The newly discovered ant, with mouthparts like forceps and no eyes, lives under the ground in South America.

In the Amazon rainforests of Brazil, scientists have discovered a peculiar new species of ant. The insect has no eyes. Its body is pale. And its fanglike mouthparts are longer than the rest of its head.

If you happened to cross paths with the bizarre ant, you might imagine that it belongs on another planet. Even its name — Martialis heureka — playfully suggests that it came from Mars.

But Martialis heureka lives on Earth. And the creepy-crawly discovery is forcing researchers to rethink what they know about the history of ants on our planet.

Christian Rabeling, from the University of Texas at Austin, discovered the new species amid the fallen leaves of the rainforest. But he did more than just notice how weird the ant looks. He also analyzed its genetic material, or DNA.

Comparing DNA among species can give scientists insights into family trees: The more DNA two species share in common, the more closely related they are, and the more recently they split off from a common ancestor.

Rabeling’s DNA analysis of Martialis heureka showed that the species is only distantly related to other ant species. It is so distant, in fact, that it belongs in a separate subfamily — a broader grouping than a species or even a genus. The last time scientists found a new subfamily of living ants was in 1923, say the discoverers.

Scientists looked at the ant’s genes to find out where it fits in the ant family tree. They showed that the odd ant may come from the earliest branch of the ant family that still has living members.

C. Rabeling, M. Verhaagh

The DNA analysis also suggests that Martialis heureka appeared on Earth earlier than any other ant living here today. And observations suggest that the ant lives underground: Paleness and blindness are two major clues.

Some of the other oldest known ant species also live underground. So now, scientists are trying to figure out whether ants first evolved underground, or if they evolved above ground and then went under.

Corrie Moreau, an ant specialist at the Field Museum in Chicago, saw a picture of the new creature. “It’s an incredibly bizarre-looking ant … which for ant biologists is really exciting,” she says. A few other ant species have at least one of Martialis heureka’s weird features, she says. But none share them all.

So far, Rabeling has collected only one ant from the new species. Finding more specimens, he hopes, will help us better understand the science and history of ants on Earth.

Going Deeper:

Scientists and regulators are looking into the safety of two chemicals found in many plastic products — including some kinds of baby bottles. Credit: iStockphoto

Try to count everything you use that’s made of plastic. I dare you.

Done yet? I didn’t think so.

Your list may include toys, yogurt containers and pens. But did you remember to include telephones, bike helmets, spatulas and shower curtains? How about straws, food wrappers, picture frames and the seat covers on your school bus?

Plastic is everywhere because plastic is an extremely useful material. It is cheap, strong and lightweight. What’s more, it can take on nearly any form or shape, from soft and stretchy to hard and glasslike.

Plastic, however, is far from perfect. It may even be bad for us, according to a growing body of research. Studies now suggest that toxic chemicals can get out of some types of plastic, get into our bodies, and cause a variety of health problems, including cancer, birth defects and attention deficit hyperactivity disorder (ADHD).

Fetuses and young children seem to be at greatest risk. And since babies tend to put plastic things (and everything else) in their mouths, many parents are worried.

Two types of chemicals in particular have raised special concern lately. They are called phthalates (pronounced thal’ ātz) and bisphenol (biz fē’ nawl) A, BPA for short. Not all plastic products contain them. But the ones that do are surrounded by controversy. That’s because experts disagree about how dangerous these chemicals are.

If you follow the news in coming months, you’ll notice more and more stories about phthalates and BPA. And as the research builds, it’s up to you to decide how plastic will fit into your life. So, what do you need to know to make smart choices about plastic?

From Bottle to Body

Plastic is a single word, but plastic isn’t just one thing. Think about how different a food wrapper is from a water bottle. What all plastics share in common are plasticizers — special chemicals that allow the material to be molded into nearly any shape or texture. Plasticizers are added to plastic during the manufacturing process.

Phthalates and BPA are two types of plasticizers that work in different ways. Phthalates add softness and squishiness to things like shampoo bottles, raincoats and rubber duckies. These molecules are also used in perfumes and makeup. BPA, on the other hand, gives a hard, clear, almost glasslike feel to products such as baby bottles, blender bowls and reusable, see-through Nalgene-brand water bottles (milky-colored, soft Nalgene bottles don’t contain BPA). BPA also appears in the lining of many food and soda cans, in DVDs and in other unexpected places.

Widespread use of BPA and phthalates worries many scientists because both chemicals belong to a group called hormone disruptors. In the body they act like hormones. Hormones, such as estrogen and testosterone, are two of the body’s important messenger molecules. They can tell cells when to turn on or off the cells’ genetic material. That’s how hormones direct the complicated development of a fetus from just a few cells into an actual baby with arms, legs, ears and organs. They also control growth in all of us. They even control the changes at puberty that get our bodies ready to become adults.

When some other chemical imitates a hormone, though, our actual hormones can’t do what they need to do. That can cause all sorts of problems. In hundreds of experiments, animals exposed to hormone disruptors in the womb went on to develop breast cancer, early puberty, diabetes, obesity, behavioral problems and other health issues.

“What we know is that BPA and phthalates disrupt hormones, and that hormones are necessary for normal human development, brain development and reproductive development,” says David Wallinga, director of the Institute for Agriculture and Food Policy’s Food and Health Program in Minneapolis.

Especially worrisome, Wallinga says, is that just tiny doses of a hormone disruptor can have a big impact. That’s because hormones work at extremely low levels in the body, so it doesn’t take much to get in their way.

Most of us already have tiny amounts of hormone disruptors in our bodies. A recent study by the U. S. Centers for Disease Control and Prevention found traces of BPA in 93 percent of the more than 2,500 people tested in the United States.

