The Unexplored Earth

by Aaron Dy
MIT graduate student in Biological Engineering
Posted on September 10th, 2014
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Humans have yet to explore a vast portion of our planet. Below our ocean’s surface exists a largely unknown wilderness populated by animals that have never been seen by humans and are hidden far from the reach of sunlight.

The surface of the moon has been walked on by more people than have been to the deepest point of the ocean, a small valley called Challenger Deep within the Mariana Trench. This point is nearly 7 miles below the ocean’s surface, which adds up to 28 Empire State Buildings stacked on top of each other. This incredible depth makes it impossible for ordinary submarines to make the journey. In fact, only three people have dived to the Challenger Deep. Lt. Don Walsh and Jacques Piccard did it in 1960, and then no manned craft made it again until Hollywood director James Cameron did it in 2012 as part of his new movie “Deepsea Challenge 3D”.

More than 95% of the ocean in general has yet to be explored and more than 70% of Earth is covered by ocean. If you catch yourself thinking that explorers are only for the history books, think again. There’s a whole new world to be discovered deep beneath the water.

About the author
Aaron Dy
MIT graduate student in Biological Engineering

Origami Art and Science

by Herng Yi Cheng
MIT Class of 2018
Posted on September 10th, 2014
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One might think that origami, the art of paper-folding, is nothing more than a children’s pastime. However, research in origami has given us new technologies and new avenues for artistic expression. Satellite solar panel arrays are huge sheets that can’t fit in the rocket that sends the satellite to space, but in 1995 an origami engineer broke the sheet into panels hinged together so that they fold like origami into a compact shape for transport. In this way, origami can be useful when some piece of technology needs to be a large sheet when active but small and compact for storage or transport.

Click to watch it fold and unfold.  Source: "Miura-ori" by MetaNest, Wikimedia Commons.

Watch it fold and unfold. Source: “Miura-ori” by MetaNest, Wikimedia Commons.

Source: “The math and magic of origami” by Robert Lang

Source: “The math and magic of origami” by Robert Lang

In the same vein, a tiny origami tube has been designed to expand and contract by flexing. During a surgery, its contracted form is inserted into blood vessels, then expanded to support the blood vessel to prevent it from collapsing. The same principle again: small for transport, large for usage.

Source: “Fold Everything”, National Geographic Magazine

Source: “Fold Everything”, National Geographic Magazine

All these applications depend on mathematical folding patterns on surfaces. That math has advanced to the level that computer programs have been written to automatically design origami animals of astounding realism and complexity. Origami is a fascinating cross-fertilization between art, mathematics and science!

Stick figure representing the subject.  Source: “The math and magic of origami” by Robert Lang

Stick figure representing the subject. Source: “The math and magic of origami” by Robert Lang

Pattern of folding lines.

Pattern of folding lines.

Final folded product.

Final folded product.

For more on the mathematics of origami, check out Herng Yi Cheng’s blog: http://www.herngyi.com/origami-research-and-applications.html

About the author
Herng Yi Cheng
MIT Class of 2018

Counting wrong

by Y. William Yu
MIT Mathematics graduate student
Posted on September 7th, 2014
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Have you ever had to count an absolutely ginormous number of things and thought to yourself: eh, who cares if I’m off by a couple? If so, you’re not the only one. It turns out that because numbers can get really big, even computers, as accurate and precise as they are, have trouble too. This turns out to be an important problem in analyzing Big Data, the explosion of information on everything in the world from Internet traffic patterns to sequencing the human genome.

Luckily, although counting exactly right is hard, counting slightly wrong is much, much easier. By the use of clever algorithms, computers can approximately count large numbers of items, getting a pretty good answer that’s guaranteed to probably be off by only a little. Although it sounds a bit weird to describe something with the phrase “guaranteed to probably”, many of these algorithms make extensive use of random coin flips to work. Much like how if you flip a coin a million times, you’ll probably get around half heads, but not exactly, these algorithms get answers that are pretty close most of the time. By harnessing the power of randomness, we can accurately and precisely count things wrong.

