These are the facts you could find on this page:
"@ Sign", "qwerty" Keyboard, Applying Tattoos, Atom Fountain, Bat's Echolocation Calls, Before Plates, Best Meteorite Site, Bless You, Brownian Motion, Color of Water, Croissants, Driest Desert, False Maps, First Comet Visit, First Compound Eyes, First Computer Game, First Geothermal Electricity Generator, First Motorcycle, First Space Animal, First Zoos, Football Huddle, Frost-Free Freezer, Giant Ice Rivers, Guinea Pigs, History of Brands, Immortal Supercells, Largest Nebula, Largest Steam Locomotives, Laughing Bird, Leaky Earth, Longest Poem, Melting Mushrooms, Most Ancient Letter, Most Precious Spice, Moving Eyes, Muscle Cramps, Northernmost Capital, Oil-floating Telescope, Oldest Carbonated Drink, Oldest Corporation, Oscar, Pole Reversals, Primitive Flowering Plant, Radioactive Dentures, Red Moon, Robot Fish, Saharan Rock Art, Seasonal Lag, Seeing Saturn's Rings, Seven Day Week, Sonic Boom, Spider Bandits, Sticky Teflon, Stock Fractions, Street Lights, Superconductors, Teddy Bear Origins, Telephone Buttons, Traffic States, Visual Telegraphs.

"@ sign"
Everyone who uses email knows the "at sign," the little "a" with a circle around it. It separates the user's online name from his or her mail server address. Before it was used in email addresses, the "at sign" was used on invoices to show how much each item costs, and in a few other places.
Like its relative the ampersand, the "at sign" was invented in the days before printing presses, to shorten the task of transcribing documents. As short as the word "at" might be, it was still common enough in texts that medieval monks thought it would be worthwhile to shorten it even more. So they looped the "t" around and made it into a circle, saving one stroke of the pen.
The "at sign" has no official one-word name, even though many names have been proposed. Among the proposed names, we like arobase, vortex, and snail.
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"qwerty" Keyboard
Almost every alphabetic keyboard in the world has the letters in an arrangement called "qwerty," after the first six letters in the top row. There are several popular myths about the origin of today's standard keyboard arrangement. Some say it was deliberately designed to slow down typists. What is the truth?
When inventor C. L. Sholes built his first typewriters in 1868, he arranged the keys in alphabetical order. But the clumsy mechanical linkages inside the machine could tangle if certain pairs of keys were struck quickly.
The "qwerty" arrangement fixed the tangling problem by separating the internal links for frequently paired letters, making the machines more reliable. After a historic typing contest (see today's Person Of The Day, linked below), "qwerty" became the standard way to arrange the keys.
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Applying Tattoos
Early methods of tattooing were much more painful than the modern approach. Some involved applying dye to open wounds, or pulling soot- covered threads through the skin with a needle.
A modern permanent tattoo is made of pigment that is injected between living skin cells in the dermis, the layer below the constantly- replaced epidermis. Because the dermis is not being constantly renewed, the dye is not dispersed and it can remain in place for many years.
A tattoo machine works much like a sewing machine: a steel needle vibrates up and down many times per second, penetrating about two millimeters deep (1/8 inch) and delivering dye particles. Thomas Edison invented the first such machine in 1876.
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Atom Fountain
The most accurate clocks in the world are the new atomic fountain clocks, in which thousands of extremely cold atoms are tossed gently into a vacuum chamber, where they fall under gravity's pull.
Before atomic fountain clocks, the most accurate timekeepers were clocks that measured the vibrations of atoms in a beam flying through a vacuum chamber. Although they are extremely accurate, such clocks suffer from errors caused by the speed of the atoms flying through the chamber.
Atomic fountain clocks measure the atoms' vibrations at the top of the fountain, where they are practically motionless for a fraction of a second before they fall back down. As a result, the time measured by such clocks is accurate to within one second in more than thirty million years.
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Bat's Echolocation Calls
Although we can't hear the sounds a bat makes as it flies around in the dark because they are too high-pitched, they are still sounds and instruments can measure their loudness.
The loudest bats are those that usually fly in wide-open spaces. These include the common brown bat, which can be seen on summer evenings in temperate regions, flying above the treetops. These are "shouters" whose calls are sometimes as loud as a household smoke alarm (about 110 decibels). Even at that intensity, their ultrasonic calls fade out at about 50 feet because air does not carry ultrasound very well.
Quieter bats are those that fly in tighter spaces like between the trees in a forest. These "whispering" bats have calls measuring about 60 decibels, the loudness of human conversation.
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Before Plates
Plates for serving food were not used in Europe until the fifteenth century. Before that, food was usually served on thick, hollowed-out slabs of stale bread called trenchers, which were specially baked and allowed to harden so they could hold more food without falling apart.
The food's juices would soak into the bread, and after the meal the soggy trenchers might be fed to the dogs or offered to poor peasants waiting outside for leftovers.
The evolution of modern plates began when trenchers were carved out of wood, sometimes with special compartments for spices and condiments. For a while, wooden trenchers were used as supports for bread trenchers. Wooden trenchers were later replaced by clay or ceramic plates, which did not rot under long use.