How do these chemicals get into us? When plastic is heated in the microwave or dishwasher, chewed on or scratched, the chemicals can seep out of the plastic. Even though we can’t see these molecules, we eat them, drink them and breathe them in.

Scientists and parents are especially worried about young children, who tend to chew on everything, including plastic. BPA is a common ingredient in baby bottles, teething rings, sippy cups, baby-formula cans and other products specifically designed to go into the mouths of little kids. Kids are a cause of concern both because they are likely to be exposed to plastics more than adults and because their bodies are more sensitive to the risky chemicals. Hormones play a particularly important role in the developing bodies of both babies and fetuses.

The Debate Goes On

Despite the growing sense of worry, debates about what to do continue between those concerned about the chemicals, the plastics industry and the government agencies charged with deciding on what’s safe and what’s not. That’s because there’s still no proof that BPA and phthalates are making people sick. So far, most experiments have involved animals and cells growing in test tubes.

Bisphenol A, a chemical linked to health problems, can seep out of hard, clear plastic water bottles, like the one shown above. Metal and glass bottles may be a safer way to store drinking water! Credit: T. Siegfried

In humans, the strongest evidence of harm comes from associations: People who have been exposed unintentionally to BPA and phthalates seem to develop the same types of health problems as animals that are deliberately exposed. In science, though, you need to show that one event directly causes another. It’s not enough to just observe that chemical exposure and diseases happen to the same people: The two might just be a coincidence.

Yet, direct proof in humans may never come, Wallinga says. For ethical reasons, researchers can’t expose pregnant women to risky chemicals, then wait to see what happens.

Scientists have also had trouble repeating some of the studies that make these plasticizers look bad, says Steven Hentges, a chemist from the American Chemistry Council, a plastics-industry group in Arlington, Virginia. The group sponsors a number of websites, which compile news reports and studies showing that plasticizers are safe.

“Consumers would have to eat more than 500 pounds of food and beverages in contact with [BPA-containing plastic] every day of their lives to exceed exposure levels determined to be safe,” reads a fact sheet on one such site, called factsonplastic.org.

But one new study that was reported online in the Sept. 13 Science News, found that in human body fat, BPA suppresses a real hormone that normally protects people from heart attacks and type 2 diabetes. The amount of BPA that it took to do this was the same as what is found in most people’s blood. These values were well below values that the government has declared are safe.

That story also reported on a Spanish study that showed BPA — in amounts typical of what’s already found in people — can alter the body’s production of insulin, a hormone that breaks down sugars. This study was conducted in mice, not people. But its findings suggest BPA might help encourage the body’s development of diabetes, a life-threatening hormonal disease where the body can’t use sugar appropriately.

A story in the Oct. 11 Science News actually links BPA concentrations in people to heart disease, changes in liver function and type 2 diabetes.

After evaluating some data — but not all of these studies — many large governmental agencies have concluded that there still is nothing to worry about. In July, Europe’s food safety organization issued a statement saying that BPA-containing products are fine for everyone, including kids. In August, a draft (not final) report by the U.S. Food and Drug Administration came to similar conclusions.

But several large groups of well-known scientists have expressed concern about hormone disruptors in plastics. And some states and countries are taking action.

New Rules, New Products

Dozens of countries, including the European Union, Japan, Canada and Mexico have already banned phthalates from products made for children younger than 3. California and Washington State have done the same. And a number of other states are considering similar rules.

As for BPA, Canada became the first country to ban the chemical from baby bottles in April. A dozen states are considering it.

Even in places where it is legal to sell baby products that contain these chemicals, many major stores are stocking their shelves with versions that don’t contain them. Toys“R”Us and Wal-Mart are two examples. At the same time, more and more manufacturers are making BPA-free and phthalate-free versions of their products.

If you want to know what’s in the plastics you eat and drink out of, look for the small number that’s usually etched into the bottom of the product. In food and drink containers, the numbers 1, 2, 4, and 5 are free of BPA and phthalates. But avoid microwaving even these plastics —or reusing them.(To learn more about safety and plastics, visit healthylegacy.org.

If you’re concerned, wood, glass and cloth make good alternatives to plastic. Or you can buy plastic toys made in countries that have bans on certain plasticizers.

“I have two rubber duckies sitting on my desk,” says Lindsay Dahl, project coordinator at Healthy Legacy, an advocacy group that opposes toxic chemicals in everyday products. “One has phthalates. One doesn’t. The one that does is sold in the United States. The one that doesn’t is sold in Europe.”

When in doubt, call the company to ask about what’s in their plastics. While you’re on the phone, tell them what you think about the issue. They might be interested to know that kids are keeping an eye on them.

Teacher’s Question Sheet: Our Plastic World

SCIENCE

Before reading:

1. What do you own that’s made out of plastic?

2. Why do you think those items were not made out of some other substance — such as wood, glass, or metal?

3. What do you think the advantages are of something being made out of plastic?

During reading:

1. What is plastic? Why might some types pose a health concern?

2. What is a plasticizer? How does it work?

3. What are hormones and how can a building block of plastics resemble a hormone?

4. How strong is the evidence that ingredients of plastics might affect health?

5. Are all members of the population at similar risk from plastics’ ingredients? Why or why not?

After Reading

1. Now that you know there are potential risks from using plastics — but that the human risks have not been proven yet — how important do you think it would be to avoid using plastic items?

2. For which plastic items in your home or school do you think there might be good substitutes? For which can you think of no substitutes?

3. Plastic baby bottles have been considered a potentially big concern. Moms used to use glass bottles. What are at least three reasons why modern moms might prefer plastic?

4. The author says these junk pieces travel at breakneck speed. Do you think that would make them more or less of a danger to astronauts in orbit?

