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10 Durable Facts About Duct Tape

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Duct tape can be found in the tool box of any self-respecting handyman, but the versatile product's potential extends far beyond home repairs. From its origins in the military to its popularity with NASA, here are some surprising facts about the reliable adhesive.

1. IT WAS INVENTED TO MEET A MILITARY NEED.

Before the invention of duct tape, packages of ammunition that were sent to the military were sealed with wax to keep their contents waterproof. The cardboard flaps were held shut with a strip of paper tape with a tab hanging loose that would allow soldiers to rip open the boxes in a hurry. Because this type of tape wasn’t very strong, the tabs would often tear off in their hands and leave soldiers struggling to free their ammunition in the heat of battle. 

Hoping to solve the problem, Vesta Stoudt, a mother of two Navy sailors and a worker at the Green River Ordnance Plant in Illinois, wrote to President Franklin Roosevelt with an idea: 

"I suggested we use a strong cloth tape to close seams, and make tab of same … I have two sons out there some where, one in the Pacific Island the other one with the Atlantic Fleet. You have sons in the service also.  We can’t let them down by giving them a box of cartridges that takes a minute or more to open, the enemy taking their lives, that could have been saved."

Roosevelt passed along the letter to the War Production Board in Washington, D.C., who contacted Johnson & Johnson to develop the product. The result was a strong, waterproof tape that soldiers could still tear apart with their hands in a pinch.

2. THE NAME "DUCK TAPE" CAME FIRST.

Since its origins, the tape has consisted of three major components: a bottom layer of glue, mesh fabric, and a polyethylene plastic coating on top to keep it water-resistant. According to Johnson & Johnson, soldiers nicknamed the material "duck tape" in reference to its ability to repel moisture "like water off a duck’s back."

3. IT OWES ITS STICKINESS TO PHYSICS.

While many adhesives, like Elmer’s glue, need to undergo a physical change in order to stick to something, duct tape works a little differently. Its stickiness is created by a pressure-sensitive adhesive, or PSA, which is a soft polymer blend that employs van der Waals forces to attract two surfaces. These intermolecular forces are weak on their own, but with enough of them, they are capable of supporting very heavy loads (this is the same principle that allows geckos to stick to walls).

"Other adhesives, like glues and epoxies, are liquid when you apply them, but they react chemically and harden," Costantino Creton, a materials scientist at the School of Industrial Physics and Chemistry in Paris, told Chemical and Engineering News. "PSAs have no chemical reaction. They don't change at all. They are in the solid state when you apply them, and they stick in their solid state." This makes duct tape the perfect option if you’re looking for a super strong adhesive that's also removable.

4. YOU CAN’T USE IT IN DUCTS.

Following World War II, duct tape began to catch on in the U.S. as a handy tool for home construction. People were using it to hold metal air ducts together, so the company rebranded the product as "duct tape" and updated it with a matching silver color made from powdered aluminum.

Today, its namesake usage is one of the few things that duct tape isn’t recommended for. Lawrence Berkeley National Laboratory conducted tests in 1998 to see how well different types of tape performed at sealing ducts, and, compared to the other products, duct tape was the clear loser. "Of all the things we tested, only duct tape failed. It failed reliably and often quite catastrophically," Max Sherman, one of the researchers, told Berkeley Lab Research News. Using duct tape on actual ductwork is now considered a code violation in many buildings.

5. DUCT TAPE HELPED SAVE APOLLO 13. 

Following an explosion aboard the ship’s service module, the three members of the Apollo 13 crew transferred to a lunar module designed to hold two people for 36 hours. They had to find a way to last more than twice that long, and the biggest threat to their survival was the carbon dioxide being created by their own bodies. While they had plenty of square carbon dioxide filters on board, they were incompatible with the lunar module’s round holes. Engineers at NASA devised a solution that involved using cardboard, plastic bags, space suit components, and duct tape that was kept on board to create an adapter that would filter out carbon dioxide. This hack ultimately saved the astronauts’ lives.

This wasn’t the only time duct tape proved to be useful in outer space. The tape has been stowed on board every NASA mission since the early Gemini era. Some of its handy applications include making emergency rover repairs, fixing leaky pipes, and keeping items secure in zero gravity.

