Karen Hill

Tin-can telephones do work, actually. The concept is pretty basic: When a person places her mouth inside the opening of a can and talks, the sound from her voice vibrates against the bottom of the can. These vibrations travel down the string and make the bottom of the other person’s can vibrate, too, transmitting the … Read more

Yes. Basic common sense dictates that driving while mentally focused on a conversation slows down reaction time by as much as half a second. But why take our word for it? Here’s what a major study on the topic found: If you talk on a cell phone while driving, you’re four times more likely to … Read more

Maybe. Probably not. Scientists still aren’t completely sure if cell phones cause brain cancer. It’s fairly accepted that cell phones don’t cause cancer with short-term use, but since cell phones haven’t been around long enough to be considered “long term,” it’s too early to say for sure. That said, major studies in recent years indicate … Read more

Sun flares are massive explosions on the sun with enough force to burn through the upper layer of Earth’s protective atmosphere. The flares are magnetic, so Earth’s magnetic field is able to protect us from the huge amount of heat and energy. However, the flares can still manage to disrupt activity on Earth’s surface for … Read more

It depends on how the cats are blowing, daddy-o. (Oh, sorry—, we momentarily flashed back to our neo-Beatnik days.) Anyway, the groove on a compact disc isn’t exactly a groove in the same sense as what’s on a phonograph record. It’s more like a path of binary-coded bumps (which some people call “pits,” though that’s … Read more

Like sonar and radar, laser is an acronym for a phrase that is much longer. LASER stands for “light amplification by the stimulated emission of radiation.”

It depends. The old phonograph records spun at a constant speed (for example, 33 or 45 revolutions per minute). That made it easy to make a turntable to handle them, but it meant that the music recorded near the outside of the record had better sound than the music recorded on the inner grooves. A … Read more

It’s a challenge, all right. DVDs use similar material and manufacturing processes, but there are several differences. Part of the solution was making the bumps that carry data smaller and jamming them closer together, making the “groove” of a DVD 7.5 miles long, more than twice what you get on a CD. But wait, there’s … Read more

We can record on both sides of a DVD, they just usually choose not to. Manufacturers believe that consumers would rather have a colorful label printed on one side than have a two-sided disk with twice the capacity. Some releases, however, have discs that are 2 sided. Although they have been few and far between … Read more

The key, of course, is to get the satellite into an orbit that is exactly the same speed as Earth (one time around every twenty-four hours). A space region called the Clarke Belt, about 22,300 miles above the surface of the planet, is the place where you find a large number of broadcast, weather, and … Read more

A newspaper column said the first person to transmit voices by radio was a Canadian guy. Italian Guglielmo Marconi was the first to send wireless transmissions, but his broadcasts contained Morse code, not voices. We’re not saying that his accomplishment wasn’t a big deal—, by 1901, for the first time in history, messages could be … Read more

Bees use a bee dance to communicate and tell other bees where the flowers are. Here’s how it works. It’s a pattern they trace in a figure-eight shape, while wiggling periodically and flapping their wings. What tells the story is the speed of the bee, the direction the bee points, and the sounds the bee … Read more

Glowworms are lightning bugs (or fireflies, if you prefer) during their larval stage. Glowworms can be found in many parts of North America in the summer. The best time to see them is at night or in the evenings.

Lightning bugs, also known as flireflys, produce light through chemical reactions in little cells called photocytes, using a substance called luciferin. When the enzyme luciferase is also present, the substances oxidize, creating a lot of energy. A spark of light is caused when the substances settle back down again. It is still unclear why fireflies … Read more

Doctors prescribed maggots to help heal wounds during World War I. How did this happen? The doctors caring for war casualties noticed that some patients’ wounds healed quicker and were more resistant to infection than others. At closer look, they realized those patients had flies landing on their open sores and laying eggs. Before long, … Read more