5. If you think plastic items may pose a health risk, what should we do with all of those that are in our homes? How would you discard them? What might be the best way to ensure that plastic trash doesn’t become a hazard in the trash?

6. Do you think plastic trash in lakes and streams would pose a risk to fish and other aquatic life? Why or why not?

SOCIAL STUDIES

1. How has the widespread availability of plastics in the last 50 years changed society? To figure out, imagine a world where all of today’s plastics were instead made of wood, rubber, metal, stone or glass.

2. What features of plastic make them better than wood, rubber, metal, stone or glass? Hint: Compare the cost, weight and flexibility of plastic items against similar materials made from wood, rubber, metal, stone or glass.

3. If plastics were totally nontoxic, that is posed no health risk, what aspects of plastic items might make less desirable than similar items made from other materials?

LANGUAGE ARTS

1. Write a short essay on why plastic baby bottles are better or worse for today’s infants. Imagine having to explain to your mom or a neighbor — someone who knows nothing about the science plastics — why concerns have been raised about the safety of plastics. Explain why you think this mom should or should not be concerned about these new studies.

2. Imagine a world in which all plastics were banned. Describe in a 10 sentences or less how this would change your environment? Hint: Consider what things in your bedroom, your game room, your kitchen and your yard might be different.

3. Hold a classroom debate on the value of keeping plastics. Let one group argue persuasively that any benefits they pose would outweigh their risks. Let the other group argue that their potential risks outweigh the benefits.

Bee researcher Gerald Kastberger stands next to a giant honeybee nest.

When a buzzing hornet comes near, most people want to run away as quickly as possible. But if the hornet targets your home, you will need to find a way to shoo it away.

Fortunately, hornets generally don’t target people’s homes. In southern Asia, however, a type of big hornet does frequently attack giant honeybees while they are clustered around their homes.

Scientists have discovered how this clever bee species uses “shimmering” to drive such predators away.

Shimmering creates a rippling effect on the beehive, similar to the effect seen in a sports stadium when thousands of fans create a “wave.” The waves are created when hundreds of bees coordinate their movements and flip their abdomens upward.

Though scientists had observed shimmering in field studies, it was unknown whether the rippling effect could keep predators away.

Gerald Kastberger, a bee researcher at the University of Graz in Austria, set up cameras to catch two colonies of the giant honeybees in action.

Unlike western honeybees, giant honeybees do not have outer walls on their nests. Instead, thousands of bees, in layers up to seven bees deep, surround a honeycomb.

Because the nests lack any outer protection, the bees are vulnerable to predators such as hornets, which feed on the bees.

Kastberger recorded more than 450 shimmering events. When he reviewed his recordings, he discovered that shimmering was triggered when hornets approached the nest.

If a hornet was nearby, the bees would flip into action, creating a very fast rippling effect. If the hornets remained, or dared to get closer, the shimmering would increase.

Kastberger says shimmering is an example of self-organization in nature. During an attack, many bees work together to coordinate rippling waves that protect their lives and home.

Shimmering Giant Honeybees from Science News on Vimeo.

Going Deeper:

Each white dot represents an individual piece of tracked orbital debris. This image shows the Low Earth Orbit, which is the region from the Earth’s surface to 1,240 miles and contains the most space junk.

On a clear night, you can look in the sky and see the moon and stars. You might even see the blinking light of a working satellite as it flies past, on its way around the Earth.

And, even though you cannot see it, you are also looking at the largest junkyard in the solar system.

Higher than the highest clouds but much closer than the moon, the bulk of the junkyard stretches from the Earth’s surface to 20,000 miles overhead. There are tens of millions of pieces of rubbish there. Some of the pieces are rocks and dust from passing comets, but most of them are manmade and called “orbital debris” (pronounced duh-BREE).

There are some unusual things up there, like a camera that floated away from astronaut Sunita “Suni” Williams in December 2006. Other astronauts have lost tools like wrenches and screwdrivers. In 1965 astronaut Ed White even lost a spare glove. Most of the junk, however, comes from large satellites and rockets that fell apart after they stopped working.

Together, all the space junk would weigh about 11 million pounds on Earth, or more than 3,000 cars. The largest piece is a part of a rocket about the size of a minivan. The smallest piece would fit on your pinkie fingernail with room to spare.

“It’s like a classic environmental problem, like water pollution or air pollution,” says Nicholas Johnson. Johnson is the Chief Scientist for Orbital Debris at the NASA Johnson Space Center in Houston. His job is to keep track of the orbiting garbage.

The junkyard is a serious problem for the future of spaceflight.

“You’ve got multimillion satellites in orbit all the time, and manned space flights,” says Joe Gambrell, who helps keep track of both working and broken-down satellites. His main tool is the U.S. Space Surveillance Network, which is part of the U.S. military. Gambrell works at the Peterson Air Force Base in Colorado Springs, Colo. “If you don’t track debris, you risk some kind of collision,” he adds.

In 2007, the space junkyard grew by more than 100,000 pieces. That’s more than any other year since people started launching satellites into space. The problem of space junk is not going away, and scientists are watching closely.

Danger in Orbit

A “satellite” is any object that orbits another object, held close by gravity. The moon is a satellite of the Earth, and the Earth is a satellite of the sun. These are natural satellites. Manmade satellites, which are built on Earth and launched into space, are used for communications, scientific studies and military applications.

In the last 50 years, human beings have launched thousands of artificial satellites into space. When a satellite stops working, it usually falls back toward the Earth and burns up in the atmosphere. Satellites at high altitudes, however, sometimes remain in Earth’s orbit.

Later, they may fall apart or explode into thousands of smaller pieces. The higher the satellite, the longer it stays in orbit, and the more likely it is to break apart. The pieces may stay in orbit for years, decades or even centuries.

At the NASA Ames Research Center, scientists simulate what would happen were a tiny piece of space junk to hit a spacecraft.

