Long before they became fashionable accessories for sunny days, some of the earliest sunglasses served a far different purpose: In Chinese courtrooms, judges used dark-lensed glasses to hide their facial expressions. Eyeglasses became popular in Chinese society during the late 13th century and early 14th century, and around the same period, rudimentary sunglasses featuring dark lenses made from smoky quartz were invented. While they protected against glare, they were also intended to provide judges with an air of impartiality during trials by obscuring their eyes — and thus their emotional responses.
Only one person served as both U.S. president and Supreme Court judge.
William Howard Taft is the only individual to serve as U.S. president and a member of the U.S. Supreme Court. His presidency lasted one term (1909-1913). Eight years later, he was appointed chief justice by then-President Warren G. Harding.
It wasn’t until the 18th century that an early precursor to modern sunglasses, explicitly designed for dealing with sun and glare, became popular in Europe. “Goldoni’s eyeglasses” were developed circa 1700 in Venice, Italy, and were nicknamed for playwright Carlo Goldoni, who fashionably wore a pair. These green-tinted spectacles were primarily worn by Venetian gondoliers as well as high-society women and children in an effort to shield their eyes from the glare that bounced off the canal water. In 1752, British optician James Ayscough unveiled a new invention to serve a similar purpose: blue-tinted glasses that he believed protected eyes against harmful light better than white glass.
A pair of sunglasses belonging to Elvis Presley once sold for $159,900 at auction.
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Wooden “sunglasses” date back to the first century CE.
While traditional sunglasses featuring glass lenses and metal frames are a more modern invention, the world’s first known sunglasses were made of wood. Around 2,000 years ago, ancient Siberians and Inuits in the North American Arctic region donned these wooden goggles to protect from snow blindness — a painful condition caused by UV rays reflecting off the snow.
These simple shades featured a piece of wood carved to fit around the eyes and tied around the head using twine. Thin slits were carved directly above each eye, allowing the wearer to maintain their vision while limiting sun exposure. In addition to wood, these devices were also made from bone or walrus ivory. Archaeological digs have uncovered pristine examples of these early sunglasses from regions throughout Alaska, Canada, Greenland, and Russia.
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Bennett Kleinman is a New York City-based staff writer for Optimism Media, and previously contributed to television programs such as "Late Show With David Letterman" and "Impractical Jokers." Bennett is also a devoted New York Yankees and New Jersey Devils fan, and thinks plain seltzer is the best drink ever invented.
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Sloths are masters of living life in the slow lane. These tree-hugging mammals, split into two-toed and three-toed varieties, travel only about 125 feet a day — so slowly that moss and algae grow on their fur. This lethargic lifestyle is actually a survival strategy suitable for their slow metabolisms and low-calorie diets, which are mostly based on tree leaves. In fact, three-toed sloths have the slowest metabolism of any mammal (followed closely by pandas and two-toed sloths).
Humans can’t hold their breath longer than a few minutes.
The world record for the longest breath-hold clocks in at 24 minutes and 37 seconds (aided by pre-breathing pure oxygen). The human body accomplishes this process with the mammalian dive reflex, which activates physiological changes in an effort to preserve your life.
Their sluggish metabolism, as well as their ability to slow their heart to one-third its normal rate, give sloths an unexpected superpower — they can hold their breath for an impressively long time. With estimates suggesting that some two-toed sloths can hold their breath for upwards of 40 minutes, this makes sloths better at conserving oxygen than even some marine mammals such as dolphins, who can only hold their breath for 15 minutes, max. The sloth breathing technique, aided by the design of their lungs, helps make sloths excellent swimmers. So while their leisurely lifestyle may seem a bit lazy to the untrained eye, don’t blame the sloths — they’re just built that way.
The first known animal to breathe on land may have been an arthropod called Parioscorpio venator.
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Some sloths used to be the size of elephants.
Megatherium americanum, which in Latin means “great beast of America,” is a fearsome name for a fearsome animal — a giant ground sloth that weighed around 8,000 pounds. This gargantuan creature appears in the fossil record in the Middle Pleistocene around 400,000 years ago, and for hundreds of thousands of years, roamed the lightly wooded areas of South America. The beast fueled its massive bulk mostly by scavenging for meat left behind by top predators, but eventually died out at the beginning of the Holocene Epoch, around the same time as the arrival of Homo sapiens on the continent. Because it could stand and walk on its hind legs (though it was usually a quadruped), this ground sloth is considered the largest bipedal mammal that’s ever existed on Earth.
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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.
