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Agriculture

Astronomy

  •  (http://www.loc.gov/item/what-are-the-northern-lights/)
    What are the northern lights? The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky. Aurora borealis – the Northern Lights. Chena Hot Springs, Alaska, 2013. LCDR Gary Barone, NOAA Corps (ret.), photographer. NOAA Photo Library. Polar lights (aurora polaris) are a natural … Continue reading “What are the northern lights?”
  •  (http://www.loc.gov/item/what-does-it-mean-when-they-say-the-universe-is-expanding/)
    What does it mean when they say the universe is expanding? When scientists talk about the expanding universe, they mean that it has been growing ever since its beginning with the Big Bang. Galaxy NGC 1512 in Visible Light External. Photo taken by the Hubble Space Telescope External The galaxies outside of our own are moving away from us, and the ones that are farthest away … Continue reading “What does it mean when they...
  •  (http://www.loc.gov/item/what-is-a-blue-moon-is-it-ever-really-blue/)
    What is a blue moon? Is the moon ever really blue? “Once in a blue moon” is a common expression that has been used for a long time, and which means ‘not very often,’ or ‘very rarely.’ It often refers to an extra full moon; however, it has been used to describe the way the moon actually looked, when for different reasons it had turned a … Continue reading “What is a blue moon? Is...
  •  (http://www.loc.gov/item/why-is-pluto-no-longer-a-planet/)
    Why is Pluto no longer a planet? The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.” The Rich Color Variations of Pluto. … Continue reading “Why is Pluto no longer a...

Biology and Human Anatomy

  •  (http://www.loc.gov/item/does-your-heart-stop-when-you-sneeze/)
    Does your heart stop when you sneeze? No, your heart does not stop when you sneeze. Edison Kinetoscopic record of a sneeze. Print shows a man, Edison engineer Fred Ott, sneezing. The accompanying Harper’s Weekly article describes the image as “the entire record of a sneeze from the first taking of a pinch of snuff to the recover” using “eight-one prints taken … Continue reading “Does your heart stop when you...
  •  (http://www.loc.gov/item/what-are-stem-cells/)
    What are stem cells? Stem cells are the cells that have an ability to become various types of cells. They are present both during embryonic development (embryonic stem cells) and in the adult body (adult stem cells). Human ES cells differentiating into neurons. Photo courtesy of California Institute for Regenerative Medicine. National Institute of General Medical Sciences, Image and … Continue reading “What are stem cells?”
  •  (http://www.loc.gov/item/what-causes-the-noise-when-you-crack-a-joint/)
    What causes the noise when you crack a joint? Escaping gases, movement and rough surfaces. Thomas Gemini. Compendiosa totius Anatomie Delineatio… (Compendium of all anatomy delineated…). London: John Herford, 1545. Rosenwald Collection, Rare Book and Special Collections Division, Library of Congress. Your joints can make a variety of sounds: popping, cracking, grinding, and snapping. The joints that “crack” are the knuckles, knees, ankles, back, and neck. There … Continue reading “What causes the...
  •  (http://www.loc.gov/item/what-is-the-strongest-muscle-in-the-human-body/)
    What is the strongest muscle in the human body? There is no one answer for this question since there are different ways to measure strength. There is absolute strength (maximum force), dynamic strength (repeated motions), elastic strength (exert force quickly), and strength endurance (withstand fatigue). Muscles. In De humani corporis fabrica, Andreas Vesalius, 1543. National Library of Medicine Digital Collections. There are three types … Continue reading “What is the strongest muscle in...
  •  (http://www.loc.gov/item/why-do-fingers-and-toes-wrinkle-in-the-bathtub/)
    Why do fingers and toes wrinkle in the bathtub? The outermost layer of the skin swells when it absorbs water. It is tightly attached to the skin underneath, so it compensates for the increased area by wrinkling. However, new research is investigating the role of digital vasoconstriction (narrowing of blood vessels) of water immersion wrinkling of the skin. Soaking in the hot springs. Big … Continue reading “Why do fingers and toes wrinkle...
  •  (http://www.loc.gov/item/why-do-we-yawn/)
    Why do we yawn? Yawning might serve a social function (to communicate boredom) and a physiological function (regulation of body state). La Paresse: Caricature of sleep or boredom. Louis Léopold Boilly, 1824. National Library of Medicine Digital Collections The study of yawning is anything but boring. It boasts a rich history of theories that go back to Antiquity, but … Continue reading “Why do we yawn?”
  •  (http://www.loc.gov/item/why-does-hair-turn-gray/)
    Why does hair turn gray? It is well known that gray hair results from a reduction of pigment, while white hair has no pigment, but why this happens remains somewhat of a mystery. Ayer’s hair vigor for the toilet: restores gray hair to its natural vitality and color, 1886. Prints & Photographs Division, Library of Congress. Parents often cite having … Continue reading “Why does hair turn gray?”

