Dr. Universe

Ask Dr. Universe – Earth’s Garbage – Part 3

Part 3/3
Dear Dr. Universe: What happens to the world’s garbage? -Presley, 8, Spokane, Wash.
How do you recycle an object into another object? -Brianna, 12, New York

Dear Presley and Brianna,

So far, we’ve investigated how recyclables like plastic, aluminum, and paper can end up in the trash. If our clothes get damaged, or we simply outgrow them, we might toss them in the trash, too. Or send them to a thrift shop. Either way, they often end up buried in a landfill.

But my friend and Washington State University researcher Hang Liu imagines a different future for our used clothes. In her lab, she and her team are coming up with creative ways to recycle cotton into a new fiber.

My own lab coat is made of cotton. If you look at the tags on your clothes, maybe you’ll see some of them are also made from cotton. Cotton comes from a plant and is a natural fiber made up of lots of different parts that we call molecules.

As we learned last week, we can use heat in the recycling process to break down materials. However, the molecules that make up cotton stand up to heat really well. This has made it hard to recycle cotton in the past. Instead of using heat, Liu and the team created a mix of environmentally-friendly chemicals to dissolve the cotton fabrics.

Using a machine they built in the lab, they can transform those molecules back into a new fiber that can be woven into new clothes. The machine in their lab has five holes that spin out tiny fibers. But one day this method could be used in even bigger machines to create even more fiber for clothes.

Liu even showed me a spool of blue cotton made out of denim from an old pair of jeans. Denim is just one of many cotton products that can be recycled with this new process.

In the U.S., an adult discards about 68 pounds of textiles, cloth or woven fabric, every year. About at least 75 percent of that eventually reaches a landfill.

Liu and her team are excited to be able to recycle old cotton materials like clothes, sheets, and towels into new fiber— over and over again. Their invention will help keep more waste out of landfills.

Liu reminds me that finding new ways to recycle clothes is important if we want to meet the needs of people today while also making sure the next generations have what they need in the future.

One question that remains is what to do with the zippers and buttons on these recycled cotton clothes, Liu says. Who knows, maybe you can help come up with a creative way to recycle clothes or fabric. After all, recycling never goes out of style.

Dr. Universe

P.S. Thank you to all our generous Dr. Universe readers who inspired future scientists and engineers by donating items to the first-ever Science Rules STEM Supply Drive! The donations will support science education in local classrooms, libraries, and after-school programs.

Ask Dr. Universe – Earth’s Garbage – Part 2

Part 2/3
Dear Dr. Universe:
What happens to the world’s garbage? -Presley, 8, Spokane, Wash.
How exactly do you recycle an object into another object? -Brianna, 12, New York

Dear Presley and Brianna,

While a lot of our trash goes in a landfill, we can also recycle all kinds of stuff on our planet. Depending on what the object is made of, we might grind it up, mix it up or melt it down before we turn it into something new.

Let’s start with paper. When you recycle paper, it usually ends up at a recycling center where it gets washed with soapy water and mixed into a huge, thick slurry.

Sometimes we add a few other ingredients if we want a specific kind of product, like cardboard or printer paper. The slurry is poured out onto a big table and flattened with big rollers. After it dries, it can be cut into different sizes and shipped to stores. Recycling is a great way to help us make new paper without cutting down more trees.

We can also recycle things like glass, plastic and aluminum. A lot of these materials are mixed together in a recycling bin, so the first step when they arrive at a recycling center is to wash and sort them. Engineers have built conveyer belts and equipment to help divide up the different items into groups.

Once they are divided up, they can be melted down, cooled and shaped into flat sheets or new objects. A glass bottle might become a jar, a plastic bottle might become recycled clothing and a soda can might become another soda can.

While different objects go through different recycling processes, most of the time we break them down before we build them up into something new. But some materials that we want to recycle don’t break down quite as easily.

While most of us put smaller items into the recycle bin, we also have lots of really huge stuff we need to recycle, too. Things like airplane wings and giant blades from windmills often end up in landfills. My friend Jinwen Zhang, a scientist at Washington State University, is helping research ways to recycle the lightweight materials and keep these big objects out of landfills.

This kind of lightweight material, carbon fiber plastic, they work with in the lab can’t melt down like a lot of other things we recycle. Zhang and his team figured out a different way to break them down using just the right environmentally-friendly chemical mix.

Exactly what kinds of objects those wings and blades will become is a question that we are still looking to answer. It will inspire more research and help us understand how to recycle things that couldn’t really be recycled before we learned to break them down.

These are great questions you ask, Brianna and Presley. Thank you for being curious. We can help make the planet a safer and healthier place to live when we recycle.

Dr. Universe

Ask Dr. Universe – Earth’s Garbage – Part 1

Part 1

Dear Dr. Universe: What happens to the world’s garbage? -Presley, 8, Spokane, Wash.

Dear Presley,

If you’re anything like me, maybe one of your weekly chores is helping take out the trash or making sure all your tuna cans get into the right recycle bin. The truth is, I wasn’t entirely sure where the garbage goes either, so I decided to ask my friend Karl Englund.

Englund is a research engineer at Washington State University and studies all kinds of different materials in our world. He is really curious about how we can take materials and give them a new purpose. Our garbage can end up in a few different places, he says.

The average human who lives in the U.S. creates about 4.83 pounds of trash each day. As you can imagine, it piles up pretty quick. Many people don’t really see much of it, though.

Englund explained that after sanitation workers pick up the trash in their big trucks, they often drive to a landfill. A landfill is a place where we bury garbage underground.

Some garbage will break down pretty fast in a landfill. Something like a banana peel will become part of the soil again in about a week or so. Some people even let these organic things break down into something called compost and use it to help their gardens grow. But then there are other items we throw out that don’t break down as easily, such as plastic water bottles. A plastic water bottle can remain in the earth for hundreds of years.

A plastic water bottle may not break down in the dirt, but it can be pretty easily made into new plastic materials if we simply recycle it. That’s why it can be helpful to learn about what different materials are made of and how we can dispose of them in a way that helps the environment.

You could also repurpose something like a plastic water bottle. If you cut it in half, it might make a nice little container to grow some small plants, Englund says. Or if companies take the bottle and grind it up, they can make things like carpet or even a playground. It takes some science mixed with a lot of creativity.

In Englund’s lab, scientists are working with materials from old airplane wings to create a kind of pavement.

When it rains, a lot of dirty storm water often puddles up on roads and flows into the streams and rivers. But pavement made with recycled materials lets water flow straight down into the soil. The soil acts as a natural filter and the pavement keeps toxic things from running off the road into the water. This is really important to the fish and other animals that call the water home.

With Earth Day just around the corner, we’ll keep exploring more questions about ways we can use science and engineering to help our planet. Stay tuned for next week’s big question.

Dr. Universe

Ask Dr. Universe – Broccoli

Dr. Universe: How come broccoli is good for you? -Zack, 10, San Lorenzo Valley

Dear Zack,

You aren’t alone if you’ve ever heard someone at the dinner table say, “you’ve got to eat your broccoli.” Broccoli is one of nature’s superfoods, so it’s no wonder we are often encouraged to eat those little green trees.

As I cat, I don’t eat too much broccoli. So, I decided to visit my friend John Clarke, a professor of pharmacy at Washington State University. Broccoli is what got him a PhD, he says. Clarke studied how broccoli can help fight off toxic things in our bodies and may even have cancer-fighting properties.

He’s happy to help with your question and says broccoli is what we call a cruciferous vegetable. Whether it’s broccoli, cabbage, radishes, or bok choy, the veggies in this family all share a similar chemical makeup.

If you’ve explored the periodic table of elements, you know that there are a lot of different elements that make up things in our world. When two or more elements come together, they form a compound.

When we chew or cut broccoli, we damage the plant tissues and a new compound forms. It’s actually this compound in broccoli that gives off that, well, unique broccoli smell. Scientists have also discovered how this same compound can help fight off toxins in your system.

“The plant has components that can act like coffee in a tired person,” Clarke said. “It stimulates some of the body’s detoxifying bodyguards to stay awake and get rid of bad toxins in the body.

There are lots of ways to eat broccoli, too. You might steam it, fry it, roast it—maybe even sprinkle a little cheese on top. But I also found out that cooking broccoli actually reduces some of those bodyguard compounds.

“It is still good for us,” Clarke said. “It’s just that it is better to eat the whole food.”

You’re right, Zack. Broccoli is good for us– and it’s best raw.

Broccoli is also packed with vitamin C, which can be good for fighting off infection. If you are ever feeling under the weather, you might just consider having a little broccoli along with your chicken noodle soup. It also has fiber. When we get enough fiber from our food, it can help with both heart and blood health.

The chlorophyll that gives broccoli–and a lot of other plants–its green color can also be good for us. It has all kinds of nutrients and is the source of vitamins and minerals our body needs to grow strong.

Maybe sometime soon you can help make dinner at your house and see if you can find a creative way to use those little green trees.

You can learn more about all kinds of vegetables and try out these recipes from my friends at WSU Extension. http://extension.wsu.edu/skagit/harvest-of-the-month/ Tell us how it goes sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Bees’ Behinds

Dear Dr. Universe: My daughter is asking, why do bees have pointy behinds? -Asma, Pakistan

Dear Asma and Friends:

Lots of bees have pointy behinds, but not all of them. The ones that do have a pointy behind, or a stinger, can use it to help defend their homes, food, and fellow bees. That’s what I found out from my friend Megan Asche, a graduate student at Washington State University who studies honey bees and takes super close-up photos of insects.

Asche explained that when a honey bee adult emerges, it chews through one of the waxy hexagon cells in the hive before pushing itself out into the world. For the first two days of the bee’s life, it can’t sting. The bee has a pointy behind, but the venom-releasing organs attached to her stinger are still growing. She needs to walk around and eat before the stinger fully forms.

If you get stung by a bee, it’s going to be a female. Males don’t have a stinger.

Female bees’ ancestors used to lay eggs inside plants or animals using a kind of shovel-shaped thing on their rear end called an ovipositor. After a while, they didn’t need their ovipositor, so it stopped being used for laying eggs and instead became a stinger bees can use to help defend their home.

When a new queen honey bee hatches, she will use her stinger to damage the wax cells where her rival queen bees are growing. She also has to look for a mate. Once she has found a mate, she doesn’t need her stinger anymore. If there’s any stinging to be done, that’s the job of the worker bees.

In one of the photographs Asche took in the lab, you can see that a honey bee stinger has lots of tiny sharp parts, or barbs. The little barbs on a honey bee stinger are long enough to stick in your skin. Bees don’t want to hurt you, but sometimes they will sting if they feel threatened. Once a honey bee stings you, it dies. That’s because its stinger is attached to important organs inside of the abdomen.

“They are essentially making the greatest sacrifice,” Asche said.

When you get stung, the bee will release a pheromone, or a chemical. The bees are basically flagging you. Other bees can sense this pheromone in the air and may show up on the scene. Their stingers may be tiny, but they sure can use them to protect their fellow bees.

“Worker bees are defending their sisters,” added Asche. “They are protecting their home and their food.”

In the end, a pointy stinger can help a family of bees survive. That’s really important for humans and other animals, too. Bees are pollinators. We rely on them to help plants grow and reproduce so that we can have oxygen, food, and a healthy planet.