About the author
Y. William Yu
MIT Mathematics graduate student

Wigglings and jigglings

by Yasmin Chau
MIT Biology graduate student
Posted on September 7th, 2014
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“…if we were to name the most powerful assumption of all, which leads one on and on in an attempt to understand life, it is that all things are made of atoms, and that everything that living things do can be understood in terms of the jigglings and wigglings of atoms.”

–     Richard Feynman, The Feynman Lectures on Physics

Everything, including you, is constantly moving all the time. That can seem hard to believe. The table and floor definitely look quite still. But if you could look at the atoms—the basic building blocks of matter—of the table and floor, you would see that the atoms are constantly jiggling and wiggling.

The jiggle and wiggle of atoms explains phenomena such as heat and cold, but what I find most fascinating is the jiggle and wiggle of atoms of living things. If you could look at the atoms of a cell from your body, you would find that the different flavors of atoms (carbon, hydrogen, oxygen, etc.) have stuck together in different ways to make larger structures (protein, lipids, sugars, DNA). You would also see that being inside a cell is like being tightly packed into a crowd at a large, popular concert where everyone is constantly moving around and bumping against everyone else. The atomic structures in a cell are jiggling and wiggling in an extremely crowded and chaotic space! Yet somehow, the right jiggles and wiggles happen. And it is actually thanks to this constant atomic motion that things in your cell happen at all. What if nothing moved in your cell? The appropriate proteins wouldn’t get to where they need to be to break down the molecules from the food you eat. The appropriate lipid wouldn’t interact with a protein to tell your cell to make more of another protein. The “jigglings and wigglings of atoms” are to thank for making your cell function as a tiny yet important piece of you.

About the author
Yasmin Chau
MIT Biology graduate student

Proteins

by Madeline Wong
MIT Chemistry graduate student
Posted on September 7th, 2014
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As your parents might have told you, protein is a key part of the food pyramid (included on nutritional labels and often equated with meat, beans, or nuts). But proteins are also molecular machines, signal processors, and structural supports for life. There are many examples: digestive enzymes in the stomach, adrenaline receptors in the brain, and collagen in bone.

Composed of a sequence of building blocks called amino acids, proteins can broadly be thought of as science’s version of words: they’re made from a different alphabet than the ones you might find in the dictionary, but they also can be sorted into different groups and each has a unique meaning or role. And just as a scrambled word loses much of its ability to function–“art” and “rat” have the same parts but very different meanings–proteins often require a specific structure in order to remain active.  Switch up the order of the letters or drastically change the shape, and a protein will probably behave quite differently.

Want to know more?   Ask a molecular biologist, biochemist, or biophysicist.  Many of us study proteins outside the dinner plate!

About the author
Madeline Wong
MIT Chemistry graduate student

Infinity

by Davie Rolnick
MIT Mathematics graduate student
Posted on September 7th, 2014
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What happens if you start counting and never stop? That’s how you get to infinity, a mathematical idea that has puzzled people for centuries, and even driven some mad. Take the following question, posed by the Greek philosopher Zeno: An arrow is shot, and first travels half the distance to the target. It then must travel half the distance that is left, then again half the remaining distance, and so on. How can it ever reach the target? The answer: An infinite number of events can happen in a finite amount of time. If you find yourself confused by this sort of thing, don’t worry – most mathematicians are too.

Despite its strangeness, infinity is very useful. It’s what makes calculus work, and therefore underpins many principles of modern engineering. The universe is not infinite – just really big. However, the theoretical concept of infinity is nonetheless important for understanding physics, including quantum mechanics and black holes.