6. IT HAS BEEN USED TO PREVENT INFECTION ...

Hospital-acquired infections account for 99,000 preventable deaths in the U.S. each year. In order to safely fight infection while saving doctors time and effort, the Trinity Medical Center system of hospitals in the Midwest came up with a rather simple solution. They used duct tape to mark 3-foot-square “safe zones” extending from the doorway into a patient's room. This allowed physicians to casually converse with their patients without having to change into full sterile gear every time they wanted to check in. Research shows that the duct tape idea saved the hospital system $110,000 a year and 2700 hours of staff time.

7. … AND A WHOLE LOT MORE.

Mythbusters has devoted three entire episodes to exploring some of duct tape’s most extreme applications. The team was able to successfully use duct tape to patch a damaged airplane fuselage, construct a functioning cannon, build a usable bridge, and lift a 5000-pound car. Of the 18 myths they tested, only one was busted (turns out you can’t use duct tape to barricade a car driving at 60 mph).

8. THERE’S AN ANNUAL DUCT TAPE FESTIVAL.

Since 2005, Avon, Ohio has hosted an annual duct tape festival dedicated to celebrating "duct tape, its enthusiasts, and its wacky and fun uses." The event features duct tape sculptures, a duct tape fashion show, and a parade of giant floats constructed using duct tape. 

9. THERE’S DUCT TAPE TO SUIT EVERY NEED.

Specialty varieties of the product include outdoor duct tape, double-sided duct tape, glow-in-the-dark duct tape, and nuclear-grade duct tape (the latter is certified for use in nuclear power plants).

10. WEARING DUCT TAPE TO PROM COULD EARN YOU A SCHOLARSHIP.

Duck brand duct tape offers a rather unusual scholarship to high schoolers who are willing to get creative with their product. Every prom season, they call upon students to design and create their own suits and dresses for the big day using duct tape. The winning couple of the "Stuck at Prom" competition is awarded a $10,000 scholarship each along with an additional $5000 for their high school.

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iStock // Ekaterina Minaeva
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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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Cs California, Wikimedia Commons // CC BY-SA 3.0
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How Experts Say We Should Stop a 'Zombie' Infection: Kill It With Fire
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Cs California, Wikimedia Commons // CC BY-SA 3.0

Scientists are known for being pretty cautious people. But sometimes, even the most careful of us need to burn some things to the ground. Immunologists have proposed a plan to burn large swaths of parkland in an attempt to wipe out disease, as The New York Times reports. They described the problem in the journal Microbiology and Molecular Biology Reviews.

Chronic wasting disease (CWD) is a gruesome infection that’s been destroying deer and elk herds across North America. Like bovine spongiform encephalopathy (BSE, better known as mad cow disease) and Creutzfeldt-Jakob disease, CWD is caused by damaged, contagious little proteins called prions. Although it's been half a century since CWD was first discovered, scientists are still scratching their heads about how it works, how it spreads, and if, like BSE, it could someday infect humans.

Paper co-author Mark Zabel, of the Prion Research Center at Colorado State University, says animals with CWD fade away slowly at first, losing weight and starting to act kind of spacey. But "they’re not hard to pick out at the end stage," he told The New York Times. "They have a vacant stare, they have a stumbling gait, their heads are drooping, their ears are down, you can see thick saliva dripping from their mouths. It’s like a true zombie disease."

CWD has already been spotted in 24 U.S. states. Some herds are already 50 percent infected, and that number is only growing.

Prion illnesses often travel from one infected individual to another, but CWD’s expansion was so rapid that scientists began to suspect it had more than one way of finding new animals to attack.

Sure enough, it did. As it turns out, the CWD prion doesn’t go down with its host-animal ship. Infected animals shed the prion in their urine, feces, and drool. Long after the sick deer has died, others can still contract CWD from the leaves they eat and the grass in which they stand.

As if that’s not bad enough, CWD has another trick up its sleeve: spontaneous generation. That is, it doesn’t take much damage to twist a healthy prion into a zombifying pathogen. The illness just pops up.

There are some treatments, including immersing infected tissue in an ozone bath. But that won't help when the problem is literally smeared across the landscape. "You cannot treat half of the continental United States with ozone," Zabel said.

And so, to combat this many-pronged assault on our wildlife, Zabel and his colleagues are getting aggressive. They recommend a controlled burn of infected areas of national parks in Colorado and Arkansas—a pilot study to determine if fire will be enough.

"If you eliminate the plants that have prions on the surface, that would be a huge step forward," he said. "I really don’t think it’s that crazy."

[h/t The New York Times]

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