Lexile® measure 3 A Slick Little Robot 930L 5 Down a Wombat Hole 800L 7 Drilling in the Ocean Floor 980L 9 Gerbils Morphing 730L 11 How the Weaverbird Built His Nest 770L 13 Let Curiosity Lead You 900L 14 New Windows on Our Minds 980L 16 Rattlesnake Crossing 660L 18 Stroking Molecules 960L 20 How the Brain Fools the Eye 830L 22 Thinking Like Edison 790L 23 This Keyboard Fits like a Glove 830L

©Highlights for Children, Inc. This item is permitted to be used by a teacher or educator free of charge for classroom use by printing or photocopying one copy for each student in the class. Highlights® Fun with a Purpose® ISBN 978-1-62091-230-0 PAGE: 28

A SLICK LITTLE

By Harry T. Roman ROBOT OTIS is a mobile robot, and I must be cleaned and checked helped design it. regularly. The usual way of Actually, OTIS is just one of cleaning and inspecting the tanks about twenty robots I helped creates problems. Draining the oil create. CECIL crawls inside the from the tanks is messy. Also, the dangerous reactor areas of nuclear people who climb inside the tanks power plants and submarines. to inspect them are in danger, RoBall can walk inside steel pipes even though they use special suits and inspect them with a tiny and breathing equipment. These camera. And SURBOT climbs inspectors sometimes must spend stairs, guards high-security areas, weeks doing the hot, boring work. and lifts heavy objects. OTIS does the job in a couple of But OTIS is my favorite. It was days, saving time and money. The the first robot I helped design, and oil tanks need to be drained only now it is used all over the world. when OTIS finds a spot that has OTIS is short for Oil Tank to be fixed. Inspection System. It is used to inspect oil tanks at refineries, OTIS’s Job Top of page: Some of the tanks power plants, and seaports. Those When we designed OTIS, our that OTIS inspects are huge. large, tuna-can-shaped tanks hold challenge was to create a robot Above: The four-wheeled robot is fuel oil for trucks, homes, and that could clean the oil and lowered into an oil tank. factories. The tanks are often inspect the steel floor of the tank forty to one hundred feet across while all of the oil was still in the and fifty feet high. Five to eight tank! No one had ever done that would harm the robot and possibly medium-sized houses could fit into before. Here is how we did it. leak inside and destroy delicate one of these tanks. Our first problem was to choose electronic equipment. We used a To make sure oil doesn’t leak the right material for OTIS’s body. strong plastic. Rubber seals into the environment, the tanks Otherwise, the oil in the tank between body parts prevented the

oil from leaking into OTIS, even cables to do the job, we decided to vacuum hose to the top of the oil at high pressures. The pressure at lower the robot in through the tank, where a special filter the bottom of an oil tank is opening at the top of the tank. We removes the dirt. The clean oil similar to being under tons of used magnetic wheels to attach then flows back into the tank water. OTIS to the metal tank floor. through another hose. Next, we made an important Having the robot crawling on the decision about how OTIS would floor gave us a way to track where The Robot’s Brain move around inside the tank. OTIS was at any time. Maybe the hardest part to There were two choices: Let the design was OTIS’s “brain.” We robot swim through the oil or roll Seeing Through Oil had to solve the problem of how along the bottom of the tank. Next we gave our robot special OTIS could check the metal floor Since OTIS would need to bring camera eyes so we could see the of a tank for cracks, holes, or other vacuum hoses and electrical tank floor. We designed lights problems. that would allow OTIS to “see” We used high-pitched sound through the yellow-orange color of waves called ultrasonics. We Below: A worker hooks up OTIS’s the oil. These eyes show us the cannot hear these sound waves. hoses before the big job begins. floor plus any obstacles that OTIS They are beyond the range of Bottom of page: OTIS crawls may have to avoid, such as devices human ears. along, inspecting the floor of an that warm the oil in cold weather. Like a bat hunting for insects, oil tank. In OTIS’s belly, OTIS uses ultrasonics to read between his wheels, we the surface of the metal. Common placed a small but high- bats of North America hunt by powered vacuum system. sending out squeaks, which This device sucks up bounce off objects and return to dirty oil that has sunk to the bat. A bat can tell where an the bottom of the tank. insect is by how long it takes The dirty oil goes up one sound waves to bounce off that insect and enter the bat’s ears. In a similar way, OTIS gets OTIS works information about the floor of the under oil tank by sending down sounds that bounce off the floor back to pressure. the robot. OTIS is constantly sending information by sound so that the person operating the robot can tell where it is and what it’s doing. OTIS’s location is shown on a screen. As OTIS gathers information about the floor of the tank, that information also shows on the screen. The good areas of the floor appear as green, and the bad areas are shown in red. Whenever I see those large tanks I think of OTIS. I wonder where he is, helping to keep the environment clean and humans safe from dangerous work. Now there are more robots like OTIS, doing the same kind of work. I wonder what their names are! PAGE: 16