Botany

  •  (http://www.loc.gov/item/what-causes-flowers-to-have-different-colors/)
    What causes flowers to have different colors? Anthocyanins and carotenoids… plus some other things. Dahlias in Ben Burnside’s Garden. Terry Eiler, photographer, 1997. Coal River Folklife Collection, American Folklife Center, Library of Congress. Flowers come in all shapes and sizes, but what makes them truly stand apart from each other is their vibrant colors. These colors are made up of pigments and, generally … Continue reading “What causes flowers to have...
  •  (http://www.loc.gov/item/what-is-the-largest-flower-in-the-world/)
    What is the largest flower in the world? The Rafflesia arnoldii. Rafflesia arnoldii (corpse flower) growing to the east of the Lake Maninjau, Sumatra, Indonesia. Henrik Hansson. External link Plants of the World Online, Kewscience. The flower with the world’s largest bloom is the Rafflesia arnoldii. This rare flower is found in the rainforests of Indonesia. It can grow to be 3 feet … Continue reading “What is the largest flower in...
  •  (http://www.loc.gov/item/what-is-the-smallest-flower-in-the-world/)
    What is the smallest flower in the world? Watermeal. (Wolffia spp.) The smallest species of vascular plants in Europe – Spotless watermeal, Wolffia arrhiza – on human fingers. External link Every single speck of less than 1 mm length is an individual plant. Christian Fischer, photographer, 2008. Wikimedia Commons Watermeal (Wolffia spp.) is a member of the duckweed family (Lemnaceae), a family that … Continue reading “What is the smallest flower in...

Chemistry

  •  (http://www.loc.gov/item/how-do-fireworks-work/)
    How do fireworks work? Fireworks are explosions of numerous small pellets of black powder called stars. The main ingredient in fireworks is black powder, which explodes when ignited (lit on fire). In addition to black powder, firework stars contain different chemicals or metals to create certain colors. The stars are intentionally arranged to create various firework shapes or images. … Continue reading “How do fireworks work?”

