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Most fruits tend to have sweet smells that delight our olfactory systems and make our mouths water. One, however, has a reputation for being so noxious that many people can’t make it past the rind to its sweet center — or even stand to be in the same room with it. The durian fruit, sometimes called the “king of fruit” in Southeast Asia (where it’s native), is so unpleasantly fragrant that it is banned from public transportation in Singapore. The spiky fruit is also often prohibited in hotels and outdoor public spaces in the region. 

Pineapples are actually berries.

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Each pineapple is made up of many berries, which develop around a single core and eventually merge. Every scale on a pineapple was once a flower.

Describing the odor associated with durians is no easy feat. Some chefs and adventurous eaters have likened it to rotten eggs, pungent cheese, or sweaty gym socks, though lovers of the fruit say the smell is worth enduring for its creamy flesh, which tastes of caramel and almonds.

Yet the unpleasant aroma can be so overwhelming that it causes confusion and complaints. On at least two occasions in Australia, the fruit’s lingering scent was powerful enough to be mistaken for a natural gas leak. And in 2018, passengers on an Indonesian flight refused to board a plane loaded with more than 2 tons of durian in the cargo hold because of the intense smell. Scientists believe durian fruit’s nauseating aroma comes from a higher-than-usual number of genes for volatile sulfur compounds, which become “turbocharged” as the fruit ripens. However, the scent has a beneficial purpose for the plants themselves: It’s likely durian fruit trees evolved to use the sour stench as a way to attract animals that dine on the fruit and spread the seeds throughout wild areas.

Numbers Don't Lie

Numbers Don't Lie

Sale price of the world’s most expensive durian, sold in Thailand in 2019
$47,784
Pounds of bananas eaten by the average American each year
27
Population of Singapore, as of 2025
6.11 million
Approximate weight (in pounds) of the world’s largest fruit salad, constructed in Germany in 2024
25,992

The world’s largest tree fruit, ______, can weigh up to 100 pounds.

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The world’s largest tree fruit, jackfruit, can weigh up to 100 pounds.

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The Supreme Court once ruled that tomatoes are vegetables.

It’s a popular fun fact that tomatoes are botanically fruits, but in the U.S. they’ve been considered vegetables — legally — since the late 19th century. The Tariff Act of 1883 required produce importers to pay taxes on foreign-grown produce shipped into the country, specifically vegetables (fruits were exempt). Importers — such as New York’s Nix family — believed they could evade the 10% tax by dealing in tomatoes, since the vine-growing crop is a fruit. A fight with the New York Port Authority led the Nixes to argue their point in court, and after six years, the case made its way to the Supreme Court. Despite the Nixes’ argument being biologically correct, the Port Authority won the case on two points: Tomatoes are related to several nightshade vegetables such as potatoes and peppers, and unlike other fruits are typically served with dinner instead of dessert. Ultimately, the ruling closed the tomato tax controversy for good.

Nicole Garner Meeker
Writer

Nicole Garner Meeker is a writer and editor based in St. Louis. Her history, nature, and food stories have also appeared at Mental Floss and Better Report.

Original photo by Peter Hermes Furian/ Shutterstock

Seeing into the future is supposed to be impossible. But if you travel to the Diomede Islands of the Bering Strait, the impossible becomes reality. The Diomedes consist of two remote islands, Big Diomede (part of Russia) and Little Diomede (part of Alaska). They’re only 2.4 miles apart, but the international date line runs in between them. That means that when you’re in the Alaskan fishing village of Little Diomede and looking at your Russian neighbor, you’re actually gazing into tomorrow. It’s no wonder these landmasses have been nicknamed the Yesterday and Tomorrow islands

For a few hours every day, three different days occur on Earth at the same time.

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Thanks to the quirks of the international date line and time zones, there are two hours a day when three days are happening at once. Because the date line curves to encompass Kiribati, part of the island nation has begun Wednesday while other spots in the world haven’t ended Monday.

Today, Big Diomede has no permanent population (except a few observation posts), whereas Little Diomede has a population of around 100 people, mostly Native Alaskans. Native people long passed freely between these two islands, even after the U.S. bought Alaska from Russia in 1867, but things changed with the Cold War. That’s when the “Ice Curtain” (a reference, of course, to the “Iron Curtain” of the Soviet era) came down between the two islands. Since then, travel between Big and Little Diomede has been strictly forbidden, even though ice in the winter forms a land bridge between them, making it theoretically possible to walk into the next day.