Down a Wombat Hole By Douglas McInnis

For fun, American scientist Dr. Faith Walker crawls into wombat holes. Although she would love to meet a wombat, she knows their tunnels are not good meeting Dr. Walker stretches double-sided sticky tape across the tunnel entrance to collect wombat hair samples and to see who’s home. places. Wombats look like teddy bears but are built like 50-pound bulldozers. They run away when they see a human. Dr. Walker could get crushed if a wombat tried to rush past her in a tunnel. Dr. Walker is studying southern hairy-nosed wombats, which live in remote areas of South Australia. She camps near the wombat tunnels and stays several months. Insects and heat make camp life uncomfortable. Dr. Walker wears a net over her head so bugs will not bite her. The dusty holes smell musky, but she cools down by crawling inside. “It feels like air conditioning,” she says. Not much is known about wombats, so Dr. Walker is trying to learn more. “Trapping wombats is very stressful for them,” Dr. Walker says. Instead of handling them, she studies their hairs. In her field work, Dr. Walker To do this, Dr. Walker stretches sticky never captures wombats. That tape across a tunnel entrance. The tape kind of contact is stressful for catches a few hairs when a wombat them. She can hold Wanda because this orphaned baby is brushes it. She then collects the hair from a wildlife sanctuary. samples to study them.

Photos by 16: (top) Dr. Faith M. Walker, (bottom) S. Grover/B. Cleaver; 17: Dr. Faith M. Walker PAGE: 17

In a laboratory, she studies the tiny Suddenly she recognized the sound. details of the hair. Using these details, Snoring! Sleeping wombats snore, just she can tell which wombat the hair like people. came from. So each hair is like a There are many questions Dr. Walker wombat nametag. The hairs tell Dr. wants to answer. How do wombat Walker how many wombats live in each families work? How well do they get tunnel and whether they are related to along? After sleeping all day, where do one another. wombats go at night? The sticky tape also tells Dr. Walker Long drives, hard camp life, hot if a wombat is home. Before she goes weather, and bothersome bugs are all into a tunnel, Dr. Walker checks the worth it to Dr. Walker. Field research is tape. If there is hair on it, much more than a chance to she knows the wombats are Dr. Walker explore wombat tunnels. It’s also inside. Then she stays out. studies the best way to learn about When the wombats are wombats in wombats. gone, Dr. Walker crawls Australia. into their holes. The tunnels are too narrow for her to go far. “I’ve gotten as far as twenty feet,” Dr. Walker says. One time a wombat charged up a tunnel toward Dr. Walker. The entrance tape had not caught any hair, so she did not know the wombat was still inside. “At first, he probably thought I was another The southern wombat,” Dr. Walker says. hairy-nosed wombat is not As the wombat got closer, he endangered, but saw that she was human, its population has and he ran away. declined. “I crawl into the tunnels for fun,” says Dr. Walker. But sometimes she discovers new information while she’s down there. One time Dr. Walker heard a strange noise in the tunnel. She had thought it was empty. But it wasn’t! Dr. Walker calls her truck the “Wombatmobile.” ©Highlights for Children, Inc. This item is permitted to be used by a teacher or educator free of charge for classroom use by printing or photocopying one copy for each student in the class. Highlights® Fun with a Purpose® ISBN 978-1-62091-137-2 PAGE: 18

What’s beneath the ocean deep?

DRILLING IN THE OCEAN FLOOR By Jack Myers The JOIDES Resolution has a tall Senior Science Editor derrick for raising and lowering If you were standing on this ship, long sections of drill pipe. you would see how odd-looking it is. It’s called the JOIDES long piece of core up to the ship. Resolution. Since 1985 it has been Then there will be a cry of “Core working its way through the on deck!”—and all hands will oceans of the world. Most of that rush to the drilling deck. time it has stayed quietly at rest Carefully they will carry the core while it drilled holes in the ocean to the ship’s laboratory, where it bottom. That’s its job—to find out will be studied and then labeled what’s down there be-neath the and stored. ocean floor. Altogether, the ship has The 147-foot-high derrick can collected a total of more than haul up long sections of drill pipe. a hundred miles of cores. They Then the sections are threaded make up a library of the seafloor’s together to make a continuous sediment and rocks for scientists pipe that can be lowered all the to study. way to the ocean bottom. JOIDES Resolution has made a There are a lot of sharp teeth at whole series of discoveries. Some the end of the pipe. That makes it tell about what happened in ages work like a long, skinny cookie past, others tell about what is cutter. As the pipe is turned round happening today. and round and pushed downward, a pencil-shaped cookie of sediment An Energy Source? The end of the drill pipe has and rock is pushed upward inside One discovery has taught us sharp-toothed wheels that can the pipe. It is called a core. more about a mysterious chemical cut through rock. Special tools will pull a 30-foot- called a gas hydrate. It occurs as