About the author
Davie Rolnick
MIT Mathematics graduate student

The Hitchhiker’s Guide to Volcanoes

by Lindsay Brownell
MIT Graduate Student, Science Writing
Posted on March 4th, 2014
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640px-Putauaki01-300x225

When the largest volcanic eruption in the last 70,000 years spewed giant clouds of ash and debris into the air, millions of tiny microorganisms got caught up in the blast and hitchhiked hundreds of miles to new locations, researchers have found. The first record of microbes being distributed by volcano, these diatoms can help scientists figure out the volcanic source of ancient ash deposits, which offers a new, more reliable way to unlock the mysteries of Earth’s past.

The most common way to identify layers of volcanic material has been carbon-14 dating, which estimates the age of non-living substances using the decay rate of radioactive carbon atoms, but that measurement is notoriously finicky, according to Alexa Van Eaton of the U.S Geological Survey. “It’s much easier to identify a diatom than volcanic matter,” Van Eaton says, adding, that this approach “is something people haven’t thought about before.”

Van Eaton and her team excavated the prehistoric remains of the Oruanui eruption of New Zealand’s Taupo volcano, which produced 530 cubic kilometers of magma when it erupted about 24,000 years ago (by comparison, the 1980 eruption of Mt. St. Helens produced a paltry half a cubic kilometer). They took samples of volcanic matter from eleven different locations around Taupo, and found that they all contained several species of diatoms – microscopic, photosynthetic algae that live in freshwater lakes and streams.

One of the three most abundant diatom species identified, Cyclostephanos novaezeelandiae, is found only in deep freshwater lakes in the volcanic region where Taupo is located, but it was discovered in samples as far away as the Chatham Islands, 850 km south of New Zealand. Because the profile of diatoms in those samples matched the species found in the fossilized lake bed of Lake Huka, which covered Taupo at the time of the eruption, the scientists were able to conclude that the Oruanui explosion blew the diatoms from the lake into the air, where they rode the wave of volcanic debris to new locations that they would not have been able to reach by other means.

Given the size of the Oruanui eruption, Van Eaton says it’s “very likely that [the diatoms] got to [other places], we just haven’t found them yet.” Dr. Andrew Knoll of Harvard University agrees that diatoms could be found in other sites, but “you’d have to get the stratigraphy very precise” in order to conclude that the diatoms in the fossil record came from that particular eruption…you want to be able to make the claim that an endemic diatom shows up at the same time the volcano goes off,” and that it wasn’t present in a given location before the ash layer fell.

Some diatoms are classified as “cosmopolitan” and are known to exist across multiple locations, which could interfere with future studies. However, there are plenty of local diatoms like Cyclostephanos which are found in only one geographic region, and can act as a kind of unique fingerprint to trace volcanic debris back to its source eruption. According to Van Eaton, these types of species are a new “tool in the toolbox” that scientists can use to more easily and accurately identify fossilized ash layers, leading to a more complete picture of Earth’s geological history.

A version of this article previously appeared in SCOPE on December 9, 2013

About the author
Lindsay-Brownell-128x128
Lindsay Brownell
MIT Graduate Student, Science Writing

Lindsay Brownell is a native of Detroit, MI, and spent most of her childhood either digging for worms and collecting rocks or with her face buried in a book, often at the dinner table. She attended Davidson College in North Carolina, where she indulged in such nerdy activities as a twelve-hour reading/performance of John Milton’s epic poem “Paradise Lost” and Dance Dance Revolution tournaments. She also studied abroad twice, in Costa Rica for tropical biology and in the UK for British literature and art history. She became fascinated with evolution, genetics, and Romantic writing (are you noticing a bit of a split-brain tendency)?

 

After graduating with a dual degree in English and Biology, she taught Spanish in Switzerland, worked at Google in Ann Arbor, MI for two years, and traveled extensively (just hiked the Inca Trail in Peru and the Camino de Santiago in Spain). She is very excited to finally get to wrangle the literary and scientific parts of her brain into cooperation, and will be focusing on the biological sciences. In her spare time, she likes anything having to do with Disney, dancing, Ultimate Frisbee, rock climbing, trying to learn how DSLR cameras work, roaming farmer’s markets, and watching thunderstorms from her window while listening to Beethoven sonatas.