Numbers Don't Lie

Numbers Don't Lie

Years ago the Bering Land Bridge became submerged
12,000
Distance (in miles) of the U.S.-Canadian border, the longest border in the world
5,525
Amount (in USD) Russia sold Alaska for in 1867 (about $148 million today)
$7.2 million
Federally recognized tribes living in Alaska
229

When Secretary of State William Seward bought Alaska from Russia, the press called it “______.”

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When Secretary of State William Seward bought Alaska from Russia, the press called it “Seward’s Folly.”

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The U.S. has one ongoing territorial land dispute with Canada.

No matter how much you like your neighbor, you might have a few disagreements if your backyards share the largest land border in the world. Since April 11, 1908, the border between the U.S. and Canada has been a mostly settled issue, but one spot is still up for debate (on land, that is; other maritime disputes exist). Machias Seal Island, along northern Maine’s coast (or possibly New Brunswick’s coast), got stuck in a geographic “gray zone” when two separate documents essentially granted each country claim to the island. Although the place has an old Canadian lighthouse (Canada even makes sure to staff the lighthouse 24/7 for “sovereignty purposes”), the U.S. doesn’t recognize the land as Canadian. Luckily, this hasn’t escalated into too big of a deal, as it mostly inconveniences only lobster fishermen and tourists watching puffins.

Darren Orf
Writer

Darren Orf lives in Portland, has a cat, and writes about all things science and climate. You can find his previous work at Popular Mechanics, Inverse, Gizmodo, and Paste, among others.

Original photo by Thorsten Schmitt/ Shutterstock

Humans have a few biological advantages compared to other species. The most obvious is our big brains, which have empowered us to become the dominant species on Earth. But another feature that is often overlooked is our chins — a trait unique to humans. Yes, we’re the only animals on Earth with true chins. You might be thinking, “Wait a minute, I give my cat chin scratches all the time,” or “Surely chimpanzees, our closest animal cousin, sport some kind of chimp chin,” but the answer is nope and nope (respectively). When you’re scratching the “chin” of your feline companion, what you’re really doing is scratching the mandible, i.e., the lower part of the jaw — not the chin, which is the bony part that juts out at the bottom of your face. Elephants and manatees also have chin-like protrusions in their lower jaws, but they don’t quite qualify as true chins.

William Shakespeare originated the phrase “take it on the chin.”

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William Shakespeare is the progenitor of some 1,700 words, but the phrase “take it on the chin” originates from the world of boxing, a sport where the phrase essentially describes the entire profession.

The mystery of why no other animal has a real chin gets even more interesting because past human species, such as Homo erectus and Homo neanderthalensis, didn’t have chins either — instead, their faces simply ended in a flat plane. So why did evolution find the need for human chins? Scientists aren’t exactly sure. The most prominent theory is that chins help humans chew, but scientists from Duke University and the University of Florida found that chins aren’t actually much help there; they technically make chewing more difficult, as they reinforce the wrong part of the face for aiding mastication. Chins also don’t help much with human speech, which is another theory that’s been suggested, and researchers say it’s unlikely they’re a mere product of sexual selection or a protection against violence, such as punching. Some scientists think the chin might be a spandrel, a byproduct of other evolutionary changes that on its own serves no real purpose — basically, a happy accident. We may never truly know exactly why humans have these extra bony bits on the ends of our faces, but keep your chin up. After all, you’re the only species that can.

Numbers Don't Lie

Numbers Don't Lie

Average strength (in pounds per square inch) of the human bite
162
Duration (in seconds) of the world’s longest chin stand (1:44:25)
6,265
Years ago the human chin began to form in our ancestors
80,000
Chromosome number containing genetic marker rs11684042, which may indicate the presence of a cleft chin
2

The scientific name for the chin is the ______.

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The scientific name for the chin is the mentum osseum.

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Scientists aren’t exactly sure about the biological reason for beards.