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Best Meteorite Site
Meteors fall into Earth's atmosphere over every spot on the planet. However, there is one place that's far better than anywhere else to find the meteorites that make it all the way to the ground. That place is a windswept field of ice near the edge of the East Antarctic Ice Sheet.
There, near the Allan Hills (which are actually the tips of huge mountains buried in the ice) one can find hundreds of meteorites lying around on the surface of the ice. There are tons of them. How did they get there?
Meteorites fall into the snow all across Antarctica, then sink down until they hit a layer of solid ice. That ice flows slowly across the continent, to certain places where ice-buried mountains push it up. The upthrust ice evaporates in the dry Antarctic wind, leaving the meteorites exposed.
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Bless You!
In ancient times, it was customary to congratulate someone who just sneezed, because sneezing was viewed as the body's way to expel evil spirits. This view may have been based on the observation that people sneeze more often when they are ill, and illness was thought to be caused by evil spirits.
In the fourteenth century, the black plague came to Europe accompanied by violent sneezing among those afflicted. The Pope passed a law that anyone who sneezed was to be blessed by those nearby, with the hope that death might be averted. Today, most people still say "Bless you!" when someone sneezes.
The Germans were a bit less religious about their sneezing customs. To this day, they say "gesundheit" [geh-ZUND-hyt] after someone sneezes, which simply means "good health."
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Brownian Motion
Look through a powerful microscope at a water suspension of tiny particles like pollen grains, bacteria, or just plain old dirt and you may notice that they are jumping and jiggling around. Why do they jiggle?
The jiggling is called Brownian motion, after the Scottish botanist Robert Brown, who noticed it in 1828. While Brown could not explain the jiggling motion, we know today that it is the result of the movements of water molecules. Smoke particles floating in the air also show Brownian motion.
All molecules are in motion all the time, even at a temperature of absolute zero. At room temperature, the chaotic, unpredictable movements of water molecules are strong enough that much larger particles get bounced around, and the bouncing is visible under the microscope.
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Color of Water
You might think that absolutely pure water would be perfectly clear and utterly transparent, but it's actually blue. The blue color of the water in the oceans (and not the blue of the sky) is the reason why Earth is mostly blue as seen from space.
Pure water absorbs some of the light that passes through it. It absorbs red light more than yellow, yellow more than green, and green more than blue. Only the deepest blue light can travel very far through water, so a large mass of water takes on a deep blue color.
The blueness of water is easily visible in a swimming pool lined with white concrete. It's even visible in a white porcelain bathtub. But the bluest water of all is the clear tropical ocean far from land, where the sea is much bluer than the sky.
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Croissants
The delicate, flaky croissant or crescent roll is a baked pastry that is curved with pointed tips. Although its popular name in English speaking countries is French, the roll itself is of Austrian origin, commemorating a Turkish shape.
According to the most popular story, in 1683 the Ottoman Turks invaded Vienna by trying to tunnel under the city's walls. The Turks were successfully repelled, thanks to the vigilance of the only people who were awake during the night-time raid: the bakers. In celebration of the victory the bakers created the croissant, shaping it like the crescent found on the Turkish flag.
Since there are several different stories of this event, the true details may be different. But all sources agree that the croissant's shape is the Turkish crescent, and that it was created in celebration of an Austrian victory over the Turks.
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Driest Desert
At some places in Chile's Atacama Desert, it does not rain for centuries at a time. A long, narrow strip of land along the western coast of South America, the Atacama is protected from clouds by the Andes Mountains, the world's second highest mountain range.
Many parts of the Atacama Desert receive average annual rainfall of less than 0.004 inches (0.1 mm), and some spots have not seen rain in 400 years. Although the desert is located right next to the Pacific Ocean, the prevailing winds come down from the lofty mountains and sweep out to sea.
But as dry as it is, even the Atacama supports life. There are tiny pockets where fog from the sea creates enough moisture for plants and even some animals, and there are also a few humans living in the Atacama.
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False Maps
In the old Soviet Union, maps were often made with deliberate errors. Towns, rivers, and roads were placed incorrectly, and entire towns would be missing in some versions. Moscow street maps were especially inaccurate.
The false maps were part of a plan to prevent foreigners and even the Soviet citizens from knowing the details of the geography of the Soviet Union. It was thought that this would increase security, but actually it made the whole country less efficient.
The false maps were part of a much broader concept called Maskirovka, a word that has meanings relating to misdirection, camouflage, misinformation, and diversion. According to some experts, the Maskirovka philosophy is still very much a part of Russian strategy, and influences many parts of the society.
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First Comet Visit
When Halley's Comet came through the inner solar system in 1986, spacecraft from Japan, the Soviet Union, and Europe were there to meet it. But six months before these spacecraft met up with Halley, another one had already made the first comet rendezvous, with a different comet.
The craft was the International Sun-Earth Explorer 3, which was renamed the International Cometary Explorer (ICE) for this special mission. Its historic first comet visit was made possible by a unique, complex orbit that took it from its original station between the Earth and the Sun, past the Earth-Moon system five times, then looping out in a long arc that passed right through the tail of comet Jiacobi-Zinner.
