May 22, 2013
Concepts from science and nature pervade our language’s common phrases, idioms and colloquialisms. The incredulous expression”Well, I’ll be a monkey’s uncle” stems from sarcastic disbelief over Darwin’s writings on evolution. To be “in the limelight”—at the center of attention—harks back to how theater stages used to be lit by heating lime (calcium oxide) until it glowed a brilliant white, then focusing the light emitted into a spotlight.
Someone as “mad as a hatter” exhibits behavior similar to 18th and 19th century hat makers who stiffened felt cloth with mercury—an ingredient that after continued exposure causes dementia. “Tuning in” to someone’s message has its origins in the slight turns of a dial needed to focus on a radio signal.
These colorful expressions bring spice to our language. Yet certain well-used phrases from science are misrepresentations of what they’re trying to express. Others are just plain wrong!
Some are obvious, yet we use them anyhow. A person who sagaciously shakes her head and says “A watched pot never boils” while you are waiting second after agonizing second for test results to arrive or job offers to come in knows that if she sat down and watched a vessel containing water on a stove over high heat for long enough, the water will eventually boil. Or the person who utters the placating phrase that “the darkest hour is just before dawn,” meant to give hope to people during troubled times, probably knows that well before the Sun rises, the sky gets progressively lighter, just as how well after the Sun sets, light lingers until the Earth rotates beyond the reach of the Sun’s rays. Thus, the darkest hour of the night (in the absence of the Moon) is midway between sunset and sunrise.
A few phrases, however, have less obvious scientific inaccuracies. Here are a few for you to consider:
1. Once in a blue moon: This poetic phrase refers to something extremely rare in occurrence. A blue moon is the term commonly used for a second full moon that occasionally appears in a single month of our solar-based calendars. The problem with the phrase, however, is that blue moons are not so rare—they happen every few years at least, and can even happen within months of each other when the 29.5-day lunar cycle puts the full moon at the beginning of any month but February.
The usage of “blue moon” as the second full moon in a month dates back to a 1937 Marine Farmer’s Almanac. But prior to that, blue moons meant something slightly different. Typically, 12 full moons occur from winter solstice to the next winter solstice (roughly three per season), but occasionally a fourth full moon in a season could be observed. In such a case, one of the four full moons in that season was labeled “blue.”
Readers may recall that baby Smurfs are delivered to the Smurf village during blue moons. If this were to occur every blue moon, we’d soon be awash in blue creatures three apples high!
2. Where there’s smoke, there’s fire: The phrase means that if something looks wrong, it likely is wrong. But let’s step back—do you always have to have fire if you see smoke?
Answering that first requires defining “fire.” Merriam-Webster’s first definition of fire is “the phenomenon of combustion manifested in light, flame, and heat.” Combustion is the chemical reaction that occurs when fuel is burned in the presence of oxygen. So for a fire to ignite and be sustained, it needs heat, fuel and oxygen—denying a fire any of these three things will extinguish the fire; attempting to start a fire without one of three things will be futile.
In complete combustion—what occurs when you light a gas stove—the fire produces no smoke. However, when most materials are burned, they undergo incomplete combustion, which means that the fire isn’t able to completely burn all of the fuel. Smoke is an airborne collection of little particles of these unburned materials.
The reason why these materials didn’t burn is because of pyrolysis—the breakdown of of organic material at elevated temperatures in the absence, or under a shortage, of oxygen. Think of it this way: a wood fire’s quick consumption of oxygen depletes the gas’s presence around a burning log, and this localized lack of oxygen while the log is at high temperatures causes log to char, breaking the log down into a substance much richer in carbon content. The resulting charcoal, if still under high heat, can then smolder—a flameless form of combustion—until all the fuel is consumed.
Smoke, then, can be considered to be a product of pyrolysis rather than of fire itself. You’re probably thinking—so what? To get the smoke, a fire needed to be present at some point, right?
Not always. Let’s consider pyrolysis to the extreme. For example, tobacco leaves heated to 800 degrees Celsius in a pure nitrogen atmosphere undergo pyrolysis and release smoke without actually being on fire.
Pyrolysis without fire can also occur in more familiar circumstances. Imagine blackening a piece of fish on a pan using an electric range, where electricity heats metal coils on the cooktop until they are incandescent, but not on fire. Leave the fish unattended for too long and it will start to char and smoke. But why bother with putting fish in the pan? Those looking for fireless smoke need to go no further than melting a slab of butter in a sauté pan. All oils and fats used in cooking have smoke points—the temperature at which they start to degrade into a charred goo of glycerol and fatty acids—as seen in this video.