If you’re a practicing pogonophile (aka a lover of beards), you may not be too concerned about the reasons behind the time-honored art of beard-growing. However, scientists like to get at the why of things. While hair on our head protects us from the sun, body hair aids in thermoregulation, and hair below the belt protects against bacteria, beards have no known specific biological function. Some scientists have argued that facial hair could aid in protecting the body against ingesting harmful bacteria, but then it’d be likely that women would have evolved to have beards as well. Instead, some evolutionary biologists theorize that beards act as a tool for intersexual attraction regarding women and intrasexual competition with men. In other words, beards subconsciously message virility to women and formidability to men. But as is typical of fashion, beard popularity trends come and go, and studies show that attraction is often influenced by “negative frequency depen­dence,” meaning if everyone has a beard, preference for clean-shaven faces increases (and vice versa). So, just as the beautiful plumage of a male bird is merely a color display to impress a feathered female while intimidating the competition, beards (or a lack thereof) may be a man’s own form of peacock posturing.

Darren Orf
Writer

Darren Orf lives in Portland, has a cat, and writes about all things science and climate. You can find his previous work at Popular Mechanics, Inverse, Gizmodo, and Paste, among others.

Original photo by Ro_ksy/ Shutterstock

Human ears have two main jobs: alerting us to noises in the world around us, and keeping our bodies balanced as we move throughout the day. However, researchers have found another small trick our ears can perform: determining the temperature of water. While they may look identical, hot and cold water make different sounds when poured. With a little help from our brains — which learn to recognize the contrasting tones over a lifetime of repeated exposure — most people can tell the difference between cold water poured from a pitcher or hot water transferred from a kettle, without even seeing the cup being filled.

Salt makes water boil faster.

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There is truth to this kitchen lore — adding salt makes it harder for water molecules to become steam, creates a higher boiling point, and makes water hotter, faster. But in small amounts, like a teaspoon, salt’s effects are limited, meaning this trick saves just a few seconds of time.

Without the cues of visible boiling or a collection of ice crystals, liquid water tends to look the same regardless of its temperature. What humans can’t see is that temperature actually affects water’s viscosity (aka thickness), which produces different sounds that we can hear. At lower temperatures, water molecules are sluggish and create temporary bonds that thicken the liquid, producing a lower-frequency sound when poured. Conversely, heated water molecules are more energetic, making it harder for molecules to join together. Fewer bonds result in thinner water, which produces a noticeably higher-pitched sound when transferred into a cup. Researchers say bubbling also plays a role in water acoustics — hot liquids have more bubbles than cool liquids, which contribute to the higher tones we hear while pouring out a cup of coffee or tea.

Numbers Don't Lie

Numbers Don't Lie

Boiling point (in degrees Fahrenheit) of water at sea level
212
Temperature (in degrees Fahrenheit) of the ocean’s surface near the North and South Poles
28
Year scientists began recognizing heat as a form of energy
1798
Size (in gallons) of the world’s largest cup of hot tea, brewed in Mexico in 2023
2,410

The study of heat, temperature, and energy is called ______.

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The study of heat, temperature, and energy is called thermodynamics.

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Humans can’t actually feel wetness.

Feeling wet — from stepping out of the shower, diving into a pool, or getting caught in the rain — seems like a straightforward sensation, though amazingly, humans can’t actually feel wetness itself. While our skin contains thousands of nerve endings that recognize temperature, texture, and pain, there are none for wetness. Instead, scientists believe humans are born without an understanding of wetness, though one slowly develops through a mix of temperature and texture sensations; over time, experience helps our brains build an understanding of wet and dry. However, even with decades of data, our brains aren’t foolproof and can cause occasional confusion. That’s why it can be difficult to determine whether something is cold or wet, like a metal park bench on a chilly day.

Nicole Garner Meeker
Writer

Nicole Garner Meeker is a writer and editor based in St. Louis. Her history, nature, and food stories have also appeared at Mental Floss and Better Report.

Original photo by martinedoucet/ iStock

There’s nothing silly about a broken bone, but if laughter is the best medicine, then the creators of Silly String may well have helped more people than they ever envisioned. In the 1960s, inventor Leonard A. Fish and chemist Robert P. Cox set about producing a mixture that would rapidly harden after delivery via a spray can, providing a near-instant cast for anyone unfortunate enough to sustain a broken limb. They came up with a sticky concoction that set quickly and held, then tested some 500 nozzles in search of the best application from a pressurized can. When one nozzle propelled a stream 30 feet across the room, Fish and Cox had another idea: Maybe this stringy goo would work better as a plaything?

A New Jersey town has banned the public use of Silly String.