After the comet encounter, ICE coasted farther out into empty space, but in 2014 it will return to Earth, with fuel still in its tanks. Where will they send it next?
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First Compound Eyes
The first eyes with more than one simple lens belonged to bottom- dwelling, aquatic creatures that lived more than 500 million years ago. Scientists suspect that through mutation some of these primitive creatures were born with multiple eyes, instead of one on each side of the body.
The multiple eyes probably gave them greater light-gathering ability, an advantage in deep or muddy waters, and over time evolution made their eyes more effective. In their descendants the trilobites compound eyes became quite complex, some of them containing as many as 20,000 lenses
Today's insects, which also came from the same ancestors, bear compound and simple eyes adapted for many different lifestyles. Among the best are those of dragonflies, who can track tiny insects on the wing and scoop them up for dinner.
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First Computer Game
The very first interactive computer game was built in 1958 by Willy Higinbotham, a researcher at the Brookhaven National Lab. He used an analog computer and a tiny, five-inch (13 cm) circular screen.
The screen showed an upside down "T", with a moving dot that bounced like a tennis ball under the influence of gravity. Each player could hit the "ball" by pressing a button, and could control the angle of the hit by turning a knob. The screen was a side view of a tennis court, and the ball's path was modeled complete with gravity and friction.
Higginbotham's simple game was the first to use a computer and a graphic display. It was not a true video game, because it used an analog oscilloscope display instead of a video screen. His machine was soon disassembled, but it was the seed for what later became a huge industry.
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First Geothermal Electricity Generator
In 1904, the world's first geothermal electric generator went into operation at Italy's Larderello Hot Springs. Using pressurized steam from underground, the original plant was able to generate about 250 kilowatts, barely enough to run one modern home. Electricity was not the first use of the hot springs at Larderello. Hot water was used in 1777, and starting in 1790 brine from the springs was processed to extract boric acid and other compounds of boron. Today, Larderello has 300 wells as deep as 700 meters (2300 feet), which yield ultra-hot water at 235 degrees Celsius (455 F) and a pressure of 30 atmospheres. The site now produces 300-400 megawatts of power.
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First Motorcycle
Most sources claim that the first motorcycle was built by Gottlieb Daimler, an assistant to Nicholaus Otto (who invented the Otto cycle, a kind of engine). In 1885, Daimler added a gasoline motor to a wooden bicycle, replacing the pedals. Daimler's motorbike was propelled by an engine, but it was not the first motor-driven cycle.
Actually, the first motorbike was built seventeen years earlier in 1868. It was not powered by a gasoline engine, but by a steam engine. Its builder was Sylvester Roper. His steam-powered bike did not catch on, but it anticipated many modern motorbike features, including the twisting-handgrip throttle control.
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First Space Animal
The first animal in space was carried into orbit in the second artificial satellite, Sputnik 2. She was the dog Laika (Barker), launched from the Baikonur Cosmodrome by the Soviets on November 3, 1957.
The capsule's primitive life support system kept Laika alive until the oxygen ran out a few days later. On April 14, 1958 Sputnik 2 fell into the atmosphere and burned up.
The Soviet Sputnik program sent more than a dozen dogs into space. The last Sputnik dog was Chernushka (Blackie), whose successful flight in March, 1961 preceded Yuri Gagarin's manned orbital flight the following month.
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First Zoos
Menageries, zoos, and botanical gardens have been around for a very long time. The first records of such parks where exotic animals and plants were kept date from more than 4,000 years ago, in the Egyptian and Mesopotamian empires.
The rulers of these ancient lands were proud of their gardens and zoos. They set out on extended expeditions to distant lands to bring back animals and plants, and they hired and trained expert keepers to make sure the exotic life forms were kept healthy and able to breed.
Some of the modern world's most useful animals and plants were first collected and grown by ancient zoo-keepers. The first four chickens in Egypt were the proud possessions of Pharaoh Tuthmosis III.
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Football Huddle
When players of American football want to talk about the next play, they form a "huddle" in which they all face inward in a tight group. But the huddle has not always been part of the game. Prior to the 1890s, football players just stood around discussing the play, far enough away from the other team that they could not be overheard.
The huddle was invented by Paul Hubbard, quarterback for Gallaudet University's Bisons. Gallaudet was a university for deaf people, and the players used sign language to discuss strategy. The tight huddle was a way to hide the sign language from anyone on the opposing team who might be able to understand it.
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Frost-Free Freezer
If you own an old refrigerator you may need to defrost the freezer from time to time, a difficult task possibly requiring a lot of scraping and hot water. How do modern freezers stay free of accumulated ice?
Ice condenses in the freezer because cold air can't hold as much water vapor as warm air. In an older freezer frost forms on everything every time warm, moist air enters from outside. In a more modern freezer the air is circulated by a fan and the frost forms mostly on the coldest surface, which is the cooling coils in the back.
