CLOSE
Original image

Siberian Hamster Testicles are Growing, Which Means the Vernal Equinox is Here

Original image
Standing before the Pyramid of the Sun in Teotihuacan, Mexico, a woman embraces spring on the vernal equinox. Image Credit: Ronaldo Schemidt/AFP/Getty Images

 
Today you, I, and everyone in the world have something in common. Regardless of whether you live in Australia or Austria or Austin, day and night are approximately the same length the whole world over. Today is the vernal equinox—the first day of spring. If you live in the Northern Hemisphere, your days will be getting longer, your trees greener, and your animals friskier. We think it all happens because billions of years ago, a proto-planet collided with an embryonic Earth. Here's what's going on.

TILT-O-WHIRL

Winter and summer have nothing to do with the distance of the Earth from the Sun. Rather, seasons are the product of axial tilt and orbital dynamics. The Earth is tilted slightly at 23.5 degrees relative to its orbital plane. (That tilt is thought related to the aforementioned collision.) The orientation of the tilt never changes, and as Earth revolves around the Sun over the course of a year, different latitudes are thus in direct sunlight. When the Northern Hemisphere is in direct sun, it is summertime there and wintertime down under, and vice versa when the Southern Hemisphere is in direct sunlight.

If this is hard to visualize, take your cell phone and hold it upright next to the left side of your computer screen, tilted slightly toward the computer. The top-right corner should be closest to the screen. It is summertime in that corner (the screen being the Sun in this demonstration). Now keep everything the same, but bring your phone to the right side of your screen. Now the bottom-left of your phone is closer. It is summertime there. If your phone were a spinning sphere, those two corners would be the Tropics of Cancer and Capricorn, respectively. Over a full orbit of the Earth around the Sun, this means the center of the Earth—the Equator—is in direct sunlight twice.

Today is one of those times, marking the transition from winter to spring in the Northern Hemisphere. (The other, autumnal equinox, transitions fall to winter.)

ANIMALS KNOW

Humans today have it pretty easy. We have coats and fires during the winter, and shorts, air conditioning, and Disney vacations in the summer. For many in the developed world, seasons are in some ways a neat way of marking time, but they don’t necessarily dictate the course of our lives. For plants and animals, though, the seasons are serious business. The availability of food and warmth are vital for reproduction and rearing young animals. During the fall and short winter days, for example, the testicles of Siberian hamsters change dramatically in size (and under no circumstances should you google that). That’s a pretty granular-level effect of the axial tilt of an entire planet.

The same goes for birds flying south for the winter. Studies suggest that the migration is in large measure simply birds following the food. (Starvation winters in the north can be summer feasts in the south. Go where the worms are.) There is some evidence that the migratory patterns are also wired into the DNA of some birds. We’ve discussed this previously at mental_floss:

Captive birds have been observed getting pretty fidgety and changing their sleep patterns right before their natural migration time. Ethologists—those who study animal behavior—call the birds' behavior zugunruhe ("migratory restlessness"). Captive birds display zugunruhe even if they're not exposed to natural light or to seasonal temperature changes.

It goes far beyond that, though. Even plants know what’s up. “Spring is sooner recognized by plants than by men,” says the Chinese proverb. Plants produce phytochromes, which are compounds sensitive to the light spectrum and used to regulate flowering and budding. In some regions, the vernal equinox and the longer days of direct sunlight it brings lead to an increased production of red phytochromes. (In the winter, the Sun’s position in the sky, and the sunlight often shining indirectly, leads to the increased production of far-red phytochromes.) As the ratios shift, you get flowering. No tilt, no bouquets.

So while today is an interesting day to mark for social reasons—a rare point of global harmony and equality imposed by the natural world, even if only concerning light and dark—it’s also a day marking a shift in the behaviors of the natural world itself. Today we are all equal, and for the next few months, the Northern Hemisphere begins anew.

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

SECTIONS
BIG QUESTIONS
arrow
BIG QUESTIONS
SECTIONS
WEATHER WATCH
BE THE CHANGE
JOB SECRETS
QUIZZES
WORLD WAR 1
SMART SHOPPING
STONES, BONES, & WRECKS
#TBT
THE PRESIDENTS
WORDS
RETROBITUARIES