Karen Hill

For a temporary drawing, you can use a marker or henna, of course. But it’s even cooler to use a Polaroid picture, and it’s an interesting, photo-realistic alternative to gumball-machine tattoos. Here’s how you do it: Using a Polaroid camera, take a picture of whatever image you’d like to use—it could be of yourself, your … Read more

Go to your workshop or toolbox and retrieve a new D battery, a big iron nail, electrical tape, and several feet of thinly coated copper wire. Wrap the middle of the copper wire around the nail evenly. Leave a good length of the wire free on either end, and strip the coating off the ends. … Read more

The hard-boiled egg trick is a fun trick that sounds even more impressive before you see it than after. That’s because you use a peeled egg. If you want to add a little more scientific mystery, you can combine this with the rubberized-chicken-bone stunt. It turns out that if you soak a hard-boiled egg in … Read more

Probably by using vinegar, an acid that will dissolve the calcium in bones. Calcium, as you probably know from school or television commercials, is what makes bones hard and strong. Try it yourself: take the drumstick of a chicken and clean off all of the meat. Place the bone in a jar of vinegar and … Read more

Any time at the equinox is a good time to try to get an egg to stand on end. Or, for that matter, on Easter, Hanukkah, Arbor Day, Ramadan, Shrove Tuesday, or your mom’s birthday. The truth is that if you’re patient or steady enough, you can get an egg to stand on end at … Read more

To make gooey Slime first get white glue, borax, food coloring, and water. Take a cup of water and add one tablespoon of borax to it and stir. Take a half cup of water and add a half cup of white glue. Add the two mixes together with some food coloring, mixing thoroughly (an easy, … Read more

Homemade rock candy is easy, fun, and illustrates the scientific concept of crystallization. It also teaches patience, because you have to wait a long time before you can actually eat the stuff. First get a jar, a pencil, and some twine. Tie the string to the pencil and prop the pencil over the mouth of … Read more

A Depression flower garden is also called a coal garden or a crystal garden. It’s a homemade set of colorful crystals. They’re a lot of fun for kids and grown-ups, and are a hands-on way of learning about crystal formations. You begin by breaking up several charcoal briquettes and putting them into the bottom of … Read more

Baking soda and vinegar probably make the best-known kitchen science combination around. There are few that have results quite as impressive. Here’s an alternative to the age-old volcano. You will need a leak-proof Ziploc sandwich bag, vinegar, warm water, a tissue, and two tablespoons of baking soda. Now place about a half cup of vinegar … Read more

Start with a glass of ice water. Pull out a thread or a strand of hair. Start by asking your seven-year-old if he can use the thread to lift an ice cube out of the glass. Let him work on it awhile until he gives up, then take the thread back. Lay the thread or … Read more

We forgot boss rock, which was a geological term long before Bruce Springsteen came along. But seriously, yes, your teacher is correct. If you’re looking for a good genre name, it’s always best to turn to science first. Check out some of these other geological terms and see if any could apply to your band’s … Read more

If you have a deep-seated fear of money, you’re suffering from chrematophobia. However, most people don’t have this fear, and love money. Some of us love money too much. When that happens, it’s called greed. Greed can occur in free market economies that have no monetary regulation and is often the result of a capitalist … Read more

Only about 2.5 percent of a penny is copper. The layer is just thick enough to give the coin its distinctive copper color. Most of the penny is made with zinc, but that’s a relatively new development in the history of the coin. Before 1982, pennies were about 95 percent copper. So why the switch? … Read more

A mile is 5,280 feet instead of an even number like 5,000 and you can blame it on the Tudors and their fondness for the furlong. The mile was originally 5,000 feet, but Queen Elizabeth I wanted it divisible by a furlong. Each furlong measured exactly 220 yards, so in 1575 she made it a … Read more