Sure, leaving these smoking substances on the range for too long will cause them to eventually combust (oils and fats, after all, do have flash points), but before that, you have a whole lot of smoke with no fire!
3. The fish rots from the head down: The phrase seems to pop up more frequently when political scandals or accusations of malfeasance make headlines. The origin of the phrase is murky, likely stemming from folk proverbs of Europe and Asia Minor. But the meaning is simple–if a system is corrupt, its leaders instigated the corruption.
The authoritative ring to this phrase belies its accuracy. Fish, in fact, start to rot from the gut. According to David Groman, an expert on fish pathology at the University of Prince Edward Island, the proverb is a “poor metaphor. And, I must say, it’s biologically incorrect,” he told Anna Muoio of the business magazine Fast Company. “When a fish rots, the organs in the gut go first. If you can’t tell that a fish is rotting by the smell of it, you’ll sure know when you cut it open and everything pours out–when all the internal tissue loses its integrity and turns into liquid.”
The reporter then got hold of Richard Yokoyama, manager of Seattle’s Pike Place Fish Market, who said “Before I buy a fish from one of our dealers, I always look at the belly. On a fish, that’s the first thing to go. That’s where all the action is–in the gut. If the belly is brown and the bones are breaking through the skin, I toss the fish out. It’s rotten.”
Unfortunately for scientific accuracy, saying “The fish rots from the belly outward” lacks gravitas and is unlikely to be picked up by the punditsphere.
4. Hard as nails: The saying is often used to describe a person who is stern, unyeilding, unsympathetic, bordering on ruthless. An early appearance of the phrase can be found in Dickens’ Oliver Twist, when the Artful Dodger and the other street urchins describe their pickpocketing work ethic.
But let’s take a step back–are nails really that hard? The hardness of a material can be estimated relative to other substances according to where it falls on Mohs scale of mineral hardness. This scale, which ranges from one through 10, was developed by the German geologist in 1812 to help him classify the minerals he encountered in his excursions. Talc, a soft mineral easily powdered, is a one on the scale. The malleable element copper sits at a three. Quartz—the clear crystal common in sand or the spiny lining on the inside of a geode—is a seven. Diamond, the hardest natural substance on the planet, is a 10.
Mohs’ scale is an ordinal scale, which means that it doesn’t estimate the degree to which one substance is harder than another. Rather, it is based on the idea that materials that fall at higher values on this scale can scratch anything with lower numbers, and that materials with low hardness numbers cannot scratch anything with a higher hardness value. On this scale, a steel nail used to fasten wood together would hit at about 5.5. Feldspars, such as the pink minerals of granite, are harder than those nails, as are topaz, quartz, sapphires and of course diamonds. Even unglazed porcelain, which is about a seven on the scale, is harder than an average nail.
But not all nails are created equally. The nails used in wood are are made of low-carbon or “mild” steel, meaning that the chemical composition of their alloys are only between 0.05 to 0.6 percent carbon. Nails used to fasten concrete together, for example, have higher percentages of carbon–approaching one percent–which can push the hardness up to as high as a nine on Mohs scale.
So the more correct version of this phrase would be, “Hard as high-carbon steel nails,” but somehow that just doesn’t have the same ring, does it?
5. Diamonds are forever: Thanks to the DeBeers slogan, adorning your honey’s neck, wrists and fingers with bits of pressurized carbon has somehow become a metaphor for true and timeless love. Of course, no object that you can hold in your hand can last forever. But diamonds have a special reason for being incapable of eternity–without the extreme pressures of the deep Earth where they formed, a diamond will slowly revert back into graphite–which is why the older a diamond is, the more inclusions it’s likely to have.
Although it usually will take millions of years for the rock on your finger to become ready for use in pencils, some mineral forms of carbon seem to quickly flash between diamond and graphite depending on the pressures that they are exposed to in the lab. For those mutable sometimes-gems, diamonds are in fact transient.
What common phrases push your buttons when viewed under the microscope of science? Or perhaps you have the inside scoop on whether wet hens really get angry? Let us know!
March 29, 2013
If the Easter Bunny comes to your house this weekend, you may find yourself with a plethora of marshmallows and Peeps. What to do with them all? Aside from simply eating them, cooking with them, or unleashing your artistic side by making dioramas, consider using them….for science!