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Mashed, boiled, fried: Most of the interactions we have with potatoes revolve entirely around preparing them for our plates. However, there are occasions when the starchy spuds have more scientific uses — such as helping researchers test and tweak Wi-Fi signals. On these occasions, potatoes act as stand-ins for human bodies, mimicking our forms thanks to their similarly high water content. While our bodies are made up of about 60% water, potatoes are loaded with about 80%. All of that water impacts just how well we can connect to the internet — Wi-Fi signals are transmitted through radio waves, which are easily absorbed by water. Even the water inside a potato (or the human body) can reflect the signal back and weaken its strength.
The word “Wi-Fi” doesn’t actually stand for anything.
While long believed to be an abbreviation for “Wireless Fidelity,” the word “Wi-Fi” doesn’t actually have a meaning. The trademarked term, owned by the nonprofit Wi-Fi Alliance, was created by a marketing company in 1999 as an easy, nontechnical term for wireless communications.
While any container of water can actually do this trick, scientists have turned to sacks of potatoes for more accurate testing of Wi-Fi signals in tricky places such as airplanes. In 2012, Boeing heaped about 20,000 pounds of tubers into humanlike shapes in a grounded airplane to observe how well Wi-Fi flowed through a packed cabin. Gathering the data took several days, and using nonmoving potato test subjects in place of human participants made it possible for researchers to do their work. With this system, Boeing engineers were able to fine-tune Wi-Fi signals to transmit uniformly through a plane cabin and account for wiggling passengers and passing drink carts — ensuring the best possible internet connection at 35,000 feet.
Potatoes are the official state vegetable of New Hampshire, as well as spud-growing Idaho and Oregon.
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There are thousands of miles of internet cables under the ocean.
Water has a way of disrupting Wi-Fi connections, so it may come as a surprise that there are hundreds of thousands of miles of internet cables along the ocean’s floor. In fact, our ability to communicate globally is thanks to nearly 750,000 miles of fiber optic cables that crisscross underwater. While it’s commonly believed that our phones and computers connect us through satellites, about 95% of all voice and data transmissions are routed through these cables. The first such cable connected the United States, U.K., and France in 1988, but the concept dates back more than 150 years — the first transatlantic communications cable was a simple copper wire used to transmit telegraphs between the U.S. and Great Britain. First used in 1858 following two years of planning and line laying, the cable worked for just a few weeks — but would inspire a world of communication for years to come.
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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.
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Conversation hearts — also known as Necco hearts, candy hearts, or Sweethearts — are considered Valentine’s Day iconography, but their origins are far from romantic. In fact, they were originally created by a pharmacist who got his start making medical lozenges.
In 1847, pharmacist Oliver Chase was working on building his lozenge business after making his way from England to Boston. The production process was slow: Chase hand-rolled ropes of dough made from peppermint, brown sugar, and gum arabic and cut them into individual tablets; he then sold them to apothecaries where customers sought them out for sore throats, coughs, and other minor ailments. To speed things up, the enterprising Chase invented a machine that cut the lozenges mechanically. Recognizing the potential, he shifted focus from medicine to confections, founding what became the New England Confectionery Company, or Necco, and introducing its namesake candy, the Necco Wafer.
Lindt invented Valentine's chocolates as we know them.
That distinction belongs to Cadbury. In 1868, British chocolate maker Richard Cadbury designed and started selling boxes of chocolates in heart-shaped boxes (the first of their kind).
It was still a while before the colorful, chalky candy became heart-shaped and adorned with their trademark messages, though. In 1866, Oliver's brother Daniel Chase devised a way to press words onto the round candy wafers using a felt roller pad and red vegetable dye. The conversation candies — or motto lozenges, as they were known — were shaped into baseballs, horseshoes, and kites, and featured much more elaborate messages than those we see today, including “Married in white, you have chosen right,” and “How long shall I have to wait? Please be considerate.” In 1902, the candies took on their now-famous heart shape, and the phrases evolved into classics such as “Be Mine” and “Kiss Me.” Each year, about 80 different sayings circulate, including around 20 that are new for that holiday season.
In 2024, America’s most popular candy was Snickers.
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Many popular sodas started as medicine.
In the 19th century, carbonated water was considered a medicinal aid. Pharmacists began mixing it with various herbs, extracts, and syrups to create drinks marketed as remedies for a range of ailments. One of the most famous examples is Coca-Cola, invented in 1886 by Atlanta pharmacist John Pemberton. The now-ubiquitous soft drink was originally marketed as a cure for headaches, fatigue, and other common ailments. It contained small amounts of cocaine, extracted from coca leaves, which was legal at the time and common in medicine. (It was later removed from the beverage around the turn of the 20th century.)