Well, yes, but British royalty (as noted above) don’t always do things because they make sense. The original marathon from the first modern Olympics in 1896 was actually based on physical landmarks. It began at Marathon Bridge and ended at Olympic Stadium in Athens. This gave it a distance of 24.85 miles, or an exact … Read more

You can’t see any man-made object on earth from the moon. It’s too far of a distance from earth to see anything. If you look at pictures of astronauts on the moon with the full Earth behind them, you can see why—, Earth from the moon doesn’t look much bigger than the moon looks from … Read more

It’s a good question. You’d think that a rocket’s exhaust has to push against something, like a paddle needs to push against water to propel a canoe. But in reality, a rocket doesn’t need to push against the atmosphere to fly. What it’s doing is essentially pushing against the inertia of the rocket exhaust. But … Read more

The squid uses jet propulsion to get around. It fills up a sac within its body with water and then forces it out through a tube below its head. This jet action makes the animals glide through the water at pretty high speeds.

On November 3, 1957, less than a month after its first ever space launch, the Soviets sent up Sputnik 2, complete with a dog named Laika. She didn’t survive in space for very long. Conflicting accounts put the number of days at somewhere between four and seven, but that was it. The Soviets, rushing to … Read more

Surprisingly, eating and drinking in space isn’t quite like you’ve seen in movies. Not everything has to be sucked out of a tube. It turns out that astronauts can eat most foods normally without having them float out of their containers. True, food containers need to be fastened to a surface with Velcro, magnets, or … Read more

It’s hard to get an exact figure on how many nuclear bombs have detonated since World War II, because governments try to keep these things secret. We do know that up until 1996, there were 2,036 known nuclear bomb explosions. Three-quarters of those were exploded underground, with 511 taking place in the open air. More … Read more

The British were pounding Fort McHenry with a weapon that had been used against them twenty years earlier while they were conquering India in the 1790s. Indian gunpowder experts had enlisted in the fight against British imperialism, pounding the British troops with a hail of primitive exploding rockets. Though India eventually lost, the devastating effect … Read more

How would you explain the “rockets’ red glare, the bombs bursting in air,” written during the War of 1812? Now go back even further, to A.D. 1232. That year signaled the oldest known reference to using rockets in battle. At the time, the Chinese were fighting against Mongol invaders. The written record shows that the … Read more

The sound a whip makes is the tip of the whip being propelled at over 700 miles per hour. When flicked just right, the end breaks the sound barrier, creating a small sonic boom. The sonic boom is what you hear when it’s “cracked.”

No one invented time; it was likely discovered, even if subconsciously, by every culture. At some point early on, humans were aware of time passing and began keeping track of it. Although we don’t know who was the first, archaeologists are discovering more and more ancient civilizations that devised their own unique ways of marking … Read more

Self-winding watches wind themselves by using a little pendulum that swings when you move your arm. A few hours of natural arm movement will wind a self-winding watch enough that it can go for thirty-six hours without further winding.

Yes, there is a type of wine that will make you tipsy faster than other wine. It’s champagne. The little bubbles in champagne are carbon dioxide, which moves into your bloodstream faster. But there could be a more contextual reason why it gets you intoxicated more quickly than regular wine. It’s usually consumed during momentous … Read more

To measure how many calories there are in food, we use a hot little device called a bomb calorimeter. It burns foods and measures the difference between how much energy went in versus how much energy comes out. Here’s where it gets confusing if you ever talk to a physicist about your weight loss program: … Read more

Not all corn kernels are equal. In order to pop, the kernel needs a water content of about 13.5 percent. Each popcorn kernel consists of soft, moist starch inside a hard outer shell. When heat is applied, the moisture expands and the starch is cooked. Eventually, the pressure gets so high that it bursts the … Read more

No matter how much high-impact channel surfing you might do with the remote control, you burn only 1 to 2 calories per minute when you watch TV. What you should do instead is get off your bum and get outside. Do something. Anything.