Almost all of the ladybugs will go elsewhere after you release them in your garden or yard. If you have enough aphids for the ladybugs to eat to make it worth their while, about 5 to 10 percent will stay. It helps to have water readily available near where they are released—, some suggest watering … Read more

Some spiders do stick to their own webs. A spider’s web is constructed of two types of silk: “anchor” and “snare” threads. The anchor threads are used to construct the basic web; the snare threads are sticky and are used to trap insects. To get around the web, the spider uses the non sticky anchor … Read more

You can die from a black widow spider bite, but most people who have been bitten don’t. Although a female black widow is not particularly aggressive (and the males are harmless), she will bite in self-defense and is quite poisonous. The effect of her bite is painful and frightening, and there isn’t much that can … Read more

A black widow spider bite starts with a stinging pinprick at the location. Dull numbing pain soon follows, often accompanied by some swelling. Within about thirty minutes, severe stomach pains and clenching of the abdominal muscles begin. After a while, you may get spasms and severe pain in the arms, legs, and feet. Finally, the … Read more

If it were true that earthworms could grow back if cut in half, then worms could dispense with that messy sex business. Worm sex is messy, although pretty efficient. Worms are hermaphrodites, so they can mate with any other worm of their species (although not, as some would have you believe, with themselves). They do … Read more

It’s a good question. It gets unbelievably cold in the Arctic, —down to an average temperature of 90 degrees below zero, with a windchill factor like you wouldn’t believe. The animals living in the Arctic have developed strategies to help them beat the cold. These include ears and tails that reduce heat loss, lots of … Read more

The penguin dives the deepest underwater of all the birds on earth. This is probably because it’s an excellent swimmer. Some species can dive 900 feet, the height of a typical seventy-five-story building, and hold their breath for nearly twenty minutes while swimming.

Scientists penguins would probably not survive if they were transported from their native environment in the Antarctic to the Arctic. For one thing, they would find none of the landmarks that they used to establish their ancestral breeding grounds. For another, they don’t defend themselves and their young well—, they thrive so well in the … Read more

We know it’s hard to imagine flocks of penguins flying overhead, but millions of years ago penguins did fly. Eventually, though, flying became superfluous to their lives. They didn’t have any land-bound natural enemies that would make fast escape by air necessary, and they spent most of their time in the water. Air wings gave … Read more

Alligators, like many other reptiles, don’t have sex chromosomes. As a result, alligator gender isn’t determined by the interaction of the parents’ genes. Instead, it is completely decided by temperature. When it’s egg-laying time, the female finds a nice large area on the bank of her swamp and digs a large hole, up to six … Read more

The lizards that climb walls and ceilings don’t usually fall off. But it’s not because they have great suction. Actually, they’re not really using suction at all. Here’s how their feet work: On the bottom, there are dozens and dozens of grooves. (You can see them if you look closely at the bottom of a … Read more

A newt is a type of salamander in that it fulfills the basic requirements: its skin is thin, it breathes through gills until its lungs grow, and the adults can leave the water and walk among us as land-dwellers. The biggest difference from other salamanders is that adult newts have flatter tails than most. This … Read more

Frogs don’t have teeth, so blinking when they swallow helps them get their food down. Frogs’ eyes, not unlike those of the hippopotamus, are big, bulgy, and located on the tops of their heads. This helps them to see, even when their bodies are submerged in water. The problem is that it also means these … Read more

Both shark oil and cod-liver oil were once very commonly used as supplements for vitamins A and D. However, in the 1940s scientists figured out how to cheaply manufacture the vitamins, saving generations of kids from spoonfuls of the fishy, slimy swill. These days, the dietary supplement in vogue is fish oils. Omega-3 and Omega-6 … Read more

Here’s why it happens: Most fish keep their equilibrium while in the water with an air bladder that balances out their body mass and makes them essentially weightless, neither sinking nor floating to the surface. This is energy-efficient for them, so they don’t have to continuously flap their fins and tails to stay at a … Read more

