What Causes Sinkholes?

Mark Ralston/AFP/Getty Images
Mark Ralston/AFP/Getty Images

This week, a sinkhole opened up on the White House lawn—likely the result of excess rainfall on the "legitimate swamp" surrounding the storied building, a geologist told The New York Times. While the event had some suggesting we call for Buffy's help, sinkholes are pretty common. In the past few days alone, cavernous maws in the earth have appeared in Maryland, North Carolina, Tennessee, and of course Florida, home to more sinkholes than any other state.

Sinkholes have gulped down suburban homes, cars, and entire fields in the past. How does the ground just open up like that?

Sinkholes are a simple matter of cause and effect. Urban sinkholes may be directly traced to underground water main breaks or collapsed sewer pipelines, into which city sidewalks crumple in the absence of any structural support. In more rural areas, such catastrophes might be attributed to abandoned mine shafts or salt caverns that can't take the weight anymore. These types of sinkholes are heavily influenced by human action, but most sinkholes are unpredictable, inevitable natural occurrences.

Florida is so prone to sinkholes because it has the misfortune of being built upon a foundation of limestone—solid rock, but the kind that is easily dissolved by acidic rain or groundwater. The karst process, in which the mildly acidic water wears away at fractures in the limestone, leaves empty space where there used to be stone, and even the residue is washed away. Any loose soil, grass, or—for example—luxury condominiums perched atop the hole in the ground aren't left with much support. Just as a house built on a weak foundation is more likely to collapse, the same is true of the ground itself. Gravity eventually takes its toll, aided by natural erosion, and so the hole begins to sink.

About 10 percent of the world's landscape is composed of karst regions. Despite being common, sinkholes' unforeseeable nature serves as proof that the ground beneath our feet may not be as solid as we think.

A version of this story originally ran in 2014.

Amazon's Under-the-Radar Coupon Page Features Deals on Home Goods, Electronics, and Groceries

Stock Catalog, Flickr // CC BY 2.0
Stock Catalog, Flickr // CC BY 2.0

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Now that Prime Day is over, and with Black Friday and Cyber Monday still a few weeks away, online deals may seem harder to come by. And while it can be a hassle to scour the internet for promo codes, buy-one-get-one deals, and flash sales, Amazon actually has an extensive coupon page you might not know about that features deals to look through every day.

As pointed out by People, the coupon page breaks deals down by categories, like electronics, home & kitchen, and groceries (the coupons even work with SNAP benefits). Since most of the deals revolve around the essentials, it's easy to stock up on items like Cottonelle toilet paper, Tide Pods, Cascade dishwasher detergent, and a 50 pack of surgical masks whenever you're running low.

But the low prices don't just stop at necessities. If you’re looking for the best deal on headphones, all you have to do is go to the electronics coupon page and it will bring up a deal on these COWIN E7 PRO noise-canceling headphones, which are now $80, thanks to a $10 coupon you could have missed.

Alternatively, if you are looking for deals on specific brands, you can search for their coupons from the page. So if you've had your eye on the Homall S-Racer gaming chair, you’ll find there's currently a coupon that saves you 5 percent, thanks to a simple search.

To discover all the deals you have been missing out on, head over to the Amazon Coupons page.

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The Reason Supreme Court Justices Wear Black Robes

Judge Thomas Patrick Thornton (left) is sworn in as a federal judge by Judge Arthur F. Lederle (right) on February 15, 1949.
Judge Thomas Patrick Thornton (left) is sworn in as a federal judge by Judge Arthur F. Lederle (right) on February 15, 1949.

Professional attire can go a long way in communicating the level of respect you have for your occupation and the people around you. Lawyers don’t show up for court in shorts and politicians don’t often address crowds in sleeveless T-shirts.

So it stands to reason that the highest court in the country should have a dress code that reflects the gravity of their business, which is why most judges, including judges on the Supreme Court, are almost always bedecked in black robes. Why black?

As Reader's Digest reports, judges donning black robes is a tradition that goes back to judicial proceedings in European countries for centuries prior to the initial sitting of the U.S. Supreme Court in 1790. Despite that, there’s no record of whether the Justices went for a black ensemble. That wasn’t officially recorded until 1792—but the robes weren’t a totally solid color. From 1792 to 1800, the robes were black with red and white accents on the sleeves and in the front.

It is likely that Chief Justice John Marshall, who joined as the fourth chief justice of the Supreme Court in 1801, led the shift to a black robe—most likely because a robe without distinctive markings reinforces the idea that justice is blind. The all-black tradition soon spread to other federal judges.

But according to former Supreme Court Justice Sandra Day O’Connor, there is no written or official policy about the robes, and the Justices are free to source them however they like—typically from the same companies who outfit college graduates and choir singers. It’s certainly possible to break with tradition and arrive on the bench without one, as Justice Hugo Black did in 1969; Chief Justice William Rehnquist once added gold stripes to one of his sleeves. But for the most part, judges opt for basic black—a message that they’re ready to serve the law.

[h/t Reader’s Digest]