You might think that the coils would quickly be surrounded by solid ice, and they would, if not for the defrost function. Every so often a heating element warms up the air around the coils just long enough to melt the frost. The water trickles down the back of the freezer to a tray near the floor where it evaporates.
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Giant Ice Rivers
The greatest glaciers of the Northern Hemisphere are puny trickles next to the vast ice rivers that flow off the Siple Coast into the Ross Ice Shelf of West Antarctica. The five giant ice streams there are up to fifty kilometers wide (31 miles), 1000 meters deep (3280 feet) and hundreds of kilometers long.
Huge ice sheets that hardly flow at all surround these vast streams. While the surrounding ice sheet moves maybe a meter per month, the ice streams can move at more than a meter per day. Why do they move so fast?
The secret is what's underneath. While most of the West Antarctic Ice Sheet sits on solid rock, the Siple Coast ice rivers rest on a thick layer of wet, warm, slippery mud. The heat comes up from the Earth itself, melting the bottom layer of the ice, and the movement of the ice grinds the bedrock into fine mud.
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Guinea Pigs
In spite of their name, guinea pigs did not originate in Guinea, nor are they pigs. They are rodents, in the same order as mice and hamsters.
Guinea pigs (Cavia porcellus) were first domesticated 9000-6000 years ago by the ancient Incas of Peru, who used them for food, as personal pets, and for religious sacrifices. Their natural range originally extended up and down the Andes mountain chain, along South America's west coast.
Guinea pigs are social herbivores (plant eaters), adapted to roughly the same ecological niche as rabbits. Their gnawing front teeth (incisors) are self-sharpening and continue to grow throughout the animal's life.
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History Of Brands
The practice of branding animals (permanently marking them by applying a heated tool) is ancient indeed. The earliest clear evidence of branding comes from Egyptian tomb paintings 4,000 years old, but the practice probably began much earlier than that. Cave paintings 7,000 years old show bison with markings on the flanks, possibly to indicate ownership.
When humans first began to herd animals, it became worthwhile to identify the ownership of each animal. The first prehistoric brands were probably made by nomadic herdsmen with burning wooden sticks. Later, red-hot iron tools were used to draw or stamp the designs onto the animals.
When Spaniards began to colonize the New World, they brought the practice of branding with them, and developed it further. Ranch cattle brands evolved into a complex language with technical terminology and multi-symbol phrases that carried specific meanings.
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Immortal Supercells
The first time scientists were able to grow human cells in a long-term tissue culture (an artificial medium designed to nourish the cells) was in 1951. Those cells were taken from a tumor in a woman named Henrietta Lacks.
Those cells were incredibly hardy. Scientists were able to culture many kinds of human cells in the years that followed, but many of those cultures were accidentally contaminated with what became known as the HeLa cells. When it was discovered that HeLa cells had spread so widely, many research projects had to be started over, because the cells in the cultures were HeLa, not the kind the scientists thought they were.
Today, the HeLa supercells are still going strong in labs all around the world. They are the subject of research because like many cancer cells, they are immortal, reproducing without limit. Scientists are more careful now, and accidental HeLa contamination of other cell cultures is less of a problem.
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Largest Nebula
The largest known nebula (cloud of gas and dust) is the Tarantula Nebula, named for its shape. More than 1000 light years across, it is one hundred times as large as the famous Orion Nebula.
The Tarantula Nebula is about 165,000 light years from Earth, in a small, nearby galaxy called the Large Magellanic Cloud. It's the only extra-galactic (outside of our galaxy) nebula that can be seen without a telescope. If it were as close as the Orion Nebula (about 1500 light years) it would be as wide as 60 full moons, and bright enough to cast shadows.
Nebulas like the Tarantula are the birthplaces of new stars, which collapse at the center of swirling whirlpools. Our solar system was probably born within such a nebula.
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Largest Steam Locomotives
The largest, heaviest, most powerful steam locomotives ever built were the giant 2-6-6-6 Allegheny engines, used by the Chesapeake & Ohio Railroad during the 1940s. These 600-ton behemoths could reach a maximum speed of 60 miles per hour (97 km/hr).
To supply the Allegheny steam engines with fuel and water, a new tender car had to be developed that could hold 25,000 gallons of water (95,000 liters) and 25 tons of coal.
The monster locomotives were used to pull trains of coal and timber across the Allegheny mountains, out of the New River Valley of West Virginia. When diesel engines replaced them in the 1950s, the local steam train industry collapsed, ruining the economies of several railroad-based towns.
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Laughing Bird
The laughing kookaburra of Australia and New Guinea has a loud, braying call that sounds a lot like a human laughing. It also has a softer "chuckle" call.
The kookaburra is a small, stout hunting bird closely related to kingfishers. Its loud call is not actually laughter, but rather a territorial sound to warn other kookaburras to stay clear. The chuckle sound is a location call to keep family members together.
Kookaburras are most likely to laugh in the evening and morning hours, when they sometimes cackle together in loud choruses. They are so punctual that they are also known as the "bushman's clock."
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Leaky Earth
Every day, more than 1,000 gallons of water are lost into space from the top of Earth's atmosphere. Most of the water is lost near the magnetic poles, where charged particles from the Sun split water molecules into electrically charged hydrogen and oxygen ions.
