Science

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

If the hot water tap in your showers start out fast then slows down to a trickle, it sounds like you have a defective washer, that rubber disk within the faucet that helps stop the water from flowing when you turn off the tap. Although the washers in both faucets can erode with time, the … Read more

Only you can test this one out, and find out if taking long showers would save you more water taking a bath. Plug your tub while showering, and see how high the water level is when you’re done. In general, a shower usually uses 10 to 15 gallons of water, while a bath usually takes … Read more

Better yet, we can give you an account from the first century B.C., written by Marcus Vitruvius Pollio, a Roman architect, engineer, and writer: In the case of Archimedes, although he made many wonderful discoveries of diverse kinds, yet of them all, the following, which I shall relate, seems to have been the result of … Read more

As it turns out, fluoride helps prevents tooth cavities in at least three ways. Science has known for a while that fluoride acts as a building block for teeth. Fluoride supplements, whether in drinking water or vitamins, help build stronger enamel in kids’ teeth before they even emerge from the gums. After the teeth emerge, … Read more

There are good reasons for using soap and shampoo for specific purposes. Soap cleans by using two methods. First, the fat in soap seeks out and surrounds dirt. The other substances in soap cling to water and help to wash away the fat and dirt molecules. But soap doesn’t work well on hair. Because soap … Read more

Marketing is the reason vitamins are put in shampoo. Because they make the shampoo sound like it’s more than just expensive glorified dish detergent. Although a lot of shampoo brands imply that the various vitamins they put in their products help make hair healthy and shiny, the truth is that vitamins can’t do much of … Read more

From a bacterial standpoint, it takes about twenty seconds for the germs and dirt to be picked up and washed away. Then there’s the case of why Ivory soap floats. Ivory soap floats because of air. They whip the soap, allowing air pockets to get into the mixture before it solidifies. As with a flotation … Read more

Actually, no one’s really sure how Rogaine makes your hair start growing again. What we do know is that it can’t make hair suddenly start growing after years of not growing. Because of this, it’s most effective on people who have just begun to notice a little bit of thinning. On most people, after about … Read more

People rode around in gliders before the Wright brothers were even born. In 1849 British engineer George Cayley built a glider that he tested by flying it like a kite. It had enough lift to carry a small boy briefly into the air, but it still wasn’t large or maneuverable enough to fly untethered. Finally, … Read more

A lot of people did think about adding an engine to a glider before the Wright brothers. For example, in 1843, William Samuel Henson wrote an article in Mechanics Magazine that proposed an “Aerial Steam Carriage” that would use a steam engine to drive a propeller in a fixed-wing aircraft. The problem wasn’t a lack … Read more

Designers of the B-2 Spirit stealth bomber say that they used radar-absorbing surfaces and a weird shape to outsmart radar systems. However, the more complicated and more disturbing answer is that the much-ballyhooed stealth design works only against a certain class of radar, and that the planes can be detected by newer radar systems. As … Read more

It’s an old childhood dream, isn’t it? Getting together enough helium balloons to “slip the surly bonds of earth” and glide peacefully over the rooftops. Well, that was Larry Walters’s idea as well. On July 2, 1982, the North Hollywood truck driver tied forty-five weather balloons to a lawn chair outfitted with a pellet gun, … Read more

The ancient myth of Daedalus and Icarus notwithstanding, it wasn’t until 1977 that a human-powered airplane managed to go any significant distance. Called the Gossamer Condor, the plane was designed by a California-based engineer named Paul MacCready. MacCready built the plane in order to collect on a long-standing award that British industrialist Henry Kremer established … Read more

If you’ve got a fear of flying and an active imagination, your mind can generate vividly horrifying scenes: ball lightning rolling down the aisle, shorting out laptops and cell phones, electrocuting passengers, overcooking the chicken It la king, that sort of thing. It probably doesn’t help to hear that lightning strikes airplanes more often than … Read more

A lot of nervous fliers have come under the impression that passenger jets will pretty much fall out of the sky if all the engines fail. The truth is that large planes can glide about as well as small ones. In fact, sometimes while landing a pilot will put the engines into idle and let … Read more

Increasing temperature or altitude can make a plane fly less efficiently by decreasing the overall density of air. The heat wouldn’t make the plane unable to fly, but it could increase the distance the plane needs to lift off and reach a good altitude. That could be a problem when taking off on a short … Read more