NASA

Space junk races around the Earth at breakneck speeds. Most pieces fly through space at more than 20 times the speed that sound travels on Earth. Going that fast, even the smallest pieces mean big trouble for spacecraft. For example, a tiny marble in orbit around the Earth can have as much energy as a bowling ball going 500 miles per hour, or a car going 30 miles per hour.

A tiny fleck of paint struck and cracked one window of the space shuttle Challenger while it was in space in 1983. The shuttle returned to Earth safely from that mission.

NASA Johnson Space Center

In 1983, a small gouge appeared in one window of the space shuttle Challenger while it was in space. When the shuttle returned to Earth and scientists analyzed the window, they found that the crack was caused by a tiny, orbiting fleck of paint. If the shuttle had been struck by a larger piece of junk, the astronauts may have been in danger.

Many other satellites and space shuttles have also shown damage from tiny pieces of trash. When the space shuttle Endeavour returned to Earth last August, its radiator panels had small holes from space garbage. Last year, two satellites had to be redirected to avoid collisions with big pieces of junk.

The U.S. Space Surveillance Network and NASA work together to keep track of the largest pieces. When the shuttle is in orbit, for example, their attention is on nearby junk that may get in the way. If there is even a small chance of a collision, then the shuttle changes direction.

Watching the garbage

About 17,000 pieces of garbage are larger than 4 inches, which is slightly smaller than a softball. The Space Surveillance Network keeps a list of all these pieces, using dozens of telescopes and antennas on Earth and in space to watch them. Because all the pieces are in motion all the time, keeping track is difficult (but not impossible).

Monitoring the space junk is a problem of energy and motion. To keep track of the junk, the scientists have to know two things: where the garbage is now, and where it is going to be in the future.

This antenna, located in the Mojave Desert, California, can use radio to detect tiny pieces of junk, if they’re not too high.

NASA Johnson Space Center

To find out where a piece is now, scientists use telescopes and high-powered antennas to watch it fly through space. Every day, scientists must make sure each piece is where they expect to find it. A “lost piece” could mean serious danger for a working satellite or space shuttle.

To find out where the piece is going, scientists measure its speed and direction as it crosses the sky. Some of the pieces move in an almost perfect circle around the Earth. Other pieces move in elliptical orbits, which means they are sometimes closer to Earth and sometimes farther as they fly. The measurement of direction is complicated because junk can move north or south, east or west, and up or down.

By knowing the location, speed and direction of each big piece of junk, the scientists can predict where all the pieces will go. (Similarly, in baseball, an outfielder has to predict where a pop fly will land, if she wants to catch it. In soccer, a goalie has to predict where a ball will go, so he can block it.)

“We’re always looking about four days into the future, tracking objects which might come close,” says Johnson.

There are tens of millions of pieces smaller than softballs. Because there are so many small pieces, “We can’t [keep track] of them all,” Johnson says. Instead of watching each piece individually, scientists use telescopes and antennas to watch one patch of sky and count the number of pieces that pass overhead. With that small measurement, they can use a computer program to get a good idea of what the whole sky looks like.

Keeping track of all the junk is necessary to ensure that astronauts and working satellites can be safe. Like other environmental problems, space junk will get worse without careful monitoring and attention. In the future, pieces of junk will probably hit each other, making even more trash.

The more garbage that remains in orbit, the greater the risk to space flights. What can be done about the problem of space junk? The large pieces of junk cannot be brought back to Earth, Johnson says, because the technology is too expensive. Instead, he says, we should try to stop adding new garbage. For example, engineers are changing the way they build spacecraft.

“How you build your satellite can minimize debris,” Gambrell says.

A solution will require international cooperation. Last year, the United Nations General Assembly approved guidelines for how to reduce the risk of space junk. Johnson says that spacefaring countries came together because “the environment was getting worse every year.”

If countries work together to control the amount of trash we send into space, Johnson says, we can keep the problem under control. In the future, perhaps we can even clean up the mess.

“In time, either technology or economics will allow us to go out and [improve] the environment,” he says.

Going Deeper:

When it comes to lighting, though, we’re stuck in the past. The incandescent light bulb that you probably have in your bedside lamp is based on the same technology invented by Thomas Edison more than a century ago. Electricity flows into a metal filament, and the filament heats up and emits light as a byproduct.

Now, the same technology that forms the basis for our computers is set to revolutionize electric lighting as well. It’s known as solid-state lighting, and it has the potential to transform the way we use light.

Light from Computers

Computer chips are made up of what are known as semiconductors. These are solid materials (such as silicon) that can carry an electrical current but, unlike regular conductors like copper wire, can also be easily turned off so that electricity will not flow through it.

LEDs and their organic cousins, OLEDs, will one day make our homes and offices much brighter, while using less energy.

RPI Lighting Res. Center

Solid-state lighting includes two similar technologies: light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs). A diode is a simple form of a semiconductor, so both LEDs and OLEDs are like tiny computer chip parts that give off light.

Both technologies are composed of layers: one is negatively charged, and one is positively charged. When electric current flows through the diode, it excites negatively charged particles, or electrons, in one layer and causes them to fall into holes in the other layer. The energy released in that fall is emitted as light. The color of the LED depends on the material used in the layers and the distance the electrons fall.

Why LEDs?

We don’t think about it much when we flick on the lights, but keeping our houses lit uses up roughly 10 percent of all the electricity we use in homes. Add the lighting needs of businesses and the percentage is even higher. Incandescent light-bulbs are horribly inefficient: only about 5 percent of the energy goes into creating light. The rest is wasted as heat. Fluorescent bulbs are more efficient and last longer, but the toxic mercury in the bulbs means they have to be thrown out in special collections.