Pepsi, Dr. Pepper, and 7Up also started out as medicinal drinks, the latter of which was formulated to treat depression. The Pure Food and Drug Act of 1906 placed more regulations on ingredients used at soda fountains, and by the 1950s, soft drinks were no longer marketed as “miracle elixirs,” but remained popular as bottled and canned treats.
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The earliest known writing system, called cuneiform, was initially used by bookkeepers to track beer and food rations in ancient Mesopotamian cities. Eventually, the tablets became home to more interesting reading material — like professions of love and passion. Historians now believe the world’s oldest romantic poem was written in cuneiform 4,000 years ago, sometime around 2000 BCE. Called “The Love Song for Shu-Sin,” the poem expresses affection between Inanna, the Sumerian goddess of love, and Shu-Sin, the king of Ur (a Mesopotamian city that once stood in present-day southern Iraq).
Historians believe poems and music have long been interwoven art forms, with the earliest poems shared through song. Many of the oldest surviving poems from ancient Greece and China were performed orally, and today, ballads remain a commonly used form for both poetry and music.
Despite being uncovered at an archaeological dig site in the late 19th century, the clay tablet featuring “The Love Song for Shu-Sin” sat untranslated for decades following its discovery. Tucked into storage at the Istanbul Museum in Turkey, the ancient notepad went unnoticed until 1951, when scholar Samuel Noah Kramer deciphered its inscription and interpreted its meaning. He surmised that the poem wasn’t just a statement of love, but part of a larger religious ceremony. Each year, the Sumerian king was responsible for symbolically marrying the goddess Inanna to ensure prosperity and bountiful harvests in the year ahead. While Shu-Sin — who ruled from 1973 to 1964 BCE — was featured in a series of other poems, researchers aren’t sure about details of the ritual. But even without us knowing more, the poem remains historically significant, shaping our understanding of early writing and world history — and perhaps even inspiring a little romance.
“Sonnet 18,” the romantic poem that compares its subject to a “summer’s day,” was penned by Shakespeare.
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The world’s longest poem took more than 500 years to write.
One of history’s oldest poems holds the record for being the world’s longest. The “Mahabharata” is a roughly 2,500-year-old poem written in Sanskrit, an ancient language once used in parts of India and Southeast Asia. With a title that translates to “Great Epic of the Bharata Dynasty,” the poem recounts the tale of two cousins who become bitter enemies in the struggle for political control over India’s Bharata kingdom. Drafted by multiple writers over half a millennium, the “Mahabharata” includes 200,000 verses and a staggering 1.8 million words, making it seven times longer than Homer’s “The Iliad” and “The Odyssey.” Scholars consider the “Mahabharata” an important source for understanding how Hinduism developed between 400 BCE and 200 CE, though it’s not just enjoyed by academics — many of the poem’s stories have been reworked for stage and screen for modern audiences.
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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.
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Julia Roberts, the actress best known for her roles in Pretty Woman, Erin Brockovich, and Steel Magnolias, was born in Smyrna, Georgia, in 1967. But when it came time for her parents, Betty and Walter Roberts, to take home their new bundle of joy, there was one hiccup: They couldn’t afford the hospital bill. That’s when Martin Luther King Jr. and Coretta Scott King — friends of the Roberts’ — stepped in to help, covering the cost of the future actress’s birth.
Martin Luther King Jr. was once the youngest Nobel Peace Prize winner.
Dr. King was awarded the Nobel Peace Prize in 1964 for his civil rights activism, becoming the then-youngest Peace Prize winner at age 35. However, today’s record-holder — education activist Malala Yousafzai — was far younger, accepting the honor in 2014 at the age of 17.
The arts drew the King and Roberts families together. Before marrying her activist husband, Coretta Scott King had earned a bachelor’s in music education from the New England Conservatory, one of the country’s most selective music schools. By the 1960s, married actors Betty and Walter Roberts had launched the Actors and Writers Workshop, a theater school in Atlanta near the Kings’ home. With four young children and a passion for the arts, Coretta had been searching for a youth theater program, but struggled to find one that would accept Black students. She reached out to Betty to inquire about the Robertses’ school, which stood out as the only integrated children’s acting program in the area.
While the Actors and Writers Workshop was successful and molded several actors who pursued the craft into adulthood, it wasn’t free from monetary issues. By the time Julia (the youngest of three children) was born, the Roberts family was struggling financially. However, the Kings and Robertses had developed a friendship that helped the family through a rough patch; Martin and Coretta graciously covered the expense, forever linking the two families.