Can you think of other ways insects might defend and protect themselves in nature? Tell me about it sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Puffer Fish

Dear Dr. Universe: How do puffer fish puff up? Do they fill with water or air? Why do they get so big? Thank you. – Ben, 6, Madison, WI

Dear Ben,
You’re right, a puffer fish can get pretty big. In fact, some of them can even inflate to the size of a balloon or a beachball.

My friend Wes Dowd is an associate professor in the School of Biological Sciences at Washington State University who currently studies mussels and tiny crustaceans called copepods in tidepools. Much of his training was with fish and he has always been curious about life in the ocean.

In fact he said he’s shared your fascination with puffer fish ever since he was a kid himself, fishing for the Northern puffer fish on the waters of the Chesapeake Bay.

He remembers these fish were a lot different than the bass or flounder he usually caught. The yellowish puffer fish had spines around its body, puffy cheeks, and a little beak-like mouth.

One idea scientists have about the pufferfish is its puffiness is a defense against predators, Dowd explained.

If puffer fish are swimming, they gulp water into a special sack near their belly. But if they are frightened while in the air, perhaps while being fished out of the water, they will also gulp in air.

“In the fish world, dinner is often consumed in one bite,” says Dowd. “So making yourself as big around as possible minimizes your chances of being eaten.”

Being able to puff up while also having lots of spines on your body is also a great way to ward off predators.

Even if a predator is big enough to eat a puffer fish whole, it will be in for a big surprise. Some pufferfish also have another potent way to defend themselves: tetrodotoxin. It blocks the ability for an animal’s nerves to communicate with each other, causing paralysis or death. However, some puffer fish like the ones Dowd caught as a kid aren’t toxic.

Believe it or not, the puffer fish is just one of more than 200,000 known species of animals that live in our oceans—and there are likely millions more we don’t even know about yet. Who knows Ben, maybe one day you’ll discover something about the puffer fish or other kinds of life out there in the ocean.

Dr. Universe

Ask Dr. Universe – Bees Making Honey

Dr. Universe: How do bees make honey? – Nisi, 10, Nampa, Idaho

Dear Nisi,

All around the world bees are busy turning nectar from flowers into sweet, golden honey. That’s what I found out from my friend Brandon Hopkins, a honey bee researcher at Washington State University.

When a bee sucks up nectar from a flower, the sugary liquid flows into its honey stomach. Unlike the stomach where its food goes, the bee uses this tiny compartment just for carrying honey. It can haul about one-third of a bee’s body weight in nectar.

Once the bee’s honey stomach is full, it heads to the hive, where it is greeted by housekeeping bees who are ready to help with the next step.

The full-bellied bee spits up, or regurgitates, the nectar. It passes the nectar to some of the housekeeping bees then heads back outside to fill up again. Meanwhile, the housekeeping bees get to work. They pass the regurgitated nectar to other bees in the hive and it is eventually put into the hexagon-shaped honeycomb cells.

Hopkins said sometimes the nectar has too much water in it for the bees to make honey, so the bees fan the nectar with their wings to help some of the water evaporate.

After the bees get rid of the moisture it is ready for storage. Using a gland in their body, the bees produce small flakes of wax. They can use their jaws, or mandibles, to move it around and shape it. Finally, the bees create a wax cap for the honeycomb cell to seal in the honey.

Bees are quite the honey-making machines. They are also important for helping plants and flowers survive. While sipping nectar, they also move around tiny grains of pollen from flower to flower. This process helps flowers reproduce. The pollen is also food for the bee.

Bees are not only good for plants, but also for any humans who like to eat dinner. Bees help pollinate fruits, nuts, and all kinds of other food sources. Of course, we also eat the honey they make. Honey has been part of the human diet for a long time.

Archeologists have actually found old pots full of honey in tombs from ancient Egypt. It had crystalized into more of a solid, but could be melted back into liquid. Even though the honey was put in ceramic pots thousands of years ago, it was still good to eat. Honey has the longest shelf life of any food out there, Hopkins adds.

There are lots of bees that make honey and there are lots of different kinds of honey to try.

The flavor often depends on what plant nectar the bee used to make it—clover, berries, trees, or whatever flower the bee happened to visit. Send an e-mail with the subject “honey” to Dr.Universe@wsu.edu this month and you’ll be entered into a raffle for a jar of honey from WSU. The winner will be announced the last week of June.

Dr. Universe

Ask Dr. Universe – Worms

Dear Dr. Universe: Why do worms come out when it rains? -Courtney, Moscow, ID

Dear Courtney,

That’s a great observation. When it rains, worms sometimes leave their home in the soil and wiggle their way up to the surface, where we see them on sidewalks and roads.

Worms come to the surface to move around, but exactly why they do it or where they are headed remains a bit of a mystery. Still, scientists have some interesting theories about it.

That’s what I found out from my friend Tarah Sullivan, a scientist at Washington State University who studies the living soil. Soil is very much alive, she reminds me.

It’s not only home to worms, but also all kinds of plants, insects, and billions of tiny living things called microbes. The different kinds of life in the soil depend on water to survive, so rain is quite often a really good thing.

One theory for why worms come to the surface is so they don’t drown, Sullivan says. But worms breathe through their skin and they can actually get some of their oxygen from water. They also need a wet environment to live and breathe, so it seems like there would need to be a lot of rain for this theory to work out, she adds.

Another idea scientists have is that rain creates some pretty good travel conditions for worms. Imagine you were trying to move through a big tunnel of soil. It would probably be hard to move around with all kinds of dirt clods, roots, and other things in your way.

Yes, worms can wriggle and squirm through the soil. But it’s still going to be easier for them to travel, and faster, if they are moving around in the more open space on the surface. They may be able to find other worms easier, too. This is especially helpful if they happen to be looking for a mate or trying to find a new home.

Worms like to avoid light and don’t want to get fried in the sun, so moving when it’s rainy or cooler outside can make for safer travel conditions. If you see worms on the sidewalk, it’s best to not disturb them. They have some important work to do and have to continue on their journey.

Worms can help soil stay healthy, which is especially important to us because we need healthy soils to grow the food that we eat.

Maybe the next time it rains in your neighborhood you can go out and make some worm observations. How many worms can you count? How long was it raining and what were their travel conditions? Are they headed in a certain direction?

Tell me about it sometime at Dr.Universe@wsu.edu. Keep asking great questions and maybe one day you’ll be helping us answer big questions about the living soil that supports life on earth.

Dr. Universe

Ask Dr. Universe – Recommended Experiments

Dr. Universe: Do you have any experiments you recommend? Thanks! -Etta, 7, Milwaukee

Dear Etta and Friends:

You can try all kinds of fun experiments at home. It really all depends on what you are curious about. Lately, I’ve seen some really great sunsets and started wondering what gives them their colors.

I decided to ask my friend Tom Johnson, who leads fun physics demonstrations for kids visiting Washington State University. I asked him if he had any simple ideas for an experiment I could try out in my lab, or even the kitchen. One idea he had was to create a sunset in a cup.

Maybe you can try it, too. You’ll need a flashlight, a transparent cup or two, water, and some milk. We cats have a reputation for liking milk. But it really isn’t so great for our digestion. So instead, I like to use it for science.

Once you’ve collected all your supplies, you’ll want to fill your glass about 2/3 of the way with water. Then, you’ll want to add milk until the liquid gets pretty cloudy. Be sure and stir it up well.

Turn on your flashlight and turn down any other lights in the room. Now you can shine the flashlight down into the water and look through the side of the glass. What color do you see?

This time, shine the flashlight through the side of the glass while looking at it from the opposite side. Any changes? Then hold your glass up off the table. Shine the flashlight up through the bottom of the glass and look down into the liquid. What colors can you see now? Perhaps the colors are looking more like those you’d see during a sunset.

Milk in the water scatters the light from the flashlight. It’s similar to the way different molecules and dust in our atmosphere scatter light from the sun.

Light travels from one end of the glass to the other and then up to your eyes. The further the light has to travel through the water, the more blue light gets scattered. That leaves more red light for your eyes to pick up.

Now that we’ve started to get an idea of how light scatters, runs into particles, and travels long distances, you can really get to experimenting.

What happens when you use less or more milk? Will you see any changes if you use a different kind of flashlight, like an LED? What kind of milk gives off more orange or reddish colors? Two percent? Whole milk?

Does the shape of the glass change anything? Why do you think that might be? Make a prediction and give it a try sometime. I’d love to hear more about your experiments and how your own sunset in a cup turns out. E-mail: Dr.Universe@wsu.edu.

Dr. Universe

P.S. Science rules! Join Dr. Universe for a STEM Supply Drive to support local schools, libraries, and after-school programs on the Palouse. Visit askDrUniverse.wsu.edu/ScienceRules to find a list of supplies and drop-off sites.

Ask Dr. Universe – Personality

Dr. Universe: How do we get our personality? – Jamie, 11

Dear Jamie,

Everyone is different. Maybe you are adventurous, shy, outgoing, funny, or kind. Before you were even born, your unique personality was beginning to take shape.

Part of the answer to your question is that some of your personality comes from your parents. Just as parents pass down physical traits like hair and eye color to their offspring, they can also give them different personality traits. They’re in your genes, the information passed throughout generations.

But your personality isn’t set in stone from the beginning. There are a few other things that go into it.

That’s what I found out from my friend Chris Barry, a psychologist at Washington State University. He studies personality in young people, including how people express themselves on social media. He was really excited to hear about your question.

Even as little babies, people start to express their own personalities, he said. Maybe you were a really fussy infant. Maybe you laughed or smiled a lot. As you grew up and learned how to communicate, your personality started to grow, too.

You’ve had a lot of different life experiences and those play into your personality, too. Barry reminded me that humans are social animals. He explained that as the brain develops, you become much more aware of the world around you.

For example, when you were little, you could run around with spaghetti all over your face and no one would think much about it. But now that you are an 11-year-old, running around with spaghetti on your face could be a little embarrassing.

Perhaps your family and friends would suggest you find a napkin. Barry explained that as you get older you are not only more aware of different social situations, but also your own personality.

Humans are often looking for information from other humans to figure out how to navigate the world. Meanwhile, an almond-shaped brain structure called the amygdala is especially helpful as you figure out these new situations and emotions.

You may notice that your family, friends, or others may react to the way you behave. You might learn to change your behavior depending on their reactions. While everyone has their own personality, in a way, other people are helping shape it, too.

Humans have all kinds of words to describe each other’s personality traits. In fact, some researchers have come up with a list of more than 600 characteristics.

Barry explained that we still have a lot of unanswered questions to explore when it comes to understanding personality. He said that while your personality develops a lot as you grow from a baby into a kid, it probably won’t change too much once you become a grown-up.

Based on your question, it appears that you are very curious. That can be a great personality trait. Have you ever thought about become a scientist or researcher one day? Keep asking great questions and you’ll be well on your way.

Dr. Universe

Ask Dr. Universe – Mooing Cows

Why do cows moo? -Sam, 11, Gahanna, Ohio

Dear Sam,

If you’ve ever been near a herd of mooing cows, it might have sounded like all their moos were the same. But just as each person’s voice is a little different, so is each cow’s moo.

Human ears might not always pick up the small differences in moos, but cow ears sure can. In fact, cows have great hearing. They can even tell that different moos mean different things.

That’s what I found out from my friend Amber Adams-Progar, an animal scientist at Washington State University who studies cow behavior. She learns a lot about how we can better care for cows and spends time visiting our herd out at the Knott Dairy Center in Pullman, Wash.

Adams-Progar explained that before humans domesticated cows and started raising them on farms, these animals lived in the wild. In nature, mother cows go off on their own to find a spot to have their baby.