A Squid can swim faster than an octopus. Octopi are smooth, gliding along on their tentacles like an eight-legged Fred Astaire, but they’re no match in speed for a squid. Squids can shoot water backward like a rocket engine, pushing them forward in great bursts of speed. Some can glide through the water at about … Read more

Standard procedure is for the octopus to squirt the ink, change its own color as camouflage, and simultaneously jet away under the inky murk’s cover. While the ink does do a good job of this, it also holds a secret weapon that further facilitates an octopus’s escape. The ink, even when diluted in the ocean, … Read more

Oh, an electric eel can produce about 350 to 650 watts of electricity, but you better get a surge protector. An electric eel delivers only three to five bursts of electricity when it discharges, each lasting about one-five hundredth of a second. While its voltage is enough to temporarily stupefy a human being, the eel … Read more

It’s not their blood that makes lobsters turn red when they’re cooked. Lobster blood is colorless unless exposed to oxygen, at which point it develops a bluish tint. The shells of lobsters are mostly gray, green, or brown when they’re alive, but never red. Boiling them breaks down the various pigments that color their shells. … Read more

The record for living out of water by a sea creature is about 10,000 years, set by some brine shrimp. Also known as “sea monkeys” in toy stores, the little crustaceans go into a form of suspended animation when they get caught outside the salt water where they make their home. While they remain in … Read more

Before people discovered the mysteries of blood type, transfusions were a hit-or-miss procedure. Some historians believe that the Incas may have been the first to do successful blood transfusions. If that’s true, what would have made the job easier is that they were all the same blood type (0 positive). The year of Columbus, 1492, … Read more

Mixing incompatible blood quickly creates a sea of red dumplings swimming in yellowish liquid, bringing on instantaneous death. In 1900 Dr. Karl Landsteiner discovered the A, B, and 0 blood groups and demonstrated that blood could be successfully mixed within the same group. He named the differences the “Rh factor.”

RH is short for “rhesus,” in honor of the research monkeys that gave their blood (and sometimes their lives) as Dr. Karl Landsteiner tested out these properties.

The first artificial heart valve was implanted in 1952 and used a tiny plastic ball to alternately open and close the blood flow. One problem was that when patients opened their mouths, clicks from the valve were annoyingly loud. The first artificial heart was made of Dacron and was in a Texas man’s chest in … Read more

One day in 1893, a Chicago man named James Cornish was stabbed in the chest and rushed to Provident Hospital, bleeding to death. Despite the medical profession’s lack of success in fixing damaged hearts, Dr. Daniel Hale Williams rushed Cornish into the operating room and called in a team of surgeons. At the time, attempts … Read more

You don’t want any of them, but if you had to choose which not to get, pick the heart attack. Here are the reasons: An estimated 40 percent of all heart attacks are fatal. A heart attack occurs when blood flow is cut off to and from the heart. Over 220,000 people a year die … Read more

The theory we like best is that it’s your body’s reaction to perceptual dissonance. While riding in a car, you’re in an enclosed area in which your eyes perceive that nothing nearby is moving, but your ears and the rest of your body feel like you indeed are moving. In an effort to solve that … Read more

Traffic these days is not much faster than when there were horses on the street, alas. The average speed of a horse-drawn carriage traveling in a big city a century ago was about eight miles per hour. The average speed of a car driving through New York City today, —accounting for traffic lights, pedestrians, double-parked … Read more

Both Detroit and Cleveland claim to be the home of the first traffic light. We do know that both cities installed traffic lights in 1920, apparently independently of each other, and both inspired by the red, yellow, and green safety-light combo used by railroads. However, London beats them both: In 1868, long before motorcars were … Read more

It’s true that earthquakes can create tsunami waves that often devastate distant coastlines. Strangely, though, they don’t do much damage until they actually approach land. That’s because in the open sea, a tsunami is a lateral wave that travels far beneath the surface of the water. Traveling underwater at great speed, it barely affects the … Read more