ice-like deposits of methane and where cold seawater can water deep beneath the ocean trickle down into hot Holding Still on floor. (Methane is the stuff we call places and other natural gas.) channels where the the Rocking Sea Gas hydrate is hard to study heated seawater is You may have wondered how the because it decomposes when taken rising. ship can stay steady over the hole that from the high pressures at which So hot seawater is it is drilling, maybe a mile below. That it was formed. It took an inven- continuously trickling, takes some special gear. The ship has tion of a pressure core sampler to or percolating, through twelve thrusters—jet pumps—pointed bring samples up to the ship for channels in the rock. outward from the ship in different study. The surprise was in how Percolation is a process directions. They are operated auto- much of the stuff was found. often used by chemists to matically by controls that work to keep Scientists of the program believe extract materials that the ship right over the drill hole. And that the total amount of gas can dissolve in water. the derrick contains a shock absorber hydrate down there is greater (In kitchens it is used that protects the drill pipe from the than all other kinds of fossil fuel by some coffee makers ship’s up-and-down motion. (coal, oil, and gas) put together. to extract coffee from Someday in the future we may crushed coffee beans.) confirmed the percolator idea and find a way to recover it. Because it’s under great showed how big a percolating pressure, the super- hot seawater system can be—in one case a mile Heat from Below can’t boil, but it’s great at wide and more than a mile deep. I think the most exciting dis- dissolving stuff out of the rock. These percolators churn up the coveries are in what’s happening Some of the stuff “undissolves” seafloor. They deposit sulfur- right now beneath the seafloor. again when it reaches the cold containing minerals that provide Far below, around the Earth’s water above. That leaves big food for seafloor bacteria. Those center, there is a hot, hot liquid deposits of minerals extracted bacteria are food for animals that iron core. Its heat slowly rises from the crust. have never been seen up where through a thick layer called the The idea of seafloor percolation we live. And studying how the mantle and up to the crust below is not a new one, but JOIDES percolators work tells us a lot the ocean floor. Resolution has learned how it about how our mineral deposits We think of the mantle as being works. Instruments were left in were formed in ages past. The mostly rock, but it slowly flows several boreholes, and their JOIDES Resolution is letting us under high temperature and information was retrieved several look at parts of the Earth we pressure. So in a sluggish way the years later. That information never saw before. mantle behaves as a layer of thick liquid heated from below. The hottest places expand, become less dense, and rise. Since mantle composition is not the same all over, some places are better at carrying heat upward. They cause hot spots in the crust above. A hot spot in the crust under the ocean floor gives lots of action. The crust is made of rocks with cracks and crevices between them. That creates channels

Scientists on board the ship study core samples, which have been sliced in half lengthwise. PAGE: 36

When the gerbil pups were one day old, they had Here, they were four days old. We could see the no hair. They slept almost all the time. beginnings of their fur, and their “bumps” were growing into ears.

GerbilsBy Dani Sneed Morphing Surprise! he crawled until he bumped into a An odd squeak startled my son, As Rosey left the nest, we warm body. Then he cuddled up Kyle, as he passed the gerbil cage. gasped at the first sight of the next to his brothers and sisters. He lifted the screen lid and peered baby gerbils. They lay in the soft “Let’s keep a log of the changes in at Rosey and Stinky. bedding. I counted five pups. the babies go through,” I said. To his surprise the squeaking One newborn was lying on his Kyle found a notebook on his came from beneath Rosey. She had back. With his pink skin, he desk. “They will have to morph a a bunch of wiggling pink legs looked like a piglet. His eyes were lot to look like Rosey and Stinky.” sticking out from under her. not open yet, and two big black The next day Kyle brought me “Mom, come quick!” yelled Kyle. eyes showed through his eyelids. to the cage saying, “They are “Rosey had babies!” Kyle pointed changing colors!” as I entered his room. “Look. They’re teeny. They don’t have The pups grew and fur.” changed every day. I joined Kyle staring through the glass at the tiny creatures. Several months before, we had Two bumps showed where his ears gone to the pet store to buy one would soon grow. A curious white gerbil. The store owner explained oval on the side of his tummy was that wild Mongolian gerbils are a stomach full of milk. A tiny scab community animals. Gerbils are was a future belly button. We happier living together. Two boys wanted to pick up the babies, but would be happy together, and so we didn’t. That might have would two girls. We had picked a alarmed the new mother. boy and a girl, hoping to raise After a few minutes, the baby baby gerbils. As the weeks rolled surprised us by curling and into months, we had given up on straightening his body until he the idea of babies. rolled to his feet. On unsteady legs

At the age of fourteen days, they all had fur and This twenty-day-old pup could see. We had to hold it whiskers. The ears were more fully developed. carefully because it could also jump and hurt itself.

