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The Early History of Bungee Jumping

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Talk about a serious leap of faith. The first land divers plunged head first toward hard soil, all in the name of agriculture.
The Jump and Grind
If all your friends jumped off a cliff, would you do it, too? Chances are, if you're a Vanuatan male and hoping for a really spectacular yam crop this year, the answer's yes. Vanuatu, an archipelago in the Southern Pacific perhaps best known for its starring role in 2004's Survivor: Vanuatu, also has another claim to fame. Its Pentecost Island is the home of a death-defying religious ceremony known as naghol (a.k.a. land diving) that inspired modern-day bungee jumping.

To be fair, land divers don't really jump off cliffs. Instead, they construct 75-foot-tall wooden towers in their village centers, tilling the ground below the towers by removing any rocks or debris. Then, they tie long, elastic vines around their ankles. And then, on one or two days in late spring, they jump. The islanders believe that as the men's hair brushes against the ground at the nadir of their fall, it fertilizes the soil and helps ensure a bountiful yam crop.

Naghol is also a great excuse for village-wide parties; as the men line up to dive, crowds dance and sing below. Before they jump, they raise their arms in a signal that silences the cheering throng, and "“ as if acknowledging that their next act may be their last "“ they reveal their most private thoughts. Then they clap their hands, cross their arms in a corpse pose, and take the plunge. At the bottom, assuming the diver survives, male relatives untie his ankles and flip him right-side up, to the cheers of adoring crowds. (We'd like to see the well-coiffed Survivor contestants try that.) When legendary naturalist David Attenborough visited Pentecost Island with a BBC camera crew in 1950, the world got its first glimpse of land diving. Naturally, it was only a matter of years (29, to be exact) before thrill-seeking westerners followed suit.

The West Gets Roped In

bungee-jumping.jpgBelieve it or not, the West's first glimpse of a bungee jump occurred on April Fool's Day, 1979, when onlookers at the Clifton Suspension Bridge in Bristol, England, witnessed what appeared to be a suicide. Dressed in a top hat and tails and hugging a bottle of champagne, 33-year-old David Kirke did a back flip off the bridge, 250 feet above the River Avon. To the great surprise of horrified witnesses, Kirke never hit the water; instead, he slowed just before reaching its surface, then began a re-ascent toward the bridge. Whereupon three similarly tuxedoed friends of Kirke "“ members of what they called the "Dangerous Sports Club" "“ made the jump as well.When police arrived the four were hanging from the ends of their homemade elastic ropes. In quick succession they were each arrested, fined £100, and became overnight celebrities. Of course, Kirke didn't exactly stop there. He and his club also tried hang gliding from active volcanoes, BASE jumping and experimented with a human catapult capable of tossing a person 55 feet into the air in just 1.9 seconds. Seriously, kids, don't try this stuff at home (or anywhere, really); that last one figured prominently in a 2002 manslaughter trial.

This article was written by Ransom Riggs and excerpted from the mental_floss book In the Beginning: The Origins of Everything. You can pick up a copy in our store.
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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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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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Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
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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]