Sound is a big part of how a mother and baby cow bond. While a calf might send out one kind of moo when she is hungry, another moo might mean she’s lost.

“Sometimes a calf will go running off and the mom will look around. All of a sudden you hear her moo and then somewhere in the distance you hear a little moo respond back,” Adams-Progar said. “It’s kind of cute.”

Some cows will also moo when they are looking to find a mate. Finding other cows in the herd is part of why these animals moo, but there other reasons, too.

In the wild, cows are prey animals. Sometimes mooing attracts predators, but sometimes cows can also use their moos to help keep each other safe. They can use their moos and their great sense of hearing to let other cows in the herd know there might be danger afoot.

While mooing can help cows find and protect one another, they also use other kinds of behaviors to communicate. Sometimes cows will grunt. Usually when we see cows grunting, they are pretty content, like when they are eating. They may also use their grunts when they are defending themselves or letting other cows know about their rank in the herd.

A wag of their tail can also help communicate to animals around them. When its tail is between its legs, the animal may be cold. A wagging tail could also mean it is in pain or just irritated. Cows also use their tails to swat away flies and sometimes calves wag their tails when they are nursing.

It’s a great question you ask, Sam. Maybe the next time you drive by a herd of mooing cows you can think about all the different communication that is going on out there in the pasture.

In fact, your question leaves me with even more questions about animal communication. Why does a bat screech? A bee buzz? Or an elephant trumpet? What is your favorite animal? What sounds does it make to communicate? Tell me about it sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Gray Hair

Dear Dr. Universe: Why does hair turn gray? –Darae, 10

Dear Darae,

Hair comes in lots of different colors. There’s black, medium brown, auburn, light brown, strawberry blonde, and copper, to name just a few. But in the end, almost everyone will have hair that’s gray or white.

Ever since you were born, different cells have been working on your hair. Each hair sprouts from a follicle, a sort of little hair-making factory under your skin. Here, some of your cells are making your hair and others are coloring it.

The cells that color your hair are called melanocytes. They produce a pigment, or natural coloring matter, called melanin. This is the same pigment that gives your eyes and skin their color, too.

I decided to visit my friend Cynthia Cooper, a biologist and researcher at Washington State University, for help answering your question.

A close-up look at cells

Cooper and the other scientists in her Vancouver, Wash., lab are really curious about cells. They are investigating questions about how some cells end up becoming the kind that produce skin pigment.

As people get older, she said, the pigment-producing cells in their hair follicles gradually die. They can no longer make enough pigment to keep coloring their hair.

If we took out all the pigment from your hair, it would be totally white.  So when melanocytes stop producing melanin altogether, your hair turns white.

“Why hair follicle melanocytes die over time, and are not replaced, we don’t entirely know,” Cooper said. “Our skin doesn’t turn gray, so the biology is quite different,” she adds.

While Cooper works on pigment in skin, she said some scientists are also working on other big questions about the pigment in hair, too. These scientists are especially curious about the inner-workings of the cells and how gray hair is part of people’s DNA.

Perhaps, you’ve heard someone say their kids are giving them gray hair. But scientifically, if anyone is giving someone gray hair, it’s likely their own parents. Those that come before us pass down their hair color to us through the genes we inherit from them. It’s the same with graying hair.

Scientists have even pinpointed specific genes and parts of cells that are involved in growing gray hair. The new knowledge is helping us put together a better picture of how pigment works. Still, there’s a lot more to discover.

Maybe as you get older and find that first gray hair, you’ll remember some of the science that’s at the root of it all. If you have a cat or dog, maybe you’ll notice that they’ll go gray around their muzzles, too.

I’ve actually had gray and white hair ever since I was a kitten. I think it’s pretty great. Our pigment, or lack of it, help make us all unique.

Dr. Universe

Ask Dr. Universe – Fever

Dr. Universe: Why do we get a fever when we are sick? – Marcelina, 11, Ovid, N.Y.

Dear Marcelina,

Lots of warm-blooded animals get sick, including cats. I’ve had a fever before, but I wasn’t entirely sure why we warm up when we get sick. I decided to ask my friend and professor Phil Mixter at Washington State University.

Mixter is curious about the germs, or microbes, that we all carry around with us. In fact, scientists estimate that humans carry more than 100 trillion of these tiny microbes with them wherever they go. Not all of these microbes are bad, but some of them can make you sick.

Thankfully, a lot of animals—from starfish to cats to humans—also have an immune system that helps them fight off bad germs. In humans, fevers are one way your body helps fight back.

It’s sort of like that story about Goldilocks and the three bears, Mixter said. In the middle of your brain is a control center, the hypothalamus, which helps your body know if it’s too hot, too cold, or just right.

Maybe the last time you went in for a check-up the doctor took your temperature and told you it was somewhere around 98.6 degrees Fahrenheit—or 37 degrees Centigrade for readers outside the United States. That’s a pretty normal temperature for humans.

Cats run a little warmer, with temperatures around 100 degrees Fahrenheit. As we go about our day, sometimes our body temperatures will rise or fall just a little. But if germs come on the scene, things can really heat up.

When your immune system realizes something unusual is going on, some of your white blood cells will release a substance into your blood stream. The substance is made up chemicals that your brain can detect. When the hypothalamus receives the chemical message, it sends an alert back out to the body: Turn up the heat! We’ve got to slow down these germs.

Many microbes that make us sick do best in an environment that is about 98.6 degrees F. The temperature is just right. When we get a fever, the heat helps slow down these troublemakers. You might feel sweaty and hot on the outside, but the microbes are also getting too hot. The heat helps keep them from multiplying rapidly.

One thing a fever can’t really tell us is what kinds of germs are in our system. Sometimes there might be something else going on and we might need to visit with a doctor.

A fever may not make us feel great, but it’s usually a good sign that our body’s immune system has kicked into gear and that we’ll get better real soon.

Dr. Universe

Ask Dr. Universe – Glass

Dr. Universe: How is glass made? And, what is it made out of? What about thick glass like they are putting up on the Space Needle? – Tali, almost 8 years old, Seattle, Wash.

Dear Tali,

We can make glass in factories and we can find it in nature. Some volcanoes make glass. When they spew out lava, it often cools into obsidian, a black glass. Glass can also form on sandy beaches. Small tubes with smooth glass on the inside may appear after super-hot lightning strikes the sand.

In fact, sand is one of the most important ingredients we use to make glass. We may also use things like seashells, salt, and other chemicals. That’s what I found out when I visited my friend John McCloy, an engineer at Washington State University. McCloy and graduate student Jose Marcial were testing out different materials to make glass in the lab.

Marcial explained that glass is made of molecules—think of them as building blocks—arranged in a pretty random order. Most of the time we think of glass as a solid. But the way its molecules are arranged actually allows it to act as both a solid and a liquid. When we heat up the mix of sand, seashells, salt, and other chemicals, it can become molten, kind of like lava.

In the lab, Marcial poured a mixture of solid materials into a tiny metal cup. He heated it way up until the mix turned to something in-between a solid and liquid, similar to a thick honey. It was so hot that as Marcial poured it out onto a table, the molten material started glowing orange. As the mix cooled down, the molten liquid turned to a solid piece of glass right before our very eyes.

Marcial said that in factories, glass is made in a similar way. We take sand, add in different chemicals, heat it up, and pour it out onto a bed of molten metal. Just as oil sits on top of water, the lighter, liquid-like glass material floats atop the metal.

As everything cools down, the metal stays molten, but the glass on top solidifies. The glass might end up in a pair of eyeglasses, a computer screen, fish tank, or window. The big pieces of glass you see in buildings or observation decks are often made up of thinner layers of glass that have been combined.

As you’ve observed, the Space Needle is getting a big renovation. According to friends at the Space Needle, more than 10 types of glass will be used to renovate the landmark. They will also bring in 176 tons of glass during construction—that’s more than twice the weight of a NASA space shuttle.

As you can see, glass is made in lots of different ways. Believe it or not, you can also make something very similar to glass in your kitchen. Instead of grains of sand, salt, and seashells, you can use tiny grains of sugar.

With the help of a grown-up you can make your own edible sugar glass by mixing together ingredients like sugar, corn syrup, water, and cream of tartar. Try it out sometime and let me know what you learn at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Animal Farts

Dr. Universe: Do all animals pass gas? Do cats fart? 
Hasandi, 11, Jeddah; Harrison, 10, Albany, Ore.

Dear Hasandi and Harrison,

If you’ve ever been near a cat or dog when they tooted, the smell might have sent you running right out of the room. A lot of animals pass gas. But believe it or not, some animals do not.

First, let’s talk about the gassy ones. When us cats and humans eat food, we are also swallowing air, or gas. It’s made up of elements like nitrogen and oxygen. The gas travels down into our digestive system and can take up space in our stomach and intestines. In our digestive systems, we also find tiny living things called bacteria.

You might blame the dog for your farts, but the real credit goes to your bacteria. Not all bacteria are bad. In fact, a lot of bacteria are helpful. Some of them help break down your food into its simplest form, like proteins and sugars that you can use for energy and growing. Some get rid of waste. But as they do their different jobs, they produce a bit of gas.

That’s what I found out from my friend Kristen Johnson. She’s a researcher at Washington State University who has tackled some big questions about how cow gas impacts the environment. She explained that while each bacterium makes a small amount of gas, there are millions of them doing it. It really adds up.

This gas needs to leave your body somehow, so you can release it either as a burp, a fart or by breathing. But if you were a clam or other mollusk, you wouldn’t toot. If you were a sea anemone, you wouldn’t fart, but you could probably burp.

Last year, a bunch of researchers listed which animals they studied farted. According to their list, it appears that some worms don’t pass gas either. Then there are some animals that scientists aren’t sure about, like spiders and parakeets. One researcher even found that some millipedes have hard valves on their rear ends that silence their toots. It would be nice if some other animals I know had those.

Birds have the equipment to fart but apparently don’t. Some scientists have found that a lot of them don’t usually carry the same kinds of gas-forming bacteria in their guts that humans and other mammals do.

As it is, humans toot around 20 times a day, producing enough gas to fill up about half a two-liter bottle of soda. A lot of the time these farts don’t smell. But sometimes your bacteria release sulfur and other things that can get pretty stinky. It might not always be pleasant, but it’s totally normal. Silent or deadly, a fart is usually a sign that our bodies are healthy.

Dr. Universe

Ask Dr. Universe – Cold in the Mountains

Dear Dr. Universe: Why is it so cold up in the mountains if heat rises and it’s closer to the sun? –Andrea, 11 

Dear Andrea,

You’re right. If we took a trip into the mountains, we would find that it felt a lot colder. It all has to do with our atmosphere. We may not always think about it, but we are basically living in a giant ocean of air.

“It’s a big part of what makes Earth livable,” said my friend Shelley Pressley. She’s an environmental engineer at Washington State University’s Laboratory for Atmospheric Research. “Without gravity and our atmosphere, all the oxygen we breathe would fly out into space.”

Our atmosphere contains small building blocks, or gas molecules, that make up the air we breathe, she said. We can’t always see or feel how much gas there is, but we can measure it. We can calculate the mass of gas, or the number of molecules there are in a certain area.

Air is actually pushing down on us all the time, even if we can’t really feel it.

“Imagine you are standing on Earth’s surface,” Pressley said. “There’s a column of air above your head that stretches up to the top of the atmosphere. The column of air is pushing down on your head. This is pressure.”