Food and Nutrition

  •  (http://www.loc.gov/item/can-you-make-a-better-cookie/)
    Can you make a better cookie? Yes. Escambia Farms, Florida. Sunday morning in the McLelland kitchen. Making cookies for dinner. John Collier, photographer, 1942. Prints and Photographs Division, Library of Congress. Use the right measuring tools Use the right equipment for wet and dry ingredients. Milk, water, eggs, extracts and oils are all wet ingredients; dry ingredients include flour, sugar and … Continue reading “Can you make a better cookie?”
  •  (http://www.loc.gov/item/how-do-fortunes-get-inside-fortune-cookies/)
    How do fortunes get inside of fortune cookies? The cookies are baked as flat circles. After they are removed from the oven, slips of paper are folded inside while the cookies are still warm and flexible. As the fortune cookies cool, they harden into shape. Image of fortune cookies. External link 2011. Wikimedia Commons. If you’ve ever been to a Chinese restaurant, you’ve most … Continue reading “How do fortunes get inside...
  •  (http://www.loc.gov/item/what-is-freezer-burn/)
    What is "freezer burn?" The outcome of frozen food losing its moisture as a result of poor wrapping. Ask the man who repairs one, and he’ll tell you to turn the freeze control back to normal after quick-freezing ice-cubes or ice cream. United States Office for Emergency Management, 1942. Prints and Photographs Division, Library of Congress. Have you ever … Continue reading “What is “freezer burn?””
  •  (http://www.loc.gov/item/who-invented-frozen-food/)
    Who invented frozen food? Several individuals, but most credit Clarence Birdseye. USDA scientists flash-freeze and store berries for later evaluation of their suitability as a frozen product. Agricultural Research Service, U.S. Department of Agriculture. Of course, frozen food has always existed in climates that were cold enough for the food to freeze. Many people developed innovative food-freezing techniques, including … Continue reading “Who invented frozen food?”
  •  (http://www.loc.gov/item/who-invented-the-tv-dinner/)
    Who "invented" the TV dinner? Several individuals developed the TV dinner. Convenience foods. Warren K. Leffler, photographer, 1965. Prints & Photographs Division, Library of Congress. Like many creations, the story of the development of the TV dinner is not straightforward. Many people and companies played a role in the development of the concept of a complete meal that needed only … Continue reading “Who “invented” the TV dinner?”
  •  (http://www.loc.gov/item/why-does-chopping-an-onion-make-you-cry/)
    Why does chopping an onion make you cry? Unstable chemicals. Camp Kearny, Cal. “Anti-onion” gas mask. Between 1917-1919. Prints & Photographs Division, Library of Congress. Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes’ lachrymal glands so they release tears. Scientists used to blame the enzyme allinase for the instability of substances in a cut onion. Recent studies from Japan, … Continue reading “Why does chopping an onion make...
  •  (http://www.loc.gov/item/why-does-pepper-make-you-sneeze/)
    Why does pepper make you sneeze? Because the chemical piperine, an irritant, gets into the nose. Black pepper: Piper nigrum.External link From “Spices: Exotic Flavors and Medicines,” History & Special Collections, UCLA Louise M. Darling Biomedical Library. A sneeze is a reflex that is triggered when nerve endings inside the mucous membrane of the nose are stimulated. Pepper, be it white, black, … Continue reading “Why does pepper make you...

Geography, Anthropology, Recreation

  •  (http://www.loc.gov/item/what-are-the-seven-seas/)
    What are the seven seas? There is no definitive answer to this question. The phrase is a figure of speech and has been used to refer to different bodies of water at various times and places. Greece and the Aegean and Ionian Seas. Taken by a member of the Expedition 55 crew aboard the International Space Station on April 2, … Continue reading “What are the seven seas?”