Depending on the color, LEDs are 20 to 50 percent efficient, so they save a tremendous amount of energy. The rest of the energy becomes heat, but they’re not hot to touch like incandescent bulbs. Researchers at Sandia National Lab estimate that within a little more than a decade, LEDs could cut the energy used for lighting in half!

LEDs also produce more than 70,000 hours of light — they last a long, long time. And they’re encased in plastic, not glass, so they’re nearly impossible to break.

These digital lights have already replaced traditional bulbs in traffic lights and in displays on clocks and cell phones. They’re used to colorfully light up bridges at night, and for larger-than-life videos, such as the enormous sign that hangs on the corner of a building in New York’s Times Square.

White LEDs are still too expensive to replace all our home and office lighting. But they make great camping flashlights, because they’re bright, tiny, energy-efficient, long-lasting, unbreakable, and can be powered by rechargeable batteries.

Many poor people around the world have no electricity in their homes, so they rely on expensive and polluting kerosene lamps. The same characteristics that make LEDs perfect for camping lights also make them ideal an ideal way to provide light for families who have never owned a bulb.

Groups such as the Light up the World Foundation have designed LEDs, powered by renewable energy, for people who lack electricity. Suddenly, children can study at night, and parents can keep working into the evening. LEDs have already improved the lives of thousands of people around the world!

The firm Kennedy and Violich Architecture created a fabric woven with tiny LEDS for a community in Mexico. It can be worn as a bag during the day, and turns into a lamp at night. (Read more about how it works here.)

New Ideas in Lighting

Imagine a room where you could push a button and change the color of the light. LEDs come in red, green and blue. Each one can be the size of a dot, and when those dots are combined, they can be lit up in different combinations to create an endless variety of colors. Companies have created LEDs that flow from one color to another, all through the rainbow.

“With the touch of a button you can create pretty much any color scheme,” explains Nadarajah Narendran, research director at the Lighting Research Center of Rensselaer Polytechnic Institute. “You could change the color in your room to suit your mood.”

Designers are developing new ways to use LEDs in a building. Light glows from a tile on the floor, or a panel on the wall. (This is hard to do with the breakable glass bulbs used today.) These tiles have already been built, but they don’t fit the standard systems in houses today, where bulbs get screwed into sockets. Narendran says that houses would have to be designed differently to create the right wiring for these blocks of light. He has some lighting up his lab!

But the uses of LEDs don’t end with indoor and outdoor light. Babak Parviz, a scientist at the University of Washington, is designing special lenses that use dust-sized particles of LEDs to display information. Parviz wants to create futuristic contact lenses that could sense changes in your body, such as from a disease, and notify you on the corner of the lens. These don’t exist yet, but someday you might be able to read information broadcast by LEDs literally right in front of your eyes.

LEDs, the Next Generation

LEDs are manufactured in the same manner as computer chips. The materials are deposited in very thin layers under extremely hot temperatures, as high as almost 1,000 degrees Fahrenheit. That costs a great deal of money. They’re also based on the material silicon, the same material that forms the basis for computer semiconductors.

OLEDs function similarly to LEDs, however, they can be manufactured much more easily; use even less power, and can be made extremely thin to be used on paper or even fabric.

Yogurt6255520 / Wikimedia Commons

Organic LEDs (OLEDs), on the other hand, have a carbon base instead of a silicon base. (Carbon forms the building-blocks of life on earth, which is why these are called “organic.”)They work in somewhat the same way as LEDs do: a current flows into the material, one layer gives off electrons, and those electrons fall into another layer. Then there’s a layer that transmits that energy into light we can see. The color of the light depends on the material in that final layer, and most OLEDs have different layers that emit different colors.

Unlike those super high LED manufacturing temperatures, OLEDs can be created at room temperature, which is significantly cheaper. Layers are deposited on a surface, as ink is layered on paper. OLEDs are also extremely thin and can be potentially printed on any substance, even paper or fabric.

“This flexibility is what makes people dream about all the different ways to use OLED technology,” says Bernard Kippelen, an OLED researcher at the Georgia Institute of Technology in Atlanta.

With OLEDs, Narendran imagines entire wall-sized sheets. He says, “You could hang one up and change lighting designs easily, like a shifting wallpaper of light design.” Because OLEDs are transparent when they’re off, a window covered by an OLED could glow brightly when night comes. Or a shimmering picture could be printed directly on a T-shirt.

OLEDs are used today in cell phone screens, but most of those other ideas are still in the design phase. Recently, though, Sony showed off the world’s very first OLED television. It’s only 11 inches large, and it costs about $2,500. It’s incredibly thin, only 3 millimeters at its widest spot — thinner than your finger from front to back — and uses about 40 percent less energy than other thin-screen televisions. The colors and picture are said to be some of the best yet. But with an expensive price-tag, and because it can’t yet be easily scaled up into a bigger screen, it may take years before you buy an OLED TV for the living room.

The path ahead

There are still challenges to overcome before solid-state lighting replaces all the bulbs in our sockets. Scientists are investigating ways to make both LEDs and OLEDs still more efficient and cheaper. The organic materials in OLEDs are fragile and don’t last as long as traditional LEDs, so scientists are looking for ways to make them sturdier. Plus, moisture harms OLEDs, so researchers are trying to figure out how to protect these lights of the future.

Kippelen says the scientists at his lab, like others around the world, are the innovators who are advancing the technology. But as for all the potential uses, Kippelen says, “I leave it to artists and designers to predict what can be done.”

Going Deeper:

These ballpark estimates can often be done without counting. That’s because humans are born with the ability to approximate, or closely guess, the number of items in a group. Researchers refer to this trait as a person’s “number sense.”