Most American cities use the recommendations of The Traffic Engineer’s Handbook, which presumes an average speed of 6 feet per second for Joe Pedestrian. If you would like this expressed as a formula, take the total number of feet across the street and divide by 6. Subtract that figure from the total amount of time … Read more

You’re right, it goes against all common sense. Yet it happens. That’s why, when sailing, it becomes necessary to mentally throw out much of what you know about the wind. Forget paper blowing down the street. Forget leaves blowing across the surface of a pond. Sailboats don’t work that way. If they did, the only … Read more

The easiest way to understand the science involved is to float a metal bowl. While the metal itself is heavier than water and would normally sink like a stone, the shape spreads the weight over a large area. So, while the metal’s weight causes the bowl to sink somewhat, the bowl’s rim is high enough … Read more

Elevators have multiple safety features, including brakes to stop them immediately if a cable breaks. This is done mechanically, using variations of an idea dreamed up by elevator engineer Elisha Graves Otis, founder of the elevator company that still bears his name. His safety brake was a large, bow-shaped spring that attached to the car … Read more

No, railroad tracks are not based on the width between the ruts made by Roman chariots, but we know where your friend got this idea. You have to love the Internet: a piece of misinformation gets posted as a joke to a small mailing list in 1994 and takes on a life of its own, … Read more

Dogs’ hind legs move when they are scratched in certain spots for the same reason a person get shivers when someone touches his back or shudders when fingernails are scraped down a chalkboard. It’s a reflex. Some experts say it’s a method that dogs’ wild ancestors once used to scare away predatory animals looking for … Read more

Hippos don’t actually sweat blood, but this erroneous belief is based on an oddity that bears mentioning. A hippopotamus has no oil or sweat glands on its entire body; it does, however, sport a gland that only kicks into action when it gets excited or nervous. This gland excretes a reddish, oozing liquid that is … Read more

Homo sapiens means “Wise human.” However, because anthropologists now identify other ancient subspecies of Homo sapiens (for example, Homo sapiens neandertalensis), modern humans are now known in the scientific world as Homo sapiens sapiens. This, of course, means “wise wise human,” which seems to be overstating the matter.

You’d think so, wouldn’t you? Both are large, ill-tempered, stumpy-legged herbivores. The hippo is second only to the elephant in the category of “heaviest land mammal”; the rhino is third. However, they are not related. The rhino’s habitat may vary, depending on the species, but they are exclusively land-dwellers. The hippo, in contrast, spends over … Read more

As far as scientists can tell, most primates see pretty much the same as people do. However, many of the New World monkeys are an exception to that, —they don’t see red well, leaving their world colored with hues of blue, green, and gold.

Would you believe that they can hide behind picket fences? We didn’t think you would, but it was worth the try. The stripes on a zebra make it quite camouflaged, even in its desert environment. The predators that prey on it, —lions, hyenas, leopards, and cheetahs— don’t see the same colors we do; the black … Read more

The Asian elephant is the only other animal besides humans that, with training and a great deal of coaxing, has demonstrated this ability to stand on its head. Bet you can’t stand on your head.

The giraffe has highly elongated neck bones, giving it its great height, but a giraffe has no more and no fewer vertebrae than a human. Both a giraffe and a human also have the same number as a mouse, a pig, a dog, or an aardvark. All mammals except for two—, the sea cow and … Read more

Indeed, a gigantic ground sloth called Mylodon was very much alive and living concurrently with humans during the Pleistocene epoch—, or the Ice Age— some ten thousand years ago. It became extinct as recently as five thousand years ago. Except for the fact that the Mylodon had no tail (and was about the size of … Read more

A whale, though its penis is not easily measured to exact inches. Whales don’t have erections exactly, but projections —the penis is usually hidden except during intercourse, when it is still partially hidden. But somehow those crafty marine biologists were able to measure it, and here’s what they discovered: the right whale’s penis measures over … Read more

No. A cow has one stomach, but it has four chambers. Those chambers are a necessity, because grass is very hard to fully digest. It takes a lot of nutrients to make a contented cow, so a typical cow takes in 100 pounds of grass and 300 pounds of water a day. The food first … Read more

Cowslips are called that because they have become dependent on cow poop left behind in grazing meadows. So there’s definitely a connection there, with the names at least.