The charged ions move in paths that follow the lines of Earth's magnetic field. Since that field points straight up near the poles, they can escape there. The amount lost can be much larger during solar storms when the solar wind becomes more powerful. If Earth had no magnetic field, the amount lost would be far greater and the oceans would have evaporated millions of years ago.
Scientists suspect that a similar mechanism might have removed water from the atmospheres of Mars and Venus, both very dry planets today.
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Longest Poem
The world's longest poem is the Mahabharata, an epic containing 100,000 couplets in some 18 books. Composed thousands of years ago in India, the Mahabharata was recently made into a TV series that became a smash hit in modern India.
The epic poem describes events that took place around 5,000 BC in a place called bhaarata. It describes the appearance and adventures of Lord Krishna, a Hindu diety also known as the eighth incarnation of Vishnu, preserver of the universe. The climax of the story is a gigantic battle lasting 18 days.
The Mahabharata is a powerful and important religious, spiritual, and historical document that contains many of the most fundamental concepts of modern Hinduism. It continues to have a profound effect on Hindu philosophy and culture.
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Melting Mushrooms
When they reach maturity, several kinds of mushrooms in the genus Coprinus begin to deliquesce, or dissolve into black, inky fluid. After a few hours, all that's left is a patch of dark moisture. These mushrooms, called inky caps, have evolved this strange trait as a way of spreading their spores.
When rain falls, the black fluid (which contains billions of spores) is diluted and carried away. As the rain and fluid soaks into the ground, the spores are carried with it.
Coprinus mushrooms include the common, edible shaggy mane mushroom (Coprinus comatus), which is often seen in lawns in the autumn, as well as other smaller mushrooms that inhabit decaying wood or dung or pop up in flowerpots.
(Warning: do not eat wild mushrooms! Many wild mushrooms are poisonous, and resemble edible species.)
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Most Ancient Letter
Of the 26 letters in the modern Roman alphabet, the only one that remains unchanged since its invention is the letter "O," which has remained the same since it was used in the Phoenician alphabet about 3,300 years ago.
No one knows when or where the first true alphabet was invented. It was a revolutionary concept, to use symbols for the sounds that made up words, instead of using a symbol for each word. Like the letter "O," many of the letters of the earliest alphabets corresponded in some way to the shape of the mouth when the letters were pronounced.
The Phoenician system of sound-symbols was the first widely successful alphabet, replacing the cumbersome, complex cuneiform writing system. It spread throughout the ancient world, giving rise to the Greek alphabet, the Russian cyrillic system, and our Roman alphabet.
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Most Precious Spice
The golden-orange spice called saffron is the most expensive spice in the world. Although it can sell for as much as $8 per gram, it is available for as little as $36 for an ounce ($1.29 per gram) if you know where to look.
Why is it so expensive? It is produced from one tiny part (the stigma) of the flowers of a certain kind of purple crocus that blooms only once each year in the fall. The yield per acre is very small, since it takes thousands of flowers to make a handful of spice. The bright red stigmas must be removed from the flowers in the early morning, when they are still fresh.
Saffron is a versatile spice that can be used in many ways, ranging from the traditional rice dishes to sweet baked goods. There's even potent saffron liquor from northern Greece.
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Moving Eyes
On the average, a normal person's eye muscles move about 100,000 to 150,000 times in one day. During the daytime, our eyes move as often as three or four times per second, while in the deepest sleep they hardly move at all.
Our eyes must move that fast because there is only one tiny area on our retina that is able to see any real detail. With each movement that tiny area, which is called the fovea, can see another little bit of detail to build up a larger picture.
With our eyes moving that often, why don't we see a sequence of rapidly flickering images? Our brains are experts at combining the fast-changing images into a whole, so that we see a complete view even as our eyes scan around rapidly.
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Muscle Cramps
Almost everyone has experienced a muscle cramp. The muscle becomes contracted and rigid, and is usually quite painful. The contracted muscle gets locked into a self-sustaining knot, which can last for hours or days.
Many muscle cramps are associated with exercise. These cramps are often due to a depletion or imbalance of salts in the muscle tissue, especially calcium, sodium, and potassium, which are lost in our sweat. A buildup of lactic acid, one of the byproducts of heavy exercise, also can contribute to the cramping. Such cramps can often be relieved by drinking "electrolyte" drinks that restore the salt balance.
If you get a cramp, it may be helpful to move the muscle into its least extended (shortest) position and massage it very gently. Eat something with sodium and potassium (like a banana) and wait for the cramp to ease.
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Northernmost Capital
The northernmost capital city in the world is Iceland's capital, Reykjavik, which is also one of the world's newest capitals, incorporated in the late 19th century.
Reykjavik means "smoky bay," but the city is no longer smoky. Like the rest of highly volcanic Iceland, Reykjavik is now almost entirely powered by hydrothermal energy, provided by hot rock just under the city.
The city's points of interest include the Hallgrimskirkja, a church designed to look like a gigantic pile of lava, named after Iceland's favorite poet, Hallgrimur Petursson. Also in Reykjavik is a theater called the Volcano Show, featuring fascinating programs about the local geology.