“Now, climb the tallest mountain you can find and stand on it,” she adds. “The column of air pushing down on your head is shorter. It has less mass than the column in the first spot.”

The air pressure is greater when you are closer to the level of the ocean’s surface. Here, the building blocks or molecules are pretty squished together. When the gas’ pressure is greater, temperature increases.

Maybe you’ve heard people say the air is thinner up in the mountains, where there is less pressure and the molecules or building blocks are more spread out. When the pressure of a gas decreases, so does temperature.

Pressure is a big part of the answer to the first part of your question. The other part of your question involves the sun. Our sun is about 490 billion feet away from the surface of the Earth.

While a mountain might seem tall, it’s pretty puny in comparison to the distance between Earth and our sun. It actually doesn’t make a huge difference in temperature.

Pressley said that pressure and our sun also have a lot to do with weather. When sunlight travels through the atmosphere, it heats the surface of the planet. When the surface gets warmer, it sends heat back up to air molecules near the surface and warms them up. The molecules of air rise. As they do, they expand and cool.

Somewhere else, air over a mountain that is even colder actually starts to sink. This sinking air gets compressed, squished together, and heats up. This mixing of air is called convection and is at the heart of our weather. This system also keeps the surface of our home planet warm enough to live—from the colder mountains to the warmer beaches around our world.

Dr. Universe

Ask Dr. Universe – Parasites

Dear Dr. Universe: What can you tell me about parasites? -Brianna, 12, Eastern Wash.

Dear Brianna,

A parasite is an organism that steals resources from another organism in order to survive. Our planet is home to all kinds of parasites and organisms that host them.

My friends Kevin Zobrist and Lisa Shipley, scientists at Washington State University, told me about a few holiday-inspired parasites. After all, ‘tis the season.

The first parasite is a type of plant that people often smooch under around the holidays: mistletoe. There are a lot of species of mistletoe, explains Zobrist, a forester at WSU.

An example in the Pacific Northwest is hemlock dwarf mistletoe, which explosively releases sticky seeds during the summer. The seeds can fly up to 50 feet and stick to tree branches they fall on. When the seeds land on trees like western hemlock (the state tree of Washington), the mistletoe starts to grow.

Some kinds of mistletoe have leaves they can use to take in sunlight and help make food. But they still aren’t able to get enough food on their own. They have to feed off trees. Dwarf mistletoes don’t have any leaves. They get everything they need from their host.

In the process, this little mistletoe parasite causes trees to form weird clumps called “witch’s brooms” that can ultimately end up killing them. While the trees might die and become snags of dead wood, this can actually be a good thing for the forest ecosystems.

Zobrist explained that some animals, including some endangered species, will use witch’s broom branches or the insides of dead trees to make their habitat or nest. Even though the parasite takes life from the tree, it’s not all bad for life in the forest.

While some parasites live off plants, other parasites need animals. Lisa Shipley, a WSU professor who works with animals in the deer family, said some reindeers are host to a parasite that is so small we’d need a microscope to see it. It’s a kind of nematode more commonly called a brain worm.

Before the nematode finds the reindeer host, it lives in a different animal. When it’s young, it will go into the slimy bottom part of a snail, called its foot.

As snails slide along leaves of plants, reindeer that are munching on leaves will sometimes eat a snail, too. When they eat the snail, they eat the young nematode. The young nematodes move through the body and are eventually pooped out. But along the way, they can lay eggs and cause damage to the reindeer’s brain.

“The worm can be treated with parasite medications, so if you have your own reindeer—like some people in the North Pole do—you can give them medicine,” Shipley said.

Mistletoe and nematodes are just two of many parasites. Other parasites like ticks or fleas rely on hosts like us cats to get their food. Parasites can be inconvenient and even deadly, but to them, it’s all about survival.

Dr. Universe

Ask Dr. Universe – Grasshoppers

How do grasshoppers survive the winter? –Lucy, 9

Dear Lucy,

There are a lot of different grasshoppers living on our planet. In fact, scientists have discovered more than 11,000 species. Exactly how these grasshoppers spend their winter depends on what kind of winter they experience.

That’s what I found out when I went to visit my friend Laura Lavine. She’s an entomologist at Washington State University and was happy to help with your question. Let’s hop to it.

Lavine explained that in places with colder winters, such as Washington State, grasshoppers spend the winter as eggs. That means that their mothers will have buried them deep in the ground.

The grasshopper mom has an egg-laying organ, called an ovipositor, that’s shaped like a knife or sword. It’s really handy for digging in the soil.

“The ovipositor has a hard external skeleton and the grasshopper digs into the ground to lay her eggs below the surface,” Lavine said.

Some Pacific Northwest grasshoppers, like the red-legged grasshopper, will lay about 20 eggs at once. The mother will cover them all with a gummy coating.

The coating hardens and binds the eggs together so they can survive the harsh winter conditions. The mother grasshoppers will also bury them.

Lavine explained that some grasshoppers will lay their eggs in other safe, warm places such as plant roots, wood, or even cow manure.

“They hatch in the spring when the weather warms up and the sun comes out,” she said. Spring is a great season for us cats to chase these little hopping insects around. I must say it’s pretty entertaining.

While a lot of grasshoppers overwinter as eggs, some will survive the winters in a different stage of life. Between their egg stage and adult stage, grasshoppers are juveniles, or nymphs. In winter, nymphs will find a nice warm spot to hide. They probably won’t move or hop around much at all until it warms up again.

Of course, not all winters are so cold and harsh. For example, the giant grasshopper that lives in South America experiences a pretty warm habitat. It will still lay eggs underground to keep them safe, though.

“In warm places, grasshoppers are more active in the winter because the temperature is good and there are plenty of plants around to eat. So, they can spend the winter as eggs, as nymphs, and even as adults,” Lavine said.

Here are a few activities you can try at home to learn a little bit more about grasshoppers: Draw a grasshopper or make one out of a toilet paper tube and label its anatomy. Don’t forget to include the five eyes.

If you are feeling up to the challenge, you can also play around with some geometry in this grasshopper origami project. Have fun and tell us what else you learn about grasshoppers sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Cold

Hi Dr. Wendy Sue: Me and my brother had a little bit of an argument about the point that there is no such thing as cold. He said liquid nitrogen produces cold, which I think is absurd, but lack the knowledge to explain it. Can you please explain to us why there is no cold? 
– Brody, 12

Dear Brody,

It’s a snowy morning and the thermometer reads 20 degrees Fahrenheit. You grab a jacket and a pair of mittens for your paws. It’s going to be a cold day.

We might use the word “cold” to describe what that feels like, but you’re right: there isn’t actually something called “cold.” Not scientifically speaking, at least.

My friend Jake Leachman is an engineer at Washington State University and was happy to help with this question. He said that a long time ago people thought heat was a kind of fluid. The idea was that this fluid was inside different objects and it could move around to make something hot or cold. It wasn’t until a person named Count Rumford was making some cannons that a better idea came about.

Rumford’s oxen were helping turn a large tool that carved out the insides of cannons. He noticed that as long as oxen were doing work to move the tool, the inside of the cannon would get super-hot and could even boil water. The work from the oxen was being converted into heat by friction on the inside of the cannon barrels. That’s much more heat than you could make by rubbing your paws together to keep them warm.

Rumford realized that if heat was some fluid coming out of the cannon barrels, it would eventually run out, but that wasn’t the case. As long as the oxen worked, more heat would be produced.

Then there was James Joule, who used thermometers to show that even water falling over a waterfall warms after the fall. Rumford and Joule were some of the first to help us realize energy isn’t created or destroyed.  Energy is converted between things such as work and heat. And heat, not “cold”, can transfer from object to object.

As you may remember, molecules are the building blocks of pretty much everything in our world. The motions of molecules are also related to heat, or thermal energy. We measure the movement of the molecules, also known as temperature, using thermometers.

Leachman explained that heat, like time, actually has direction. It always flows from something with higher temperature to something with lower temperature.

“Yes, something feels cold because your thermal energy is flowing from you, the warmer thing, to the thing at a lower temperature,” Leachman said.

Leachman explained that for nitrogen to be in a very cold liquid state (-321°F!), the nitrogen molecules must be moving very slowly.

They are moving so slowly that they can rest right on top of each other and any energy, or heat, transferred from room temperature is enough to cause nitrogen molecules to move very quickly.

They can no longer exist as a liquid and boil to become a gas. It’s just a process of slow-moving molecules being sped up—heated—by faster moving molecules.

Now, maybe your brother is also thinking about something like this: If energy is only converted between objects and heat only goes from hot to cold, how does a refrigerator work to keep things cold? Stay tuned for the answer.

Dr. Universe

Ask Dr. Universe – Eyeballs

Dr. Universe: How much does an eyeball weigh? – Rahman, 10, Tollygunge, India

Dear Rahman,

Our animal kingdom is full of different eyes. The human eye weighs less than an ounce. That’s about as heavy as 11 pennies. But I suppose the answer to your question really depends on which eyeballs you are curious about. Perhaps you are looking for an answer about the biggest animal eyes on our planet.

An elephant’s eye is about the size of a golf ball, but there are even bigger eyes. A gray whale’s eyes are about the size of a baseball. But they still aren’t the biggest eyes. Those belong to the giant squid.

I decided to ask my friend Kirt Onthank exactly how much giant squid eyes weigh. He studied cephalopods, which include squid, as a student at Washington State University and now teaches biology at Walla Walla University.

“I don’t know the exact answer,” Onthank said. “But we can get a really good estimation.”

He said the largest giant squid was actually measured from a photograph. No one actually weighed it. But we do know its eye had a diameter of 10.5 inches, which is just a little bigger than a basketball.

While human eyes are made up of a more jelly-like material, a squid’s eyes are pretty much all seawater. Knowing this, we can estimate its weight.

After a little math, it comes out to about 22.7 pounds—more than 3,000 pennies.

“That is one really big eye,” Onthank said.

Colossal squid have even bigger eyes that weigh in at about 25.3 pounds. Even though their eyes are much bigger than yours, they still have some of the same parts.

Both squid and people have a lenses, irises, pupils to let light in, and retinas to capture the light and help send a message to your brain. One thing squids don’t have is eyelids.

Exactly why colossal squid need the world’s biggest eyeballs is a question some scientists are still investigating. The best theory is that their eyes are geared to see sperm whales, Onthank said.

Sperm whales have eyes that are only 7 centimeters in diameter. They are super tiny compared to their 40-foot-long bodies. They depend on sound waves that bounce off things to figure out where they are and to find food. And their favorite food is squid.

A squid’s big eye helps it detect very dim light deep in the ocean. It turns out, there are also some bioluminescent creatures in the deep waters. Bioluminescent creatures make their own light through a chemical reaction that allows them to glow in total darkness. If there was a sperm whale around, it would disturb some of these creatures who give off light.

The squid can use its big eyes to take in the light and receive a signal that might just help it avoid becoming a sperm whale’s lunch.

Dr. Universe

Ask Dr. Universe – Directions in Space

In space, which way is up? –Pablo, 10, Spokane, WA

Dear Pablo,

We might not always think about it, but every day gravity keeps us pulled to the Earth. It’s what brings us back down when we jump on a trampoline. It’s why a Slinky tumbles down stairs.

Now think about what it would be like to live in a place with very little gravity. Let’s say you were 200 miles off the ground, orbiting earth in the International Space Station. Here, the idea of up and down really gets flipped around.