T.W.I.N.K.I.E.S. stands for Tests with Inorganic Noxious Kakes in Extreme Situations, and was conducted by students at Rice University during finals week in 1995. These tests were conducted on Twinkies, with a special emphasis on experiments using the force of gravity, radiation, flame, and heat, etc.

You have to leave a tooth in Coke for mighty long time for it to completely dissolve. Despite the facts, this long-running myth just keeps going and going. A tooth won’t dissolve in Coke or carbonated soda of any kind. However, if you eat lots of candy and drink lots of pop, and you don’t … Read more

It sounds reasonable to put up fences on San Francisco’s Golden Gate Bridge to deter suicide jumpers, considering the bridge is open to pedestrians and is a popular tourist spot. The average is about twenty-two deaths a year. Only a few have ever survived the 250-foot drop into the chilly, raging Pacific below. We’ve heard … Read more

Burnished copper gives the Statue of Liberty that green hue. The copper sheets are no thicker than a penny, and were made in France, shipped over, then riveted to the iron frame of the statue. Because the rusted green copper actually serves as a coating that protects the integrity of the metal below, there have … Read more

When constructed in the 1800s, aluminum was a semiprecious metal, both hard to find and difficult to extract from bauxite, also known as aluminum ore. So at the time, it was considered a fine luxury to have an aluminum cap crowning the top of the monument. Still, there were practical reasons as well. For starters, … Read more

No, a light bulb can’t turn on in your mouth like Uncle Fester did in The Addams Family unless you’re electrically charged. That, of course, would require having enough electricity running through you to electrocute you. Uncle Fester’s lit-up bulb was just a stage trick for the show. You can, however, make a light bulb … Read more

A computer engineer named Ray Tomlinson invented e-mail, otherwise known as electronic mail. He’s also the guy who designated the @ sign as a crucial part of email addresses. Long before the Internet as we know it existed, there was ARPANET, an experimental forerunner commissioned by the Defense Department in 1971. It consisted of fifteen … Read more

Here’s how a candle burning at both ends rocks like a perpetual-motion drinking bird. Grab a candlestick, a match, and a pin, and let’s do the impossible: burn the candle at both ends. First, make sure you’re working on a clean, flat surface like a bare kitchen counter or table—one that won’t instantly go up … Read more

The best way to see if you’ve generated static electricity is to put on wool socks, run around on a plush carpet rubbing your feet briskly, and touch metal or another human. See how many times you come out unscathed. We also recommend a less painful way, like bending water. You’ll need clean and dry … Read more

One of the three best in-the-dark revelations of adolescence is that if you crack a Wint-O-Green Life Saver between your teeth, tiny blue and green sparks will flash in your mouth. If you’ve never seen it happen, pick up a pack of Wint-0-Greens and wait until after dark. Turn out the lights and crunch one … Read more

In 1906 Thaddeus Cahill first unveiled the Telharmonium, an instrument made up of 145 modified electrical generators and specially geared shafts and inductors that produced alternating currents of different frequencies. Since it was twenty years before the invention of the amplifier, Cahill ran the resulting current through the Bell Telephone system to phone receivers equipped … Read more

A global positioning system receiver is a pretty cool little gadget. It’s somewhat based on the navigational systems of old in which skilled sailors using compasses, astrolabes, and sextants could tell where they were (give or take a hundred miles) by combining the data of the stars, sun, and moon positions. Of course, there were … Read more

The person who invented the Moog synthesizer is Dr. Robert Moog, the man who invented the instrument that helped define the psychedelic sound of the late 1960s. A decade earlier, as a graduate student at Cornell, Moog financed his musical science dreams by selling about a thousand of his do-it-yourself Theremin kits for $49.95 each, … Read more

It’s a theremin, which sounds like it should be one of the B vitamins, but instead it’s a spooky-sounding electronic instrument developed by a Russian scientist named Leon Theremin in 1920. The instrument used two radio wave oscillators to generate the sounds, and musicians obtained its sliding sound by moving their hands along the theremin’s … Read more