Marshmallows, it turns out, are must-have pieces of equipment for at-home science experiments. Sure, you can use them test your kids’ self control through the the field of psychology’s notorious marshmallow test and its ever-more complex iterations. But if you’d rather not torture your kids by leaving tantalizingly in reach a marshmallow they’re ordered not to have, consider trying these easy science projects:
Marshmallows in a vacuum
No, not that kind of vacuum, despite the intriguing possibilities conjured by this phrase. You’ll need:
- A glass jar with a lid
- A mechanism to pump some of the air out of the jar
Place a few marshmallows in the jar, seal it, and then pump the air out:
What’s going on? Marshmallows are basically a foam spun out of sugar, water, air, and gelatin. The sugar makes them sweet, the water and sugar combo makes them sticky and the gelatin makes them stretchy. But the air–which actually makes up most of the confection’s volume–makes marshmallows the tastiest way to encapsulate a gas in a solid. As you pump air out of the jar, the air inside the marshmallow expands and the marshmallow puffs up. Release the seal, and the marshmallows return to their normal size.
Congratulations! You’ve just demonstrated Boyle’s Law, which states that when the temperature doesn’t change, that the relationship between pressure (which is decreased by pumping air out of the jar) and volume of any set amount of gas (the marshmallow) is inversely proportional. In other words, decreasing one necessitates an increase of the other.
If you can’t eat ‘em, nuke ‘em!
If you’ve ever roasted a marshmallow over a campfire, you’ll know where this next demonstration is going. You’ll need:
- A microwave
- A microwavable plate
- A standard-sized marshmallow (avoid minis or jumbos; the former will fry and the latter may make an enormous mess!)
Place the marshmallow on one of its flat sides in the center of a plate. Then microwave the marshmallow for, say, 45 seconds on high.
It’s alive! This time, rather than changing the pressure surrounding the marshmallow, you’re changing the temperature. As the microwave bakes the marshmallow, the water in the marshmallow heats up and warms the air. When air becomes hot, it expands, forcing the marshmallow to puff up. The confection’s water also softens the sugars, causing it to ooze, as seen in the video above (created by YouTube user bbbpwns).
The relationship between temperature and volume is representative of Charles’ Law, which holds that any set amount of gas will expand when heated–increasing the temperature of a gas necessitates an increase in the gas’ volume.
Trying this with Peeps makes for a slightly alarming outcome, showcased by YouTube user UBrocks:
If you flashed back to the Stay Puft Marshmallow Man, alas–the monster marshmallow you pulled from your microwave doesn’t last–it will cool and deflate into a glob of ooze. But before it cools completely, the ooze is quite malleable and can be sculpted into shapes. But careful! The marshmallow remnants are like naplam–they’ll stick to you and burn. After it cools a bit, brush some oil on your palms before you mold anything, else your sculpture will stay glued to your hands.
A gooey way to calculate the speed of light
For this demonstration you need a bit of background knowledge as you start out. The speed of a wave can be calculated by multiplying the wavelength (the distance from crest to crest) with the frequency (the number of crest-to-crest cycles that repeat in a stretch of time). Light is a wave, and its speed can be calculated the same way without fancy equipment. You’ll need:
- A microwave with the turntable removed
- A glass casserole dish or baking tray
- Mini marshmallows
- A ruler
- A calculator
Take the baking tray and pack one layer of marshmallows along the bottom, lined up like tiny puffy soldiers. Make sure the turntable is removed from the microwave–this allows microwaves to move through the glass and the marshmallows in a standing wave pattern. Cook for a few minutes on low, watching the marshmallows carefully. With the turntable removed, the microwave doesn’t heat evenly–you’ll notice melted patches forming in your marshmallow field.
As soon as you see a few such patches, remove the dish and measure the distance between two that form a line parallel to the microwave’s door–these mark the locations of highest amplitudes within the standing wave. Multiply this by two to get the full wavelength of the microwaves that passed through your marshmallows (if you look at the geometry of a standing wave, your initial measurement only gave you half the wavelength). Convert this into meters.
Multiplying this result by frequency of the microwave, found in the microwave’s manual or in a label inside the device, gives ~299,000,000 meters per second–roughly speed of light! Catch a video of this here.
April 17, 2012
At the Monterey Bay Aquarium, jellyfish are a fan favorite—as long as the stinging swimmers are behind glass. Something about the even pulsing of the delicate, bell-shaped creatures has a calming effect on visitors. Some even say their heart rates slow when watching the jellies.