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Oil-floating Telescope
The Gemini North and Gemini South astronomical telescopes float on oil bearings so turning and aiming are very smooth and only require a tiny force. Even though each of these monster telescopes weighs 377tons, a single person can turn it if the drive motors are not engaged.
Gemini North (on Hawaii's Mauna Kea volcano) and Gemini South (on Chile's Cerro Pachon) are among the most advanced telescopes in the world, in some ways even outperforming the orbiting Hubble Telescope.
Each has an 8.1-meter mirror (more than 26 feet) and is optimized for infrared observations, which will allow astronomers to observe very distant galaxies and penetrate clouds of dust in our own galaxy.
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Oldest Carbonated Drink
The oldest commercially marketed carbonated drink is Moxie, which became available in apothecaries as a medical tonic in 1876. Made by the Nerve Food Company of Lowell, Massachusetts, Moxie was first sold as a beverage in 1884. (Hires Root Beer was also introduced in 1876.)
Moxie has an odd flavor that has been described as a combination of cola, root beer, and licorice. The first version contained wintergreen as well as a bitter-sweet herb, root gentian. According to those who like it, it is definitely an acquired taste.
Moxie was also the first carbonated beverage to offer a sugar-free version. The potent brew with its distinctive orange labels is still available in Maine, where it is something of a local classic.
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Oldest Corporation
The world's oldest continuously incorporated company is Canada's Hudson's Bay Company, which was founded in 1670. The company also became the largest corporate landowner with holdings that at one time included about one third of present-day Canada.
During its first two centuries of existence, the Hudson's Bay Company mainly pursued the fur trade, exploration, and settlement of Canada's northern reaches. One of its greatest exploration projects was the unsuccessful attempt to find the fabled "northwest passage" to eastern Asia.
Today, Hudson's Bay Company operates the largest chain of department stores in Canada. It was split into several companies in 1930, so today's Hudson Bay Company is considerably smaller than its illustrious ancestor.
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Oscar
An Oscar is one of a set of awards given annually by the Academy of Motion Picture Arts and Sciences. The trophies recognize achievement in films.
Officially named the Academy Award of Merit, an Oscar trophy depicts a knight standing on a reel of film. The Academy has been handing out the statuettes, designed by L.A. sculptor George Stanley, since 1929.
The origins of the nickname are unclear but a popular story is that the staff started calling the trophy Oscar because it reminded an Academy executive director of her Uncle Oscar. A Hollywood columnist first used the nickname publicly when writing about the 1934 awards. In 1939 the Academy started officially using the now trademarked name.
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Pole Reversals
The magnetic field of Earth is not constant. Not only does the magnetic pole wander slowly, every so often the entire magnetic field flips completely over. No one knows why this happens, although there are theories relating it to the movement of liquid iron deep inside the Earth.
Pole reversals happen at unpredictable intervals of 5000 years to nearly one million years. By studying the magnetic fields of rocks that solidified at various times in the past, scientists have been able to reconstruct the history of Earth's magnetic pole reversals.
Once that history was clear, it became possible to date certain rock formations by studying their magnetic fields. Together, these two approaches have helped us pin down the age of the Earth and the times of various events in its history.
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Primitive Flowering Plant
According to genetic research the most primitive species of flowering plant that is still alive is Amborella trichopoda, an obscure shrub with tiny flowers and red berries from the South Pacific island of New Caledonia.
Until recently the most primitive flowering plants were thought to be magnolias or water lilies, but detailed analysis of the genetic code of more than 100 plants has revealed that Amborella branched off the main line before any other known flowering plant.
The single species of Amborella surviving today is probably very similar to plants that grew 145 million years ago, when the first birds were learning how to fly. It is so primitive that it lacks the water-conducting vessels present in the stems of other flowering plants.
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Radioactive Dentures
Millions of people wear some type of dentures (false teeth). Some of them, especially the oldest ones, are made out of porcelain that includes a trace of uranium, a radioactive element.
The uranium was added to these old-style dentures because it flouresces (glows in response to certain wavelengths of light), giving the dentures a bright, white look. Without it the porcelain teeth would appear dingy and greenish under artificial light.
A full set of porcelain dentures releases about 1,500 millirems of radiation in a year, which is about four times the natural background level. Other factors that can lead to similar levels of exposure include living at a high altitude (from cosmic rays) and smoking (from elements in the smoke).
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Red Moon
When the Earth moves between the Sun and the Moon, it casts its shadow on its own satellite, causing a lunar eclipse. From the Earth a bright, full Moon turns into a dark disc that usually has a deep, red color.
Viewed from the Moon, the Earth is much bigger than the Sun, so during a total lunar eclipse the Sun's disc is completely blocked by the Earth. Why isn't the Moon plunged into complete darkness during a total lunar eclipse?
When the Sun's light enters Earth's atmosphere at a shallow angle, it passes through many layers that scatter almost all of the blue and green light and bend the remaining light around the edge of the planet. The deep, red light shining on the Moon is the combined light of all the sunrises and sunsets that are happening on Earth at the moment of the eclipse.