A Scottish clockmaker and inventor named Alexander Bain patented the first facsimile machine on May 27, 1843, —thirty-three years before Alexander Graham Bell’s invention of the telephone. It took another few decades before the invention got any significant use. A commercial fax service (called “pantelegraphes”) opened between the French cities of Paris and Lyon in … Read more

The technology in a fax machine is pretty simple. A bright light reflects off the document as it passes along a strip containing hundreds of tiny photocells. If a white area of the page passes below, the photocells convert the light shining off the document into electricity. If the area is black, the photocell generates … Read more

The first computer mouse was invented by Douglas Engelbart in the early 1960s. Douglas Engelbart was Director of the Stanford Research Institute’s Augmentation Research Center, located in Menlo Park. The mouse has been widely used since the time of its introduction. It’s now the standard peripheral of all new computers. There are more than a … Read more

A bubble jet printer uses a principle as old as mud bubbling out of the ground. Have you ever noticed that when bubbles pop, a little of the liquid gets propelled outward? Sure you have, —think of the misty feeling you get when you put your nose up to ginger ale, or the stickiness that … Read more

Here’s how a laser printer works. Inside the printer is a large metal roller (the “photoreceptive drum”). As the drum rotates past an electrified wire (“the corona”), the surface gets a positive electrical charge in preparation for the laser beam. The beam is guided by the computer, of course, invisibly scanning the text and images … Read more

The joystick predates computers by decades. It has been a part of airplanes almost since their introduction—its first known reference dates back to 1914. An airplane joystick works much the same as with computer games—you pull or push it, or lean it to the side, to control direction of movement. Where did it get its … Read more

A lava lamp works on two principles: heat rises, and some liquids don’t mix. Waxy liquid shares a glass bottle with thin, watery liquid. The bottom of the metal base underneath the glass bottle holds a light. When you plug it in and turn it on, the light slowly heats up the contents of the … Read more

Polaroid photos are seemingly a magic trick, and in reality there is something of an illusion in the way it “develops before your eyes.” After you take an instant photo, it passes through two stainless-steel rollers, which spread chemicals that are collected in a blob at the edge of the plastic film sheet. These chemicals … Read more

It’s called Kirlian photography, and there is indeed something to it. However, it isn’t what its parapsychological proponents claim. The process is named after Semyon and Valentina Kirlian, a husband-and-wife team who first reported their findings in the Russian Journal of Scientific and Applied Photography in 1961. What they discovered was that if you put … Read more

When Francisco Goya’s work changed drastically from conventional portraits to dark and grotesque subjects, it was probably the result of lead poisoning. Through his mid-forties, Francisco Goya was not only a court painter but also well known for his tame and innocuous subjects. But all that changed when he was forty-six. In 1792 he contracted … Read more

Indian yellow was first introduced in the 1750s and quickly became a staple of every artist’s palette because of its rich yellow hue. To get the deep color, manufacturers fed mango leaves to cows, collected their urine, and made a concentrate from it. In 1908 officials decided that feeding large quantities of mangoes to cows … Read more

There were many patents for typewriter-like machines, but only in 1868 did Christopher Latham Sholes invent the first typewriter that was also practical to use. The Remington Arms Company began producing it in 1873. One of its biggest fans was writer/humorist Mark Twain. He called it “a curiosity-breeding little joker” and was one of the … Read more

Graphite is a rock—, a carbon compound that’s been used for writing since long before modern pencils were invented. But it was an eighteenth-century geologist—, Abraham Werner, —who named the stuff graphite, from the Greek word meaning “write.” Eventually, we figured out how to enclose the graphite in wood so our hands don’t get dirty … Read more

Seeing that pencil “leads” are made from graphite, the name doesn’t make much sense, does it? But there once was a time when people thought graphite was a type of lead, hence the name. Lead is extremely toxic to humans and pencils should not contain any lead, even in the wood or paint. This is … Read more