On Earth, the human balance system  helps the head figure out how move up and down under the force of gravity. It’s what helps people figure out to look up to the ceiling or down to the floor. If you are floating around in space, up and down is different.

I decided to visit my friend Afshin Khan to find out more about it. She is a researcher and astrobiologist at Washington State University.

Khan explained that even things in space have a little gravity, and whichever object is being pulled toward another due to stronger or larger gravity is what we call “down.” The opposite is what we call “up.” We use these words to help us navigate.

But in reality, there really are no true directions, Khan said. There is no up and down in space.

It’s kind of like when we look at a globe, she explains. If you are trying to get to Japan from the U.S., you can see it is both east and west of the U.S. It depends on the direction you want to travel. If you want to cross the Atlantic Ocean, you go east. If you want to fly over the Pacific Ocean, you go west. It’s all relative.

Inside the International Space Station, the ceiling might as well be the floor. The walls might as well be the ceilings. It’s enough to make your head spin.

In fact, researchers at NASA are asking big questions about what happens to the human brain when it can’t figure out which way is up or down. They are curious how it changes the activity of the brain.

Some scientists have even tackled questions about how to help plants “grow up” in these environments with very little gravity. To help plants grow upright, scientists have developed little plant pillows. The pillows are full of dirt, water and plant food to help the plants stay grounded. Otherwise, their roots would grow out in all different directions.

As the concept of direction may be different in space, engineers and scientists have to think about it when they are designing tools to help us navigate the universe. Who knows, maybe one day you’ll come up with a great idea that can help us explore, too.

Dr. Universe

Ask Dr. Universe – Rain and Water Pollution

Where does rain go? –Finn, 8, New Zealand
How does pollution effect the world’s water? – Emily, 13

Dear, Finn, Emily, and friends,

When a raindrop falls from a cloud, there are quite a few places it could end up.

We might follow that raindrop into a stream, river or ocean. If it’s in the ocean and it gets warm enough, it might evaporate into even tinier droplets of water to form clouds. It’s part of the water cycle.

Clouds can only hold so much rain before they get saturated. Then it starts to rain again.  Maybe this time the raindrop falls into soil and helps a plant grow. Or perhaps the raindrop falls onto the sidewalk, street, or highway. If it falls on the pavement, it could flow into a drain and back into the streams and oceans.

Lots of these raindrops make up what scientists call storm water. But it’s not just water. Along the way, water can pick up other things on the road. It might sweep away something like leaves. It also picks up things that aren’t very good for our planet, like oil, animal waste, metal from car brakes, or other kinds of chemicals and pollutants.

We can’t always see these pollutants with our eyes, but they can really threaten animals who call the streams, rivers, and ocean home. Pollution can create a toxic environment for fish. As a researcher at Washington State University, my friend Michelle Chow studies some of the fish that get sick from pollutants in storm water.

Coho salmon that live in the Pacific Northwest of the U.S. will often die if they are in this polluted water for a couple of days. But Chow and other researchers at WSU are working on ways to help save the salmon.

It turns out soil is really great at filtering toxic stuff out of water. If you are curious how it works, check out this video, “Polluted Puddles.” One thing people can do to help clean up the environment and help save salmon is to plant a rain garden. When the rain comes down, it gets filtered through the garden’s soil instead of running off into the road. You can find out how to plant a rain garden in your community with the help of friends at WSU Extension.

Another way researchers are helping is by developing a kind of pavement that looks a bit like a Rice Krispies Treat. It’s called permeable pavement and is designed to let water go straight through the pavement down into the soil. That way, it doesn’t run off and carry pollutants to nearby bodies of water.

Chow said there are other ways we can also help keep pollutants out of our environment. Can you think of something you might be able to do? I might just walk to work or ride my bike. Helping find solutions is good for salmon who live in the water and good for animals who like to eat them, too. Together, we can help improve and restore healthy water habitats.

Dr. Universe

Ask Dr. Universe – Feet

Why do feet smell?
-Jose, 10, Costa Mesa, Calif.

Dear Jose,

We live in a world filled with all kinds of smells. Take off a pair of tennis shoes after a long day and you might even get a whiff of something pretty stinky. You can blame it on your bacteria. Millions of these tiny things live on your feet.

While bacteria are too small to see without a microscope, sometimes you can just smell them doing their job. They like dark, damp, warm places, where they can eat dead skin and drink sweat. Inside your shoes and socks, for example.

There are more glands that produce sweat on your feet than any other part of the body. As bacteria eat there, they also turn your dead skin and sweat into chemical products that can really reek.

It might just make you want to plug your nose. But at least you’ll know the system that helps you smell, the olfactory system, is working well. Your brain, nose, and a bunch of smell receptors work together to help you figure out what you are smelling.

Maybe it’s stinky feet. Or maybe it’s fresh-baked chocolate chip cookies. Do either of these bring back any memories for you? Scientists have found that our sense of smell is tied pretty closely to our memories—and there are more than 10,000 different kinds of smells, or aromas.

Sniffing out chemical combos

Smell is a really important part of our daily life, said my friend Sindhuja Sankaran, a biological engineer and researcher at Washington State University. The ability to smell can also help us identify spoiled foods, find quality foods, and even remind us to take out the trash.

She said that knowledge of the way humans smell has allowed us to develop electronic devices that can help pick up on these different combinations of chemicals.

Scientists like Sankaran can use a kind of sensor, you might call it an electronic nose, to study the quality of foods and sniff out any problems bacteria might be causing when food is in storage. She even uses this technology to study what chemicals released by plants can tell us about whether they are infected by a disease or attacked by an insect.

For example, some kinds of plants can release chemical combinations into the air to warn other plants that a particular predator is around. Some evidence points to the idea that plants can sense some chemical messages in their roots, too.

Lucky for them they can’t smell stinky feet. What kinds of things have you smelled lately? Keep exploring all the aromas around you. You might even try to find out what combinations of chemicals give things like fresh cut grass, garbage and bacon their smells.

Dr. Universe

And now for 3 smelly facts with Dr. Sankaran

  1. Humans have about 5 million receptor cells in their olfactory system to help them smell.
  2. Dogs noses are about a thousand times more sensitive than humans. They have around 220 million olfactory sensors.
  3. A pair of feet can have about 250,000 glands for making sweat.

Ask Dr. Universe – Mirages

What causes mirages? –Georgia, 10, Wash. 

Dear Georgia,

Imagine you’re riding in the car on a very hot day, when you look out the window and see a shimmering puddle of water up ahead. As you get closer, you find there’s not really anything there. It’s a mirage.

While you aren’t really seeing a puddle, you are definitely seeing one of light’s many wonders. It has to do with the way light travels, and with the way our eyes and brain take in light.

That’s what I found out when I went to visit my friend Jeff McMahon, a physicist at Washington State University.

If you’ve ever tried to get some place in a hurry, you probably took the fastest way possible. Light does this, too. It travels fast and wants to take the shortest path, McMahon said. But sometimes it will slow down if something gets in its way. Cold air, for example. Light can travel faster through hot air than cold air.

Now think of a paved road on a hot day. The ground would be really hot and so would the layer of air right above it. Meanwhile, any air above this warm layer would get colder and colder.

Light will travel slowly through the cold air. However, if light wants to take the shortest and fastest trip, it will swoop down into the warm air near the ground and speed up.

But the light still has to go back up to your eyes so you can see. The light heads back up toward you, traveling through the colder air again. It makes a bit of a U-shaped trip. And where the cold and warm air layers meet, the light bends.

Your eyes and brain try to figure out what’s going on. After all, they are used to taking in light that comes in at a straight line. When the light bends, your brain and eyes see a mirage.

This bending light is what we call refraction. Where the light bends, you’ll likely see an image of the sky refracted on the ground.

This doesn’t just happen on pavement, McMahon said. It can also happen on water. People have seen mirages of boats and islands. Some people think this is where we might have come up with the stories of ghost ships. Little did they know at the time it was all refraction—a journey of light. Can you think of how refraction might happen on the ocean?

Refraction happens in lots of places in our universe. Here’s an easy way to really surprise your friends and classmates, while also seeing how light can work when it passes through different materials. Draw an arrow on a piece of paper. Then, place the paper behind a glass. Fill the glass with water. What happens to the arrow? Tell me about it sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Ant Headaches

Dear Dr. Universe: I have a question for you about ants. From what I searched on Google, an ant has a nervous system, blood, open circular system, muscles, and a brain. So, Dr. Universe, the question is, do ants or other insects get headaches? Cause they work hard.
–Joseph, 14, Singapore

Dear Joseph,
If you’ve ever had a headache, it might have felt like pain was radiating right out of your brain.

Curious about how exactly headaches happen, I visited my friend Samantha Gizerian. She’s a brain scientist at Washington State University.

It turns out the brain doesn’t have sensors or receptor cells for pain. It’s the reason a lot of patients can be awake and even talk during brain surgery.

Headaches most often happen when sensors or receptor cells in your skin, head or neck, send a message to the brain. There, the brain helps you translate the message into a feeling of pain.
It happens with the help of the central nervous system, the network of your brain, spinal cord, and a whole lot of nerves in your body. It’s all part of what allows you to sense your world.

You’ve done some great research in finding out that the humans and insects have some similar anatomy. Of course, there’s also quite a lot of differences. Insects do not have pain receptors like we do.

Even though they don’t have these same receptors, there’s still the question of whether they experience pain or some kind of headache. Good science takes collaboration, so I also visited fellow scientist Jenny Glass. She’s a scientist at WSU who studies insects.

She explained that while insects don’t have these particular kinds of pain receptors, they do respond to things in their environment with touch, smell, taste, vision, and chemical signals.

Some insects scurry or roll away from whatever might be harming them. It’s often an automatic response that helps them survive.

Many studies have shown that insects are capable of learning from their experiences. They know to avoid certain situations that might be harmful.

Glass explained that there are still a lot of questions when it comes to whether or not this response or learning translates to feeling pain, effort, or injury. The research doesn’t yet have a clear answer.

“But Joseph is onto something as many scientists are looking into the consciousness, or awareness, of insects and other animals,” Glass said.

Who knows, maybe one day you’ll be a scientist who helps us investigate big questions like this one. In fact, continuing to explore this question might just change the way some of us think about ants and other animals. Either way, we can all agree, you ask a very compassionate question.

Dr. Universe

Ask Dr. Universe – Weeds

Dr. Universe:
Why do weeds grow sooo fast? 
– Leah, 9, British Columbia

Dear Leah,

If you’re like me, you’ve picked up a little dandelion fluff ball and blown the seeds around. Weeds like these make a lot of seeds. They get picked up by the wind and planted far and wide. And as you observe, they grow pretty fast, too.

My friend Tim Miller is a researcher at Washington State University working to help stop weeds from making life difficult for plants we would rather have. Sometimes, weeds are bullies to other plants.

“Weeds are simply plants that are able to compete well with the plants we want to grow,” Miller said. “Imagine two plants growing side by side. Let’s say one is a squash and one is a weed.”

He explained that these plants compete for resources both of them need to grow: sunlight, water, nutrients, and space.

“The weed is able to grab those resources before the vegetable plant can get them, so they tend to grow a little faster and a little better than the vegetable does,” Miller explained.

The weed seeds are already in the garden soil. They wait for just the right temperature and moisture conditions. So, when you plant your seeds, the weeds race out of the ground before whatever you planted can even get started.

Sometimes gardeners help their vegetables by growing them in pots and then transplanting them into the garden. That gives the veggie a head start against the weed.