Scientists have discovered that this inborn sense of numbers may influence learning and achievement in the classroom. Studies with teenagers show that students who excel at estimating quantities also did well on standard math achievement tests, going as far back as kindergarten.

These results suggest a “strong and significant relationship” between a person’s inborn number sense and his or her ability to learn mathematics in school, says psychologist Justin Halberda of Johns Hopkins University in Baltimore.

Researchers already knew that humans have a natural grasp of numbers. The ability to make rough approximations can be found in infants as young as 4 months old, and even in some animals. This inborn numerical sense reaches back millions of years, researchers say, and has been used by humans and animals to help guide everyday behaviors such as hunting for food.

But sometimes an approximation just won’t do. Most mathematical calculations carried out in the classroom and in day-to-day transactions require an exact number. To succeed in formal mathematics requires verbal reasoning, not to mention hours of homework and training.

To see how a person’s inborn, or intuitive, number sense might be linked to mathematical performance in the classroom, Halberda and his colleagues ran some tests.

In a new study, 14-year-olds had a fraction of a second to identify the more numerous of two sets of colored dots, such as those in the images shown here.

Halberda

The scientists asked 64 14-year-olds to look at images of yellow and blue dots that flashed on a computer screen for a fraction of a second. Each image contained between 10 and 32 dots that varied in size.

Some images contained twice as many blue dots as yellow dots. In other images, however, the number of blue and yellow dots was nearly equal. For each image, the students were asked to estimate which color had more dots.

The scientists found a wide variation in how well students could pick the color with the most dots. Some students could correctly approximate images with nearly equal numbers of dots. But others found it difficult to make such estimates, even when the ratio, the number of one color of dots compared to the number of another color of dots, wasn’t as close.

The scientists then looked at the students’ math scores dating back to kindergarten. Children that performed best in the image test also scored the highest in standard math achievement tests.

The same finding held true at the other end of the spectrum. Students who didn’t score well on the image test tended to receive lower math scores, even after factors, such as IQ levels, were taken into account.

The study was the first to show a link between a person’s inborn number sense and his or her achievement in formal math training.

Does this connection mean that one cannot be good in math if they have a weak number sense? Or that having a strong number sense is a guarantee for good grades in math? The answers are not clear.

While scientists continue looking at the possible links between a person’s number sense and math achievement, one thing is certain: Doing lots of math homework will boost your chances of success.

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A brain chemical called dopamine can help you stay alert even when you feel tired. Some people’s brains are better at this than others letting them perform well on tests and pick up new information even after staying up all night. Science still shows thou

sjlocke / iStockphoto

A chemical in the brain called dopamine might be part of the answer. According to new research, dopamine is what keeps people who don’t get enough sleep from conking out. The chemical also has a complicated influence on your ability to think and learn when you don’t get enough zzzzz’s.

To study sleep loss and its effect on the brain, scientists from the National Institutes of Health in Bethesda, Md., and the Brookhaven National Laboratory in Upton, N.Y., rounded up 15 healthy volunteers. The scientists tested each person’s memory and ability to pay attention twice: once after a good night’s sleep and once after being kept up all night long. During the tests, the scientists measured levels of dopamine in the brains of the volunteers.

The results showed that when the volunteers stayed up all night, dopamine levels increased in two parts of the brain: the striatum and the thalamus. The striatum responds to motivations and rewards. The thalamus controls how alert you feel.

Higher levels of dopamine, the study suggested, kept the volunteers awake even though they felt tired.

In addition, the new research suggests that dopamine levels might play a part in controlling how well people can function without sleep.

Some people are miraculously able to think clearly and react quickly, even when they haven’t had much sleep. Other people have a really hard time paying attention when exhausted, and their reaction times slow way down. The researchers found that higher levels of dopamine don’t fend off the trouble people have thinking and learning while sleep-deprived. But the new research does suggest that dopamine levels may play a part in controlling how well people can function without sleep.

Dopamine is a complicated chemical, and sleep-deprivation is a complicated state of mind. Even when people think they feel OK, exhaustion makes it difficult for them to learn or think as well as they can when they’re rested.

“A little bit of dopamine is good,” says Paul Shaw, a sleep researcher at Washington University in St. Louis. “More is bad. Less is bad too. You’ve got to be in the sweet spot,” to think, respond and learn to your full potential.

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Mineral oil, a lab surrogate for spilled crude (1) is treated with a ferrofluid (2). It’s magnetic slurry mixes with the oil (3). When an external magnetic field is applied (4), the ferrofluid and the oil its corralled will move to the magnet.

McHenry Group / Carnegie Mellon

Now, scientists have discovered another magnetic trick. By mixing unbelievably small magnets with oil, bigger magnets can be used to move the oily globs around. The trick isn’t just cool to watch. Some day, the technique could help clean up messy oil spills in the sea mistakenly dumped by ships.

Researchers at Carnegie Mellon University in Pittsburgh make teeny tiny magnets out of two metals: iron and cobalt. Unlike the palm-sized magnets you may have played with in school, these magnets are measured in nanometers. One nanometer equals one-billionth of a meter. That may be hard to picture, so think of this: A human hair is about 80,000 nanometers wide.(Read this story to learn more.)

To simulate an oil spill in the ocean, the CMU scientists plopped a few drops of mineral oil onto the surface of some water in a petri dish, a small container used in a lab. The scientists dyed the oil blue to make it stand out.

Next, they mixed a bunch of tiny nanomagnets into another batch of oil, creating a black liquid. Using an eye dropper, the scientists added some of this syrupy black stuff to the petri dish. Almost immediately, the black syrup surrounded the blue oil in the center of the dish. Afterward, the researchers placed a strong magnet next to the dish. Right away, the nanomagnet-filled syrup floated toward the big magnet. More importantly, it brought the blue oil with it. [ SEE VIDEO HERE ]

One hope is that the technique might some day help clean up oil spills. Using vats of nanomagnets and large magnetic fences, workers might round up oil spills at sea and prevent them from harming the environment and killing animals.