Planes on aircraft carriers use a technology that was perfected in the days of chariots and togas: the catapult. Under the deck of the carrier are two huge cylinders that measure more than 150 feet long. The cylinders, connected to a launcher, build up a great deal of pressure as they’re filled with steam diverted … Read more

While planes occasionally make an emergency landing on a freeway, there isn’t (and never has been) any such policy. “As with Dracula, it is very difficult to put a stake through the heart of this ‘fact,’ ” writes Richard F. Weingroff, an information liaison specialist for the Federal Highway Administration’s Office of Infrastructure. “It’s like … Read more

Well, it’s really quite clever in a low-tech sort of way. Most cars these days have a rearview mirror that deflects headlights when you tilt it. Picture a sheet of glass that isn’t the same thickness all the way through, but instead is cut at an angle so its top is thicker than its bottom. … Read more

You’d think it would take twice as far to stop a car going 60 mph than one going 30, but in fact it’ll take about four times as far—, roughly 180 feet at 60 mph, versus 45 feet at 30 mph. It’s an illustration of the principle that as you increase speed, your momentum (and … Read more

Wham-O, the company that brought the world the Superball, starts with a good, bouncy rubber—in this case, Zectron, which is Superball’s trademarked name for the synthetic rubber polybutadiene with some sulfur added for reinforcement. They take that and add a whole mess of pressure when they mold the ball. How much pressure? The company says … Read more

Well, in a sense there’s only one way to solve a Rubik’s Cube, but according to the Rubik’s Cube official Web site, there are about 4.3 times 10 to the 19th power, or 43,252,003,274,489,856,000, possible combinations. With so many possibilities, you’d think it would be a lot easier!

Mathematically, there are 2,598,960 five-card hands possible with a standard fifty-two-card deck in Poker. But that’s child’s play, considering there are 635,013,559,600 possible hands in a game of bridge. Still, these can’t hold a candle to chess: a mathematician once calculated that the first ten moves in a game could be played in 170,000,000,000,000,000,000,000,000 different … Read more

Here’s how it works: the oily extracts of the smells are placed inside really tiny bubbles of plastic, —millions of microscopic bubbles. How do they do this? By emulsion, —the mixing of oil and water. When they furiously mix the extracts with water, the oil is broken up into very tiny droplets, at which point … Read more

Most of us have an inexplicable fascination with bubbles. Even Mark Twain once noted, “A soap bubble is the most beautiful thing, and the most exquisite in nature. I wonder how much it would take to buy a soap bubble, if there was only one in the world.” Fortunately for us, there’s not. Here’s a … Read more

It would be cool if the story of the Slinky went back to the ancient Phoenicians, or Thorg, a druid from the Iron Age who discovered the property of a metal coil on stairs, but alas, Slinky’s history is shorter than that. It was during World War II that a marine engineer for the U.S. … Read more

First of all, a lot is owed to the stairs (or stack of books, or shelves) themselves. If the stairs you used were taller, the Slinky would flip over and end up rolling the rest of the way down. If the stair were shorter, the initial fall off the first step wouldn’t give the toy … Read more

The silver stuff in an Etch A Sketch is the metal aluminum, ground so finely that it sticks to everything. This is true even if it manages to escape the insides of the Etch A Sketch. This powder inside the toy is peppered with little plastic beads that keep it from clumping. The window of … Read more

The Star Trek television show was created by a man named Gene Roddenberry. In tribute to the man and his promotion of far-ranging space travel, some Trek-loving scientists have coined the term “Roddenberry” to mean the distance traveled at the speed of light during a “traveler year.” A traveler year is an Earth year as … Read more

We’ve all heard the story of the penny falling from the top of the Empire State Building and slicing its way through a parked car (or a pedestrian) below. It never happened, no matter what Jimmy Doofus in the fifth grade may have told you. Have you ever dropped a coin into a wishing well … Read more

Don’t try it. The ball’s extra weight and shape would do some real damage. Not that it would necessarily kill someone below, but getting hit by a falling baseball sure wouldn’t do them any good. There is, in fact, some data to back this up. In 1938, for a publicity stunt, some Cleveland Indians caught … Read more

