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Dietribes: Salt

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Just after I asked you guys how to get rid of that high salt content in Ramen a few weeks ago, here I am pouring it on (nudge nudge) this week. This post contains 27% of your daily value for salt, one of the most important compounds and foodstuffs known to man.

"¢ Of course, salt has many other uses besides enhancing flavor and preserving food. As most of you know, it was also used to preserve humans. One of the most interesting naturally-occurring cases is that of the "Iranian Salt Men," whose remains from 1800 years ago have been preserved naturally in salt mines. Even their hair stayed intact!

"¢ You may pour salt on everything you eat, but you certainly don't pour ... bleach? Still, Clorox bleach starts and ends as salt and water. Clorox was in fact founded on converting brine from a salt pond into bleach. This all sounds too good and non-toxic to be true ... any chemists want to weigh in with their two cents?

"¢ One major non-food related use of salt is for de-icing roads. Not something we much think about here in Hotlanta, but "in the United States, only 8 percent of salt production is for food. The largest single use for American salt, 51 percent, is for de-icing roads." Salt was first used in this capacity in the 1930s.

"¢ Speaking of the 1930s—1930 itself to be exact—it was the year Gandhi and 78 other men walked 240 miles from the Sabarmati Ashram to the Sea of Dandi, in an act of civil disobedience against the British Salt Tax (which forbade the production or selling of salt by anyone but the British government, and also heavily taxed salt in general). After arriving at the Dandi coastline, Gandhi illegally collected salt and encouraged others to do so, for which he was arrested—a seminal moment in the movement for Indian independence.

morton-salt.gif"¢ There are many uses for salt, but what about varieties (such as iodized)? What's the deal with that umbrella girl? In the early 20th century, Michigan seemed to have a high prevalence of goiter. (A 1922 study even identified it as a "goiter belt.") The Michigan State Medical Society and a man by the name of Dr. David Murray Cowie took up the cause and eventually tried to promote the use of iodized salt (potassium iodine added to salt) as a solution. Michigan salt producers took their advice, and Morton's took it national in the fall of 1924. For more on salt additives, check this out.

"¢ If you're like me and the early Romans (the word "salary" originates from the word for money allotted to Roman soldiers for the purchase of salt; hence, their pay), and you can't get enough of salt in general, try visiting the Salt Museum in Hutchinson, Kansas. Has anyone ever been?

"¢ Other stops on your Salty Tour of the US might include the mystical wonder of the Galos Caves in Chicago, and of course the Great Salt Lake in Utah. At the end of your salty journey, find relaxation at a Salt Spa for a mere $15.

"¢ Take this site with a grain of salt, you salty dogs, but it has theories on the origins of some common salt-related phrases that might make it worth its salt. Ok, I'm just rubbing salt in the wound now. Seriously, I'm stopping.

Hungry for more? Venture into the Dietribes archive.

"˜Dietribes' appears every Wednesday. Food photos taken by Johanna Beyenbach. You might remember that name from our post about her colorful diet.

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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]