It’s Not the Twinkie, It’s the Triglycerides

by Lindsay Brownell
MIT Graduate Student, Science Writing
Posted on March 4th, 2014
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Hostess_twinkies_tweakedEven if you’re not trying to lose weight, your fat may be working against you. Researchers have found that in healthy and moderately overweight people, fat cells can lose their ability to break down and release fat molecules normally.

When this process, called “triglyceride turnover,” is disrupted, triglycerides (the building block molecules of fat) can stay in the body longer — which may contribute to weight gain. While this research does not pin down exactly what causes some people to gain weight while others stay thin, identifying this process gives scientists a new potential target for weight loss research.

A team of scientists led by Peter Arner of the Karolinska Institute in Stockholm examined the age of triglycerides in abdominal fat cells taken from 41 subjects who were in the “normal” (Body Mass Index of 17-24) to “overweight” (BMI from 25-29.9) range. They found that the triglycerides in the bodies of their overweight subjects were an average of two years old, while those of their lean subjects averaged one and a half years old — an indication that triglyceride turnover drops in heavier people.

The team’s next experiment looked at what might prevent fat molecules from cycling at a normal rate. To find out, they took fat cells from 333 new subjects and exposed them to chemicals that break up triglycerides. They found that fat cells with older fat molecules, as well as fat cells from subjects whose BMIs were higher, saw reduced rates of triglyceride turnover, suggesting that heavier people may not be able to properly process fat.

These results raise an important question: which comes first? Does weight gain cause the fat cells to malfunction, or is it a problem with the fat cells that induces weight gain?

For Michael Jensen of the Mayo Clinic it’s helpful to imagine the human body as a car, with muscles as the engine and fat cells serving as the gas tank: “Overweight people don’t have bigger engines, just bigger gas tanks. That means any given triglyceride molecule…in the big gas tank is less likely to be sent to the engine than [it would be if it were] in a small gas tank.” In other words, a larger number of fat molecules are in reserve to fuel the same amount of muscle, so the fat has to wait longer before it’s used, which is why it tends to stick around. “As long as [the fat cells] don’t dysfunction, we’re fine.”

Fahumiya Samad from the Torrey Pines Institute for Molecular Studies agrees: “the current thinking in the field is that it’s not the amount of fat, but the dysfunction of the fat” that causes the health problems often associated with weight gain, she says.

The results of this study could help change the way we think about obesity, Gary Taubes argues via email.  Taubes, author of Good Calories, Bad Calories and Why We Get Fat says, “it’s not that people eat too much and that makes them a little fat, and then they’re on the ‘slippery slope’ [to obesity]. It’s that the same amount of food consumed will lead to a greater or lesser degree of fat stored in the fat cells, depending on this [triglyceride breakdown] factor.”  Taubes adds that this research may have identified “at least one factor that determines why some people gain fat easily and others stay lean easily.”

Dr. Samuel Bernard, one of the study’s primary authors, cautions that the origins of weight gain are still unclear. People can become overweight for a variety of reasons, he says, whether they are “genetically determined to have a slower [triglyceride] turnover, or lack exercise or have bad nutrition, but they eventually become fat, which triggers a slower [triglyceride] turnover rate” in their fat cells.

But by linking weight gain with fat cells that have problems processing fat, Bernard thinks his research has uncovered another clue that can help determine the root cause of why people get fat in the first place, and possibly develop new approaches to weight management.