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Robot Fish
Researchers at Massachusetts Institute of Technology (MIT) have built a robot tuna fish, and now they are working on a robot pike. They hope to answer some important questions about how fish swim.
Fish can swim very efficiently, in fact more efficiently than the laws of physics would seem to allow. If we could understand how they do this, it might be possible to design boats, submarines, and other machines that swim much more efficiently using fins instead of propellers.
Meanwhile researchers in Japan have built a robot sea-bream, another kind of fish. They plan to create a museum exhibit containing robot models of extinct sea creatures, all swimming as if they are alive.
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Saharan Rock Art
Until about 4,000 years ago the vast Sahara of northern Africa had abundant wildlife and grassy meadows. By studying rock artworks of various ages scientists have reconstructed some of the history of the tribes who lived there.
The oldest art dates to 12,000 years ago, when humans saw themselves as part of the natural order, and nature was seen as a friendly force. In later periods after the adoption of domestic animals, people saw themselves as superior to nature, as shown in their rock art.
After 1650 BC, when the Sahara was conquered by humans riding horses, the art changed again. By this time the Sahara had turned into a huge desert and human life there was very difficult, which was reflected in the kinds of images drawn on the rocks.
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Seasonal Lag
The time when the Sun is brightest and the days are longest is the summer solstice, near June 21 in the northern hemisphere. Yet the hottest days of summer usually come in July or August, when the days are shorter and the Sun is lower in the sky. Winter's coldest days also lag the solstice by about two months. Why?
When the sunshine maximum comes in June, the landscape and atmosphere are still warming from the winter's chill. Although the Sun begins to lose strength after the solstice, there is still enough heat to continue warming the landscape until the balance shifts about two months later.
In the days after the winter solstice, although the Sun's heat is returning, it is still not warm enough to keep the landscape from cooling further, especially during the night. It is not until early March that the balance of solar heat and nighttime cooling shifts into a warming trend.
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Seeing Saturn's Rings
Although Galileo Galilei was the first to see the rings of Saturn, his telescope did not provide a very good view and he did not correctly interpret them. He thought he was seeing two smaller planets just touching the central planet. When the rings became edge-on to Earth, Galileo was confused by the sudden disappearance of the two "side planets."
For many years, Saturn was a mystery. The strange side protruberances came to be called ansae (handles), but no one could explain what they were, or why they sometimes disappeared.
The first correct interpretation of Saturn's rings was by the Dutch astronomer Christiaan Huygens [KRIS-chan HOW-kenz] in 1656. For some time, Huygens kept his discovery a secret, while he finished other projects. Finally, in 1658 he revealed the secret, then explained it more fully in his 1659 book, "Systema Saturnium."
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Seven Day Week
No one knows exactly where and when the seven day week got started, but it is known to be extremely ancient. The most common theory about its origin relates the seven days to the ancient astrological idea that there were seven celestial bodies revolving around the stationary Earth.
For thousands of years, the astrological seven day week was used in Mesopotamia. It was adopted by the Egyptians, who then passed it on to the Greeks. In 321 AD, Constantine The Great added the seven day week to the Roman calendar, making the first day a day of rest and worship.
What were the days of the Roman week? They were Dies Solis (Sun's Day), Dies Lunae (Moon's Day), Dies Martis (Mars's Day), Dies Mercurii (Mercury's Day), Dies Iovis (Jupiter's Day), Dies Veneris (Venus's Day), and Dies Saturni (Saturn's Day).
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Sonic Boom
Sonic booms are not often heard these days in most inhabited parts of the world. That's because they can be somewhat destructive, not to ment ion annoying. They are caused by aircraft that travel faster than the speed of sound.
The sonic boom is a shock wave that forms when the aircraft's speed outstrips the ability of air molecules to get out of the way. It's a m oving pressure wave that starts at the nose, wingtips, and other forward-projecting parts of the aircraft and forms a cone trailing back from the plane and expanding up, down, and out to the sides.
When that cone-shaped pressure field passes across a point on the ground, a sonic boom is heard. Since the pressure wave of a moderate son ic boom can be enough to break windows, non-military aircraft are no longer allowed to travel faster than sound near inhabited areas.
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Spider Bandits
If you look closely at the web of a giant golden orb spider (Nephila edulis), you might see much smaller spiders on it. These round, silvery nest parasites are droplet spiders (Argyrodes antipodianus) waiting for small prey that their giant host ignores.
Small prey insects are not the droplet spiders' only food. These crafty little thieves sometimes band together and carefully steal large prey that the host spider has caught and wrapped, but not yet eaten.
One by one, they cut the lines between the catch and the main web, carefully repairing damage by bridging the gap with their own webs. Then they carry the prey off to a corner, where they can safely consume it.
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Sticky Teflon
Teflon, or polytetraflouroethylene, (PTFE) is one of the most inert substances known. It's so inert that nothing sticks to it; to stick, it would have to react in some way. So how does it stick onto the surface of a frying pan?