Miller said some weeds grow from a root that has been alive for many years. These kinds of plants are called perennials. The grasses in your lawn are also perennials. Perennial weeds grow especially fast and are much harder to kill than annuals, which have to grow from seed every year.

Perennial roots have lots of energy in them from previous years of growth. Miller explained that energy helps the shoots grow very quickly. This makes perennial weeds particularly hard to control.

Dandelions are one kind of perennial. Each dandelion fuzz ball has as many as 100 seeds that travel in the wind. If a dandelion plant makes 10 flower heads, that’s 1,000 seeds waiting to sprout wherever they land. How many dandelions do you think you have in your lawn? If there are 50 plants, just think of those 50,000 new dandelions that can sprout from all those seeds. It’s no wonder weeds are so hard to control.

While they may be bullies to plants, weeds have also inspired some interesting ideas. The engineer who invented Velcro was inspired by those prickly weed burrs that stuck to his clothes and his dog’s fur. You never know what might inspire a great idea or when that idea will strike.

Dr. Universe

Ask Dr. Universe – Ocean Water Movement

Dear Dr. Universe:
–Case, 5, Yakima

Dear Case,
You know, most cats like to stay a comfortable distance from water.

But when I got your science question about our big ocean, I was ready to jump right in.

Ocean water moves in all kinds of ways. Waves curl and crash on the shore. Big conveyer belts of water, currents, flow for thousands of miles around our planet. The tides go out and come back in.

And yes, the wind plays a big part in all of it. That’s what I found out when I went to visit my friend Jeff Vervoort, a geologist and professor of oceanography at Washington State University.

If you stand on the shore, you can often hear and feel the ocean breeze. On windy days, waves start stirring. The smallest waves, called capillaries, start growing as the wind blows across their surfaces.

The stronger the wind blows, the bigger the waves can get. They can reach great heights—some as tall as six-story buildings. When the wave reaches shallower waters, it will start to curl, then break.

If you’re anything like me, you might be wondering where the wind comes from, too. Vervoort explained that our planet is rotating around on its tilted axis. The sun heats the Earth unevenly as it turns. These conditions actually affect the air and wind patterns on the planet surface. All of this moving air pushes the water in the ocean around.

Vervoort pulled down an Earth-shaped beach ball from the shelf in his office. He explained that winds blow in different directions. If Earth wasn’t rotating on a tilted axis, winds would blow very differently.

But, because of the Earth’s spin, wind belts in the northern hemisphere bend to the right. It also makes the winds in the southern hemisphere go to the left. Ocean currents bend in the same way, caused by the Coriolis effect.

The moving water can sometimes also act like a food delivery system. Some currents deliver important sources of nutrients and oxygen down to animals that live in the deep ocean.

Other currents bring up nutrients for animals that live near the surface. These nutrients allow tiny organisms—plankton—to live and grow to great numbers. These very tiny plankton get eaten by bigger animals like krill. Krill are an important food source for even bigger animals such as whales.

Meanwhile, back up on the surface tides go in and out. While wind impacts the tides a little bit, they mostly happen because gravity from the moon, and a little less from the sun’s gravity, pull water on Earth.

For the most part when it comes to water moving in the ocean, your hypothesis is correct, Case. It’s wind that mostly keeps our ocean surface in motion.

Dr. Universe

Find this article printed in Washington State Magazine!

Ask Dr. Universe – Twins

Here’s a treat! We are raffling off some fun field guides to elementary/middle school explorers! E-mail Dr.Universe@wsu.edu w/ subject: “science rules” for a chance to win a class set! Ends Nov. 30. 

Dear Dr. Universe: How are twins made? –Brody, 8, Kauai, Hawaii 

Dear Brody,

By the time you finish reading this sentence, about twenty babies will have been born into our world. Sometimes they’re twins.

When I got your question, I figured what better place to go than the Washington State Twin Registry based in Washington State University’s Elson S. Floyd College of Medicine. Ally Avery, a researcher who studies twins, was happy to help with the answer.

You may remember that cells are the building blocks of life, Avery says. We are made up of billions of cells. Each one carries DNA, the miniaturized master plan that, among other things, influences how tall we are or what color our hair will be.

“People also have cells for making babies,” Avery says. “Males carry sperm cells. Females carry egg cells.”

When these two kinds of cells come together, the sperm cell fertilizes the egg, which begins growing and dividing.

“Nine months later, a baby is born,” says Avery.

As you’ve noted, sometimes two babies are born. Twins start their journey like most babies do. Then something pretty rare happens.

Sometimes a single egg cell will divide into two. When I asked Avery why it happens, she said the research hasn’t yet shown us exactly why. It’s still one of the mysteries of science.

We do know that when an egg cell divides into two, identical twins are born. They have very similar DNA and may look alike, but they aren’t exactly the same. They may have very different personalities. They even have different fingerprints.

Humans aren’t the only ones that can be identical. One animal that scientists study to learn about multiple births is the nine-banded armadillo. They are very curious about this critter because it very often gives birth to not just two, but four identical babies.

Of course, not all twins are identical. Some are fraternal. Fraternal twins happen when two totally different eggs are fertilized.

The number of fraternal twins born differs around the world, while the number of identical twins is the same. Again, we aren’t entirely sure why. Registries of twins can help us learn more about twins around the world, though. We know that Benin, a country in central Africa, is home to the most twins on the planet.

Meanwhile, in the Washington State Twin Registry, there are more than 18,000 twins who have agreed to be studied. That’s more than 9,000 pairs of adult twins.

One thing Avery and WSU researchers study is discordance. That means one twin has a health condition and the other does not. They can look at twins living in different environments, how they travel, and how it affects their health. One study has helped them find evidence supporting the idea that living in a place with access to outside activities is really good for health.

Together twins are helping researchers answer big questions that can help improve health for all of us—whether you came into the world solo or with a buddy.

Dr. Universe

Ask Dr. Universe – Earthquakes

Dear Dr. Universe: When will the next major earthquake be? Earthquakes really interest me and I want to know so I can be prepared when the next major quake happens. – Carmen, 11, Chowchilla, CA

Dear Carmen,

Our planet’s surface is constantly on the move. Sometimes this movement really shakes things up.

The Earth’s crust is made up 14 major pieces and dozens of smaller ones, called plates, that move in super slow motion. Earthquakes can happen when these plates suddenly slip past each other. They send out waves of energy that make the ground shake.

We can learn a lot about earthquakes after they happen, but the truth is they are pretty unpredictable.

“Everyone wants to know precisely when the next earthquake will be, but the best answer is that we really don’t know the exact timing,” said my friend Katie Cooper, a geologist at Washington State University.

According to the National Earthquake Information Center, more than a million large and small earthquakes shake the planet’s surface each year. By the way, if you’re curious about where some of the recent earthquakes have happened, check out this cool map from the USGS.

You’ll be able to spot some places where there have been earthquakes today. If we look at earthquake patterns, we can say with pretty good confidence that they happen every day along plate boundaries. We just can’t pinpoint exactly where or when they’ll happen next.

Because we don’t precisely know, it’s a good idea to be prepared, especially if you live in an earthquake-prone region like a plate boundary. Cooper said scientists are working on ways to inform people at the very early part of an earthquake.

Some earthquake warning systems can pick up on some of the first seismic waves generated by an earthquake. This may give people ten or so seconds to prepare before the ground starts shaking. That might sound like a really short time, but even a few seconds can help save lives, Cooper said.

Engineers are also helping us prepare for earthquakes. Along with fellow universities, engineers here at WSU are working on new building materials to help people’s houses stay upright on shaky ground. They are using layers of lumber glued together to create thick solid panels. Later, they’ll use the materials to construct a 10-story building. Then they’ll simulate an earthquake in a laboratory. I can’t wait to see what they discover.

One thing you can do to prepare for earthquakes is join the millions of people who participate in the Great ShakeOut, which helps people prepare for earthquakes at school or at home. If you haven’t already, you might even put together your own earthquake kit. It could include items such as a three-day supply of food and water, a flashlight, batteries, and other things you might need in case of a disaster.

Who knows, maybe one day you’ll discover another way to help us prepare for earthquakes—or help find ways to predict them. It’s a good question you ask, Carmen. Even when we don’t know exactly when an earthquake will happen, we can do our best to get ready.

Dr. Universe

Ask Dr. Universe – Ants

Dear Dr. Universe: I would like to find out how ants are so strong. How is it possible that they can carry weight that is heavier than themselves?

–Anita, 11

Dear Anita,
Ants are pretty good little weightlifters. My friend Rich Zack, a scientist at Washington State University who studies insects, knows a lot about ants. One kind of ant that he has studied can carry up to 20 times its own weight.

Ants don’t have special muscles that give them super strength. In fact, their muscles are actually quite a bit like the muscles of other animals.

Zack explained that we often think about strength as the ability of an animal to carry something heavy. Ants can lift big sticks, leaves, and some can even carry a full-grown grasshopper. Of course, they couldn’t lift a fork at the dinner table like you can. Their strength is all relative to their size.

When it comes to figuring out how they are so strong, it also helps to do a bit of measuring, adds my friend Dan Rodgers. He’s an animal scientist at WSU and the Washington Center for Muscle Biology.

One thing we can look at is the animal’s volume, or the amount of space something takes up. Then, there’s the surface area of the object. When we measure the outside of an ant’s body we can find its surface area.

As you observed, a regular-sized ant is able to lift things much heavier than itself. But what if we doubled the size of the ant? Do you think the ant might get even stronger?

“An ant the size of your house would have much more absolute strength than a regular-sized ant,” Rodgers said. “However, it could no longer lift 50 or so times its weight and the small ant would be stronger, relatively.”

If we doubled the size of an ant, the surface area of the ant would also double. But its volume would actually more than double. This is an idea that holds true with pretty much all objects. If things appear twice as big, they actually weigh more than twice as much.
You may have also heard ants wear their skeletons on the outside. Their muscles don’t have to support such a heavy skeleton, so they can instead use their strength to help carry other things.

Ants and other insects have a large surface area compared to their volume. And the muscle strength of an animal is pretty closely related to surface area, Rodgers said. Yes, it’s true ants are strong. But it’s all compared to their size.

There are actually some insects that, for their size, are even stronger than ants. Do you know what insect that might be? Send me your best guess at Dr.Universe@wsu.edu for a chance to win a Dr. Universe sticker.

Dr. Universe

Try it out! You can explore area with a fun, simple activity. Print your own graph paper and make your own pop-up paper creature. Can you find its surface area?

Ask Dr. Universe – Facial Hair

Why do people grow hair under their nose? Why does it grow down instead of up? 
–Riley, 11, Prior Lake, MN

Dear Riley,

Humans have hair all over their bodies, including above the upper lip. Of course, not all hair is quite the same. A lot of people have very fine hairs on their faces. Others can sprout a beard or mustache.

Cats might not have mustaches, but we do have another kind of hair: whiskers. In fact, hair is one of the things mammals have in common. Even dolphins have it. Hair can help keep us warm and protected from the elements.

Human hairs sprout from tiny little sacks under the skin called follicles. The root of the hair feeds off of tiny blood vessels to keep growing. Some hair follicles are too small for the eye to see. As males develop from kids to adults, the size of these hair follicles can get bigger.

This change is related to a chemical in the body called testosterone, said my friend Lori Nelson, a biologist at Washington State University. When follicles get bigger, the hair also gets thicker, and it can draw some attention to the upper lip.