A version of this article previously appeared in SCOPE on October 11, 2013

About the author
Lindsay-Brownell-128x128
Lindsay Brownell
MIT Graduate Student, Science Writing

Lindsay Brownell is a native of Detroit, MI, and spent most of her childhood either digging for worms and collecting rocks or with her face buried in a book, often at the dinner table. She attended Davidson College in North Carolina, where she indulged in such nerdy activities as a twelve-hour reading/performance of John Milton’s epic poem “Paradise Lost” and Dance Dance Revolution tournaments. She also studied abroad twice, in Costa Rica for tropical biology and in the UK for British literature and art history. She became fascinated with evolution, genetics, and Romantic writing (are you noticing a bit of a split-brain tendency)?

 

After graduating with a dual degree in English and Biology, she taught Spanish in Switzerland, worked at Google in Ann Arbor, MI for two years, and traveled extensively (just hiked the Inca Trail in Peru and the Camino de Santiago in Spain). She is very excited to finally get to wrangle the literary and scientific parts of her brain into cooperation, and will be focusing on the biological sciences. In her spare time, she likes anything having to do with Disney, dancing, Ultimate Frisbee, rock climbing, trying to learn how DSLR cameras work, roaming farmer’s markets, and watching thunderstorms from her window while listening to Beethoven sonatas.

A glacier’s gift: The story of New England’s forests

by David Rolnick
MIT Department of Mathematics
Posted on January 15th, 2014
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forestcolorsI’m from Vermont. My state has many trees and a few people. When you combine those two things, you get delicious maple syrup. In October, you also get hordes of tourists — the so-called “leaf-peepers.” Vermont calls itself the Green Mountain State, but it is really now, when the mountains are red and orange, that the forest gets the most attention. With winter approaching, trees pump the precious chlorophyll from their leaves and store it safely in their roots, revealing other leaf pigments that were previously obscured by green: the carotenoids (yellow/orange) and anthocyanins (red).

The autumn transformation starts with occasional splashes of color. Spots of scarlet appear on the leaves of the red maples, then whole trees seem to burst into flame. Next, the sugar maples glow golden orange. On the mountain slopes, birches and aspens add a stroke of yellow, and are matched by white ash and silver maple in the valleys. Red oaks join in, asserting a sober chestnut-red. The beeches become rainbows, as the outermost leaves of each tree turn orange-brown, the middle leaves change to yellow, and the innermost leaves preserve a bright spring-green. Finally, a few roadside sumacs are left to redden the landscape as it settles into winter stillness.

Colorful trees and rich forests have only recently come to New England. Only 20,000 years ago, a glacier covered the entire Northeast in ice up to a mile thick. As it oozed southward under the pressure of its own weight, it scoured vegetation and earth from the ground and gouged large chunks out of mountains. About 10,000 years ago, the climate warmed and the glacier receded, leaving behind a barren wasteland. As the glacier melted, it kindly replaced all the rocks and detritus it had picked up in its headlong advance. This is the origin of those giant boulders you may find lying around in the forest; they were chiseled out by the glacier and left behind.

Trees colonized the newly exposed mountains. Some slopes faced north and received less sunlight, making them cold and damp. In the darkest ravines, the hemlocks — giant conifers that can live up to a thousand years — took root. On the windy upper slopes, the birches and poplars settled, trees from the far north. Birch bark peels off in sheets, enabling the tree to rid itself of a pesky fungus. This attribute makes it an ideal material for dishes and canoes. Poplars (also called aspens) are known for bending in the wind, an adaptation for enduring harsh northern blizzards and heavy snowfall. The bark of poplars is slightly green from chlorophyll, which is used for photosynthesis even when the cold of winter makes it impossible for leaves to grow.

The sunny south-facing slopes, covered with rocks by the glacier, were warm and dry — the perfect place for forest fires. We humans flatter ourselves for having “invented” fire, but natural fires are a common occurrence over much of the world, and are actually necessary to the survival of many species. Trees like oaks, pines, and hickories are specially adapted to resist fire. They have thick bark and large tough seeds that sometimes don’t sprout at all unless they’re lightly burned first. Now that people have started extinguishing forest fires, some of these trees are having a hard time competing.