The difference between a pig and a hog is all about poundage or weight. Any swine below 180 pounds is called a pig, and anything above that is called a hog. That’s in the United States only, though. In England, all swine are considered pigs, whatever their weight. There are other specialized names for pigs … Read more

First there was the wild ass, way before the donkey, mule, burro, and jackass. A relative of the zebra, the African ass became a beast of human burdens thousands of years ago. This domesticated ass is what we came to call a donkey. It quickly spread to Europe and Asia. Burros, often used as pack … Read more

That’s easy: the egg came first. Chickens have been traced back genetically to an earlier bird in Indochina called the “red jungle fowl.” At some point one of these jungle foremothers laid an egg that had genetic mutations within it. The mutations were severe enough that the bird that hatched would have to be considered … Read more

An eggshell may look solid and impermeable, but it has about 8,000 pores that are large enough for oxygen to flow in and carbon dioxide to flow out. It was John Davy of Edinburgh, Scotland, who proved this in 1863 by pumping pressurized air into an underwater egg and watching thousands of tiny bubbles float … Read more

Brown eggs are laid by rust-red chickens, most notably the Rhode Island red. White eggs are laid by white chickens, notably the white leghorn, which makes up about 90 percent of the U.S. egg-laying population. What’s the difference between brown and white chicken eggs? You tell us.

Yes, flamingos come in different colors besides pink. Flamingo babies, for example, are born white with gray streaks and take one or two years to develop their pinkish color. And depending on which of the five flamingo species you look at, the color will vary in intensity to the point that some of the lighter … Read more

The dodo, a relative of the pigeon, settled on an island named Mauritius millions of years ago. Because the island housed no predators, the ability to fly had no evolutionary benefit, and the bird eventually became flightless. Dodos lived in relative peace for over 4 million years. In the 1500s, sailors began using the island … Read more

Migrating birds fly in a V formation because it gives them the best of both worlds, reducing air resistance while allowing the geese or ducks in the back to see where they’re going. Think of the V formation as the front of a boat cutting a path through water. The first fowl in the V … Read more

The arctic tern migrates the farthest in a year, by a long way. It migrates 22,000 miles each year, flying from the Arctic Circle to Antarctica— and then, half a year later, flies back again. That’s quite the journey for a bird.

One estimate pegs the number at about 10,000 bugs for every human being, which comes as no surprise to anyone who goes outside on a hot summer night. Others say that estimate is way too low. Over 1.5 million known insect species populate the world today, but entomologists believe there may be millions more out … Read more

If you’re an average adult, it would take about 1,120,000 mosquitoes to completely drain your blood. And in case you were wondering, this event would be highly unlikely, even in the tropics. You’d be more likely to be eaten by some other animal.

“Killer bees,” properly known as Africanized honeybees, are not more poisonous than other honeybees. They are, however, much more aggressive than the gentle European honeybee when they feel threatened or encroached upon, and are more likely to kill people or animals by bombarding them and delivering multiple bee stings. There’s a reason behind this aggressiveness. … Read more

Not at all, bees are definitely not blind. Bees actually have 5 eyes; 3 simple eyes called ocelli, and 2 compound eyes. The compound eyes are made of lots of small, repeating eye parts called ommatidia. About 150 ommatidia in each compound eye specializes in seeing patterns. This allows bees to detect polarized light, something … Read more

Next time you hear someone complain about never using the math you learned in school in real life, remember this question. You’d think the two smaller pies would have more, but that would be wrong. You just need some pi with your pizza. Remember the formula? A = irR2. The “pi R squared” thing works … Read more

