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Dr. Universe: How fast does a bunny hop? How long does a bunny live? Can a bunny swim? How many babies does a bunny have? -Rueben, 7, Pennsylvania

Bunnies are hopping all over our planet. Some hop through snow and deserts while others hop through wetlands and woods. There are lots of different kinds of rabbits and they are all a little different. For the most part, a bunny hops, or actually runs, anywhere between 25 and 45 mph That’s even faster than most house cats can run. Rabbits are related to another group of animals called hares. Actually, rabbits and hares are in the same family, Leporidae. Hares look a lot like rabbits, but they have much bigger ears and bigger feet. Read More ...

Dr. Universe: How do earthquakes happen? -Aescli E., 10, Utah

We’ve had a lot of earthquakes on our planet this year. Maybe you’ve learned about them from the news or felt one shaking up your own neighborhood. First, it is important to know a bit about the Earth’s outer layer, or crust. The crust is made of seven big pieces called “plates.” They are about 60 miles thick and sort of float on the molten rock beneath them. That’s what I found out from my friend Sean Long, a geology professor at Washington State University who knows a lot about earthquakes. Read More ...

Dr. Universe: Why do we have five fingers and five toes? -Eli, 11, Edinburgh, Indiana

Dear Eli, While humans may be one of the few animals that can give a high five, they are one of many with five fingers and toes. Humans are part of the primate family, which also includes monkeys, apes, and even lemurs. As a member of the family, you also have fingernails instead of claws and pads on your fingertips that help with your sense of touch. Read More ...

Why does caffeine make us stay up longer? -Cooper, 12

Dear Cooper, You’re right, caffeine can help us stay awake—but only for so long. To understand exactly why it works, it helps to know about one of my favorite things: sleep. All animals need rest to stay healthy. But sometimes humans don’t get quite as much sleep as they need. They might be tired during the day or have a lot of work to do. To feel more alert, they might drink a cup of coffee, tea, or soda. These kinds of drinks contain caffeine, a chemical and stimulant that can trigger changes in the body. Read More ...

How many suns are in the universe?

Hey cool cats, I’m Dr. Universe, here to answer your baffling science questions like this one. How many suns are in the universe? The sun is actually a star, our nearest star, but there are lots of stars out there. Maybe you’ve tried counting them before. One, two, three, four, five, six, seven stars make up the big dipper. Astronomers estimate that the human eye could spot about 9,000 stars. Of course, the Earth blocks our vision so we only see about half of those in the night sky. If we use binoculars, we could see even more stars, about 200,000 of them. A small telescope can help us see more than 15 million stars and even more powerful telescopes can help us look for other galaxies which are home to even more stars. Have you ever been stargazing? What did you see in the night sky? Tell us about it sometime at Dr.Universe@wsu.edu.

Why do bees make hexagons in their hives?

Hey cool cats, I’m Dr. Universe, here to answer your baffling science questions, like this one. Why do bees make hexagons in their hives? When bees make hexagons in their hives, the six-sided shapes fit together perfectly. You know, if you think about it, other shapes wouldn’t work quite as well. Circles would leave gaps in the honeycomb. Squares and triangles wouldn’t leave gaps, but the hexagon works even better. The hexagon uses the least amount of material to hold the most weight. Bees can use these hexagons to store things. The queen bees eggs, pollen, and honey. For having never done a day of math homework in their lives, bees use some pretty creative geometry and engineering to build their headquarters. You can send your own science question to Dr. Universe at Washington State University. Visit AskDrUniverse.wsu.edu.

Do plants get sunburns?

Hey cool cats, I’m Dr. Universe here to answer your baffling science questions. Like this one, “Dear Dr. Universe, Why don’t plants get sunburns?” That’s a great observation. For as much time as plants spend outside, we don’t see too many with a sunburn. Plants need sun to grow, but not too much sun. Since they can’t move into the shade, put on a hat or sunscreen, they have their own way of staying safe in the sun. They make their own kind of sunblock. Of course, it isn’t much like the sunscreen you and I might use. Plants make their sunscreen out of a special combination of building blocks called molecules. They join together to make a compound, and block out ultraviolet light from the sun. It’s the kind of light that can cause damage to skin, or other living tissues. The compound still allows other kinds of sunlight to come through. That way, the plant can live and grow without getting fried in the sun. Send me a science question of your own at stage.web.wsu.edu/askdruniverse.

What is slime?

Hey, cool cats. I’m Dr. Universe here to answer your baffling science questions like this one. What is slime? Our world is full of slime makers. Slugs make gooey trails. Bacteria create slippery slime in pipes. Slime in your joints helps protect your bones. Slime is between a solid and a liquid. It’s a non-Newtonian fluid. You can make it right at home. Dissolve a teaspoon of borax in a cup of water. In another bowl, mix together half a cup of liquid glue and half a cup of water. Then combine everything. The glue contains long chains of molecules. We call them polymers. You might think of them like cooked spaghetti noodles that are all tangled up. If we let the noodles dry out a bit, we’d see they’d start sticking to one another. What was once a free flowing liquid is now thickened by polymers, a fun slime you can mold, bounce, twist and stretch. Send me a science question of your own at AskDrUniverse.wsu.edu.

Why is the ocean salty?