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While some communities, like Beverly Hills, have enacted temporary bans for Halloween, the New Jersey town of Ridgewood strictly prohibits “the discharge of a product called ‘Silly String’ in or along the public streets, sidewalks, parks, or public places … at any time.”

After tweaking their recipe, the duo arranged a meeting with an executive at Wham-O, the company behind such popular toys as the Frisbee and Hula Hoop. At first, a business relationship seemed unlikely; overeager to demonstrate, Fish and Cox all but decorated the office with loads of colorful string, and were unceremoniously shown the door. Fortunately, the company’s owners later spotted some leftover gunk and were intrigued enough to seek a larger sample. The next day, Fish and Cox received a telegram from Wham-O requesting 24 cans of the stuff for a market test. By 1972, when a patent was granted for this “foamable resinous composition,” Silly String had clearly moved on from its roots as a tool for healing and was well on the way to its destiny as a mess-making accoutrement for partygoers of all ages.

Numbers Don't Lie

Numbers Don't Lie

Miles of string advertised on early Silly String labels
.25
Canisters of Silly String handed out at a baseball game in 2017
4,025
Maximum temperature (in degrees Fahrenheit) suggested for safe Silly String storage
120
Year the Car-­Freshner Corporation acquired the rights to Silly String
1997

75% of the liquid inside a can of Silly String comes from its ______.

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75% of the liquid inside a can of Silly String comes from its propellant.

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Silly String is used by the military to detect booby traps.

Although Fish and Cox chose the path of entertainment for their creation, they may have been heartened by news of a real-world application that fulfilled their original goal of helping people. As far back as 1997, the U.S. military used Silly String to weed out the presence of dangerous improvised explosive devices (IEDs) in hostile areas. A spritz of the stringy stuff is light enough to drape across nearly invisible trip wires without setting them off, calling attention to these deadly traps often nestled in doorways and gates. While the military has been quiet about publicizing this use, the revelation of its effectiveness prompted one mother, whose son was stationed in Iraq in the early 2000s, to collect 80,000 cans of Silly String and nearly identical products to send overseas to aid the war effort and save a few more lives.

Tim Ott
Writer

Tim Ott has written for sites including Biography.com, History.com, and MLB.com, and is known to delude himself into thinking he can craft a marketable screenplay.

Interesting Facts

You may love Disney, but you probably don’t love it as much as Jeff Reitz. The California resident brought new meaning to the term “Disney adult” by visiting the Happiest Place on Earth 2,995 days in a row — a streak that ended only when Disneyland shut down during the pandemic. It began as “a joke and a fun thing to do” between him and a friend when the two were in between jobs on New Year’s Eve 2011, and it continued for eight years, three months, and 13 days. The original plan was to spend every day of 2012 at the park, in part because it was a leap year and Reitz liked the idea of going 366 days in a single year, but he didn’t feel inclined to stop once 2013 rolled around. He became the unofficial record-holder at the 1,000-day mark and was oh so close to reaching 3,000 days before COVID-19 prevented that particular milestone when Disneyland shut down on March 14, 2020.

Mickey Mouse was Walt Disney’s first character.

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Mickey was actually preceded by one Oswald the Lucky Rabbit, the star of 26 short cartoons beginning in 1927. After losing the rights to Oswald, Disney came up with Mickey — and the two creatures bear a striking resemblance to one another.

Reitz, who worked in nearby Long Beach, would usually arrive at Disneyland between 4:30 and 5 p.m. and log some 10,000 steps during his three-to-five-hour visits. Though he initially struggled with the park’s closure, he eventually made peace with it: “A lot has changed over the eight years that I started it,” he said after his streak ended. “I’m good with it. I went more than eight years. I got to see a lot of changes at the park. Now, I’m not worried about going every day like I was.” After more than a year of being closed, Disneyland reopened in April 2021. It’s not clear if Reitz has been back, but he has enough memories to last him a while.

Numbers Don't Lie

Numbers Don't Lie

Days Disneyland was closed due to the pandemic
412
Disney parks in Asia, the most of any continent
3
Year Disneyland Resort welcomed its 1 billionth guest
2026
Distance (in miles) covered by the Disneyland Monorail
2.5

Disneyland employees aren’t allowed to use the phrase “______.”

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Disneyland employees aren’t allowed to use the phrase “I don’t know.”