Many challenges remain, however. Nanomagnets are expensive to make, for one thing, and it would take a lot of them to clean up a big spill. In addition, scientists will want to find a way to gather the little magnets back up once they’ve finished their work. They’ll also need to figure out what to do with the oil once it’s been gathered and moved.

For now, what’s exciting is that the CMU scientists have overcome the first hurdle: showing that the idea can work.

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This may sound like a strange connection. But a new study suggests that children who often get serious ear infections (bad enough to require medication) are twice as likely to become obese later in life than kids with healthier ears.

A middle ear infection is one of the most common of childhood infections. Bacteria trapped in the Eustachian tube causes the middle ear to turn red and swell. And now, science shows nerve damage from the infections could even give you a desire for fatty f

friztin / iStockphoto.com

Why? Frequent ear infections seem to make kids develop a strong preference for fatty foods. And the more fatty foods kids eat, the more weight they gain.

Three out of four children develop an infection in the middle part of their ear at least once by age 3, according to the National Institute on Deafness and Other Communication Disorders, or NIDCD. One out of three kids has at least three middle ear infections by their third birthday.

Researchers from the University of Florida noticed a link between frequent, serious ear infections and obesity after analyzing thousands of questionnaires that asked people about their sense of taste. Data from other surveys show the same link.

To explain the findings, lead researcher Linda Bartoshuk says repeated ear infections might permanently damage a nerve called the chorda tympani. This nerve starts at the front of the tongue, where it picks up taste sensations. From there, the nerve runs through the middle ear to the brain, where it delivers messages about what the tongue just tasted.

Bartoshuk has conducted previous research on the chorda tympani. When the nerve is damaged, she says, people become extra sensitive to the feel or texture of fatty foods, such as butter, which tend to be creamy and slippery. The food doesn’t taste different, but feeling fatty sensations more intensely makes people like the foods even more than usual. That drives them to eat even more fatty foods.

The chorda tympani is not the only nerve that delivers taste messages to the brain, and it is not the only nerve that can go haywire. Other research shows that kids who had their tonsils removed gain weight more often than kids who did not. Bartoshuk says that having your tonsils removed can damage a different taste nerve, which may explain the weight gain.

You’re not doomed to obesity if your ears bother you often, of course, though you might want to focus on eating well and keeping your ice cream portions small. At the same time, consider the plus side: You probably enjoy each juicy bite more than the average person!

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The South Pole has the most extreme weather conditions on Earth, but some scientists think it’s the best place to watch for neutrinos.

Francis Halzen has an unusual job. This scientist studies itsy bitsy, teeny tiny objects zipping through the universe. They’re called neutrinos.

His job should be easy because neutrinos are all around us, all the time. They pass from the depths of outer space to the depths of your sock drawer — and then just keep going. And don’t even think about trying to count these super-tiny particles. The neutrinos flying around our universe outnumber all of the people, animals, plants, satellites, planets, stars, galaxies, black holes and asteroids combined.

They’re also fast, traveling at almost the speed of light. In the time it took you to read the previous paragraph, more than a trillion neutrinos zoomed through you.

They always travel in straight lines. Some fly from your eyes to your ears, others from your feet to your head. They fly from the left, from the right and from everywhere in between. Although you can’t see them, they’re also flying through everything you can see.

So you would think Halzen’s job at the University of Wisconsin-Madison should be a snap. All he has to do is catch a few of the gazillions passing through his university every day.

But they are so small and fast that they can fly through almost anything without leaving a trace. Not even photons, the “particles” that carry light, can do that. Neutrinos are so amazingly hard to see that some scientists have taken to calling them “ghost particles.”

“Neutrinos are one of the most common particles in the universe, but in some ways one of the hardest to capture,” says Jim Madsen of the University of Wisconsin-River Falls. Like Halzen, he looks for neutrinos.

Even Wolfgang Pauli, the first scientist to think of neutrinos, had his doubts. He reportedly wrote in a letter, “I have done a terrible thing. I have invented a particle that cannot be detected.”

Since Pauli’s time, scientists have found ways to build neutrino detectors and search for the strange particle. Halzen is in on the hunt. He is leading a team of scientists building a neutrino detector at the bottom of the world, not far from the South Pole. The machine, called IceCube, is about half done.

When complete, IceCube will be the largest scientific instrument in the world, the size of about 1,000 Empire State Buildings. Isn’t it strange that to find the smallest thing, scientists will have to use the biggest machine?

Why bother looking for neutrinos? These tiny particles can tell us about black holes and exploding stars. Scientists at the South Pole believe IceCube might also pull back the curtain on outer space, revealing strange new things that we can’t yet even imagine.

Tiny ghosts from outer space

Neutrinos travel in straight lines, passing right through almost every kind of matter without changing direction. That means “we can use these particles to bring us information from regions of space that other things can’t,” explains Doug Cowen, an IceCube scientist at Pennsylvania State University in University Park.

Take the area around black holes, for example. Believed to exist at the core of most galaxies, black holes are ultra-compact objects with a mass millions to billions of times that of our sun. They’re difficult to study because they absorb most kinds of radiation, including visible light. If light from a black hole doesn’t get to Earth, then we can’t “see” it.

Scientists suspect that when supermassive black holes “eat” some nearby matter, powerful jets of energy escape into space. The jets can quickly create a stream of high-energy neutrinos, which travel in an everlasting straight beam through space. Other particles might also escape a black hole, but they can be quickly absorbed by dust or deflected by electromagnetic fields.