It is this trance-inducing quality that helped inspire the aquarium’s new 1960s-themed, Jimi Hendrix-esque exhibition: “The Jellies Experience.” The show, open through September 2014, is the latest chapter in the aquarium’s history of cultivating and exhibiting jellyfish. In 1985, the Monterey facility became a pioneer in jellyfish display when it exhibited moon jellies for the first time. Seven years later, the aquarium staged “Planet of the Jellies,” its first all-jellies exhibition. A permanent jellies gallery opened in 1996, as part of the Open Sea wing, and in 2002, the aquarium hosted “Jellies: Living Art,” another temporary show. But “The Jellies Experience,” says Raúl Nava, an exhibit developer and writer at the aquarium, is by far the most interactive.
Nava recently gave me a tour. We walked through the exhibit’s six rooms, each centered on a different aspect of jellyfish—their movement, body structure, stinging capabilities, diversity, possible population booms and bioluminescence. Hands-on elements along the way give a sense of what it is like to be a jelly. Press down on one of three waist-high columns in one room, for instance, and you can control the image of a jelly pulsing across a screen. Stand in front of a camera mounted in the wall in another gallery and see a kaleidoscopic image of yourself that mimics a jellyfish’s radial symmetry. Draw a digital jellyfish on a touch screen and free it into a virtual ocean, along with other visitors’ creations. And walk through a mirrored room with three cylindrical tanks of live jellies to experience the illusion of being in a swarm of jellyfish.
The interactive features, however, do not outshine the 16 species of live jellies displayed. Exhibit designer Koen Liem came up with the show’s psychedelic vibe, but as he says, ”the animals are the real stars.” From Japanese sea nettles to upside-down jellies, flower hat jellies to cross jellies and blubber jellies, the creatures, some raised at the aquarium and others collected, are mesmerizing. I found myself studying them and their intricate details—crimped tentacles, fluorescent colors, stripes and spots.
Here are 14 fun facts about jellies:
1) A group of fish is called a school. A gathering of dolphins is a pod. Several otters makes up a romp. And an assemblage of jellies is a swarm or, better yet, a smack.
2) “Swarm” and “bloom” should not be used interchangeably when talking about jellies. A swarm refers to jellies that collect in one area as a result of strong winds or currents, whereas a bloom is a dense cloud of jellies caused by an actual spike in reproduction.
3) Jellies are 95 percent water.
4) Musician Frank Zappa is the namesake of one species of jelly, Phialella zappai. (For an explanation, see Smithsonian writer Abigail Tucker’s story, “Extreme Jellyfish.”)
5) Though jellies are soft-bodied and lack a skeleton, making fossils rare, there is evidence that jellyfish predate dinosaurs by some 400 million years.
6) A historic moment for jellyfish came in May 1991, when 2,478 moon jelly polyps and babies were launched into space aboard the shuttle Columbia. Biologist Dorothy Spangenberg of the Eastern Virginia Medical School wanted to learn about how weightlessness affected the development of juvenile jellies. She monitored calcium loss in the jellies, which by extension could further scientists’ understanding of humans’ calcium loss in space.
7) Some jellyfish, such as blubber jellies, a delicacy in parts of Asia, are edible. A former colleague wrote about her culinary adventure tasting jellyfish in Washington D.C.’s Chinatown.
8) Most jellyfish live anywhere from a few hours to a few months. But a species of jelly called Turritopsis nutricula may be immortal. The jelly reportedly can play its lifecycle in reverse, transforming from an adult medusa back to an immature polyp.
9) Jellies have been known to eat other jellies.
10) The creatures lack not only bones, but heads, hearts and brains.
11) Researchers from the Monterey Bay Aquarium Research Institute surmise that cross jellies (Mitrocoma cellularia), common to Monterey Bay in the spring and summer, can “smell” prey through chemicals in the water.
12) A recent study found that four of the box jellyfish Tripedalia cystophora‘s 24 eyes always point up. The jellyfish looks through the water surface for tree branches. This way, it can swim towards mangrove swamps where it feeds.
13) GFP, a green fluorescent protein found in crystal jellies, has important medical applications. Mayo Clinic scientists recently inserted a version of GFP and a gene from a rhesus macaque known to block a virus that causes feline AIDS into a cat’s unfertilized eggs. When the kittens were born, they glowed green in ultraviolet light, indicating that the gene was successfully transferred. Biologist Osamu Shimomura won a Nobel Prize in Chemistry in 2008 for discovering GFP.
14) Jellyfish can sting even when they are dead. In 2010, about 150 swimmers at Wallis Sands State Park in New Hampshire were stung by the floating, 40-pound carcass of a lion’s mane jellyfish.
December 8, 2011
On the night of May 22, 1453, the people of Byzantium could see an eerie red shadow cross the Moon. It was a partial eclipse–the Earth had gotten in between the Sun and Moon–and the Byzantines took it as a bad omen. And perhaps they were right–the city of Constantinople fell before the month’s end.
