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10 of History’s Most Terrifying Swords

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Humans have always been cooking up brand new ways to slice, dice, hack, and stab. You definitely wouldn’t want to tangle with any of the historical swords in this gallery—especially the last one.

1. The Khopesh

Believed to have evolved from either battle axes or farm implements, this intimidating weapon was used in ancient Egypt. Only the outer edge of the curved blade was sharp. The weapon was a symbol of authority, and several Pharaohs owned Khopeshes—including Ramses II and Tutankhamun, who was entombed with his. 

2. The Ulfbehrt Sword

Strong, lightweight, and flexible, Viking Ulfberht blades were forged with astonishingly pure metal called Crucible Steel. Even today’s best blacksmiths have had a hard time reproducing this material, which is much better than what's found in average medieval swords. How did Viking warriors develop such an advanced sword? The jury’s still out—though Middle Eastern trade might have helped them pick up a few technical pointers.

3. The Khanda

This weapon's tip was blunt, so it would have been bad at skewering your enemies. But India’s Khanda (introduced somewhere between 300 and 600 CE) didn’t need to: Its heavy construction made it a perfect chopping device, and some swordsmen upped the ante by giving the weapon serrated edges.

4. The Ngombe Executioner’s Sword

Back in the 19th and 20th centuries, European explorers made numerous sketches of tribal Congo residents decapitating prisoners with this ferocious-looking weapon. The extent to which their dramatizations reflect reality is debatable.

5. The Flammard

Wavy-bladed rapiers were a Renaissance staple. Flammard fanciers mistakenly believed that this undulating design could inflict deadlier wounds. The shape did provide one genuine dueling advantage, though: When an opponent’s sword ran across one, those curves would slow it down.

6. The Chinese Hook Sword

Double trouble! These weapons not only feature curved tips, but sharp, hand-protecting guards as well. The weapons were commonly handled in pairs, and, according to a 1985 issue of Black Belt magazine, "When put together, two hook swords could easily tear apart an opponent." Yikes.

7. The Kilij


The first Kilij appeared in Turkey around 400 CE. A perfect choice for horsemen, this style of saber went through several variations over the next 1400 years. In a skilled rider’s hands, this sword could mutilate those with their feet on the ground with devastating efficiency.

8. The Estoc

Armor doesn’t always guarantee safety. Renaissance swordsmen could split through the links with the estoc, a dull-edged thrusting sword designed specifically for this purpose.

9. The Zweihander

Zweihander means “two hand,” and these weapons were so large that swordsmen did indeed need two hands to wield them. According to one tale, the swords were so powerful that they could behead up to seven victims with a single stroke.

10. The Urumi

The best bladed weapons are at least somewhat flexible—but the urumi is downright floppy. When swung, it acts like a whip. A metal whip. A metal whip with two sharp edges. If that description doesn’t scare you, this demo reel should do the trick: 

Invented during India’s Mauryan Dynasty (circa 350-150 BCE), urumis have undergone plenty of variations over the centuries. Today, several blades are often attached to the same grip for added effectiveness. The constant risk of accidentally slicing yourself up makes the urumi anything but user-friendly.

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technology
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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Health
200 Health Experts Call for Ban on Two Antibacterial Chemicals
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In September 2016, the U.S. Food and Drug Administration (FDA) issued a ban on antibacterial soap and body wash. But a large collective of scientists and medical professionals says the agency should have done more to stop the spread of harmful chemicals into our bodies and environment, most notably the antimicrobials triclosan and triclocarban. They published their recommendations in the journal Environmental Health Perspectives.

The 2016 report from the FDA concluded that 19 of the most commonly used antimicrobial ingredients are no more effective than ordinary soap and water, and forbade their use in soap and body wash.

"Customers may think added antimicrobials are a way to reduce infections, but in most products there is no evidence that they do," Ted Schettler, science director of the Science and Environmental Health Network, said in a statement.

Studies have shown that these chemicals may actually do more harm than good. They don't keep us from getting sick, but they can contribute to the development of antibiotic-resistant bacteria, also known as superbugs. Triclosan and triclocarban can also damage our hormones and immune systems.

And while they may no longer be appearing on our bathroom sinks or shower shelves, they're still all around us. They've leached into the environment from years of use. They're also still being added to a staggering array of consumer products, as companies create "antibacterial" clothing, toys, yoga mats, paint, food storage containers, electronics, doorknobs, and countertops.

The authors of the new consensus statement say it's time for that to stop.

"We must develop better alternatives and prevent unneeded exposures to antimicrobial chemicals," Rolf Haden of the University of Arizona said in the statement. Haden researches where mass-produced chemicals wind up in the environment.

The statement notes that many manufacturers have simply replaced the banned chemicals with others. "I was happy that the FDA finally acted to remove these chemicals from soaps," said Arlene Blum, executive director of the Green Science Policy Institute. "But I was dismayed to discover at my local drugstore that most products now contain substitutes that may be worse."

Blum, Haden, Schettler, and their colleagues "urge scientists, governments, chemical and product manufacturers, purchasing organizations, retailers, and consumers" to avoid antimicrobial chemicals outside of medical settings. "Where antimicrobials are necessary," they write, we should "use safer alternatives that are not persistent and pose no risk to humans or ecosystems."

They recommend that manufacturers label any products containing antimicrobial chemicals so that consumers can avoid them, and they call for further research into the impacts of these compounds on us and our planet.

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