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Walt Disney received a custom-made Oscar statuette for “Snow White and the Seven Dwarfs.”

Walt Disney won 32 Academy Awards, a record for the most individual Oscars, and one that’s unlikely to be broken anytime soon (if ever). Because there was no award for Best Animated Feature until 2001, when Shrek won the inaugural prize, he received an Honorary Oscar for Snow White and the Seven Dwarfs in 1939 that included a unique custom design — one regular Oscar statuette and seven miniature ones placed along a stepped base. The Oscar was awarded for Snow White’s “significant screen innovation which has charmed millions and pioneered a great new entertainment field for the motion picture cartoon.” It was presented to him by Shirley Temple, who was a bit confused as to why the star of the film wasn’t being honored as well: “I thought that the big statue was for Walt and that the Seven Dwarfs were the little ones going down the side and that Snow White herself hadn’t gotten anything,” she later said.

Michael Nordine
Staff Writer

Michael Nordine is a writer and editor living in Denver. A native Angeleno, he has two cats and wishes he had more.

Original photo by chrisdorney/ Shutterstock

The U.S. has more than 300 types of honey, but there’s one you won’t find on store shelves: mad honey. Upon visual inspection, mad honey offers up a clue that it’s a bit different. Created when bees feast almost exclusively on nectar and pollen from flowering rhododendron bushes, the natural sweetener often has a reddish hue. It also has a slightly bitter taste, though another unusual characteristic that appears shortly after consumption is what gives mad honey its name: It causes hallucinations

Honeybees are not native to the U.S.

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The U.S. is home to around 4,000 types of bees, though the species we rely on for pollination and honey production isn’t native to the continent. English colonists likely brought the first honeybees to Virginia in 1622.

Mad honey is a rarity, found mostly among high-altitude honeycombs in the mountains of Turkey and Nepal. Harvesting it can be dangerous — Himalayan giant honeybees tend to create hives among cliffs and rugged outcrops — and consumption can be, too. Pollen and nectar from several species of rhododendrons in these areas contain grayanotoxins, a poison that helps the plants ward off hungry herbivores. While small doses of grayanotoxins can cause euphoria and lightheadedness in humans, larger doses can cause hallucinations, vomiting, temporary paralysis, and even death.  

Those sometimes-disastrous reactions haven’t stopped humans from seeking out the sticky substance, though. Some practitioners of folk medicine have long believed that small doses of the toxin-laced honey can be beneficial for human healing. Microdoses of mad honey have been used to treat high blood pressure, diabetes, and arthritis — don’t try this at home — but researchers are unsure how beneficial the stuff is for anyone other than its original creators (bees).

Numbers Don't Lie

Numbers Don't Lie

Year singer Van Morrison released his fifth album, “Tupelo Honey”
1971
Pounds of pollen collected by the average bee colony each year
125
Size (in inches) of Himalayan giant honeybee workers, the world’s largest honeybee species
1.2
Approximate height (in meters) of England’s largest rhododendron bush, “Big Rhodey”
30

______ is the top honey-producing U.S. state.

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North Dakota is the top honey-producing U.S. state.

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Mad honey has been used to slow advancing armies.

While today the word “honeytrap” brings to mind Cold War espionage and spy films, at one time in history, honey actually was used to bait and subdue enemy armies. The first known incident is preserved in writings by Xenophon of Athens, a military commander, historian, and student of the philosopher Socrates. According to Xenophon’s account, a Greek army he commanded in 401 BCE unknowingly consumed mad honey in northeast Turkey, becoming disoriented for days before the effects wore off. In 65 BCE, Mithridates VI of Pontus had combs containing mad honey purposely planted in the path of Roman soldiers to disable their defenses in battle. Even American soldiers have accidentally dined on tainted honey; according to Civil War lore, Union troops marching through the Appalachian mountains reportedly consumed mad honey, possibly made from local rhodies or mountain laurel plants, but with effects that were just as dizzying and disorienting.

Nicole Garner Meeker
Writer

Nicole Garner Meeker is a writer and editor based in St. Louis. Her history, nature, and food stories have also appeared at Mental Floss and Better Report.

Original photo by Hector John Periquin/ Unsplash

Earning the right to call yourself a pirate once meant living a rough-and-tumble life on the seas, robbing ships, and dodging naval law. However, modern swashbucklers enrolled at the Massachusetts Institute of Technology have a much easier go of it. Students who attend the esteemed university can earn a certificate in piracy by completing four classes — sailing, fencing, pistol shooting, and archery — and then taking the school’s secret pirate oath. 