A full lunar eclipse will take place this weekend, visible from Asia, Australia and western North America. But people today don’t view this astronomical event as a worrying sign. Instead, it’s time for science! And you can participate.
The Classroom Astronomer magazine has set up a website, measurethemoon.org, to coordinate observations of the position of the moon in the sky as it passes through our planet’s shadow. And if you’re in the right place, you can measure the distance from the Earth to the Moon.
There are two ways to do this. The first is called the Shadow Method, and it’s the way that the ancient Greeks first measured the distance between the Earth and Moon thousands of years ago. Amy Shira Teitel explains in Universe Today:
Start with the few knowns. We know, as did the Ancient Greeks, that the Moon travels around the Earth at a constant speed—about 29 days per revolution. The diameter of the Earth is also known to be about 12,875 kilometers, or 8,000 miles. By tracking the movement of the Earth’s shadow across the Moon, Greek astronomers found that the Earth’s shadow was roughly 2.5 times the apparent size of the Moon and lasted roughly three hours from the first to last signs of the shadow.
From these measurements, it was simple geometry that allowed Aristarchus (circa 270 B.C.) to determined that the Moon was around 60 Earth radii away (about 386,243 km or 240,000 miles). This is quite close to the currently accepted figure of 60.3 radii.
You can follow Aristarchus’ method in your own backyard if you have a clear view of a Lunar eclipse. Track the movement of the Earth’s shadow on the Moon by drawing the changes and time the eclipse. Use your measurements to determine the Moon’s distance.
The second method, the Lunar Parallax Method, was familiar to the ancient Greeks but they lacked the ability to communicate over the far distances that is necessary to carry this out. Telephones and the Internet make this easily possible now. Two observers at least 2,000 miles apart will have to snap a picture of the Moon at the exact same moment. Because the angle at which the Moon and the stars behind it will be different for each person, the images they snap will be slightly different, particularly the stars in the background. “What your images have given you is a triangle,” Teitel explains. “You know the base (the distance between you and your friend), and you can find the angle at the top (the point of the Moon in this triangle). Simple geometry will give you a value for the distance of the Moon.”
If the people behind measurethemoon.org get enough participants, they’ll be able to compare all the various calculations, determine which method is more accurate and figure out how close two people have to be to get an accurate calculation with the Lunar Parallax Method.
If you’re not up for calculations, there are a few other lunar eclipse science projects you might want to participate in:
- Roger Sinnott of Sky & Telescope is collecting telescopic timings of the the passage of Earth’s shadow across lunar craters (find instructions here) as part of a long-term project to track the unpredictability of the diameter of the shadow.
- John Westfall of the Association of Lunar and Planetary Observers is collecting timings of when the phases of the lunar eclipse begin and end, made with the unaided eye, to calibrate similar observations made in the past when mariners used the Moon to determine longitude.
- Richard Keen of the University of Chicago will collect reports of the Moon’s brightness from amateur astronomers for use in volcano-climate studies.
After reading all this and seeing the picture above, you may be wondering why the Moon in a lunar eclipse turns red, not black. “That red light on the Moon during a lunar eclipse comes from all the sunrises and sunsets around the Earth at the time,” says Robert Naeye, editor in chief of Sky & Telescope. “If you were an astronaut standing on the Moon and looking up, the whole picture would be clear. The Sun would be covered up by a dark Earth that was ringed all around with a thin, brilliant band of sunset- and sunrise-colored light, bright enough to dimly light the lunar landscape around you.”
If, like me, you’ll miss out on this chance to see a lunar eclipse, your next opportunity will come in April 2014.
July 13, 2011
What does a music teacher do when he ends up teaching science? He teaches about evolution and the geologic timeline with music, of course, and that’s what Canadian elementary school teacher John Palmer did. He originally played “Cambrian Explosion” as a rock/hip hop creation in class but has since recorded an acoustic version. (The trio is called Brighter Lights, Thicker Glasses and consists of Palmer on the guitar/vocals, Michael Dunn on the dobro and Brian Samuels on the cello.)
Palmer tells us that former students can remember his “Cambrian Explosion” even a decade later. “It always floors me,” he writes. But that’s what great teachers do—they leave their students with both knowledge and the great memories that keep those bits stuck in our brains.
(Many thanks to John Palmer for bringing this to the magazine’s attention—we wouldn’t have wanted to miss it. You can find out more about the Cambrian Explosion and the Burgess Shale in the August 2009 issue of the magazine.)