Original image
Ramadhan Abdulla holds cassava on his farm in Tanzania. © Bill & Melinda Gates Foundation/Jake Lyell

3 Insanely Important Crops You've Never Heard Of

Original image
Ramadhan Abdulla holds cassava on his farm in Tanzania. © Bill & Melinda Gates Foundation/Jake Lyell

Everybody knows the names of plants we grow in the western worldour top five are corn, soybeans, hay (grass), wheat, and cotton. But there are crops around the world feeding millions of peopleand most of us have never even heard of them. Here's a roundup of some of the most interesting crops you likely haven't seen at the supermarket.

1. Cowpea

Farmers and cowpea merchants attend the PICS bag opening ceremony in Garko village in Kano State Nigeria on April 12, 2010. Photo © Bill & Melinda Gates Foundation/Akintunde Akinleye.

Scientific name: Vigna unguiculata.

Where it's grown: Sub-Saharan Africa, South America, Asia, and parts of North America.

Why it's a big deal: The cowpea is so nutritious and adaptable that NASA chose to study it as a plant to grow on space stations. The cowpea withstands heat, drought, poor soil, and shade, so it's adaptable to poor growing conditions. It's such a bad-ass plant that it will even improve poor soil if the roots are left in the soil to rot after harvesting.

Bonus trivia: Millions of African families sell their cowpea crops for a living, but weevil infestations can destroy up to half of each year's crop after it's harvested. In 2009, Purdue University delivered a simple solution to farmers doing battle with the weevil: the PICS bag (short for Purdue Improved Cowpea Storage), a three-layer sack that protects the crop from weevils. Purdue even filmed a sketch explaining how a simple bag can solve pest problems, without the need for post-harvest pesticides.

2. Pearl Millet

Franscica Ejaa separates the seeds from a finger millet flower in front of her house in Kenya. (Right: detail of ground finger millet seeds.) Photos © Bill & Melinda Gates Foundation/Frederic Courbet.

Scientific name: Pennisetum glaucum.

Where it's grown: India, plus the drylands of West and Central Africa.

Why it's a big deal: Pearl millet is a staple food for more than 90 million people in the driest parts of Africa and Asia. It's a cereal crop, but is super drought- and heat-tolerant, so it'll grow where maize and sorghum can't. It's also a very healthy food, providing protein, amino acids, iron, and zinc.

Bonus trivia: Even though pearl millet is an extremely nutritious food, there's a cultural stigma attached to it. In some areas it's considered "poor-man's food," so it's hard to market. This is a situation similar to what potatoes and even lobster faced in the U.S. years agoso attitudes can change.

3. Cassava

Ester Wanjiru Sami and her neighbor pose for a portrait in a field in Murango, Kenya where a variety of crops are growing in November 2011. They are holding freshly harvested cassava. Photo © Bill & Melinda Gates Foundation/Frederic Courbet.

Scientific name: Manihot esculenta Crantz.

Also known as: Yuca, manioc, and mandioca.

Where it's grown: Around the world; these 10 countries account for 75% of global production: Nigeria, Brazil, Thailand, Indonesia, Congo, Ghana, Tanzania, India, and Mozambique.

Why it's a big deal: Several studies say that cassava contributes more than any other single crop to household income. It's a staple food for 500 million people, who rely on it for caloriesand many farmers feed its leaves to animals as fodder. Cassava is also handy because you can leave it in the ground until you're ready to eat it. Hey, free food storage!

Why it may soon be a bigger deal: One bummer about cassava is that it's not a great source of nutrition. This is especially a problem for children, who receive only 4% of the vitamin A they need from a typical meal of standard cassava. A team of scientists developed BioCassava Plus, which beefs up the crop's beta-carotene content by 3,000% (the body converts beta-carotene to vitamin A), and its iron content by 400%.

Original image
iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
Original image
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!

Original image
Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
Original image

When you get an incoming call to your iPhone, the options that light up your screen aren't always the same. Sometimes you have the option to decline a call, and sometimes you only see a slider that allows you to answer, without an option to send the caller straight to voicemail. Why the difference?

A while back, Business Insider tracked down the answer to this conundrum of modern communication, and the answer turns out to be fairly simple.

If you get a call while your phone is locked, you’ll see the "slide to answer" button. In order to decline the call, you have to double-tap the power button on the top of the phone.

If your phone is unlocked, however, the screen that appears during an incoming call is different. You’ll see the two buttons, "accept" or "decline."

Either way, you get the options to set a reminder to call that person back or to immediately send them a text message. ("Dad, stop calling me at work, it’s 9 a.m.!")

[h/t Business Insider]