The beautiful American beech is another tree that colonized these south-facing slopes. It isn’t a fire-resistant species: it just wanted to stay warm. Beeches come from the tropics, and this species is the northernmost of its kind. However, it still looks like a rainforest tree. It has huge, broad branches, perfect for climbing, and long-tipped leaves that channel the rain away. The smooth, pale gray bark, which lovers sometimes write on, is also an adaptation to the tropics, where it stops the tree from being overrun by vines and other plants looking for a foothold. Unfortunately, smooth bark is a terrible idea in a northern winter, since it splits easily in the cold. Almost every other tree here has ridged bark, which can expand and contract with temperature changes.

The valleys of New England were vast lakes only a few thousand years ago, filled with meltwater from the retreating glaciers. When the water receded, it left behind rich soil that is now perfect for farming. Trees such as the White Ash and American Elm grow in these soils. Ashes are straight, tall trees, with exceptionally hard wood that is used for making baseball bats and fancy furniture. Elms are stately, with spreading branches, and were once planted in gardens and parks, but have now become very rare as a result of an invasive fungus called Dutch elm disease.

The quintessential New England tree is the maple. Different species grow in each habitat. In rich lowland soils, the dominant tree is the large sugar maple. Around rivers, it is replaced by the silver maple, a drooping, elegant tree whose leaves look silver from underneath. In bogs and poor soils, there is the red maple, while on hillsides the striped maple offers its huge leaves to hikers who need toilet paper. At the very tops of mountains lives the tiny mountain maple, rarely bigger than a sapling.

As the trees of New England change color, think about glaciers as you admire the carotenoids. Even at MIT, fall foliage is quite spectacular. The banks of the Charles are planted with exotic Japanese zelkovas, which turn a bright red-brown. In Killian Court, the red maples are scarlet and the elms are yellow. There are even sugar maples on the far side of Next House, with orange leaves and the promise of syrup.

But, of course, the best maple syrup comes from Vermont.

A version of this article previously appeared in The Tech on October 18, 2013

About the author
David Rolnick
MIT Department of Mathematics

David Rolnick is a graduate student at the department of Mathematics at MIT

Cities at your feet: A closer look at the world of ants

by David Rolnick
MIT Department of Mathematics
Posted on January 15th, 2014
No Comments

City Life

The colony is the unit of ant society. Depending on the species, colonies can range from only a few dozen ants to millions. Within a colony, different jobs are performed by different castes of ants. Soldiers are large and powerful and focus on fighting. Workers make up the bulk of the colony and do the day-to-day tasks like gathering food and tending the young. There is generally a queen — or sometimes several, in large colonies. The job of the queen is to lay eggs, and she usually just sits and reproduces all day long, using sperm stored up from her youth. Her former partners are long dead. Soldiers, workers, and queens are all female, and the only purpose of male ants is to mate and die.

When ants do need to mate, they do it on a grand scale. Male ants and young queens emerge from their colonies in great swarms. They have wings and fly around in a frenzy looking for partners. You may have seen this happening and not realized it. Whenever it seems like there are a lot of insects flying about, but none of them are biting you, it is probably the mating day of some species of ant. Even after waiting a year, all the colonies somehow manage to synchronize it, so that the orgy is sometimes done within an hour.

The home that an ant colony builds is called the nest. Here in Massachusetts, you often find ant nests in sidewalks or under rocks. That is because the rocks and concrete help keep the nest warm on cold days. Archaeologists know to look for fossils on top of ant nests, because some ants cover their nests with rocks gathered from the surrounding land in order to collect solar radiation. Ants in the tropics have the opposite problem and generally nest underneath bark or in other places where they can keep cool.

Some ants go to great lengths to build the perfect nest. Weaver ants, for instance, make nests in trees. Dangling from one another, chains of workers pull leaves and branches into place, and then fasten them together using silk. Another species of ant (Camponotus femoratus) plants cactuses in its nest in order to make it sturdier. Yet another species has an alliance with a tree, in which the tree provides the ant food and shelter, while the ant stings all the trees’ competitors to death. Because of this arrangement, there are large bare patches inside South American rainforests, where no plants grow — except for this one species of tree.