First of all, very few people are actually, clinically tone-deaf. It means they have a neurological condition that renders them totally unable to hear differences in pitch. People who are truly tone-deaf can’t even hear the pitch differences in speech, —for example, whether someone’s voice is going up when asking a question, or staying even … Read more

Middle C is vibrating at a rate of 261.625 hertz. The C above middle C is vibrating at 523.25. The C below middle C is vibrating at 130.8125. You may notice that the higher C is vibrating exactly twice as fast as middle C. The lower C is vibrating at half the speed. This rule … Read more

Loudness hurts the ear, but frequency doesn’t, even if it’s really annoying. Once it goes above a certain frequency, the human ear simply won’t hear it. Also, as you get older, you will lose hearing in more of the higher frequency range. This can also happen if you damage your hearing by subjecting your eardrums … Read more

When you put colored sugar granules in the top of a hot metal cup that has tiny holes in it, it’s a lot like how polyester fiber is made. The sugar melts, and when the cup rotates at a high speed, tiny threads of molten sugar come shooting out of the spinnerets (the little holes) … Read more

Given the fuzzy pajamas that babies are wont to wear, we’ve often thought that panels of Velcro around the house would be a great way to get them off the floor and out of the way. Unfortunately, the good people at Child Protective Services had other opinions. But an adult? Let’s consider David Letterman as … Read more

A Swiss engineer named George de Mestral invented Velcro. In 1948 he was walking through woods and fields with his dog, presumably yodeling into the mountains, when he got intrigued by cockleburs that were getting stuck to his pants and his dog’s coat. Being an engineer, he took some home, looked at them under a … Read more

Death Valley, California, is situated 282 feet below sea level, making it the lowest dry land in the United States.

Earthquake weather means different things to different people. Some people believe that long stretches of abnormally hot temperatures precede earthquakes. Others believe bouts of low humidity are good indicators. There are as many weather theories as there are weather patterns. The truth is that weather plays no apparent role at all in the shifting of … Read more

Gibraltar stands as the northern gateway to the Mediterranean Sea, and has historically been a much-coveted fortress for observing all the movement in and out of the area. Despite its history as an impenetrable fortress, the Rock of Gibraltar consists almost entirely of soft gray limestone with a touch of shale thrown in for good … Read more

Despite its name, catgut isn’t actually made from the guts of cats. It was originally derived from the intestines of sheep, which were dried and twisted into thin, strong strands. While catgut could be made from the intestines of cows and other animals, there’s no evidence that cats were ever its source. So why isn’t … Read more

There is a difference between kidney stones and gallstones. The “stones” that grow in each are related to what each organ does for the body. The gallbladder is a small sac that lies just below the liver. It holds bile that’s been produced by the liver, saving it until the stomach needs it to add … Read more

No, kidney stone jewelry is not made from kidney stones, but it can be pretty confusing. What’s called a kidney stone in the jewelry business is really nephrite or hematite. The stones have been historically used by crystal healers and others in “treating” problems with the kidney, hence the name kidney stone. That doesn’t mean, … Read more

Not a diagnosis per se, but there is a name for the condition. It’s called an epigastric sensation.

A regular, routine chest X ray gives you the equivalent of three days’ worth of background radiation, —the levels of radiation you receive naturally from the sun, Earth, and other celestial bodies over the course of three days. A full-body CAT scan gives you the equivalent of four years of background radiation. This means that … Read more

There’s so much genetic work going on, some of which is still secret, that it’s hard to really determine which one is the weirdest. As far as we’re concerned, one of them has to be the glow-in-the-dark mice that obtained this ability courtesy of glowing jellyfish DNA transplants. Another is the pig teeth that grew … Read more

Originally proposed by the Department of Energy in 1990, the Human Genome Project set out on a fifteen-year biological journey, to discover all of the human genes. By early in 2001, both a government group and a private group of scientists had done an initial rough draft of the human genome. As of this writing, … Read more

No, a genome is the DNA—, or all of the genes within an organism. The human genome projects aims to map the entire human genome so that we can better understand diseases such as cancer. Hopefully one of these days, this information can be used to cure cancer and solve many other medical mysteries.

