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U.S. Department of Energy

Offbeat Plans to Protect Nuclear Waste (With Cats)

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U.S. Department of Energy

by Rachel Kaufman

Radioactive junkyards remain dangerous for millennia. So how do you keep future generations of urban explorers and dumpster divers away from all that toxic trash? With a sign, of course!

New Mexico’s Waste Isolation Pilot Plant (WIPP) may be the trashiest place on Earth. Buried deep in the Chihuahuan Desert, the plant contains nearly 2 million cubic feet of radioactive sludge and debris leftover from various nuclear weapons and defense projects. But don’t mistake the WIPP for a simple pit in the ground. Scientists at the U.S. Department of Energy spent nearly 20 years carefully planning the safest way to throw out the country’s nuclear trash before committing to the site.

Today, the plant resides inside a 250 million-year-old salt deposit that’s positioned half a mile underground. And there’s good reason for that. Scientists chose the location because of its ability to prevent radiation from contaminating groundwater and seeping out to the surface. Because salt deposits tend to slowly collapse on themselves over time, scientists are banking on the idea that the structure will naturally seal in the nuclear waste, safely entombing the site deep underground.

Under the WIPP’s current charter, the site will continue to receive radioactive garbage from the country’s nuclear weapons and energy programs until about 2070—at which point it will be sealed up and never opened again. At least, that’s the plan. The WIPP still has one major problem, though. Radioactive waste remains dangerous to humans for at least 10,000 years. So, how do we tell people living in the far distant future to stay out of our trash? The government’s solution: some good, old-fashioned warning signs.

Global Warning

Of course, coming up with such a simple plan wasn’t all that easy. To keep future generations safe, the U.S. government had to do some seriously long-term thinking. In the 1990s, when the WIPP was still being completed, federal officials convened a panel of scientists, anthropologists, and linguists to brainstorm. And just to ensure they had enough diverse minds involved, they also invited a team of science-fiction writers to join the mix.

The group realized early on that big “Do Not Enter” signs wouldn’t suffice for the WIPP site. After all, they reasoned, there were plenty of curses and warnings carved into the ancient pyramids to ward off grave robbers, and clearly, legions of Egyptologists ignored the pictograms and raided the tombs anyway. What’s more, it’s doubtful that folks 10,000 years from now will even be able to read modern English. Think of it this way: Only a few of today’s scholars can understand the original Beowulf without a translation, and that text is only 1,000 years old.

Creating an ominous warning sign that lasts forever and translates for generations across all cultures wasn’t going to be easy. But as Germany learned when it faced a similar problem in the 1980s (thanks to some leaky nuclear-storage incidents), academics aren’t shy about offering out-of-the-box suggestions. One expert proposed writing a message on an artificial moon and launching it into space. Because the moon would always be visible in the night sky, the warning would be impossible to forget. Yet another expert proposed creating an “atomic priesthood”—an elite class of people who would protect the area from one generation to the next by scaring the public with veiled threats of a supernatural curse. On the opposite end of the spectrum, one researcher suggested leaving the site entirely unmarked, reasoning that human curiosity is too powerful a force
to overcome.

But the strangest suggestion by far came from two German linguists. They argued that governments around the world should breed cats that turn colors when exposed to radiation. These so-called “ray cats” could then be immortalized in song and legend, so that even after the scientific knowledge of radiation had been lost to the sands of time, folklore would tell of their supernatural power to change their fur in the presence of extreme danger.

For the time being, the U.S. government has settled on a much simpler idea. Surrounding the WIPP will be a forest of concrete obelisks, etched with messages in multiple languages, including English, Chinese, Spanish, Latin, Hebrew, and Navajo. The structures will also contain a series of pictograms that depict human faces in pain. Admittedly, it sounds a whole lot like the warnings on the Egyptian pyramids. But fortunately, the government still has time to come up with a different plan. The WIPP site won’t be sealed for at least another 60 years—and that’s plenty of time to breed a ray cat.

This story originally appeared in a 2011 issue of mental_floss magazine.

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iStock // Ekaterina Minaeva
technology
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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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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iStock
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Scientists Think They Know How Whales Got So Big
May 24, 2017
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iStock

It can be difficult to understand how enormous the blue whale—the largest animal to ever exist—really is. The mammal can measure up to 105 feet long, have a tongue that can weigh as much as an elephant, and have a massive, golf cart–sized heart powering a 200-ton frame. But while the blue whale might currently be the Andre the Giant of the sea, it wasn’t always so imposing.

For the majority of the 30 million years that baleen whales (the blue whale is one) have occupied the Earth, the mammals usually topped off at roughly 30 feet in length. It wasn’t until about 3 million years ago that the clade of whales experienced an evolutionary growth spurt, tripling in size. And scientists haven’t had any concrete idea why, Wired reports.

A study published in the journal Proceedings of the Royal Society B might help change that. Researchers examined fossil records and studied phylogenetic models (evolutionary relationships) among baleen whales, and found some evidence that climate change may have been the catalyst for turning the large animals into behemoths.

As the ice ages wore on and oceans were receiving nutrient-rich runoff, the whales encountered an increasing number of krill—the small, shrimp-like creatures that provided a food source—resulting from upwelling waters. The more they ate, the more they grew, and their bodies adapted over time. Their mouths grew larger and their fat stores increased, helping them to fuel longer migrations to additional food-enriched areas. Today blue whales eat up to four tons of krill every day.

If climate change set the ancestors of the blue whale on the path to its enormous size today, the study invites the question of what it might do to them in the future. Changes in ocean currents or temperature could alter the amount of available nutrients to whales, cutting off their food supply. With demand for whale oil in the 1900s having already dented their numbers, scientists are hoping that further shifts in their oceanic ecosystem won’t relegate them to history.

[h/t Wired]

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