As a college student, Coretta Scott King was a babysitter for six-time Emmy winner John Lithgow.
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The Coretta Scott King Book Awards were created by two school librarians.
Today, children’s literature is more reflective of its readers than ever before — a 2022 study by the University of Wisconsin found that 40% of books published that year were written, illustrated, or compiled by people of color. However, creators from diverse communities haven’t always had their work published or recognized, which is one reason why the Coretta Scott King Book Awards were created. In 1969, two school librarians — Mabel McKissick from Connecticut and Glyndon Greer of New Jersey — met at the American Library Association Conference in Atlantic City. After attending a banquet for the Caldecott and Newbery book awards, the librarians discussed a lack of acknowledgment for Black writers, and used their remaining time at the conference to develop the Coretta Scott King Awards. The designation, named for the civil rights activist and her work toward peace and equality, continues to recognize Black writers and illustrators and literature that represents African American culture and human rights.
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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.
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It began as a bit of creative problem-solving. Some trees in Melbourne, Australia, had dangerous branches that needed to be trimmed and other issues, prompting city officials in 2013 to give 70,000 of them ID numbers and email addresses where people could report problems. As an “unintended but positive consequence” of the program, according to Councilor Arron Wood of Melbourne's Environment Portfolio, people began writing their favorite trees whimsical letters. “I have exams coming up and I should be busy studying,” one reads. “You do not have exams because you are a tree. I don’t think that there is much more to talk about as we don't have a lot in common, you being a tree and such. But I’m glad we’re in this together.”
The inside of a palm tree isn’t full of wood. Instead, palms have thousands of fibrous strands, which allows them to bend in tropical storms without breaking. By some accounts, palms are more “tree-like” than actual trees.
That one, addressed to Green Leaf Elm, Tree ID 1022165, even received a response: “I hope you do well in your exams. Research has shown that nature can influence the way people learn in a positive way, so I hope I inspire your learning.” The initiative’s website (the program is still going strong) features a map of every tree as well as links to their email addresses, should you feel like writing a love letter of your own. The responses are actually crafted by employees at the City of Melbourne — and as of 2018, the trees had received more than 4,000 emails from all over the world.
The U.S. has more trees now than it did 100 years ago.
When it comes to trees, the more the merrier. So while it may come as a surprise to learn that there are more trees in the U.S. today than there were a century ago, at least it’s a pleasant one. Forest growth has exceeded harvest since the 1940s, according to the Food and Agriculture Organization, and by 1997, growth exceeded harvest by a full 42%. Quantity isn’t always the same as quality, as old-growth forests contain the most biodiversity and are generally the best for the environment, but conservation efforts (including good old fashioned tree-planting) have been remarkably successful.
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Michael Nordine is a writer and editor living in Denver. A native Angeleno, he has two cats and wishes he had more.
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Of all the world records to hold, “most world records” might be the most impressive. That title belongs to American Ashrita Furman, who has set more than 600 world records and currently holds more than 200. He first became smitten with Guinness’ famous book as a child in the 1960s and made it his lifelong mission to set as many records as he could. Among his many feats are the longest continuous distance somersaulting (12 miles and 390 yards), most hopscotch games completed in 24 hours (434), world's largest popcorn sculpture (20 feet, 10 inches), most apples cut midair with a samurai sword in one minute (29), and translating and reciting a poem in the most languages (203).
His pursuits have indeed taken him to every continent — including Antarctica, where he set both speed and distance records for pogo stick jumping.
His first attempt in 1978 ended in disappointment when he failed to break the record for most consecutive jumping jacks, but he persevered and broke it the following year by completing a whopping 27,000 in 6 hours and 45 minutes. He has since gone on to break hundreds more records and regularly works to reclaim titles that have been taken from him by other record-breakers.
Furman holds the record for most Ping-Pong balls caught with chopsticks in one minute.
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Guinness has more world records than it can print.
The company tracks a total of around 65,000 records, which is far more than can fit into the annual book. It makes a number of editorial decisions to whittle that number down to about 4,000, and the rest are featured online. Some record-holders have been unhappy with the promotion (or lack thereof) their feats have achieved, which led one of them, Dean Gould, to launch his own registry of world records, Record Holders Republic, in response. Other Guinness critics include former adjudicators such as Anna Nicholas, who told USA Today the company’s current output is “a far cry from the book [she] worked on” in the late 1980s, and that the current version places too much emphasis on sensationalism. Guinness nonetheless remains synonymous with world records, an association that’s unlikely to be broken anytime soon.