Four of the babies had dark dangerous for mammal babies the babies were in the nest. Even shadows on their backs. One was because they need their mother’s so, on day ten Kyle found the still pink. We guessed the shadow milk and warmth. smallest and thinnest baby lying was fur growing underneath the Kyle enjoyed the responsibility still in the nest. He couldn’t help skin. But why was one pink? of caring for the new family. He feeling sad and guilty that it had couldn’t wait for the pups to be old died, even though he had given all On the Move enough for him to play with them. of them the best care. Before they were a week old, When they were eight days old, their ears began to stick out. The their sleek soft fur came in. Four Ready to Go pups also started wandering had black fur, and the pink one At three weeks old, the pups around the cage, sniffing, and now had white fur. scurried with new speed. They had feeling with their whiskers. Rosey Every night Kyle gave the their eyes open. put them back in the nest, where parents fresh gerbil food and Rosey had given up trying to she and Stinky licked them clean. celery. He picked up Stinky to put the pups back in the nest. Straying from the nest can be stroke his back. He made sure all Finally, they were old enough to come out to play. Kyle gently put all four in the dry bathtub with Baby Gerbils’ Growth Log some boxes to explore. We laughed Stinky rears as they scampered around, dug Day 1—Five babies, all pink, no fur. Eyes are shut. holes through the cardboard, and up to look They sleep most of the time. around. Be- tunneled through paper-towel hind him, a Day 2—Back shows beginning of fur. Four pups are rolls. pup snoozes in black. One is still pink. At thirty-five days old, the baby a paper tube. Day 6—Ears are no longer flat on the head. gerbils had made amazing changes. They now ran in the Day 8—Thin fur on back. Whiskers are noticeable. exercise wheel, ate seeds from the Day 10—One baby died. food bowl, and had even started Day 13—Fur now on underside. Pups walk around gnawing on paper-towel rolls. the cage and still sleep a lot. Some fur on tails. These darling miniature gerbils Day 17—Eyes opening. were independent, playful, and ready for a new home. Day 22—Pups eat food from bowl. Wow, what changes they had Day 35—Pups go to their new homes. made in just a little more than a month! Gerbils morphing! PAGE: 16

The nest builder, a male weaverbird in Tanzania.

yanked a foot-long blade of grass until he broke it, nearly falling over backward. As he carried it How the Weaverbird to the tree, it sailed out behind him like a festive green ribbon. Standing on one end of the grass, Built His Nest the bird used his beak to tie By George W. Frame, Ph.D., and Lory Herbison Frame the other end to the branch. He

Outside our kitchen window in Tanzania were some trees, and one day a beautiful Vitelline masked weaverbird came to build a nest. We had seen many old weaver nests, beautiful little baskets still hanging from trees months after the nesting season had ended. How did the birds make such perfect things? Now we would see. The first thing the weaverbird did was to pluck all the leaves from the nearest branches. Leaves fluttered to the ground, and bare twigs stood out against The weaverbird strips the leaves He makes a rope of grasses into a the blue sky. We wondered if he from a few branches. He is loop on the branch. He perches in did this so that a mate would clearing the way for his nest. the loop and begins to weave a more easily see his nest. nest around himself. Then he flew to the ground and

quickly got another blade of grass couldn’t help but keep our fingers the doorway and peered inside. and twisted it with the first piece. crossed for him. Would she like “What does she require?” we He repeated this until he had a the nest? wondered. “A strong doorsill?” rope. When he was satisfied with No, she did not. She flew away. There would be hundreds of its thickness, he pulled up the The weaverbird did not waste landings there, as the parents free end and fastened it, making time trying to improve the nest. brought bugs to feed their babies. a loop. To our great amusement, he She disappeared inside. The The weaverbird perched inside pulled it to pieces. He removed nest shook, as if she were stamp- the ring and built the walls and some more leaves from a nearby ing or poking around in there. roof around himself by weaving branch and started all over again. Were the walls firm enough to long blades of grass in and out. Again a female inspected his withstand wind, thick enough to Gradually the nest became handiwork, and again rejected it. repel rain? She looked out. Was more and more ball-shaped. there a clear view around, so When the bird wove one end of a snakes could not hide? grass blade from inside, he had Could he make Did she like the nest? The male to go outside to pull it through. one that would flew to the nest to hang upside Then he poked it into the nest at down and buzzle and flutter as if another place and had to go inside attract a mate? to persuade her. Yes, it appeared to pull it in. that she liked the nest. She did Finished! Now the colorful The weaverbird built and not fly away! yellow male had to attract a demolished twenty-five nests, Many months after the birds’ mate. He hung upside down at and the ground was littered with chicks had learned to fly and the doorway on the bottom of the tree leaves and broken basketry. had moved away, the neat little nest, fluttering his wings and We wondered what he was doing basket, dried and brown now, was buzzing his peculiar song. wrong and whether he would ever still hanging outside the kitchen Soon a female landed nearby. give up. window. The male withdrew to another A female landed on nest Now we knew how the weaver- branch and watched intently number twenty-six. Again the bird built something so perfect: while she went inside. We male watched as she perched in over and over until he got it right.