According to scientists who have tested such things, here are the approximate terminal speeds for various common objects. As you can see, variables include weight and wind resistance. Raindrop: 15-20 mph Ping-Pong ball: 20 mph Golf ball: 90 mph Baseball: 95 mph Person spread-eagled: 125 mph Person balled up: 200 mph 30-caliber bullet: 200 mph … Read more

There’s controversy about the effects shaving has on swimmers. A few studies using a small number of swimmers have shown some improvement in performance after shaving. So that may be the answer. Skeptics, though, say the studies are flawed. Since most swimmers believe that shaving will help them go faster, they say it’s not surprising … Read more

It was golfers themselves who discovered that golf balls with nicks, dents, and scrapes flew farther than the round, smooth balls that were originally used in the modern game of golf. The effects were so dramatic that they began aging their new balls as quickly as possible by pounding and scraping them. Eventually, the manufacturers … Read more

“You never hear the one that hits you” was the fatalistic saying on the front trenches of many wars (not to mention the song of the same name by the rock group Stiff Little Fingers). Well, it turns out that the soldiers and the punk rockers had their physics down pat—, a bullet travels faster … Read more

What you’re hearing is part of the constant ambient sound that we don’t often register because it always surrounds us. The shell reflects and focuses higher frequencies back to our ears. The reason is that high-pitched sounds have short wavelengths, so they tend to bounce when they hit a hard surface. The longer wavelengths of … Read more

Oh, no, you don’t. This is one of those pointlessly endless questions with an answer that depends on how you define sound. If you define sound as “vibrations within a certain frequency,” then the answer is yes. If you define it as “something perceived by an ear,” then the answer is no. So to answer … Read more

After New Jersey Monthly journalist Steven Levy asked this question back in the mid-1970s, he tracked Einstein’s brain down to a shelf in the study of Dr. Thomas Harvey, —the doctor in Wichita, Kansas, who performed Einstein’s autopsy in 1955. The brain was separated into lobes and kept in two mason jars inside a cardboard … Read more

No, brain size doesn’t seem to matter that much. During early tests on Albert Einstein’s brain, for example, scientists found no significant difference between the size of his brain and those of people with normal intelligence. That said, there does seem to be evidence that genius brains may be different from average people’s brains. Although … Read more

Well, let us answer your question as you asked it and then answer what we think you’re really asking. Spontaneous combustion happens when heat-generating chemical reactions occur in an enclosed place. Usually heat from oily rags or mouldering vegetation escapes into the surrounding atmosphere, but if it’s stored in a place with poor ventilation, the … Read more

Ah, yes, that mysterious phenomenon that people like to scare themselves with around campfires and on supernatural Web sites. The stories have been around for centuries in legend, temperance tracts, and fiction. In Jacob Faithful (1834), novelist Frederick Marryat wrote about a character’s disreputable mother who “perished in that very peculiar and dreadful manner, which … Read more

In theory, water that has been boiled and cooled will freeze faster than plain cold tap water. Boiling removes the air bubbles that tend to slow down the freezing process, and it also reduces the amount of liquid. However, in your kitchen or ours, the time difference is so minuscule, it wouldn’t be noticeable. So … Read more

Russian scientist Dmitri Ivanovich Mendeleyev invented the periodic table in 1869. In gratitude, scientists named element 101 after him. mendelevium.

The invention of the thermoscope, a thermometer like device used to measure body temperature, is usually credited to the physician Santorio Santorio in 1612. Many argue that knowledgeable men of the day, including Galileo, collectively invented the device. However, Santorio was the first to actually add a number system to gauge changes in temperature.

Swede Anders Celsius invented the metric model or Celsius scale for temperature in 1742. But his version paradoxically had water boiling at 0 °C and freezing at 100 °C. Another Swede by the name of Carolus Linnaeus (who incidentally was also the guy who came up with the genus/species method of naming plants and animals) … Read more

Noble, in this case, has nothing to do with royalty. “Noble” metals stands for metals like gold, silver, platinum, and mercury that are resistant to reactions with other things. They don’t oxidize or rust quickly like base metals do. Base metals include copper, aluminum, lead, tin, nickel, and zinc.

Elements 57 through 71 plus the elements scandium (21), yttrium (39), and thorium (90) are all called rare earth elements. When many of these elements were discovered, the process of extracting them was difficult and costly. Scientists also believed they weren’t largely available in Earth’s crust. This is how they came to be called “rare.” … Read more