A couple of pills are specifically used in the treatment of alcoholism. The latest one is naltrexone HC1 (brand name ReVia)—a pill that blocks the effects of opoids. Opoids are neurotransmitters that the brain releases when thrilled—and also when drinking. They bind to receptors in the brain, and are believed to cause the “high” that … Read more

After Anton van Leeuwenhoek invented his microscope in 1642, a colleague was using it to look at thinly sliced cork. He thought that the neat rows of squares looked like the living quarters of monks —”cells”— and so the name stuck.

While people had figured out long ago that sex produced babies, they hadn’t yet discovered spermatozoa. In fact, it wasn’t until the invention of the microscope that people even knew the little fellas existed. Anton van Leeuwenhoek, inventor of the microscope, became one of the first to see sperm, bacteria, and protozoa. However, he didn’t … Read more

Boiling water will kill most bacteria and viruses, including those that want to do you harm. However, if you’re looking for complete sterility, boiling temperatures won’t kill every type of microorganism. For example, heat-loving bacteria have been found swimming in superheated volcanic vents bubbling up from the ocean’s floor, in the hot springs of Yellowstone … Read more

There’s a big difference between homeopathy and holistic medicine. Homeopathy comes from the belief that bringing on a small amount of the symptoms that all you will make you well—, homeo means “similar” in Greek; pathos means “suffering.” Founded in the 1800s by a doctor named Samuel Hahnemann, the practice was born out of Hahnemann’s … Read more

Any amount of soot or smoke in your lungs and bloodstream can damage your health, regardless of the source or composition. It’s true, though, that some sources of smoke are worse than others. With about four thousand chemicals found in cigarette smoke, merely taking out the nicotine wouldn’t be enough to make a healthy cigarette. … Read more

If you smoke, you’re anywhere from twenty to thirty times more likely to die of lung cancer than a nonsmoker. And you are much more likely to die of heart disease or another lung disorder than a nonsmoker, too. Nicotine patch, anyone? Or just quit cold turkey, that works too.

The bacteria Clostridium botulnum is the deadliest toxin that occurs naturally. It’s the cause of botulism, the deadly food poisoning that is sometimes contracted from canned goods or meats. Strangely, it’s also a medication who have involuntary muscle spasms. In very small quantities, botulinal toxin causes local paralysis, easing painful and debilitating muscle contractions. A … Read more

Despite anecdotal stories of athletes healing faster and pushing harder as a result, science has been unable to definitely prove that using anabolic steroids actually increases performance. As a matter of fact, because steroids are psychologically addictive drugs, most doctors believe that at least some of the positive effects are in the users’ minds. Anabolic … Read more

We’re glad you asked about Incubator Babies, because the history behind the incubator is a little bizarre. When Alexandre Lion invented the baby incubator in 1891, it was in response to an alarming infant mortality rate in France. Lion built a device with a water boiler and a fan system that blew warm, filtered air … Read more

Long after the Ottomans, the Chinese, and the Byzantines had realized the finer points of anatomy and physiology, western Europe stayed stuck in an old paradigm they’d learned from the ancient Greeks. It went something like this: The body consists of the four humours (fluids): blood, yellow bile, phlegm, and black bile. For the body, … Read more

As with so many great events in history, the first words spoken over the phone came purely by accident. When Alexander Graham Bell spilled acid on his pants in his workroom, his shriek of pain and panic came through a system he was testing. In the next room, Thomas Watson heard Bell’s electronically transmitted voice … Read more

Alexander Graham Bell invented many things, including a man-carrying kite, a land-mine detector, the hydrofoil boat, takeoff and landing gear for the airplane, and the aileron, —a part of an airplane wing that moves and helps control rolling. He was also a co-founder of the National Geographic Society.