What Causes Those Horrifying, Car-Swallowing Sinkholes?

 Logan Mock-Bunting/Getty Images
Logan Mock-Bunting/Getty Images

On Thursday morning, a St. Louis couple left a YMCA gym and discovered that their car was conspicuously missing from its spot. Upon further investigation, they realized it was actually still parked there—only it was 20 feet underground, swallowed up by a sinkhole

However terrifying they may be, sinkholes aren't that unusual in Missouri; the state is home to at least 15,000 of them, and it's had sinkhole-related regulations since 1853. That's nothing in comparison to Florida, though, which has the most sinkholes in the U.S. There's even a company that bills itself as the Sunshine State's "most experienced residential sinkhole repair company."

So what causes sinkholes to form, anyway? YouTube’s Practical Engineering, led by civil engineer Grady Hillhouse, set out to put this question to bed by creating a miniature replica of a sinkhole.

The common denominator in both instances of natural and human-created sinkholes? Water. Not unlike the natural process that causes caves to form, many of the human-made sinkholes in recent memory have been the result of pipes leaking and causing internal erosion of the soil. This process leaves all but the roadway acting as a "final bridge" above the deep, dark void. You can probably guess what happens next. Watch the full video below:

Looking to Downsize? You Can Buy a 5-Room DIY Cabin on Amazon for Less Than $33,000

Five rooms of one's own.
Five rooms of one's own.
Allwood/Amazon

If you’ve already mastered DIY houses for birds and dogs, maybe it’s time you built one for yourself.

As Simplemost reports, there are a number of house kits that you can order on Amazon, and the Allwood Avalon Cabin Kit is one of the quaintest—and, at $32,990, most affordable—options. The 540-square-foot structure has enough space for a kitchen, a bathroom, a bedroom, and a sitting room—and there’s an additional 218-square-foot loft with the potential to be the coziest reading nook of all time.

You can opt for three larger rooms if you're willing to skip the kitchen and bathroom.Allwood/Amazon

The construction process might not be a great idea for someone who’s never picked up a hammer, but you don’t need an architectural degree to tackle it. Step-by-step instructions and all materials are included, so it’s a little like a high-level IKEA project. According to the Amazon listing, it takes two adults about a week to complete. Since the Nordic wood walls are reinforced with steel rods, the house can withstand winds up to 120 mph, and you can pay an extra $1000 to upgrade from double-glass windows and doors to triple-glass for added fortification.

Sadly, the cool ceiling lamp is not included.Allwood/Amazon

Though everything you need for the shell of the house comes in the kit, you will need to purchase whatever goes inside it: toilet, shower, sink, stove, insulation, and all other furnishings. You can also customize the blueprint to fit your own plans for the space; maybe, for example, you’re going to use the house as a small event venue, and you’d rather have two or three large, airy rooms and no kitchen or bedroom.

Intrigued? Find out more here.

[h/t Simplemost]

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

The Psychological Tricks Disney Parks Use to Make Long Wait Times More Bearable

© Jorge Royan, Wikimedia Commons // CC BY-SA 3.0
© Jorge Royan, Wikimedia Commons // CC BY-SA 3.0

No one goes to Disneyland or Disney World to spend the day waiting in line, but when a queue is well-designed, waiting can be part of the experience. Disney knows this better than anyone, and the parks' Imagineers have developed several tricks over the years to make long wait times as painless as possible.

According to Popular Science, hacking the layout of the line itself is a simple way to influence the rider's perspective. When a queue consists of 200 people zig-zagging around ropes in a large, open room, it's easy for waiting guests to feel overwhelmed. This design allows riders to see exactly how many people are in line in front of them—which isn't necessarily a good thing when the line is long.

Imagineers prevent this by keeping riders in the dark when they enter the queue. In Space Mountain, for example, walls are built around the twisting path, so riders have no idea how much farther they have to go until they're deeper into the building. This stops people from giving up when they first get in line.

Another example of deception ride designers use is the "Machiavellian twist." If you've ever been pleasantly surprised by a line that moved faster than you expected, that was intentional. The signs listing wait times at the beginning of ride queues purposefully inflate the numbers. That way, when a wait that was supposed to be 120 minutes goes by in 90, you feel like you have more time than you did before.

The final trick is something Disney parks are famous for: By incorporating the same level of production design found on the ride into the queue, Imagineers make waiting in line an engaging experience that has entertainment value of its own. The Tower of Terror queue in Disney World, which is modeled after a decrepit 1930s hotel lobby down to the cobwebs and the abandoned coffee cups, feels like it could be a movie set. Some ride lines even use special effects. While waiting to ride Star Wars: Ride of the Resistance in Galaxy's Edge, guests get to watch holograms and animatronics that set up the story of the ride. This strategy exploits the so-called dual-task paradigm, which makes the line feel as if it's going by faster by giving riders mental stimulation as they wait.

Tricky ride design is just one of Disney's secrets. Here are more behind-the-scenes facts about the beloved theme parks.

[h/t Popular Science]