Meteorology, Climatology

  •  (http://www.loc.gov/item/can-it-rain-frogs-fish-and-other-objects/)
    Can it rain frogs, fish, and other objects? There have been reports of raining frogs and fish dating back to ancient civilization. Of course, it doesn’t “rain” frogs or fish in the sense that it rains water – no one has ever seen frogs or fish vaporize into the air before a rainfall. However, strong winds, such as those in a tornado or … Continue reading “Can it rain frogs, fish, and...
  •  (http://www.loc.gov/item/can-you-tell-the-temperature-by-listening-to-the-chirping-of-a-cricket/)
    Can you tell the temperature by listening to the chirping of a cricket? Yes! Life stages of the Mormon cricket: egg, first instar nymph, third instar nymph, and adult female. Agricultural Research Service, U.S. Department of Agriculture. The frequency of chirping varies according to temperature. To get a rough estimate of the temperature in degrees fahrenheit, count the number of chirps in 15 seconds and then add 37. … Continue reading “Can you tell the temperature by...
  •  (http://www.loc.gov/item/groundhog-shadow/)
    Can a groundhog's shadow really predict if there will be six more weeks of winter? No, the shadow-observing lore has no scientific basis and will not tell you if there will be six more weeks of winter. However, seeing wild groundhogs out and about during winter months might indicate that the season is almost over. Woodchuck – Arctomys monax. L. Prang & Co. 1874. Library of Congress Prints & Photographs … Continue reading “Can a groundhog’s shadow really predict...
  •  (http://www.loc.gov/item/is-it-true-that-no-two-snow-crystals-are-alike/)
    Is it true that no two snow crystals are alike? The scientific consensus states that the likelihood of two large snow crystals being identical is zero. Winter scenes: Snowflakes. ca. 1920-1950. Theodor Horydczak, photographer. Prints & Photographs Division, Library of Congress. The probability that two snow crystals (a single ice crystal) or flakes (a snow crystal or multiple snow crystals stuck together) will be exactly … Continue reading “Is it true that no two...
  •  (http://www.loc.gov/item/is-the-old-adage-red-sky-at-night-sailors-delight-red-sky-in-morning-sailors-warning-true-or-is-it-just-an-old-wives-tale/)
    Is the old adage "Red sky at night, sailor's delight. Red sky in morning, sailor's warning" true, or is it just an old wives' tale? Within limits, there is truth in this saying. A small coastal freighter plying its way through a placid sea at sunset. Photo by Commander John Bortniak, NOAA Corps (ret). NOAA Photo Library. Have you ever heard anyone use the proverb above?Shakespeare did. He said something similar in his play, Venus and Adonis. “Like a red … Continue reading “Is the old adage “Red sky...
  •  (http://www.loc.gov/item/what-causes-the-sound-of-thunder/)
    What causes the sound of thunder? Thunder is caused by the rapid expansion of the air surrounding the path of a lightning bolt. Monsoon storm producing a forked lightning bolt from the Red Hills Visitors Center at Saguaro National Park in Arizona. Pete Gregoire, photographer, NOAA Weather in Focus Photo Contest 2015. NOAA Photo Library. From the clouds to a nearby … Continue reading “What causes the sound of thunder?”
  •  (http://www.loc.gov/item/what-is-the-origin-of-the-phrase-its-raining-cats-and-dogs/)
    What is the origin of the phrase "it's raining cats and dogs?" We don’t know. The phrase might have its roots in Norse mythology, medieval superstitions, the obsolete word catadupe (waterfall), or dead animals in the streets of Britain being picked up by storm waters. Very unpleasant weather. George Cruikshank, 1820. Ailsa Mellon Bruce Fund, National Gallery of Art The first recorded use of a phrase similar … Continue reading “What is the origin of the...
  •  (http://www.loc.gov/item/why-do-i-see-my-breath-when-its-cold-outside/)
    Why do I see my breath when it's cold outside? Cold air causes the warm moisture in our breath to condense into tiny droplets of water that appear like a small, misty cloud. Airman Keith Miller, 52nd Security Forces Squadron, catches his breath during Operation Saber Crown. Airman 1st Class Nathanael Callon, photographer. Spangdahlem Air Base Photos, U.S. Air Force. Many people think seeing your breath … Continue reading “Why do I see my...
  •  (http://www.loc.gov/item/why-is-it-hot-in-summer-and-cold-in-winter/)
    Why is it hot in summer and cold in winter? Because the earth’s axis is tilted. Earth at the beginning of each season. From National Weather Service, National Oceanic and Atmospheric Administration Web site. It is all about the tilt of the Earth’s axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the … Continue reading “Why is it hot in summer...

Motor Vehicles, Aeronautics, Astronautics

  •  (http://www.loc.gov/item/how-do-skywriting-and-skytyping-work/)
    How do skywriting and skytyping work? Both are a type of advertising that use aircraft to spell words in the sky by mixing paraffin oil into smoky plane exhaust. Skywriting. Theodor Horydczak, photographer. Prints and Photographs Division, Library of Congress Ever sat at the beach or an outdoor event and watched a plane writing in the sky? It was captivating, wasn’t … Continue reading “How do skywriting and skytyping work?”
  •  (http://www.loc.gov/item/who-invented-the-automobile/)
    Who invented the automobile? This question does not have a straightforward answer. The history of the automobile is very rich and dates back to the 15th century when Leonardo da Vinci was creating designs and models for transport vehicles. Das erste praktisch brauchbare automobil der welt, das Benz-Dreirad von 1885. Photograph shows the Benz three-wheeler, made in 1885. Prints and … Continue reading “Who invented the automobile?”