When an instrument like IceCube detects high-energy neutrinos, scientists can trace the straight line backwards to pinpoint its parent black hole. The neutrinos’ path through the detector will serve, like an arrow, to point at the black hole. Once astronomers know where to look, they can then use other instruments to study the black hole.

When a star explodes in a supernova, it ejects neutrinos that travel through space at nearly the speed of light. Scientists try to analyze the neutrinos when they pass through the Earth.

NASA

Scientists can use the same technique to find exploding stars. The most common type of neutrino forms within the cores of stars like our sun. When the star “dies,” it can explode into a bright ball called a supernova. Like black holes, supernovas are difficult to observe. The sky is big and only two or three supernovas may occur in our galaxy every century. What’s more, their explosions may last only a few seconds. But like black holes, supernovas eject streams of neutrinos, which can serve as a sort of energy “fingerprint” by which the supernova can be traced.

Neutrinos from supernovas, however, have much less energy than those spewed by black holes. That’s one way scientists can tell them apart.

In 1987, astronomers found a nearby supernova. The stream of neutrinos it had emitted were detected all around Earth. Those neutrinos arrived at the Earth a few hours before light from the supernova did, apparently because the neutrinos weren’t slowed down through interactions with dust and other matter along the way. So neutrinos can provide a first alert for astronomers, suggesting where they should point their telescopes to catch major upcoming events.

Scientists working on IceCube hope their machine will also solve one of the biggest mysteries in outer space. “Cosmic rays” are powerful streams of radiation that blow through the universe. Many scientists suspect that they’re leftover radiation from old supernovas. To find out, they hope to find neutrinos from these old explosions and match them to the cosmic rays.

“We expect to detect neutrinos from these sources.” Doing so would provide not only the first solid evidence but indeed “the smoking gun for that theory,” Halzen says.

While scientists are excited about looking for such things, they’re even more excited at the idea of stumbling onto unexpected deep-space surprises with IceCube.

“To me the really fascinating thing would be to discover something that hasn’t been seen with any other technique,” Madsen says. He likens that to the excitement experienced when people peered through the first microscopes.

Looking for a faint blue light

IceCube is made up of a grid of sensors that can detect the blue light from a collision between a neutrino and an atom.

NSF

Neutrinos are one type of subatomic particle (see “The Particle Zoo”). The name means “little neutral one.” They’re described as neutral because they don’t have a positive or a negative electric charge.

Finding neutrinos is tricky, but not impossible. Most pass through matter without running into anything. Occasionally, however, a neutrino smashes into an atom. This collision produces an unusual phenomenon: a flash of eerie blue light. This glow is called Cerenkov (chair ENK uf) radiation.

Instead of trying to stop neutrinos, which is almost impossible, scientists scout for this blue light. Although faint, it can travel dozens of meters (hundreds of feet) through water or ice if the conditions are right. Because Cerenkov radiation is so faint, however, neutrino detectors must be shielded from other types of light and energy that might mask the blue light.

To screen other light out, scientists have taken their neutrino quest underground, because Earth acts like a giant filter. Earth or its atmosphere absorbs most particles that zip through the universe towards our planet. Only tiny particles like neutrinos can easily pass through. IceCube’s position at the South Pole means it can find neutrinos that entered Earth in the north and traveled all of the way through our planet.

Technicians at the Super-Kamiokande neutrino detector have to take a boat to repair one of its thousands of light sensors.

Kamioka Observatory, ICRR (Institute for Cosmic Ray Research), University of Tokyo

An older neutrino spotter lies beneath a mountain in Japan. Its giant, spherical tank holds about 50 million liters (13 million gallons) of water, enough to fill 20 Olympic-size swimming pools. The inside of the tank is lined with thousands of beach-ball–sized detectors that can pick up even the faintest flash of blue light.

Many neutrino-scouting devices look like the one in Japan: large tanks, deep underground. Some contain regular water, others a type enriched with a heavy form of hydrogen (known as deuterium). Until last year, scientists used such a tank, located in Canada. At an abandoned gold mine in South Dakota, scientists are building a similar underground neutrino-scouting system. And on the floor of the Mediterranean Sea, European scientists are installing an underwater neutrino detector with sensors that float on long strings.

Although all of the tank-based systems are remote, they can be seen. But if you go to the South Pole to visit IceCube, prepare to be disappointed. Scientists are burying this detector more than a mile beneath the snowy surface. If you were standing on top of it, you’d never know it. There are a few buildings around and a landing strip for an airplane, but those are the only clues.

You’d never guess that buried beneath the snow and ice is the world’s largest scientific instrument.

NSF

That’s not the only thing that sets IceCube apart from other neutrino detectors. At nearly all of the others, the telltale blue neutrino fingerprint is identified as it passes through water. At IceCube, Francis Halzen and his team are taking a different approach. They’re building IceCube inside an enormous glacier.

First, the scientists drill a deep hole in the ice with hot water. Next, they lower into this hole a string of about 60 detectors, each the size of a beach ball. As ice refreezes around the string, the detectors are locked into place, waiting for a neutrino to whiz by.

Here, ice takes the place of the water in more conventional detectors. When a passing neutrino collides with some atom, its faint blue light begins speeding through the frozen glacier. Light detectors, frozen in place, chart the path of this small flash. By analyzing which detectors saw the light, scientists can track the neutrino’s path, which will point straight back at its source.

“This ice is fantastically clear,” says Halzen. “In our detector the blue light travels over 100 meters [328 feet].”

Burying IceCube this way requires a lot of work, but Halzen says the science it will deliver is worth the effort. For scientists like Halzen, Madsen and Cowen, that small, faint flash could bring big discoveries about the farthest reaches of outer space.

“It’s almost a certainty that we will see things no one has expected before,” Cowen says. “We are more or less opening up this window on the universe and seeing what flies in.”

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