Many males have facial hair because they have more of this hormone circulating in their blood than females do. But having more testosterone doesn’t always mean you’ll have more hair, Nelson adds.

She said there’s been some debate over whether or not facial hair might also help with attracting a mate. I suppose the exact purpose of a mustache is still a bit of a mystery. It’s an interesting observation you make about the direction the hairs grow, too.

At first, I thought the answer would be right under my nose. My guess was that it had something to do with gravity pulling the hair toward the ground. It turns out the direction of your hair follicles is actually determined when you are still growing inside your mother’s womb.

That’s what I found out from my friend Ryan Driskell, a researcher at WSU who studies wounds and how the skin regenerates.

He explained how some of the cells that make you up use different chemicals to communicate with one another. These chemicals can send and receive different messages. These messages carry instructions for how to form different parts of a human body.

Some of these chemicals will even direct hair to face a specific direction, Driskell said. These particular chemicals tell follicles on the upper lip grow downward. Each hair that sprouts out points downward, too.

Driskell isn’t just interested in why hair grows, but also why it sometimes doesn’t grow back. While we have medical procedures that help repair wounds, hair follicles and sweat glands are often lost. They don’t regenerate. In Driskell’s lab, their research is helping us learn how to help the human and other animal bodies heal up even better.

Dr. Universe

Ask Dr. Universe – Astronaut Food

What do astronauts eat in space?
–Rhemi, 12, St. Louis, Mo.

Dear Rhemi,

Astronauts eat all kinds of different foods up in space. The food is often similar to what we have here on Earth. But in space, there’s very little gravity. There’s very limited refrigeration, too. On the International Space Station, the refrigerator is only about half the size of a microwave. That means scientists who prepare and package astronaut food have to do it in ways that take up very little room and don’t need to be kept cold.

In 1962, John Glenn became the first U.S. astronaut to orbit the Earth and also the first American to eat food there. He ate applesauce from a tube. In the early days of space exploration, a lot of astronauts ate food that was in little cubes or squeezed out of tubes. It helped keep the food from drifting around or floating away.

When I got your question, I decided to visit my friend Norman Lewis, a plant scientist at Washington State University. He showed me a package of cosmonaut food some colleagues in Russia gave him from a mission many years ago. Inside was dried fruit, canned meat, and a meal in an aluminum toothpaste tube.

Astronaut food has come a long way since. NASA has prepared menus that include dried fruit, yogurt, sausage, beef jerky, mashed potatoes, mac and cheese, and shrimp cocktail. Even desserts. The meals are often dehydrated. The astronauts just add water.

Scientists and astronauts are also curious about growing fresh food in space. Project Veggie on the International Space Station has helped astronauts become farmers and grow their own lettuce and cabbage.

My friend Norm is also helping NASA learn more about how plants grow and develop in space, particularly how the microgravity environment affects a plant’s overall life processes.

A plant growth chamber, about the size of a mini-fridge, was sent up to the space station in two stages, the most recent stage going up in a pod last month. A big robotic arm, the Canadarm, reached out and grabbed the pod to bring it into the station. Researchers will now work with astronauts on the station to research and discover how the plants grow and how they are affected by microgravity.

The more we know about how plants work, the better we can figure out how to grow them in in space. That could mean places like the moon or Mars, Lewis said. For now, astronauts depend on teams back on Earth to restock their supplies. But if astronauts could grow enough of their own food, they could go on even longer trips into space.

Who knows, maybe instead of only eating applesauce out of a tube, astronauts will have a small tree of fresh, delicious apples. Until then, if I ever get the chance to go to space, I definitely think I’d like to take along some tuna salad. What kind of food would you most want to take on an expedition to space? Tell me about it sometime at Dr.Universe@wsu.edu.
Dr. Universe

Ask Dr. Universe – Eclipses

Hello Dr. Universe: I was wondering, how does an eclipse happen?
– Susan, 13, San Francisco, CA

Dear Susan,
It just so happens the Great American Eclipse is coming up on Aug. 21, 2017. This solar eclipse will be the only one visible from across the lower 48 states in nearly a hundred years. When it happens, parts of the country will experience darkness for a couple minutes during the day.

It seems prime time to answer your question. My friend Guy Worthey, an astronomer at Washington State University, was happy to help out.

“Do you have a little brother or sister? And maybe a TV?” Worthey asked. “Even if you don’t, imagine that you’re trying to watch TV, and your little brother or sister gets in the way. You can’t see the TV anymore.”

He said we can think of the TV as the sun. Your little brother or sister is the moon. You are the Earth. A total solar eclipse happens when, the sun, moon, and Earth are lined up just right and, for a few minutes, the moon blocks the Earth’s view of the sun.

The moon is on a bit of a wobbly orbit, so even though it passes in front of the sun often, there isn’t always an eclipse. If it’s not lined up perfectly, we see just a partial eclipse. Part of the moon blocks the sun.

During a total solar eclipse, the moon casts its shadow down to Earth. Just like we can make shadow puppets on the wall using a flashlight, the moon can cast a shadow with help from the sunlight.

The places where the moon will cast its shadow is called the path of totality. If you’re in the path of totality during the total lunar eclipse, you’ll know it.

This is the area where you can experience total darkness during the day. From Earth, you’d also see the glowing, white outer part of the sun’s atmosphere, or the corona, hopefully with protective goggles. It only takes a couple minutes for the moon to pass in front of the sun. Then, it’s light outside again.

Even if you aren’t in the path of totality in August, you may still be able to see a partial eclipse. Worthey explained that there are actually several kinds of eclipses.

Another kind of eclipse is called a lunar eclipse. During a lunar eclipse the line-up goes: sun-Earth-moon. It’s called a lunar eclipse because the moonlight is affected.

The moon shines because it reflects light from the sun. But when Earth blocks the sun, the moon gets darker or even a little reddish. There will be a partial lunar eclipse on Aug. 7. You don’t need to protect your eyes when watching a lunar eclipse, but it’s super important to protect your eyes when viewing a solar eclipse.

You can prepare for the upcoming solar eclipse with a few resources and tips for how to safely view it with help from NASA. Keep asking great questions and keep your eye to the sky.

Dr. Universe

Answer to last week’s question for readers: The strongest insect is the horned dung beetle.

Ask Dr. Universe – Lightning

Dear Dr. Universe: What causes lightning?
-Monica, 10, Costa Rica

And while we’re at it, let’s answer these questions:
When lightning strikes the ocean, what happens to the fish? –Olivia, 12, Manchester, UK
Why is lightning attracted to metal objects? –Grant, 11, Pullman, Wash.
Why does lightning sometimes just happen in clouds? –Leo, 11, Cayman Islands

Dear Monica, Olivia, Grant, and Leo:

While you are probably not in the middle of an electrical storm right now, there are more than 1,000 happening at any given moment on our planet. They happen on Saturn, Venus, and Jupiter, too.

These big, grey storms we see on Earth give us the chance to see electrical charges in action, said my friend Nic Loyd, a meteorologist at Washington State University.

Pretty much everything has a charge. You have a charge. I have a charge. These charges interact with each other. Founding Father and inventor Ben Franklin, who was really curious about lightning, is credited with giving these charges names: negative and positive.

They work kind of like the different ends of a magnet. Two charges that are the same will move away from each other. But put a negative and positive charge near each other and they are like best buds. Opposite charges attract.

Of course, even though we have charges, we aren’t walking around repelling and attracting different objects. Most of the time, objects have both positive and negative charges. They cancel each other out, leaving a neutral charge.

But sometimes, these charges are out of balance. Lightning is one way nature balances out these charges on our planet. Loyd told me about the ingredients.

As the sun heats the earth’s surface, the air above it warms up, too. Warm air rises. As the air rises, very tiny droplets of water, or vapor, rise up and form into a cloud. Air continues to rise and the cloud gets bigger and bigger. At the top of the cloud the temperature is really cold. The tiny droplets of water there turn into ice.

One idea is that bits of ice bump into each other to create electrical charge. Exactly how they do this is still a bit of a mystery. But when these charges in the sky interact with opposite charges on the ground, current runs between them and we see a bright flash of lightning. Lightning can happen within a cloud or it can happen between the cloud and the ground. It all depends on how these charges are jumping around.

Now, for a final lightning round of answers to the remaining questions. It turns out metal doesn’t necessarily attract lightning. But it is a good conductor of electricity. That means electricity can easily flow through it. Lighting will take the shortest path possible. Water can also be a good conductor. That’s why it’s important to stay away from water when there’s an electrical storm. Most of the electricity flows along the top of the water. A fish’s fate may depend on how close to the surface it swims.

Finally, thunderstorms happen more often in spring and summer, as the ingredients—especially warm air– are more likely to exist. Now that you know more about the electrical charge we can see in the sky, what about the sound we hear at or near the same time? What causes thunder? Send your idea to Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe – Inside Planets

What do planets have inside? –Rhianna, 10, California
Dear Rhianna,

Each planet is a little different on the inside. And what’s inside a planet can shape what’s on the outside, too. That’s what I found out from my friend Steve Reidel, a geologist at Washington State University.

“Well, there’s the rocky planets,” he said. “Then there are the big, gas giants.”

Rocky planets, like Earth, are wrapped in a thick crust. Beneath Earth’s crust is the mantle. The mantle is quite solid, but it actually behaves more like a fluid. It flows and deforms. It’s similar to Silly Putty, but a really strong version of Silly Putty. It’s about 1,800 miles thick. It is also the main source of Earth’s volcanoes.

Even deeper in our planet is the core. It’s made up of metals, like nickel and iron. In fact, at the center of Earth there may be a ball of solid nickel and iron. It’s a solid because of the intense pressure there. But the outer part of the core is under less pressure, so it’s likely more fluid.

You may have heard that Earth is like one big magnet. It’s the reason why our compasses point north. Scientists think that as Earth’s fluid interior swirls around with the spin of Earth, it helps generate the planet’s magnetic field.

Earth’s magnetism is also part of the reason we have the Northern Lights. When particles from the sun strike particles in our atmosphere near the Earth’s magnetic field, it can create colorful displays.

While we can see some of the ways deep earth shapes our planet, we can’t actually look inside it. The deepest scientists have ever explored is about 5 miles into the Earth. Since we can’t slice up a planet, scientists use different measurements to figure out what’s going on.

One way they do this is to look at waves that earthquakes produce. Scientists can use seismometers, machines to measure the shaking of the ground, to help measure the waves. Some of these waves only move through solids, like the inner core. Others move through solids and liquids, like the outer core and mantle. They can use this information from the wave measurements to put together a better picture of the planet’s composition.

Other rocky planets—Mercury, Mars, and Venus—likely have similar interiors to Earth’s. It appears Mercury has the biggest core, at least compared to its size.

Then there are the giant gas planets: Neptune, Saturn, Jupiter and Uranus.

Air is one gas we all know. We breathe it. Planes zip through it. Each of these planets in the outer solar system is surrounded by different gases. We couldn’t stand on them.

If we did travel through the center of a gas giant, we would probably find something pretty familiar to our own rocky planet on the inside.

Your friend,
Dr. Universe

Ask Dr. Universe is a science-education project from Washington State University. Submit your own science question at askDrUniverse.wsu.edu/ask.

Ask Dr. Universe – Snake Skin

Dear Dr. Universe: Why do snakes shed their skin? – Kalitia, 12, Zimmerman, Minn.

Dear Kalitia,

Believe it or not, pretty much all animals shed their skin. Some animals make it a bit more obvious than others. Snakes, and some other reptiles, will often shed all at once.