No, the Hindus of India invented the Arabic number system around A.D. 600. It was, however, an esteemed Muslim mathematician, al-Khwarizmi, who introduced the system to the Western world when his treatise on mathematics was translated into Latin in the tenth century. Which is why Westerners mistakenly attributed it to the Arabs. The Hindu number … Read more

Nope, there’s no year zero in our calendar system. he year before Christ was theoretically born is referred to as 1 B.C.; the year he was born is counted as A.D. 1, with no Year Zero in between. And if Jesus were born in A.D. 1, on December 25 (which he wasn’t), it would be … Read more

Geometry may very well have been invented by some sadistic teacher in ancient Egypt. Most scholars believe that the Egyptians were the first to make extensive use of geometry, what with measuring land, building those pyramids, and all. The truth is that geometry as a science has very obscure origins. Geometry in general, though, has … Read more

The Pythagoreans-ancient Greek followers of the mathematician Pythagoras-were a brilliant lot. They came up with the mathematical truism, The square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides. They also mathematically figured out the correct shape of Earth. In working out … Read more

Webster’s Unabridged dictionary dates the term “jiffy” back to the early eighteenth century. It was used then, much as it is now, to mean “instant,” as in, “This chapter will be done in a jiffy!” It’s also been used as a computer term. Depending on which source you ask, it’s either one-sixtieth of a second … Read more

Water from lakes, rivers, and reservoirs isn’t usually clean enough for our drinking glasses, so before it gets to our tap, it goes through a water treatment plant. First the water runs through large filters that rid it of large objects like sticks, leaves, dead animals, trash, and so on. From there, the plant injects … Read more

Credit the “stink trap,” which pretty much does what its name implies, stopping the stink from coming up from the sewer system. It stops the stench of the sewer from rising up and bothering the inhabitants of your house. How does the stink trap work? Oh, it’s a marvel of primitive technology, but it took … Read more

The stuff you flush down the toilet doesn’t go to the ocean. At least not right away, unless it rains and the extra liquid seeping into pipes overwhelms the sewage system. Here’s what happens: If you have a septic tank buried in your backyard somewhere, the waste and water go there. The solid wastes sink … Read more

No, the water in toilets and bathtubs don’t spin clockwise in the Northern Hemisphere and counterclockwise in the Southern. It’s a myth. There is something that’s called the Coriolis force, which affects huge bodies of water and tends to make them want to spin in response to Earth’s rotation. But what works with huge oceans … Read more

Gaspard-Gustave de Coriolis (1792-1843) was a French scientist who not only discovered the Coriolis force that bears his name, but also introduced the concepts of “work” and “kinetic energy” to physics. He also tried to popularize a new word he coined, “dynamode,” which he defined as 1,000 kilogram-meters of work (in other words, the amount … Read more

If you don’t mind stinking, no there isn’t a medical reason for bathing or taking a shower. Your skin doesn’t care if it’s clean or dirty. In fact, excessive bathing can do some harm, —it can irritate the skin, and dry it out in older people. Throughout history, there have been some people who have … Read more

How often you have to bathe or shower to stay clean is a judgment call that depends on what you mean by clean. Advertisements of soap and deodorant companies imply that you should bathe daily or even more frequently. In some parts of the world, it’s common practice to bathe only once a week or … Read more

Mildew only grows in between the tiles on the shower wall because it has to do with the porousness of the surface. Ceramic tile is glazed and therefore not porous like the grout between the tiles. Because it retains water, the grout creates a fertile field in which mildew can grow. The truth is, though, … Read more

Well, first of all, try using the several gallons of water in the reservoir tank of the toilet if there is ever a water shortage (the squarish thing at your back when you sit down on the seat— not the bowl). It’s fresh and clean enough to drink, unless you’re a little squeamish about drinking … Read more