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Look Up Tonight! The Lyrids Meteor Shower Is Set to Stun!

Look up tonight and you’ll see a waning crescent Moon, and, every few minutes, shooting stars falling from the sky. The Lyrids meteor shower peaks on April 21, and if light pollution is low in your area, you can expect to see around 10 meteors per hour—maybe more if you escape to the countryside.

WHAT IS GOING ON UP THERE?

The Lyrids—named for the constellation Lyra from which they seem to originate—are the happy result of the Earth slamming into the debris of the comet C/1861 G1 Thatcher (named after its discoverer, not the former British prime minister). But don’t worry: Thatcher isn’t a danger! As it flies about its four-century-long orbit around the Sun, particles fall away. It’s perfectly normal shedding, resulting in an annual evening-time spectacular.

Thatcher is a long-period comet; such comets have orbits longer than 200 years. At aphelion—that is, its farthest point from the Sun—Thatcher is at a distance of 110 astronomical units (AU). To put this in perspective, the distance from the Sun to the Earth is 1 AU. The distance from the Sun to Pluto is about 40 AU. The very farthest-known natural, observable object in the solar system, V774104, is presently 103 AU. So Thatcher has put in a lot of work to make tonight's light show happen. I hope you appreciate it. This meteor shower is 415 years and 21,225,138,770 miles in the making. If that’s not good enough for you, nothing is.

HOW DO I SEE THE LYRIDS?

Sometimes, the Lyrids deliver a mind-blowing show. Its first reported occurrence was reportedly so bright and busy that it drowned out the stars. In 1982, it reached 90 meteors an hour. Ordinarily, however, the meteor shower produces five to 20 meteors every hour. Don’t miss this chance to see them, because when it comes to dust-sized cometary particles vaporizing in Earth’s atmosphere at 30,000 miles per hour, you just never know how good the show will be.

The best time to see the Lyrids will be after midnight until just before dawn. While you wait, check out Jupiter, bright and unblinking in the south. If you have a telescope handy, or even a reasonably powered set of binoculars, you’ll easily see four of its moons: Europa, Ganymede, Io, and Callisto. You can also see Saturn to the southeast (though this isn’t the best time for viewing it). As dawn approaches, look east and you’ll see Venus up there, as bright as ever. (It reaches greatest brilliancy on April 30.)

To enjoy the Lyrids meteor shower, you won’t need binoculars or a telescope or anything, really, but a blanket and patience. Since it’s a Friday night, bring a bottle of wine. You’re not going to live forever. Because the Moon will be but a sliver, it won’t wash out the sky with moonlight. So Thatcher and the Moon are doing the heavy lifting here. All you have to do is show up and wait.

Original image
iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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
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Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
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iStock

When you get an incoming call to your iPhone, the options that light up your screen aren't always the same. Sometimes you have the option to decline a call, and sometimes you only see a slider that allows you to answer, without an option to send the caller straight to voicemail. Why the difference?

A while back, Business Insider tracked down the answer to this conundrum of modern communication, and the answer turns out to be fairly simple.

If you get a call while your phone is locked, you’ll see the "slide to answer" button. In order to decline the call, you have to double-tap the power button on the top of the phone.

If your phone is unlocked, however, the screen that appears during an incoming call is different. You’ll see the two buttons, "accept" or "decline."

Either way, you get the options to set a reminder to call that person back or to immediately send them a text message. ("Dad, stop calling me at work, it’s 9 a.m.!")

[h/t Business Insider]

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