Physics

  •  (http://www.loc.gov/item/does-water-go-down-the-drain-counterclockwise-in-the-northern-hemisphere-and-clockwise-in-the-southern-hemisphere/)
    Does water go down the drain counterclockwise in the northern hemisphere and clockwise in the southern hemisphere? It all depends upon how the water was introduced and the geometric structure of the drain. Handwashing over a sink. Amanda Mills, CDC photographer, 2011. Centers for Disease Control and Prevention, Public Health Image Library. One can find both counterclockwise and clockwise flowing drains in both hemispheres. Some people would like you to believe that the … Continue reading “Does water go down the...
  •  (http://www.loc.gov/item/how-does-a-stone-skip-across-water/)
    How does a stone "skip" across water? Spin, speed, shape and angle are the crucial factors, with angle being the most important. Skipping stones at Seneca Rocks. Ryan Hagerty, USFWS photographer, 2014. U.S. Fish and Wildlife Service National Digital Library Spin stabilizes an object and keeps it from simply falling into the water. A minimum speed must be achieved or the stone will … Continue reading “How does a stone “skip”...
  •  (http://www.loc.gov/item/how-does-static-electricity-work/)
    How does static electricity work? An imbalance between negative and positive charges in objects. Two girls are “electrified” during an experiment at the Liberty Science Center “Camp-in”, February 5, 2002. America’s Story, Library of Congress. Have you ever walked across the room to pet your dog, but got a shock instead? Perhaps you took your hat off on a dry winter’s … Continue reading “How does static electricity work?”
  •  (http://www.loc.gov/item/is-it-possible-to-fry-an-egg-on-the-sidewalk-if-its-hot-enough/)
    Is it possible to fry an egg on the sidewalk if it's hot enough? Yes, theoretically. But it doesn’t actually get hot enough. Russell Lee, photographer. Faro Caudill frying eggs over camp fire the day he was moving his dugout. Pie Town, New Mexico. 1940. Prints & Photographs Division, Library of Congress. This question comes from the saying “It’s so hot you could fry an egg on the sidewalk!” … Continue reading “Is it possible to fry an...
  •  (http://www.loc.gov/item/why-does-ultraviolet-light-cause-color-to-fade/)
    Why does ultraviolet light cause color to fade? Because of photodegradation. A faded mural on the wall of a building in Dallas, Texas, advertising the Texas and Pacific Railroad’s passenger service to Saint Louis in what at the time was apparently the expeditious time of 23 hours. Carol M. Highsmith, photographer, 2014. Prints & Photographs Division, Library of Congress. It is all about … Continue reading “Why does ultraviolet light cause color...
  •  (http://www.loc.gov/item/why-dont-i-fall-out-when-a-roller-coaster-goes-upside-down/)
    Why don't I fall out when a roller coaster goes upside down? Gravity is counteracted by centripetal force, due to acceleration, which is the force that pushes you into your seat. Roller coaster, Seaside Heights, New Jersey. John Margolies, photographer, 1978. Prints & Photographs Division, Library of Congress. Have you ever wondered how roller coasters stay on their tracks and why people can hang upside down in … Continue reading “Why don’t I fall out when...
  •  (http://www.loc.gov/item/why-is-the-ocean-blue/)
    Why is the ocean blue? There are several theories: – Blue wavelengths are absorbed the least by the deep ocean water and are scattered and reflected back to the observer’s eye – Particles in the water may help to reflect blue light – The ocean reflects the blue sky Aerial shot of the clear blue ocean off the coast of … Continue reading “Why is the ocean blue?”

