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4 Amazing Archaeological Discoveries Spotted by Satellite

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Martin Bernetti/AFP/Getty Images

Since human flight was first possible, aerial archaeology has assisted researchers in uncovering previously unknown sites that are imperceptible from the ground. Today, thanks to advanced technology, remote sensing has moved higher above the Earth: Aerial archaeology is now sometimes space archaeology. By examining maps of the planet's surface taken from space, laptop-based Indiana Joneses can search vast areas for anomalies that could indicate evidence of the human past hidden for centuries. Below are four amazing archaeological discoveries spotted from space.

1. 3100 SETTLEMENTS, 1000 LOST TOMBS, AND 17 PYRAMIDS ACROSS EGYPT

Sarah Parcak is a space archaeologist and Egyptologist who since 2003 has discovered numerous archaeological sites across Egypt, all through her computer. Parcak specializes in analyzing satellite images taken from 400 miles overhead, processing the pictures to highlight parts of the electromagnetic spectrum the naked human eye cannot see. This allows her to note anomalies that could denote archaeological sites hidden underground.

It is highly specialized work. The tiny blips on the maps would mean nothing to the uninitiated, but to Parcak they provide clues that have led her to discover the location of 17 potential pyramids, some 3100 settlements, and 1000 lost tombs across Egypt. Parcak also used remote sensing to identify the location of the lost city of Tanis, which gained notoriety when it was featured in Raiders of the Lost Ark. The network of streets and houses of Tanis are completely invisible at ground level, and yet using infrared satellite images, Parcak was able to show the massive extent of the ancient settlement.

Parcak gave a hugely popular TED talk on space archaeology in 2012, and in 2015 was awarded the 2016 $1 million TED prize. She's used the money to create the citizen science platform GlobalXplorer, which allows anyone to analyze images from space in order to discover more lost archaeological sites across the globe—and spot evidence of looters.

2. THE FINAL DAYS OF THE MAYAN CIVILIZATION

The heavily forested Petén region of northern Guatemala is home to some of the most important Maya ruins in Central America, including Tikal. Archaeologists have been working with NASA using remote sensing to examine the Petén jungle from space in the hope of identifying lost sites associated with the Maya, whose culture reached the height of its power and influence from the 7th to the 9th centuries—and then collapsed around the turn of the 10th century.

In order to gain a greater understanding of this collapse, Tom Sever, the first archaeologist to work for NASA, has been analyzing images taken from an agency satellite program known as SERVIR which was launched from Marshall Space Flight Center in Huntsville, Alabama in 2005. Sever has used the images to further his theory—one also promoted by Jared Diamond in his popular book Collapse but not accepted by all Maya scholars—that what brought down the Maya was self-induced ecological disaster. The images indicate that the Maya used slash-and-burn agricultural practices that led to severe deforestation. They also drained the wetlands known as bajos, as evidenced by images of ancient drains, causing drought and resulting in an increase in temperature. The fate of the Maya is now often held up as a prime example of the risk of deforestation and climate change.

3. HOW AND WHERE THE EASTER ISLAND MOAI WERE MOVED

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moaisin the hillside of the Rano Raraku volcano in Easter Island
Martin Bernetti/AFP/Getty Images

The iconic statues on Easter Island have fascinated archaeologists since they were first noted by a Dutch explorer in 1722. But the biggest mystery is how the Rapa Nui managed to transport these enormous monoliths from the quarries where they were made to numerous sites across the island without the help of large animals or cranes.

In 2012, Carl Lipo of California State University and Terry Hunt of the University of Hawaii used satellite imagery to trace the ancient path of the stones from the quarry to various points around the island, identifying seven major roads [PDF]. The discovery of these routes led Lipo and Hunt to suggest that the upright statues might have been “walked” to their destinations, using ropes to tilt and turn the monoliths into motion. To test out their theory, the National Geographic Society’s Expeditions Council funded an experiment in which a concrete 10-foot, 5-ton copy of a moai was constructed. Using strong ropes, 18 people were able to fairly easily walk the massive statue a few hundred yards.

4. THE LOST CITY OF IRAM/UBAR

Five thousand years ago, a grand city in the deserts of Oman formed the center of the valuable frankincense trade. Known as Iram or Ubar, the legendary city was mentioned in both the Koran and The Thousand and One Nights (a.k.a. The Arabian Nights). Yet no modern trace of this once great city could be found. Notable explorer T. E. Lawrence ("Lawrence of Arabia") referred to it as “the Atlantis of the sands,” and some historians began to doubt it had ever existed. The mystery of the lost city was sufficiently tantalizing to attract the notice of NASA, who agreed to scan the area with a shuttle radar system after being approached by filmmaker and explorer Nicholas Clapp.

A Challenger space mission in 1984 provided the perfect opportunity to scan the desert of Oman from space, searching for geological features hiding under the sand. The resultant pictures revealed ancient caravan routes, which would have been packed down over hundreds of years by the camel trains traveling between trade hubs, the intersections of these roads providing clues as to potential locations for a city. Using this information, archaeologists began to dig at promising locations, and in 1991 Clapp and his team uncovered a many-towered fortress (like that described in the Koran), which would have been the home of the king and hub for the storage of frankincense. This led them to believe that they had finally uncovered the lost city of Ubar.

Ancient sources claimed that the city had disappeared into the Earth after its citizens angered Allah with their lavish and sinful way of life. Evidence from the site in Oman suggests that the destruction of the city occurred due to the appearance of a giant sinkhole, explaining how this once great city was lost to the sands.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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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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Cs California, Wikimedia Commons // CC BY-SA 3.0
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science
How Experts Say We Should Stop a 'Zombie' Infection: Kill It With Fire
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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]

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