Most pirates buried their treasure.

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Most pirate plunder included goods like furs, fabrics, spices, and medicine — more valuable for trading or selling than hiding. Burying loot was a dangerous gamble many pirates avoided, for fear of losing their treasures to shifting sands, changing times, and double-crossing crews.

MIT began offering the optional certificate in 2011 as a way for students to enjoy fulfilling the school’s physical education requirements, though the idea also stems from a decades-long joke. Campus lore claims that students who completed the four courses began calling themselves pirates in jest sometime between the late 1990s and early 2000s, though it took years for the school to make the campus caper into an official award. (At one point during the program’s creation, receiving a commemorative eye patch was up for consideration in place of a formal certificate.) Today, MIT’s Department of Athletics, Physical Education, and Recreation issues the awards, and the school — which traditionally abstains from giving out honorary degrees — has even bestowed a pirate certificate upon actor Matt Damon for his “swashbuckling appreciation for science, engineering, and space exploration.” However, the university maintains that the program is all in good fun — the pirate certificate doesn’t actually give students license to engage in any pirate-y business.

Numbers Don't Lie

Numbers Don't Lie

Ships commanded by female pirate Ching Shih, the most in pirate history
1,800
Year Disneyland opened its Pirates of the Caribbean ride
1967
First-time applicants to MIT for the class of 2029; only 4.6% are admitted
29,281
Books housed in MIT’s campus libraries as of 2021
3 million+

The world’s only authenticated pirate shipwreck, the Whydah Gally, was found off the coast of ______.

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The world’s only authenticated pirate shipwreck, the Whydah Gally, was found off the coast of Cape Cod.

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Blackbeard’s time as a pirate lasted just two years.

One of history’s most notorious pirates has a legacy that’s lasted hundreds of years longer than his actual pirating career. Edward Teach, aka Blackbeard, began his time at sea in the early 1700s, originally sailing as a British privateer during the War of the Spanish Succession. The job, which included stealing from Spanish ships on behalf of the British government, introduced the future pirate to the unscrupulous profession. By 1716, Teach had become captain of his own ship, and rumors quickly spread about his ruthless thefts on both land and sea. However, Blackbeard’s seafaring ended in November 1718 when forces directed by Virginia Governor Alexander Spotswood ambushed him on North Carolina’s Ocracoke Island, ultimately cutting short his life and ending his career after two years.

Nicole Garner Meeker
Writer

Nicole Garner Meeker is a writer and editor based in St. Louis. Her history, nature, and food stories have also appeared at Mental Floss and Better Report.

Original photo by Getty Images via Unsplash+

While cats give off a solitary vibe, often appearing much more aloof than their canine counterparts, felines are actually very social creatures. They form bonds with littermates, establish colonies, and may develop just as strong a connection with their pet parents as dogs do. Maybe the lesser-known social nature of cats can begin to explain another fascinating finding: Cats are capable of up to 276 unique facial expressions. In 2021, researchers at UCLA recorded 194 minutes of cat-to-cat facial expressions at a nearby CatCafé Lounge. Then they coded all those facial muscle movements, excluding things like chewing and yawning, and discerned 276 unique expressions.

Purring means a cat is content.

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While cat purring can mean your favorite feline is feeling content, there are other reasons for cats to rev their little engines, including when they’re hungry, injured, or frightened. A purr’s frequency has also been known to spur bone regeneration.

Each of these feline expressions included four of 26 unique facial movements — things like parted lips, jaw moves, and even pupil dilation. Humans, by comparison, have about 44 facial movements, which some estimates say translates into about 10,000 facial expressions. Although limited compared to humans, cats still have far more expressions than experts realized. As one veterinary behaviorist put it, “there is clearly a lot going on that we are not aware of.” Even after 10,000 years of domestication (and an even greater number of cat videos), the little lions in our living room still have the capacity to surprise. 

Numbers Don't Lie

Numbers Don't Lie

Performances of the musical “Cats” during its 21-year-long run in London’s West End
8,949
Percentage of DNA shared between tigers and the common house cat
95.6%
Number of muscles humans use to create some 10,000 facial expressions
43
Estimated max number of cats in the U.S.
62 million

The smiling and frowning masks typically associated with the theater are based on ______.