Technology

  •  (http://www.loc.gov/item/can-you-really-build-a-house-with-straw/)
    Can you really build a house with straw? Yes, with dry, tightly baled straw you can build a durable, beautiful home. Pilgrim Holiness Church in Arthur, Nebraska. The church was built out of baled straw in 1928 and is listed in the National Register of Historic Places. External Ammodramus, photographer, 2010. Wikimedia Commons. The Three Little Pigs had it all wrong! Homes, schools, … Continue reading “Can you really build a house...
  •  (http://www.loc.gov/item/how-does-a-touch-screen-work/)
    How does a touch screen work? By using your finger to disrupt an electrical current. Sailors use a Submarine Engine Room touch-screen training simulator. Oct. 22, 2015. U.S. Navy photo by Mass Communication Specialist 1st Class Martin L. Carey/Released, U.S. Navy image gallery. Touch screen technology has become part of our everyday lives. We barely bat an eye while scrolling through … Continue reading “How does a touch screen work?”
  •  (http://www.loc.gov/item/how-does-an-hourglass-measure-time/)
    How does an hourglass measure time? By using carefully calculated amounts of sand. 18th Century Sandglass. Morristown National Historic Park, National Park Service Museum Collections. The hourglass is sometimes referred to as a sand clock or a sandglass. Like other timepieces, it needs to be carefully calibrated. The hourglass maker must test the instrument and fine tune it to measure the … Continue reading “How does an hourglass measure time?”
  •  (http://www.loc.gov/item/how-is-lighthouse-light-magnified/)
    How is the light of a lighthouse magnified so that it can be seen many miles out at sea? A lighthouse light is a concentrated beam, focused by special lenses. Because of its highly increased intensity, this beam of light can travel a very long distance. Interior view of Fresnel lens in lantern of Split Rock Lighthouse, Lake County, MN. Jet Lowe, 1990. Prints & Photographs Division, Library of Congress. The design of the … Continue reading “How is the light of a...
  •  (http://www.loc.gov/item/what-is-gps-how-does-it-work/)
    What is a GPS? How does it work? The Global Positioning System (GPS) tells you where you are on Earth. GPS III Satellite. U.S. Government photo, GPS.gov Multimedia Library. It’s eleven o’clock … do you know where your kids are? Would you like to? One way to track them would be to have a GPS receiver installed in the car! The GPS, or … Continue reading “What is a GPS? How does...
  •  (http://www.loc.gov/item/who-came-up-with-the-idea-for-velcro/)
    Who came up with the idea for Velcro? The invention of Velcro is just one example of design imitating nature. Human design modeled on biology and natural processes is called biomimicry. By observing nature, scientists can often find solutions to human problems–and inspiration for new inventions. Nature’s Velcro: Harvey Halvorsen of Wisconsin Dept. of Natural Resources educated scouts about burdock. Tina Shaw, photographer, … Continue reading “Who came up with the idea...
  •  (http://www.loc.gov/item/who-invented-electric-christmas-lights/)
    Who invented electric Christmas lights? Thomas Edison and Edward Johnson (1880 &1882) and Albert Sadacca (1917). National Christmas Tree on the National Mall, 1997. Prints and Photographs Division, Library of Congress. Thomas Edison, the inventor of the first successful practical light bulb, created the very first strand of electric lights. During the Christmas season of 1880, these strands were strung … Continue reading “Who invented electric Christmas lights?”
  •  (http://www.loc.gov/item/who-invented-frozen-food/)
    Who invented frozen food? Several individuals, but most credit Clarence Birdseye. USDA scientists flash-freeze and store berries for later evaluation of their suitability as a frozen product. Agricultural Research Service, U.S. Department of Agriculture. Of course, frozen food has always existed in climates that were cold enough for the food to freeze. Many people developed innovative food-freezing techniques, including … Continue reading “Who invented frozen food?”
  •  (http://www.loc.gov/item/who-invented-the-toothbrush-and-when-was-it-invented/)
    Who invented the toothbrush and when was it invented? Various peoples. 1938 (modern). Poster from Gellé Frères Perfumers, Avenue de l’Opéra, 6, Paris. J. Cheret, 1889. Prints and Photographs Division, Library of Congress. The toothbrush as we know it today was not invented until 1938. However, early forms of the toothbrush have been in existence since 3000 BC. Ancient civilizations used a “chew stick,” … Continue reading “Who invented the toothbrush and when...
  •  (http://www.loc.gov/item/who-is-credited-with-inventing-the-telephone/)
    Who is credited with inventing the telephone? Alexander Graham Bell is often credited with being the inventor of the telephone since he was awarded the first successful patent. However, there were many other inventors such as Elisha Gray and Antonio Meucci who also developed a talking telegraph. First Bell Telephone, June 1875. Emile Berliner collection, Motion Picture, Broadcasting and Recorded Sound Division, … Continue reading “Who is credited with inventing the...

