What Causes Turbulence?

iStock
iStock

No matter how many times you've flown, feeling a plane rattle at 35,000 feet in the air can be an unnerving experience. But turbulence, whether it's a small bump or a stomach-flipping drop, is nothing to get shaken up about. It's a normal part of flying through the ever-shifting atmosphere.

Just like a truck traversing uneven roads or a ship navigating choppy seas, planes often encounter tumultuous, or turbulent, air currents in the skies. These currents can come from several different sources. When flying over high mountains, planes sometimes experience what’s called terrain-induced turbulence. The wind flowing over the peaks and through the valleys disrupts the air thousands of feet above it, resulting in a bumpy ride for any passing aircraft.

Even when flying over flat land, pilots can run into rough patches. Air that's been heated up by the sun at ground level expands and rises to create an updraft. As this updraft travels higher it may cool and condense into a cloud. Cloud-based or convective turbulence is the easiest kind for pilots (and passengers) to spot and prepare for, but not every updraft turns into a menacing cloud. There's also something called clear air turbulence which occurs when the rising hot air is too dry to form into a cloud. Unlike convective turbulence, these problem areas are impossible to identify with the naked eye alone.

So what happens when a plane meets up with one of these drafts in midair? The effects are usually mild: perhaps enough jostling to wake you from your in-flight nap, but not quite enough to topple your drink from its tray. Of course turbulence can become more severe, but in such cases passengers tend to think they're in more danger than they actually are.

"Even in rough turbulence, the plane is never changing altitude more than 10 or 20 feet either way," co-pilot and Cockpit Confidential author Patrick Smith told Mental Floss. "There’s this idea it's plummeting hundreds of feet. Not true."

Planes are built to be tossed and throttled by volatile weather: If you ever see a wing bending like a diving board in high winds, remember it’s supposed to do that. The biggest threat during a bout of turbulence is being knocked around the cabin, which is why most turbulence injuries are sustained by flight attendants. So the next time your pilot announces rough skies ahead, find your seat, fasten your seatbelt, and make note of where the barf bags are.

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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

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

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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How Do Astronauts Vote From Space?

Astronaut Kate Rubins casts her ballot from space.
Astronaut Kate Rubins casts her ballot from space.
NASA

Earlier this week, NASA announced that astronaut Kate Rubins had officially cast her vote from a makeshift voting booth aboard the International Space Station. As much as we’d like to believe her ballot came back to Earth in a tiny rocket, the actual transmission was much more mundane. Basically, it got sent to her county clerk as a PDF.

As NASA explains, voting from space begins the same way as voting abroad. Astronauts, like military members and other American citizens living overseas, must first submit a Federal Postcard Application (FPCA) to request an absentee ballot. Once approved, they can blast off knowing that their ballot will soon follow.

After the astronaut’s county clerk completes a practice round with folks at the Johnson Space Center in Houston, they can start the real voting process. The astronaut will then receive two electronic documents: a password-protected ballot sent by the Space Center’s mission control center, and an email with the password sent by the county clerk. The astronaut then “downlinks” (sends via satellite signal) their filled-out ballot back to the Space Center attendants, who forward it to the county clerk. Since the clerk needs a password to open the ballot, they’re the only other person who sees the astronaut’s responses. Then, as NPR reports, they copy the votes onto a regular paper ballot and submit it with the rest of them.

Though Americans have been visiting space for more than half a century, the early jaunts weren’t long enough to necessitate setting up a voting system from orbit. That changed in 1996, when John Blaha missed out on voting in the general election because his spaceflight to Russia’s space station Mir began in September—before absentee voters received their ballots—and he didn’t return until January 1997. So, as The Washington Post reports, NASA officials collaborated with Texas government officials to pass a law allowing astronauts to cast their ballots from space. In the fall of 1997, David Wolf became the first astronaut to submit his vote from a space station. The law is specific to Texas because most active astronauts reside there, but NASA has said that the process can be done from other states if need be.