can squash the Atlantic hurricane season as the warm water triggers thunderstorms in the eastern Pacific, causing strong upper-level winds to flow east over the Caribbean and Atlantic. This wind shear tears the tops off thunderstorms, keeping tropical activity to a minimum. This is an easily observable effect that we experienced just this past summer. However, the warmer water can also alter the jet stream, which is how we most commonly feel its influence here in the United States.

The jet stream is a fast-moving river of air in the upper levels of the atmosphere that’s usually located between 25,000 and 35,000 feet, the typical cruising altitude for commercial jets. This ribbon of powerful winds is caused by the temperature difference between the tropics and the poles. Weather exists as a result of nature trying to balance itself out—in this case in the Northern Hemisphere, rising warm air in the tropics flows north toward the Arctic, turning east thanks to the Coriolis effect. The resulting river of westerly winds is the jet stream.

The subtropical jet stream over the southern U.S. on February 5, 2016. Source: Tropical Tidbits

During the summer months, the jet stream is usually weaker and stuck in the higher latitudes. This is why weather is generally calmer during the summer, allowing long stretches of hot, humid weather only broken by occasional pop-up thunderstorms. During the cooler months, however, the north-south temperature gradient is much sharper, allowing the jet stream to dive south over the United States (and sometimes even farther south than that). This curvy, dippy jet stream provides us a constant offering of volatile weather, bringing everything from heavy rain or snow to extreme bouts of cold weather.

This is where El Niño factors in. There are actually two jet streams in the Northern Hemisphere: the polar jet stream, which circulates in the higher latitudes, and the subtropical jet stream, which we’ll often find around the southern United States. The polar jet is what brings us our deep shots of frigid air during the dead of winter, and the subtropical jet is often at least partially responsible for the huge, historic snowstorms that occasionally whomp the East Coast.

When the water in the eastern equatorial Pacific Ocean is abnormally warm like it is during an El Niño, it can affect air temperature above the surface. The warmer air allows the subtropical jet stream to grow stronger and establish itself over the southern United States, shoving the polar jet stream farther north near the border between the U.S. and Canada. This brings stormy weather to the southern half of the United States, often manifesting itself in wet low-pressure systems that smack California before slowly trundling across the rest of the country. This also tends to keep the northern United States drier and warmer than normal, though snowy conditions and arctic blasts aren’t uncommon.

If you hear people talk about El Niño causing flooding and snow out west or news anchors report that “El Niño brought heavy rain to Los Angeles yet again today,” take comfort in the fact that you now know that’s not true. El Niño doesn’t directly cause rain or snow or heat or cold in the United States, and El Niño doesn’t make landfall like a hurricane, either, since it’s just abnormally warm ocean water. If all of that warm water ever comes ashore, we’ll probably have a few more problems than worrying about scientific accuracy and semantics. El Niño isn’t and won’t always be the cause of our weather woes this season, but it sure doesn’t help.

Original image
iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
Original image
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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iStock
Sponsor Content: BarkBox
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8 Common Dog Behaviors, Decoded
May 25, 2017
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iStock

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.

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