Zoology

  •  (http://www.loc.gov/item/can-an-octopus-get-to-know-you/)
    Can an octopus get to know you? Yes. An octopus, Flower Garden Banks National Marine Sanctuary, Gulf of Mexico. NOAA Photo Library An octopus is a marine animal that has a soft rounded body with eight long flexible arms about its base which have sucking disks able to seize and hold things (as prey). The octopus is an invertebrate, meaning that it … Continue reading “Can an octopus get to know...
  •  (http://www.loc.gov/item/can-zebras-be-domesticated/)
    Can zebras be domesticated? No, zebras cannot be domesticated. Grant’s Zebra Gary M. Stolz, photographer, Kenya, 2008. U.S. Fish and Wildlife Service National Digital Gallery. They are unpredictable and are known to attack people. To be domesticated, animals must meet certain criteria. For example, they must have a good disposition and should not panic under pressure. Zebras’ unpredictable nature … Continue reading “Can zebras be domesticated?”
  •  (http://www.loc.gov/item/groundhog-shadow/)
    Can a groundhog's shadow really predict if there will be six more weeks of winter? No, the shadow-observing lore has no scientific basis and will not tell you if there will be six more weeks of winter. However, seeing wild groundhogs out and about during winter months might indicate that the season is almost over. Woodchuck – Arctomys monax. L. Prang & Co. 1874. Library of Congress Prints & Photographs … Continue reading “Can a groundhog’s shadow really predict...
  •  (http://www.loc.gov/item/how-are-millipedes-and-centipedes-alike-and-how-do-they-differ/)
    How are millipedes and centipedes alike and how do they differ? While both millipedes and centipedes belong to the phylum Arthropoda and to the subphylum Myriapoda, millipedes belong to the class Diplopoda and centipedes belong to the class Chilopoda. Read on to discover additional ways in which millipedes and centipedes are alike or different. The Almond-scented millipede, Apheloria virginiensis corrugata, has beautiful coloration. Many millipedes with … Continue reading “How are millipedes and centipedes alike...
  •  (http://www.loc.gov/item/how-can-you-tell-the-difference-between-a-butterfly-and-a-moth/)
    How can you tell the difference between a butterfly and a moth? One of the easiest ways to tell the difference between a butterfly and a moth is to look at the antennae. A butterfly’s antennae are club-shaped with a long shaft and a bulb at the end. A moth’s antennae are feathery or saw-edged. Hummingbird moth (Hyles lineata) on showy milkweed at Seedskadee National Wildlife Refuge. … Continue reading “How can you tell the difference...
  •  (http://www.loc.gov/item/how-did-cats-become-domesticated/)
    How did cats become domesticated? Domesticated cats all come from wildcats called Felis silvestris lybica that originated in the Fertile Crescent in the Near East Neolithic period and in ancient Egypt in the Classical period. National Photo Co. Woman holding cat. 1926. Prints & Photographs Division, Library of Congress. According to a recent study by Claudio Ottoni, cat domestication took … Continue reading “How did cats become domesticated?”
  •  (http://www.loc.gov/item/how-do-cats-communicate-with-each-other/)
    How do cats communicate with each other? Cats have different ways of communicating with other cats and with humans. Cats communicate vocally (meowing, purring, and hissing) and with their bodies and behavior. Frances Benjamin Johnston’s cats, Herman and Vermin, seated on brick railing of New Orleans house, Louisiana. Frances Benjamin Johnston, photographer, between 1945-1950. Prints & Photographs Division, Library of Congress. For … Continue reading “How do cats communicate with each...
  •  (http://www.loc.gov/item/how-do-spiders-avoid-getting-tangled-in-their-own-webs/)
    How do spiders avoid getting tangled in their own webs? Spiders are able to spin sticky and non-sticky silk. They avoid walking on the sticky silk. In addition, spiders have moveable claws on their feet that grip and release the web’s threads as they walk. Golden Orb Weaver. Bandelier National Monument, 2010. National Park Service, NP Digital Asset Management System Spiders are invertebrate creatures in … Continue reading “How do spiders avoid getting tangled...
  •  (http://www.loc.gov/item/how-high-can-a-nine-banded-armadillo-jump/)
    How high can a nine-banded armadillo jump? Three to four feet into the air. Armadillo. Gulf Islands National Seashore, 2013. National Park Service, NP Digital Asset Management System. Of the twenty species of armadillo that exist throughout the Americas, the nine-banded armadillo (dasypus novemcinctus) is the only one found in the United States. When startled, the nine-banded armadillo can jump straight upward … Continue reading “How high can a nine-banded armadillo...