The weaverbird carries and weaves Soon the nest begins to look A female checks the view from the only one blade of grass at a time. like a ball. nest opening. Will she like the nest, or will she fly away? PAGE: 29

Flashbacks Let Curiosity Lead You By Michael Dell

When I was growing up, I was interested in science and math and computers. I loved finding out how things worked. At fifteen, I bought myself a computer and took it apart. Those were the days when you could Michael Dell is the chief take the top off and, with the help executive officer of Dell of books, figure out what each of Computer, which he founded the parts did. (Today, if you You can do big things. when he was nineteen. unplugged a computer and took off the top, you’d see a big black chip in there, and you’d have no idea what it does!) Playing with whenever I see kids becoming can I get the names of all these that computer taught me that you passionate about an interest or people who are moving or getting learn almost everything by doing. pursuit, I try to encourage them. married?” My early curiosity about com- Maybe your curiosity will lead you I did some research and found puters helped lead me to the job to a job you love, too. out that a lot of that information I have today, which I love. So It’s good to be curious. I also is legally available to anyone. think it’s good to look for oppor- Once I learned how to get those tunities and to try new ways of names and addresses, I sent out doing things. offers to buy the newspaper. My At one of my first jobs, I experiment was a success! Within learned this lesson through my first month on the job, I ex-perience. I was sixteen, and I became the top salesperson. got a job with the Houston Post, It was simply a matter of find- selling newspaper subscriptions ing an opportunity and trying a over the telephone. My co-workers new way of doing something. and I would call people and say, Kids have fresh approaches to “Hey, would you like to buy the things, and they often come up Houston Post?” with great new ideas. When you During my first few weeks, I pursue your interests and follow figured out that most people who your dreams, a lot can happen. wanted to buy the newspaper You can do big things, and you Michael Dell, about eight were either moving or getting shouldn’t be discouraged by people years old. married. So I thought, “Well, how who tell you otherwise.

brain changes. Once a change is made, it must remain, even after the effort to learn has stopped. If the change doesn’t remain, we New Windows will forget what we’ve learned. Like the memory in our computers, most of our memories are stored away out of our awareness. on Our Minds But when we need them, they can By C.W. Dingman Art by Tom Powers be “copied” and temporarily placed in what is Our brain is a wonderful and How does the brain work? New called our “working complicated organ. And scientists machines can give us answers. memory” for have been working for centuries to immediate use. understand how it works. Everything we learn must be Dr. Yang Jiang is one of the In recent years, they have stored as memories in our brain. scientists using fMRI to learn discovered new ways to study the And storing a memory requires more about how the brain works. brain. Scientists can now watch that something somewhere in our She works in a laboratory at the the activities of different parts of our brain while it is at work. We can think of these techniques as This fMRI picture of new windows on our minds. Dr. Yang Jiang’s head One new research method is shows the areas of called fMRI. It can take pictures her brain that became of your brain in much the same active (red and yellow) way as an X-ray machine can take when she was shown pictures of your bones. This patterns moving on a method makes use of the fact that computer screen. whenever a part of your brain becomes more active, it uses more oxygen. If someone were to use this technique to study your brain, your head would be surrounded by a device that includes a big magnet. This device can detect tiny signals coming from oxygen. With the help of a computer, it turns these signals into pictures. By taking pictures every few seconds, scientists can tell which parts of your brain become active when you think of something, such as multiplying three times ten.

Memory Storage Storing memories is one of the most important jobs our brain does. Without stored memories, we would not be able to recall new words we have learned or find our way home.

