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This Mexican Cave Is Full of Giant Crystals

In 2000, two miners working for the Peñoles mining company discovered the largest cave crystals anyone had ever seen. A fantastic assortment of sparkling gypsum formations, some more than 36 feet long and weighing up to 55 tons, were growing about a thousand feet beneath the earth at the Naica Mine in Chihuahua, Mexico. The site later came to be known as the "Cueva de Los Cristales,” or Cave of Crystals.

As Dylan Thuras of Atlas Obscura notes in the new video above, scientists estimate the crystals have been growing for half a million years. They’ve formed thanks to interactions between the magma chamber below the cave and the cool waters inside it. According to Thuras, there’s no limit to how much bigger the crystals will get.

Despite the difficulties of exploring the place—it’s more than 100 degrees inside with 100 percent humidity—scientists with the Naica Project have been conducting research on the crystals. They’ve discovered a new type of gypsum formation and looked at the DNA of ancient organisms, among other projects. However, access to the crystals might be fleeting. As Thuras notes, the crystals were revealed when the mining company pumped out groundwater to exploit the precious ores inside the cave. As soon as it doesn’t make financial sense for the mining company to leave the crystals uncovered, they will be flooded again—a return to their natural environment, but one that could leave them sadly off-limits once again.

Header image via Alexander Van Driessche via Wikipedia // CC BY 3.0

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Afternoon Map
Monthly Internet Costs in Every Country

Thanks to the internet, people around the world can conduct global research, trade tips, and find faraway friends without ever leaving their couch. Not everyone pays the same price for these digital privileges, though, according to new data visualizations spotted by Thrillist.

To compare internet user prices in each country, cost information site HowMuch.net created a series of maps. The data comes courtesy of English market research consultancy BDRC and Cable.co.uk, which teamed up to analyze 3351 broadband packages in 196 nations between August 18, 2017 and October 12, 2017.

In the U.S., for example, the average cost for internet service is $66 per month. That’s substantially more than what browsers pay in neighboring Mexico ($27) and Canada ($55). Still, we don’t have it bad compared to either Namibia or Burkina Faso, where users shell out a staggering $464 and $924, respectively, for monthly broadband access. In fact, internet in the U.S. is far cheaper than what residents in 113 countries pay, including those in Saudi Arabia ($84), Indonesia ($72), and Greenland ($84).

On average, internet costs in Asia and Russia tend to be among the lowest, while access is prohibitively expensive in sub-Saharan Africa and in certain parts of Oceania. As for the world’s cheapest internet, you’ll find it in Ukraine and Iran.

Check out the maps below for more broadband insights, or view HowMuch.net’s full findings here.

Map of Internet costs in each country created by information site HowMuch.net.
HowMuch.net

Map of Internet costs in each country created by information site HowMuch.net.
HowMuch.net

Map of Internet costs in each country created by information site HowMuch.net.
HowMuch.net

Map of Internet costs in each country created by information site HowMuch.net.
HowMuch.net

Map of Internet costs in each country created by information site HowMuch.net.
HowMuch.net

[h/t Thrillist]

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Can You Figure Out Why the Turtles Bulge in This Optical Illusion?
iStock
iStock

Ready for a little vision test? Akiyoshi Kitaoka, a Kyoto-based psychologist who studies visual illusions, created this eye-bending image that appears to bulge and bend. In the image, shared on Syfy.com, the horizontal and vertical lines actually run straight across and down, but they look like they ripple, and the shapes (Kitaoka calls them turtles) look like they’re different shades of gray, even though they’re an identical color.

As Phil Plait explains for Syfy, the key is in the corners—the turtle “legs,” if you will. “At each vertex between turtles, they form a rotated square divided into four smaller squares," he writes. "Note how they're offset from one another, giving a twist to the vertices.” If you zoom in closely on the image, the lines begin to straighten out.

The difference in the colors, meanwhile, is a result of the contrast between the black and white pixels outlining the turtles. If the outlines of the turtles were entirely black or entirely white, instead of a combination, the grays would look identical. But the contrast between the two fools your eyes into thinking they're different.

To see more of Kitaoka’s illusion art, you can follow him on Twitter @AkiyoshiKitaoka. Then, go check out these other amazing optical illusions.

[h/t Syfy]

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