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The smiling and frowning masks typically associated with the theater are based on Greek muses.

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Cats were actually domesticated twice.

Today’s house cat (Felis catus) is a direct descendant of Felis silvestris lybica, otherwise known as the African wildcat. Still spread across Africa but also west and central Asia, the African wildcat is slightly larger than its tamed descendants, and the process of domestication likely began around 10,800 years ago in the Middle East/North Africa region. However, evidence suggests that a second cat species, the leopard cat (Prionailurus bengalensis), was separately domesticated in neolithic China around 5,000 years ago. (Today, the modern Bengal cat is a mix between this wildcat and Felis catus.) In both instances, cats were domesticated far later than dogs, which some estimates say occurred as far back as 32,100 years ago. This explains why house cats retain more genetic, behavioral, and even physical traits of their wild ancestors compared to most dog breeds.

Darren Orf
Writer

Darren Orf lives in Portland, has a cat, and writes about all things science and climate. You can find his previous work at Popular Mechanics, Inverse, Gizmodo, and Paste, among others.

Original photo by auns85/ Shutterstock

Humans are masters of navigation. Over the course of history, we’ve developed tools to help us explore not only Earth but also other planets. Yet strip away all those tools, blindfold us, and tell us to walk in a straight line, and inevitably we become a directional mess, turning in tight loops. Many studies in the past century — though mostly informal — have cataloged this phenomenon again and again. Without some form of reference, such as a mountain, a building, or even the sun, humans are incapable of walking in a straight line, no matter how hard we try. It happens whether we’re blindfolded or just lost in the forest. So what’s going on?

The compass wasn’t originally used for navigation.

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The Chinese created the first compass — made with a lodestone — in the third century BCE. Early compasses were used for divination and other spiritual purposes rather than navigation, but eventually their useful wayfinding attributes won out.

We don’t know for sure, but scientists have been able to rule out some popular go-to explanations. Researchers from the Max Planck Institute for Biological Cybernetics in Germany discovered that body asymmetries (different-sized legs, right-handedness vs. left-handedness, etc.) didn’t account for such vast misdirection. Additionally, the idea that people can’t correctly calculate the movement of their legs doesn’t explain the tight-looped pattern. The Max Planck scientists theorize that with every blindfolded step, a very small directional discrepancy from a straight line is introduced, which then compounds with every additional step. Without the aid of visual references to unconsciously correct for these discrepancies, blindfolded people are poor at navigating a straight line, and will inevitably begin walking in tight-looped circles. While this theory explains why humans do this, scientists aren’t sure of the biological how (though they think errors in the inner ear may be to blame). For now, this straight-line conundrum remains one of the many mysteries of the human brain and body.

Numbers Don't Lie

Numbers Don't Lie

Length (in miles) of the longest straight line possible at sea, connecting Pakistan and Russia
19,940
Number of satellites that make up the modern GPS constellation
31
Year the National Highway Traffic Safety Administration developed the walk-and-turn sobriety test
1981
Highway number of the world’s longest straight road (149 miles), in Saudi Arabia, per Guinness World Records
10

For centuries, sailors used an instrument called a mariner’s ______ to navigate the seas.

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For centuries, sailors used an instrument called a mariner’s astrolabe to navigate the seas.

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The Earth’s North Star won’t always be Polaris.

When it comes to navigation, the North Star — known to astronomers as Polaris — is an important one. Because the star sits roughly above the Earth’s North Pole, being able to pick out Polaris from the tapestry of the night sky can be useful in finding your way. For centuries, seafarers measured the angle of the North Star from the horizon to determine latitude and position in the Northern Hemisphere. But although Polaris has been humanity’s navigational friend for many centuries, the North Star won’t always be Polaris — in fact, it has held the position only since 500 CE. That’s because the Earth’s rotation wobbles in a roughly 26,000-year-long cycle known as axial precession. In about a thousand years, the Earth’s North Pole will instead point to Errai (Gamma Cephei), followed by a variety of other stars, until Polaris once again becomes the North Star some 24,000 years from now.

Darren Orf
Writer

Darren Orf lives in Portland, has a cat, and writes about all things science and climate. You can find his previous work at Popular Mechanics, Inverse, Gizmodo, and Paste, among others.