  •  (http://www.loc.gov/item/how-long-is-the-life-span-of-a-flea/)
    How long is the life span of a flea? 30-90 Days (Average). A drawing of a flea by microscope pioneer Robert Hooke. Micrographia: or, Some physiological descriptions of minute bodies made by magnifying glasses. With observations and inquiries thereupon, p.334. 1665. Lessing J. Rosenwald Collection, Rare Book and Special Collections Division, Library of Congress. A flea might live a year and a half under ideal … Continue reading “How long is the life...
  •  (http://www.loc.gov/item/how-much-water-does-a-camels-hump-hold/)
    How much water does a camel's hump hold? None. Egypt, Pyramids. Pyramid & camel rider reflected in Nile overflow. Matson Photo Service, between 1950-1977. Prints & Photographs Division, Library of Congress A camel’s hump does not hold water at all – it actually stores fat. The camel uses it as nourishment when food is scarce. If a camel uses the fat inside the … Continue reading “How much water does a camel’s...
  •  (http://www.loc.gov/item/is-a-polar-bears-fur-transparent/)
    Is a polar bear's fur transparent? Yes! Most sources indicate that the long, coarse guard hairs, which protect the plush thick undercoat, are hollow and transparent. The thinner hairs of the undercoat are not hollow, but they, like the guard hairs, are colorless. Male polar bear near the Beaufort Sea, Alaska, 2016. Steven C. Amstrup, USGS photographer, USGS Science Explorer . The … Continue reading “Is a polar bear’s fur...
  •  (http://www.loc.gov/item/which-is-the-largest-bear-on-earth/)
    Which is the largest bear on earth? The polar bear. Large Polar Bear, Alaska. Mike Lockhart, photographer, 2009. USGS Science Explorer. It is a close call, but the polar bear is generally considered the largest bear on Earth. A close second is the brown bear, specifically the Kodiak bear. The Kodiak is a subspecies of the brown bear native to Alaska. Playful … Continue reading “Which is the largest bear on...
  •  (http://www.loc.gov/item/why-and-how-do-cats-purr/)
    Why and how do cats purr? No one knows for sure why a domestic cat purrs, but many people interpret the sound as one of contentment. Our understanding of how a domestic cat purrs is becoming more complete; most scientists agree that the larynx (voice box), laryngeal muscles, and a neural oscillator are involved. Woman with a Cat, Auguste Renoir, c. … Continue reading “Why and how do cats purr?”
  •  (http://www.loc.gov/item/why-do-bats-live-in-caves-why-dont-they-fly-into-objects-at-night/)
    Why do bats live in caves? Why don't they fly into objects at night? Most bats are nocturnal. Bats in a Texas evening sky. Insect-eating Brazilian Free-Tailed bats (Tadarida brasiliensis) provide a great pest-control service to agriculture and natural ecosystems. Paul Cryan, USGS photographer, 2009. USGS Science Explorer Media Gallery Most bats are nocturnal. They fly and forage for their food (bugs) at night. This means that they need … Continue reading “Why do bats live in caves?...
  •  (http://www.loc.gov/item/why-do-geese-fly-in-a-v/)
    Why do geese fly in a V? Energy conservation and visual assurance. Geese flying in classic V formation. Ben Mieremet, NOAA photographer. 1995. NOAA Photo Library. Why do geese fly in a V? Because it would be too hard to fly in an S! Just kidding. Scientists have determined that the V-shaped formation that geese use when migrating serves two important purposes: … Continue reading “Why do geese fly in a...
  •  (http://www.loc.gov/item/why-do-mosquitoes-bite-me-and-not-my-friend/)
    Why do mosquitoes bite me and not my friend? Recent evidence suggests that some people give off masking odors that prevent mosquitoes from finding them. Known as a vector for the West Nile virus, this Culex quinquefasciatus mosquito has landed on a human finger, in order to obtain its sustaining meal of blood from its host. James Gathany, CDC photographer, 2003. Public Health Image … Continue reading “Why do mosquitoes bite me and...
  •  (http://www.loc.gov/item/why-do-pigeons-bob-their-heads-when-they-walk/)
    Why do pigeons bob their heads when they walk? Most evidence suggests that the head bobbing serves a visual function. Rock Pigeon. Introduced to North America from Europe in the early 1600s, city pigeons nest on buildings and window ledges. In the countryside they also nest on barns and grain towers, under bridges, and on natural cliffs. Lee Karney, U.S. Fish and Wildlife Service, … Continue reading “Why do pigeons bob their heads...