National Institute of Mental search for your mother, you first your brain’s working memory Health in Bethesda, Maryland. put your memory of her face in that has the job of remembering one part of your working memory. the person you are seeking. Where Do Memories Live? This is the part that has the job of Dr. Jiang told me that she and remembering who it is you are Mind-Reading Machines? her colleagues wanted to know looking for. And this part is found Does all this research mean more about where in the brain our near the front of your brain. that we will soon be able to read working memories were kept. So The memories of the other others’ minds and know what they asked this question: where do familiar faces, such as your they are thinking? Most likely we store the memory of a face we brother’s, are kept in another part not, but for scientists like Dr. are looking for when we are of your working memory. This Jiang, there are plenty of exciting surrounded by people we know? part is located near the back of experiments to do to learn more For example, which parts of the brain and has the job of about how the brain works. your brain are activated when you letting you ignore the faces of Here is one of the next are at your brother’s birthday people you are not seeking. When questions Dr. Jiang wants to ask: party and want to find your you see your mother’s face, you how does the brain perceive com- mother in a room filled with other activate those areas of your brain plex motion? This is like asking relatives? And then, once you’ve that control your movements how an outfielder knows where to spoken to your mother, what toward her. run to catch a baseball that is happens when you want to find Next you want to give your flying through the air. your brother to give him a gift? brother the gift you brought for If you were a scientist who Dr. Jiang and her colleagues him. Now his face will replace studies the brain, what questions learned that when you want to your mother’s face in the part of would you like to ask? PAGE: 12

This snake helps people cross the street!

You must enter the bridge through the snake’s open mouth.

Rattle nake Crossing Story and Photos by Rene Allen

People rely on a snake Being inside the bridge is fun, too. every day in Tucson, Jake, also nine years old, said, “This Arizona. bridge is radical. I feel like a rat getting It’s really a bridge that looks like a digested by a snake.” rattlesnake. It takes walkers and It is beautiful inside the bridge. bicyclists across one of the city’s busiest Diamond-shaped shadows look like roads. the skin of a western diamondback You are “swallowed” when you walk rattlesnake. As you walk out, electronics into the snake’s mouth. Steel beams look make a rattling sound. like giant fangs. The body is a metal cage with a paved floor. At night the snake’s A Bridge as Art eyes light up with an eerie golden glow. Why make a bridge that looks like a snake? Inside the Snake You are safe inside the bridge. When Preston, age nine, walked through it, he Diamondback pattern saw the traffic passing underneath. He said, “I like being high above the cars.”

Inside Rattlesnake Bridge, people cross one of the busiest roads in Tucson, Arizona. Rattle nake Crossing

When the people of Tucson decided to build the bridge, they wanted one that I see you! would look different. They asked artists for ideas. Artist Simon Donovan thought bridge by cutting diamond shapes out of of making a bridge that looked like a flat pieces of rubber. Painters used these snake. “Bridges and snakes are a lot shapes as outlines when they painted the alike,” he said. “Both are long and can be snake’s sides. The students felt proud shaped like a tube.” to work on a project as important as a Donovan’s idea was chosen. He was bridge. happy that so many workers were Rattlesnake Bridge is a landmark. helping to build a piece of sculpture that People look for it when they drive into he had designed. downtown Tucson. The snake’s mouth Donovan teaches art to high-school is open, and you can almost hear it say, students. His students helped with the “Pleassssse come again!” PAGE: 16

STROKING MOLECULES By Nancy Burnham

Have you ever tried stroking a Long Molecules Each molecule naturally takes a cat’s fur from its tail toward its We use some special chemicals position with one end sticking into head? That’s against the natural that have molecules shaped like the water and the other end angle of the fur, and it feels more the long molecules of soap. These sticking out. difficult to do. Most cats don’t like molecules also have special prop- When we put a little of this the extra friction between your erties like those of soap molecules. compound on a bathtub full of hand and their fur. One end of each molecule is water, it acts like soap: it spreads Friction is the force between attracted to water. The other end out to make a surface film one two things that opposes their pushes away from water. When molecule thick. motion. Sometimes we want a lot these molecules are placed in By dipping in paddles, we can of it—as when the brakes on your water, they stay on the surface. squeeze the film into big islands bicycle push against the wheels in which the molecules are closely and slow you down. Sometimes We study packed together. Then we slip a we want very little friction, as in piece of smooth, flat mica under skating or skiing—the faster the friction in a the surface and lift off the film. better! high-tech way. Now we can take a picture of the Scientists want to know all they can about friction. We are learning a little more about it in my laboratory at the Swiss Federal Institute of Technology in Lausanne, Switzerland. Friction depends on what happens between the surfaces of two objects that slide against each other. So we need to understand a surface down to the smallest bumps and wiggles of its surface molecules. Molecules are the smallest bits of matter that make up any chemical compound. Some kinds of molecules are round and fat, others long and thin. One compound that was fun to study was made up of long molecules that packed together like cat’s fur— though of course about ten The author and her co-workers, from left to right: Dr. Burnham (show- million times smaller. I will tell ing how the scanning-force microscope might scan a Koosh ball), Dr. Mar- you about them. tha Liley, Delphine Gourdon, and Dr. Claus Duschl.

