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Rebus token © The Foundling Museum

A Rebus Token for an Abandoned Child

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Rebus token © The Foundling Museum

The basket hanging on the gate at London's Foundling Hospital served a sad purpose: Mothers could place their babies inside the basket and slip away into the night. But most of the children brought to the hospital—a children's home where England's poorest kids were brought for a chance at care their parents could not provide—weren't completely anonymous. Though they were given a new name when they were brought inside, most were left with a tiny token of some kind—a piece of property parents could use to identify themselves if they were ever able to take their children back.

This token is one of the more unique specimens of the thousands of such artifacts left at the Foundling Hospital over the years. These days, the hospital has been turned into a museum, and its token collection showcases the inventiveness and anguish of the destitute children's desperate parents.

The Foundling Hospital opened its doors in 1741. It wasn't a "hospital" in the traditional sense: Rather, the word hospital indicated the hospitality and charity poor children would find inside. The tokens left with children date from the early days of the hospital, when parents could leave their kids there no questions asked.

Kids who entered the Foundling Hospital didn't stay inside the building. Rather, they were baptized, given new names, and sent to wet nurses or "nurse mothers" who took care of the children in the country. When they turned 5, they returned to the hospital, where they received an education. Wet nurses could return to visit their surrogate children, but birth mothers could not.

Workers at the hospital carefully recorded the clothing and identifying markers left with every child who entered. At first, many children were left with a small scrap of fabric (the parent would take the other half and the halves could be joined together again if they reunited). But over time, that practice was discontinued, and many parents left tokens with their children instead. They would attach notes and all kinds of markers, from pennies that were engraved with names and dates to more complicated puzzles like these.

The heartbreaking rebus on this token shows a child in a Moses basket—a universal symbol for a child who was given up. The rebus spells out "I want relief" and has the child's date of birth. It's a creative gesture that shows as much about the parents' inventiveness as the plight of their child.

"It is quite remarkable that the parent(s) of the child admitted with this coin went to the trouble of having it engraved with this despairing message," Emma Yandle of The Foundling Museum told mental_floss via email. Today, the coin is on display at the Foundling Museum. The hospital collected over 18,000 such tokens in the first 50 years of its existence.

The Foundling Hospital eventually became a charity that operates to this day—an example of some of the earliest attempts to help children in an age without foster care or social services. But though the tokens left in the hospital are seen as fascinating artifacts of a bygone era today, they also have a more anguished meaning. Tragically, the fact that the token still exists means that the child was never reunited with its birth parents.

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iStock // Ekaterina Minaeva
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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Scientists Think They Know How Whales Got So Big
May 24, 2017
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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]