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Michael Nordine is a writer and editor living in Denver. A native Angeleno, he has two cats and wishes he had more.
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The company now known as 7-Eleven has a history of being ahead of the curve. Back in 1927, when its founders were running the Southland Ice Company in Texas, an executive recognized the potential of selling basic provisions like milk and bread alongside the ice blocks that were so essential to households in the days before refrigerators were common. With a little company restructuring, the first convenience store chain was up and running. (The name was changed to 7-Eleven, a reference to the hours of operation, in 1946.)
Although "Slurpee" is a 7-Eleven brand name, the famed slushy soft drink is identical to the ICEE created by Dairy Queen franchisee Omar Knedlik in the late 1950s.
In 1963, 7-Eleven opened its 1,000th store, but a more significant milestone in the convenience store realm was also about to happen. Around this time, according to Oh Thank Heaven!: The Story of the Southland Corporation, one store located near the University of Texas campus in Austin found itself unusually busy in the hours after a school football game, to the point where employees never had the chance to shut the doors for the night. When this situation unfolded again following the next football game, the company's brain trust sniffed a potentially transformative moment for the business, and established 24-hour shops near Texas Christian University in Fort Worth and Southern Methodist University in Dallas.
Meanwhile, another 24-hour experiment was unfurling at a 7-Eleven near the Strip in Las Vegas, a move that yielded an increase in profits and the surprise side effect of deterring burglaries. Eventually, both 7-Eleven and their competitors realized that it wasn't just the amped-up college students and gamblers who sometimes needed a 24-hour pit stop, paving the way for the proliferation of these ever-open outposts to provide soda, chips, and a range of other goodies to help folks everywhere make their way through the night.
The largest convenience store chain in Mexico is Oxxo.
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A Swedish entrepreneur fueled the rising trend of unmanned convenience stores.
In 2016, IT specialist Robert Ilijason rolled the dice on a new business model by opening a nonstaffed, 24-hour convenience store in the small town of Viken, Sweden. Registered customers used their smartphones to enter the store and scan items, for which they received a bill at the end of the month, while a half-dozen security cameras served to dissuade shoplifters from snatching freebies. At the time, Ilijason was hopeful his idea would spread to other villages, but the appeal turned out to be far broader than he thought. After selling his business in 2017 to a Swedish startup, which promptly opened an unmanned store in Shanghai, China, Ilijason founded his own startup to send a wave of these phone-operated shops snowballing through his home country. But the biggest sign that his idea was here to stay? When the big dog of the industry, 7-Eleven, decided to make another corporate leap with the opening of its first unmanned branch in Seoul, South Korea, in 2017.
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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.
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If you want your flag to fit in, go with red, white, and blue, the three most popular colors found on the world’s flags. If you want to go a more distinctive route, add a dash of purple, because only one national flag in the world sports this hue. That flag belongs to the Caribbean island nation of Dominica, and features the country’s national bird, the purple-plumed sisserou parrot (Amazona imperialis). This endangered bird is one of the oldest Amazon parrot species in the world, and can be found only in the remote mountain forests of Dominica.
The word “purple” originates from the Greek “porphura,” a reference to the purpura mollusk. These sea snails were the key ingredient in the Tyrian purple dye created by ancient Phoenicians. Because the dye was so costly, purple became closely associated with royalty.
Eagle-eyed flag experts might note that the flags of both Nicaragua and El Salvador feature volcano-traversing rainbows, which (theoretically) contain the full spectrum of visible color. However, Dominica still wins out on a technicality. These two countries officially label the last shade of the rainbow on their flags as “violet” and “blue,” respectively, and the color purple is a nonspectral color, meaning it isn’t represented by a specific wavelength of light (and therefore not part of a rainbow). Instead, the color purple is a construction of our brain and the limitations of the cones in our eyes. So unless some country opts for a purple-centric redesign, the chromatic glory of the sisserou parrot will remain a flag favorite.
Only one national flag in the world isn’t a rectangle.
Flags come in many different colors and a variety of designs, but most of them are rectangular. The flag of Nepal is a truly incredible departure, however. The double pennon-shaped flag, which looks like two differently sized triangles stacked on top of one another, represents both the Himalayan mountains as well as the country’s two major religions: Hinduism and Buddhism. (The exact mathematical proportions of the triangles are actually enshrined in the country’s constitution.) Just like the vast landscapes that fill the country, the Nepalese flag is certainly one of a kind.
Darren Orf
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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.
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