Figure 1: Lighter areas are taller. Figure 2: Lighter areas are harder to rub across. Here are two pictures of one group of molecules, all packed together side by side. No one knows why they make a flower shape. Each petal of the flower is made up of molecules that are leaning in one direction, and that direction is different for each petal. The scientists discovered that the tallest molecules did not create the most friction. Instead, the amount of friction depended on which way the molecules were leaning. molecules in that surface film. area about 1/10,000 the size of the more friction. The finger of our Take a picture? You might ask, period at the end of this sentence. microscope senses a different “Aren’t molecules so small that we The lighter parts show where amount of friction over each petal can’t see them even with really molecules are taller, even though of the flower pattern. strong microscopes?” actual differences in height are Using other instruments, we’ve You’re right. We cheat a little. about 1/100,000 the thickness of learned that the molecules of each We take our “picture” with a this page. The lighter parts (taller petal are all lined up together and scanning-force microscope. It has a molecules) occur in islands of film pointed in one direction, like a very sharp finger that we can that take shapes like the petals of cat’s fur. Different shades show move as it touches a surface. flowers. (Other kinds of molecules that different tilts of the surface We can sense the very small give different patterns, and we molecules can affect friction. We force between the finger and sur- don’t yet know why.) can even tell that stroking mole- face molecules. It’s like learning cules one way gives more friction about a tabletop or the side of a Microscopic Rubbing than stroking them the opposite tree by running your fingers We can also use the finger of way—just as stroking your cat across it. Then you are scanning. our scanning-force microscope to from head to tail is different from You make a picture in your head sense the friction in moving over a stroking it from tail to head. of the forces you feel against your surface. You can do that with your The surprising result is that fingers. finger, too. It takes less force to stroking the molecules backward A scanning-force microscope slide your finger over a greasy gives less friction than stroking works with the same idea but on a dinner plate than over a them forward. It is as if stroking a much smaller scale. It works by tablecloth. cat from tail to head were easier feeling the molecules at the Figure 2 is a friction map of the than stroking it from head to tail. surface of an object. You can see same patterns of film shown in We don’t understand this yet. It is in Figure 1 a picture we made of Figure l. In Figure 2, lighter color just one of our results that we will our special surface. It shows an does not mean taller, it means have a lot of fun figuring out. PAGE: 40

How the Brain the Eye 1 By Carmella Van Vleet Photos by Joshua Moglia

My father had a mustache for Our eyes see the changes, but our In the experiment, a college twenty years. One day, he shaved brains don’t keep track of each student stood on a campus it off and didn’t tell anyone. and every one. sidewalk and pretended to be lost. Everyone in the family could tell Just how big can these changes The student asked a stranger— something was different, but we be? You might be surprised. either another student or a weren’t sure what. It took my teacher—for directions. While the mom a whole week to solve the “Now You See Me . . .” stranger was giving directions, mystery! Dr. Simons and Dr. Daniel two other people, carrying a door, There is a simple explanation Levin at Vanderbilt University walked between the student and for why we didn’t see the change did an experiment that showed the stranger. right away and why you might that we can miss some big While the door blocked the miss a change, too. It’s called changes indeed. stranger’s view, another student change blindness.

A Trick of the Mind Dr. Daniel Simons at the Try This! University of Illinois studies change blindness. He calls it To see change blindness in action, try this a trick that our brains Will Anyone experiment with your family. Without telling sometimes play on us. anyone what you’re doing, go to your room “Change blindness is the See the and change your shirt. When you come out, surprising failure to see Change? don’t draw attention to the shirt in any way. large changes to a If no one notices that you’ve changed shirts, scene,” he says. In sneak off and change again. If you do it a other words, we can few times and no one says anything, ask your look at something but family if they notice anything new about you. not notice that it’s new Or draw attention to the shirt. For example, or different from what it you could say that it’s your favorite or that it was an instant ago. makes you itchy. Most of the time, change How many times do you have to change blindness is a good thing. Being shirts before someone notices? able to block out distractions is Do brighter colors or wild patterns important. If we couldn’t ignore the draw more attention? unimportant details and movements Who notices the change first? around us, we would have a hard Does drawing someone’s attention to the time getting anything done. shirt make it easier for him or her to notice But sometimes we miss changes that it has changed? that are right in front of our eyes.