Down on the farm

In Massachusetts, many species of ants rely on livestock farming for their food. Their cows are small, defenseless insects called aphids, which sit on plants all day, drinking sugary sap and trying not to get eaten. Ant colonies collect groups of these aphids and protect them from predators. In exchange, the aphids secrete a concentrated sugary secretion called honeydew (a bit like maple syrup), which the ants eat. The tie between farmers and cattle runs so deep that when a colony of ants moves to another nest, it carries the weak aphids along with it and installs them on another plant that they can use as pasture.

In South America, leafcutter ants carry out an even stranger form of agriculture. Every night, the colony goes out and defoliates an entire tree, chops up the leaves, and brings the pieces home. Like many ants, leafcutters nest underground in a network of subterranean chambers; a colony may excavate up to forty tons of earth. Inside the nest, different castes of successively smaller ants chop the pieces up into increasingly tiny fragments. The ants don’t eat the leaves. Instead, the bits of leaf are fed to the filaments of a gigantic fungus that the ants keep in their nest. This fungus is food for the entire colony, which may contain millions of ants.

A disciplined army

Ants go to war all the time. They are really the only animals that fight to an extent comparable to humans. Consider those ants that you get in ant farms (Pogonomyrmex californicus, to be precise). In the wild, when these ants go out looking for food, they get into so many fights that 6 percent of them die every hour! Not surprisingly, therefore, they have a lot of weapons that they can use in battle. Ants evolved from wasps and still have the ability to sting. They also have powerful jaws, and some species can spray acid from their mouths. (All you chemists, “formic acid” actually means “ant acid.”) Some carpenter ants in Malaysia even have the ability to explode, killing themselves in the process, but showering the enemy with chemicals that function both as immobilizing glue and as deadly poison.

Ants are powerful creatures, which can shape entire ecosystems because they work together in large numbers. Most species are predatory and the terror of the insect world. Ants are so formidable that one harmless insect in South America has an ant decoy growing out of its back, in an effort to scare away predators. In the Amazon, army ants sweep over the ground in giant swarms, methodically killing everything from grasshoppers to frogs. Birds, known as antbirds, follow the army ants, picking off other insects that are driven out of hiding. Butterflies, known as antbutterflies, follow the birds, feeding from the poop that they leave behind. Thus a whole community of organisms is centered upon the army ant.

There are many interesting ants that don’t share the fame of the army ant. The trapjaw ant, for instance, has spring-loaded jaws that bend open 180 degrees, like a bear trap, and snap shut if touched. (This is actually the fastest action of any animal on Earth.) Instead of bears, the ant catches tiny snow fleas, which can jump so fast that it takes superpowers to catch them. Another fascinating species is the African honeypot ant, which stores food in the form of a sweet liquid like honey. This honey is kept within the hugely swollen bodies of some of the ants, whose sole function is to be living jars of food. Apparently, these honey-filled ants are delicious and are often eaten by people in Africa.

Whether as fighters, farmers, or food, ants offer fascination and even inspiration. Their proverbial diligence has given birth to many metaphors and fables. In Greek mythology, ants are among the only creatures that were turned into men, rather than the other way around. Achilles’ followers, the fierce Myrmidons, take their name from the Greek word for “ant”, and supposedly sprang from ants at the command of Zeus. Thoreau writes, after studying a battle between rival colonies, “I was myself excited … as if they had been men.” We humans may think the Earth is ours, but the teeming cities at our feet remind us that it is also a world of ants.


A version of this article previously appeared in The Tech on October 29, 2013

About the author
David Rolnick
MIT Department of Mathematics

David Rolnick is a graduate student at the department of Mathematics at MIT