In early days, the Teflon was pressed onto the metal surface after the metal had been "roughed up" by abrasion and coated with a primer chemical with lots of microscopic cavities. The Teflon squeezed into the cavities and stuck to the pan by sheer mechanical strength. But those early frying pans didn't keep their coating very long, because Teflon is so inert that its long molecules slither like wet spaghetti, and it often came loose from the mechanical primer.
Modern non-stick pans are made with a much more sophisticated process. Parts of the Teflon molecules at the bottom of the coating have different side chains that actually stick to the metal, while the upper ends of the molecules are pure Teflon. The layer sticks on the bottom, but not on top.
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Stock Fractions
In the eighteenth century, the U.S. dollar's value was pegged to the value of the Spanish silver dollar, which was divided into eight parts rather than the 100 parts (pennies) into which the dollar was divided.
When the U.S. stock market opened at the end of the century, prices were based on the Spanish dollar, and they were divided into eighths accordingly. The practice has remained until today, but now the U.S. stock market is finally preparing to switch to a decimal system.
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Street Lights
Street lights usually come on around dark, and flick off when the sun rises. Are they turned on by someone in an office somewhere? Do they have timers that make them go on and off?
Most street lights have photoelectric sensors that turn them on when the light fades. Look at the top of a street light. The sensor may be visible as a cylindrical protrusion, often surrounded by spiky wires designed to keep birds from landing there.
Sometimes a street light will either stay on all day or never come on at all. Each of these behaviors is usually caused by a defective sensor. You may also notice a few street lights that turn on, then buzz and go out, only to slowly brighten up again a few minutes later. These lights are suffering from aging bulbs that are about to fail.
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Superconductors
In 1911 a Dutch physicist named Heike Kamerlingh Onnes noticed that when he cooled mercury metal to a temperature just above absolute zero its electrical resistance completely disappeared. He had discovered superconductivity, a property that some materials have at very low temperatures.
When all electrical resistance disappears, some strange things happen. Electric currents can flow forever in closed loops through the material. External magnetic fields cannot enter because they cause exactly equal and opposite currents to flow, repelling them.
Scientists are still trying to understand superconductivity. One of the great mysteries is whether there are materials that can show superconductivity at high temperatures. New superconducting materials are discovered every year, but so far they all must be cooled to very low temperatures before they become superconductors.
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Teddy Bear Origins
A teddy bear is a furry stuffed bear, usually a child's toy. The toy and its name were born together after a celebrated act of compassion by U. S. President Theodore "Teddy" Roosevelt.
There are several versions of the story. In the most popular one, Roosevelt went on a bear hunting trip in November 1902, but no bear was bagged. To give the President a chance for some kind of trophy, someone tied a bear cub to a tree so he could shoot it. He refused.
Soon after, a cartoon was published in the Washington Post depicting the incident, and there was a great popular outcry in favor of the President's thoughtful restraint. An enterprising businessman began selling stuffed "Teddy bears," and they became an instant hit.
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Telephone Buttons
The telephone's pad of twelve buttons reflects its history. There are three letters on most buttons, except for zero, one, octothorp (#) and the star symbol (*), which have no letters. "Q" and "Z" are usually missing from the list. Why?
Instead of twelve buttons, telephones used to have circular plates with ten holes numbered from zero to nine. To make phone numbers easier to remember, the phone companies assigned letters to the numbers, so people could remember mnemonics like "Charleston" for C-H instead of the first two digits of a number.
Of the ten digits, zero was already used to dial the operator and one was used for internal phone company signals. That left eight numbers to which letters could be assigned. Three letters per number took care of 24 of the alphabet's 26 letters, and the least common letters "Q" and "Z" were left out, but not forever. Many telephones now show "Q" on the seven button, and "Z" on the nine button.
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Traffic States
Traffic States 1553 Although freeway traffic flow is very complex, science is beginning to reveal its dynamics. It turns out to have distinct states, like the gas, liquid, and solid states of matter.
When traffic moves like a gas, the cars are far enough apart that each one can move freely without much affecting its neighbors. Drivers instinctively maintain large separations, and traffic flows at maximum speed.
When things get a little busier, cars slot together into clusters that travel only a little slower than they do in the gas state. The clusters are like condensed droplets of liquid, and they are separated by intervals of gaseous traffic.
If traffic gets even heavier, another transition happens. The traffic enters a thick, viscous state like honey or tar. If it gets much heavier you have gridlock, the solid state of traffic flow.
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Visual Telegraphs
Before the invention of the electric telegraph in the mid-1800s, time- critical messages were sent across long distances by various kinds of visual telegraph systems (semaphores). Messages were encoded as various combinations of flag positions or light flashes, sent between hilltop stations several kilometers apart.
In Europe, the main system was a flag semaphore invented in 1791 by Claude and Ignace Chappe. It used pairs of movable arms and beams that could represent the letters of the alphabet. By the use of this system, Napoleon Bonaparte was able to send a message from Rome to Paris in about four hours at a rate of fifteen characters per minute.
In the United States and England a different system was used in which six shutters encoded the letters and numbers. Today there are still some cities with landmarks called Signal Hill or Telegraph Hill, reminding us of their earlier function.
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