Instead of shedding their skin in one go, humans actually make and get rid of new skin all the time. It floats away in very small flakes. If you’ve ever had a sunburn, you know skin can shed in bigger pieces, too.

That leads us to a big part of the reason animals shed, said my friend Kenneth Kardong. He is a zoologist at Washington State University who is really curious about reptiles, especially rattlesnakes. He said animals shed to replace worn out or damaged skin.

When a snake gets ready to shed, its eyes turn a milky color. This is because a new layer of skin forms over the eyes, too. It can’t see very well. It may even try to find a place to hide out until it starts shedding. For that to happen, it needs to find something to help break a part of the skin up near its snout. Something like a stick or a rock.

Then the snake will start to wriggle out of the outer layer of skin. It slithers against rocks, trees, and plants. Some snakes will even go for a swim to help escape their old skin. In a snake’s shedded skin, we can see all the details of the original skin, its scales and even its eyeball cover.

For most snakes, that’s the end of it. At least, until the next time they shed. That’s usually in a year or two. But rattlesnakes are a little different.

Shedding doesn’t just get rid of their old skin. It also reveals new parts of the rattlesnake’s tail. The rattle is made of different sections of keratin—the same stuff that makes up your fingernails. Each time the snake sheds its skin, a new segment of the rattle is revealed.

When a baby rattlesnake is born, it can’t make a rattle sound yet. It isn’t until the first time it sheds that a new segment forms on its tail. Together, these segments vibrate to make the snake’s “chica-chica” sound.

As with other snakes, shedding also helps rattlesnakes repair any damaged skin. In fact, sometimes snakes have things called parasites. They’re creatures that takes away nutrients from their host animal to survive. Shedding helps snakes get rid of these creatures. And of course, the shedding also leaves the snakes with a brand-new layer of skin to wear out in the world.

Dr. Universe

Ever wonder what’s inside a rattlesnake rattle? Find out! https://www.youtube.com/watch?v=1pyfMnF6j_g

Ask Dr. Universe is a science-education project from Washington State University. Send in a science question of your own at askDrUniverse.wsu.edu/ask.

Ask Dr. Universe – Feelings

Why do we have different feelings?  – Charan and Aishwarya V., 10 & 8, Rutherford, New Jersey
Dear Charan and Aishwarya,

Imagine you are playing a game of soccer and your best friend is on the opposing team. The sun is out, you are having a great time, and you score the winning goal. You’d probably feel pretty happy and so would your team.

But if you stepped in your best friend’s shoes, the emotion might be really different. Think of the players on the other team, too. Even if they had fun and played their hardest, they may be a little disappointed.

Humans feel all kinds of different emotions. They use them to react to different situations, whether that’s playing a game or maybe coming face-to-face with a saber-toothed tiger.

For your ancestors, an emotion such as fear could help increase the chance of survival if they did run into this ferocious feline. When people are faced with a potentially dangerous situation, changes in the body happen automatically.

A fear signal from the brain makes the heart race, muscles tighten, and the mouth gets dry. The body gets ready to fight or run away. You may express this fear on your face. That’s a signal to people around you that they’ve got to get ready to act.

My friend Sara Waters, a psychologist and researcher at Washington State University, is really curious about human emotions. She asks big questions about how and why we develop them and how we share them.

When you were a baby, you probably couldn’t express your emotions very well. You had to cry a lot to express yourself and get what you needed. Maybe you threw tantrums. But you soon discovered they didn’t work very well.

You may not have had the right words for your emotions yet. When you learned to talk, you started to give your emotions names, Waters explained. The grown-ups in your life probably helped you figure out what those names were. Sad. Happy. Mad. Then, you could start figuring out your feelings on your own and express them to others.

Waters’ research actually looks at how some mothers and their babies sort of catch one another’s emotions. When moms look at their babies with a certain emotion, the babies will also show those emotions. They’re kind of like copy cats.

Maybe after winning the soccer game your friend gives you a high five. Your friend tells you that it was a little disappointing to lose. Maybe your own team has lost in the past and you remember how it feels. You have a whole range of different emotions you can use to navigate the world, better understand people, and make good decisions.

What kinds of things do you do to bring others happiness? How do you show kindness? What makes you happiest? Make a list or tell us about it sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe is a science-education project from Washington State University. Submit a question of your own at http://askDrUniverse.wsu.edu/ask

Ask Dr. Universe – Animals on Islands

How do animals get to islands? –Jax, 8, WA

Dear Jax,

Animals make their journeys to islands in different ways. Some float. Some fly. Others will swim.

My friend Jonah Piovia-Scott is a scientist at Washington State University. He studies how different living things interact with each other, especially in island habitats. He is really curious about predatory lizards that live on a chain of islands called the Bahamas.

“These lizards can get to islands,” he said. “They can swim, but not very well. They keep themselves afloat.”

Floating is one way animals get to islands. They may float on their own or they may take a kind of raft. This raft is often made up of plants, branches, or other things that blow out into the sea during a storm and are swept together in the ocean.

Flying helps animals like bats and bugs get to islands. Piovia-Scott reminded me that some animals fly for just a small part of their lives, too. Before some ants are fully grown, they go through a stage where they have wings. An ant might find it hard to swim in the ocean. But while it has wings, it can make a flight to a new place.

If animals are light enough, they may get picked up in the wind and sort of drift along. For example, spiders use their silk to catch the wind and move to new locations. Also, a lot of plants get to islands because of the wind. Plant seeds often catch a ride in the air. When they reach the island, they get buried in soil and start to sprout. These plants provide food for many animals.

Finally, there are animals that are just good swimmers, such as seals. They can paddle long distances to an island and some also find a home on the land.

Piovia-Scott explained that animals often take advantage of their new island life. We see these changes in animals such as the marine iguana. Most iguanas we know about only live on the land. But iguanas on the Galapagos Islands dive into water to look for food. They have developed ways to use the resources in and around their island environment.

Another place we see this is in the Pacific Northwest on the San Juan Islands. On these islands, we find raccoons that eat shellfish.

Piovia-Scott said you could probably say the same is true of people who live on islands—they tend to eat a lot of fish. That sounds like my kind of place. I might have to go and explore an island one of these days.

In the meantime, I’m going to see if I can make a flying device and floatation device to learn more about how things travel on water and in the air. You can try it out, too. Find this article and the instructions at askDrUniverse.wsu.edu.

Dr. Universe

Ask Dr. Universe is a science-education project from Washington State University. Submit a question of your own at http://askDrUniverse.wsu.edu/ask

Ask Dr. Universe – Blood

Why do we have blood? Where does it come from? –Norelle, Olympia, Wash.

Dear Norelle,

Our bodies have many living parts, like skin, muscle, brain and bones. Blood helps keep these parts alive and healthy. The system that moves our blood around the body is sort of like a city’s postal service, said my friend Astrid Suchy-Dicey.

Suchy-Dicey is a scientist at Washington State University who is really curious about blood. Her research helps people at risk for diseases.

She said it first helps to know that blood is actually made up of different things: red blood cells, white blood cells, platelets, and plasma.

If you think of your circulatory system like the postal service, mail carriers are the red blood cells. They transport important packages and letters (oxygen) over a vast network of streets and highways (blood vessels).

About a gallon and a half of blood circulates through the human body, dropping off these deliveries, 24 hours a day. The strong heart muscle pumps blood out into the body. It’s working hard, too. The force needed to squeeze a tennis ball is similar to what you need to squeeze blood out of the heart.

White blood cells help your body fight off infections. There are lots of different types of white blood cells with different jobs. Some of them fight off tiny bacteria and fungi. Some of them fight off viruses or other invaders.

All of the white blood cells’ jobs have one common mission: keeping you healthy.

Platelets help keep you healthy, too. Whenever you get a cut or scrape, these disc-shaped parts come to the rescue. Platelets help stop blood from flowing. They also help prevent you from losing blood and keep out invaders.
Plasma is a watery solution with a few other things floating in it, like salt and proteins. It flows, carrying other cells freely along those streets and highways we know as blood vessels.
As for your second question, Suchy-Dicey said that blood cells are produced in your bones. Specifically, they are produced in the soft fatty part inside your bones called bone marrow.

Your plasma is formed mostly using water you drink. That’s why it’s really important to drink enough water each day, Suchy-Dicey adds. While on the issue of water, here’s a quick activity you can try to find out about how much blood your heart pumps in a minute.

You’ll need a bucket of water, an empty bucket, and a small Dixie cup. Fill a bucket with about a gallon of water. Have a friend set a timer for one minute and see how many little cups of water you can move to the empty bucket.

Each time your heart beats it moves about a small Dixie cup’s worth of blood. It takes our heart about one minute to pump about a gallon of blood. Can you move the liquid faster than a heart? Try it out sometime and let me know how it works.

Dr. Universe

Ask Dr. Universe is a science-education project from Washington State University. Submit a question of your own at askDrUniverse.wsu.edu/ask

Follow-up video about why red blood cells look like donuts available at: https://askdruniverse.wsu.edu/2017/04/17/why-do-we-have-blood-where-does-it-come-from/

Ask Dr. Universe – Meat

Why does meat get brown on the grill? –Christina, 9, Seattle, Wash.

Dear Christina,

You know summer is just around the corner when the smell of barbecue is in the air. It’s a great question you ask and it leads us to the Meats Lab at Washington State University. That’s where I met up with my friend and animal scientist, Jan Busboom.

He’s really curious about animal nutrition and the meat we eat. Busboom explained that meat is muscle. It has a lot of different proteins. These proteins have different jobs. One of them delivers oxygen to the cells that make up muscles. It’s a protein called myoglobin.

Believe it or not, the red liquid we see in a package of meat comes primarily from myoglobin. The more myoglobin there is in a muscle cell, the redder the meat will look. Myoglobin is a big part of why meat is red in the first place—but it’s also part of the reason it turns brown on the grill, too.

Like almost everything on our planet, a hamburger is made up of atoms. As you may know, atoms get together to form molecules. These parts are arranged in ways that give things certain colors, tastes, and smells.

As is often the case when we heat up something, its atoms and molecules often start to move, or vibrate faster and faster. Then they transform.

When we heat up the hamburger meat, the myoglobin structure begins to change. Myoglobin loses its ability to bind onto oxygen. There’s also a change in one of the iron atoms at the center of the myoglobin.

These changes are happening on very small scale. But we can actually see the changes as the red meat transforms into a juicy brown hamburger patty.

It turns out color isn’t always the best sign that a burger is ready to eat. Busboom said sometimes a burger won’t brown on the grill. Even if it’s fully cooked, it will stay red.

On the flip side, sometimes a burger that is brown isn’t actually cooked. This is because there may be some other chemical factors going on here that influence color. That’s why it’s really important to use a thermometer and make sure your meat is safe to eat.

Not only does a burger’s chemistry influence color, but also its taste and smell. When we heat it up, proteins and sugars in the meat start to break down.

It was the French chemist Louis Camille Maillard (my-YAR) who discovered the way this works. When the Maillard reaction happens, it creates thousands of new chemical compounds that give meat flavor.

Yes, there’s a whole bunch of science happening right there on the grill. I suppose you might even say the grill master is a bit of a scientist.

Can you think of other kinds of science that go into building the perfect burger? Tell me about it sometime at Dr.Universe@wsu.edu.

Dr. Universe

Ask Dr. Universe is a science-education project from Washington State University. Submit a question of your own at http://askDrUniverse.wsu.edu/ask