2 3 4 Scientists are exploring the mystery of “change blindaness.” took the place of the first student. Sometimes we miss a change After the door passed by, almost because it happens over a long half of the people who were giving period of time. A tree takes years directions didn’t notice that they to grow. The growth is so slow were talking to someone new. that it doesn’t draw our attention. People experienced change Then one day, we look out the blindness in this experiment window and wonder, “Where did because their view was blocked. that tree come from?” Having your view blocked for How good our memories are a moment is a common cause may also play a role. Does change of change blindness. The thing 5 blindness happen because we that blocks your view doesn’t don’t see many details in the first have to be as big as a door. It place or because we just can’t Four kids show how college can be small, such as rain on the remember them well enough? students ran the experiment. windshield of your car or someone Researchers are studying this 1. A boy asks a stranger for waving a hand in front of your question. face. The block doesn’t have to directions. Most people believe they see last a long time. Even blinking 2. Two people carry a big object everything around them. You can cause change blindness. between the two. might say, “Of course, I’d notice if 3. Behind the object, two boys my dad shaved his mustache or if “Look! Over There!” switch places. I was suddenly talking to someone And the object doesn’t even 4. Will the girl notice the new.” But the more we learn about have to be right in front of what’s difference? Many people didn’t. change blindness, the more we changing. It just has to distract 5. Would you have noticed? discover we can look at something you from the thing that is changing. but not really see it! Distractions cause change we usually pay attention to big, blindness because when some- interesting things such as people thing changes or disappears, our or buildings. We don’t usually pay eyes are drawn to the movement. attention to smaller things, so we If a distraction causes us to miss don’t notice when they change. the movement, we may miss the This is why puzzles in which change. you find the differences between Not paying attention to the two pictures (such as “Check . right object can also cause change . . and Double Check”) can be blindness. When we look at a challenging. Many of the changes picture or at the world around us, are small. PAGE: 20

Flashbacks adjust the brakes of our car. Later, we found a similar tool in a store. That’s when I learned that different inventors often invent Thinking similar things. It is not unusual for this to happen. I learned, too, that How an not all great ideas like inventor of work. Failure is a common part of the robots got inventing process. Edison As my father and By Harry T. Roman his start I worked together, I began to realize that my I build robots. The ones that impressed me most dad was quite an inventor himself. I have invented robots that were motion pictures, recorded He made a remote switch for his crawl through pipes to inspect sound, and the electric light. camera, attachments for them for damage. Some of my Edison became my hero. his ladder to hold house-painting robots clean large oil tanks and My dad noticed my interest in equipment, a starter switch for the keep them from leaking oil into the inventing and encouraged me. He car, and an air-storage tank for environment. Two of my inventions showed me how to turn my ideas filling flat tires. He was always allow cars to be used as power into plans and, eventually, into looking for a better way to do a plants on wheels. The engine of new things. simple job. each car is a fuel cell that provides Soon, I had a box of spare elec- My father’s example made a power whenever needed. trical and mechanical parts and lasting impression on me. His My love of building things my own workbench in my dad’s big guiding hands, combined with began when I was a kid. It wasn’t workshop. I was becoming an my interest in inventing, led until I learned about Thomas inventor. me to become an engineer Edison, though, that I really Together, my dad and I and an inventor. But I became excited about inventing. re-paired radios and televisions. credit Thomas Edison, too, When I was in fourth grade, our We increased the electric wiring in for first lighting that bulb teacher gave us a project. We had our house. We fixed the family inside me. to write to a company and learn car. about the products it made. Each Once, I surprised my dad student would then give a report with a tool I made to in front of the class. I chose the Thomas A. Edison Company. Soon after I wrote to the An early company, our mailman delivered a mobile robot package to me. It contained a book about the life of Thomas Edison. How I enjoyed reading and re-reading about his inventions!

Harry T. Roman is an inventor of robots and the president of the New Jersey Inventors Hall of Fame. He also works with teachers to develop programs that show kids how to think like inventors.

This KEYBOARD In the future, Fits like a will computers GLOVE be stitched Computers are getting smaller By E. Renée Heiss into our and smaller—and easier to use. Now engineers are creating new clothes? computers that can be carried in fanny packs or even sewn into clothing. The engineers replaced the hard drives with tiny circuits, and they shrank the monitor so the display could be seen in a pair of special glasses. But they still had a letter or number. problem: how could you type words With a switch on each and numbers into the computer section, you can “key in” without using a key-board? any of those letters by pressing the Dr. Vaughan Pratt of Stanford correct switch. University solved the problem. He But that’s only 12 symbols. The another 12 symbols, and so on. created a system called Thumb- system has to have many more Dr. Pratt put switches between code. than that. the fingers of the Thumbcode To use Thumbcode, a person Dr. Pratt found a way to do it. glove. That way, the computer wears a special glove like the one Spread your fingers apart. Make “knows” which fingers are in the photograph above. It’s wired two fingers touch side to side. to-gether and which are apart. The to enter letters, numbers, and When you hold some fingers photographs below show some of other symbols into a computer, like together and keep others apart, the combinations he used to “type” a keyboard that fits in the palm of you make different combinations. the symbols he wanted. your hand. With just two fingers together, Thumbcode is as easy to learn How does the Thumbcode each section of each finger can as keyboarding. But don’t look for system work? Look at your open stand for a letter or number that’s a Thumbcode glove in the store hand. Notice that each finger is different from before—12 more yet. Engineers have many more divided into three sections. Each symbols! Hold a different pair of problems to solve before you will be section can stand for a different fingers together, and you can get able to wear your computer.

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