Hey cool cats, I’m Dr. Universe, here to answer your baffling science question. Like this one. Dear Dr. Universe, why is the ocean salty? If we took all of the salt from our oceans and spread it over Earth’s surface, it would be almost 500 feet high. It all starts with rocks and dirt on land. Salt is one of the many minerals in rocks. A lot of it is the kind you might sprinkle on food, sodium chloride. As you might guess, it’s made up atoms called sodium and chlorine. Water is really good at dissolving salt. You can see this in action, just by adding a little salt to a cup of water. The chemical reaction in water, pulls different parts of salt away from each other. Streams and rivers help dissolve the salts from the rock and carry it into the ocean. But not all salt stays in the ocean. Find out where it goes. Or send me a science question of your own at AskDrUniverse.wsu.edu.

Why are apples red?

Hey cool cats, I’m Dr. Universe. Here to answer your baffling science questions. Like this one. Dear Dr. Universe why are apples red? In nature different colors sometimes send a message to different plants and animals. The message might be don’t eat me as is the case of some brightly colored poisonous frogs. Other times it might be a chameleon using it’s colors to attract a mate saying hey look over here. But scientists think the apples red color might just be a way of telling hungry animals we’re delicious. Long before humans were shopping for apples at the supermarket bears were scavenging for fruit in forests. One idea is that bears are particularly attracted to red. A color that really pops against green leaves. When bears see the red fruit they eat it digest it and poop out the seeds. That way new generations of trees can grow and produce even more apples. Send me a science question of your own at AskDrUniverse.wsu.edu.

Why do feet smell?

Hey cool cats, I’m Dr. Universe here to answer your baffling science questions. Like this one. Dear Dr. Universe, why do feet smell? We live in a world filled with all kinds of smells. Take off your 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 simply 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 on any other part of the human 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 wanna plug your nose, but at least you’ll know the system that helps you smell, your olfactory system, is working well. Got a science question of your own? Send it in at AskDrUniverse.wsu.edu.

Why do animals hibernate?

Hey cool cats, I’m Dr. Universe, here to answer your baffling science questions like this one: Dear Dr. Universe, why do animals hibernate? Animals survive winter in different ways. Some penguins huddle together in groups to create heat. Lots of birds fly south to warmer weather. Maybe you put on mittens and a coat. Then there are the hibernators. Bears, bats, frogs, and salamanders for example. Hibernation is a kind of deep long winter sleep but it isn’t exactly the same kind of sleep these animals would normally have at night. During hibernation these animals have slower heartbeats, a lot of them can go without food for months at a time, and many don’t even have to wake up to go to the bathroom. All of these things help them survive the season. While some animals hibernate in winter, others estivate during hot, dry seasons. Can you think of some things animals might need to survive in these conditions? You can submit a science question of your own at AskDrUniverse.wsu.edu.

Why do we have ear wax?

Hey, cool cats. I’m Doctor Universe, here to answer you’re baffling science questions. Like this one. Dear Doctor Universe, why do we have earwax? Just the other day I was scratching my ears when I found some earwax. It was pretty gross, but it also made me very curious. We have earwax for many of the same reasons we’ve got boogers in our nose. Earwax helps invaders like bacteria and dirt from getting deep into our ears. It also protects our inner ears which connect to important nerves that we use for balance and hearing. The outer ear is an earwax factory. It’s where special glands under your skin produce the sticky, wet wax. When it comes to keeping our ears clean and fresh, it’s best to just dab our ears with a towel after a bath. And remember, don’t ever stick anything smaller than your elbow in your ear. You can submit a science question of your own at AskDrUniverse.wsu.edu.

How Do Bones Form?

Hey cool cats, I’m Dr. Universe, here to answer your baffling science questions like this one. How do bones form? Most humans have 206 bones. But did you know, you are actually born with about 300? Before you were born, your skeleton was soft and bendy. Then when you were a baby, some of those bones started to fuse together to become bigger bones. Meanwhile, cells in your body were helping make your bones even stronger. We all have bone-eating cells and bone-building cells that work in a big cycle. Since the day you were born, your skeleton has been in a way always remaking itself. Send me a science question of your own at askdruniverse.wsu.edu.

Who created the very first chocolate bar? – Emma, 11, USA

Dear Emma,

For most of human history, people have enjoyed chocolate in a spicy, bitter drink. But when people discovered how to turn chocolate into a solid, it opened up a whole new world of possibilities.

That’s what I found out from my friend Omar Cornejo, a scientist at Washington State University who is very curious about the history and life of the cacao tree. Chocolate comes from the seeds of leathery fruits that grow on the tree.

If we cut open the fruit, we would find about 20 to 60 seeds on the inside. In ancient times, people would grind up the seeds … » More …

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Why do you grow new taste buds? I read in a book once that you grow new taste buds every week. I started wondering how and why? I'm hoping you can help me with my question. -Tyra, 10, Jacksonville, NC

Dear Tyra,

You read it right— taste buds can have a lifespan of anywhere from one to two weeks. That’s what I found out from my friend Charles Diako who researched food science at Washington State University. Before he explained exactly how and why we grow our taste buds, he told me two important things about them.

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Dr. Universe: How is wasabi made and where does it come from? – Christian, 12

Dear Christian,

When you think of wasabi, you might think of that hot green paste people serve up with sushi. Some restaurants put a bit of wasabi on your plate, but it’s usually not real wasabi. It’s actually a mixture of horseradish, mustard, and green dye. Real wasabi is a lot different.

That’s what I found out from my friend Thomas Lumpkin, a plant scientist who studied wasabi as a researcher at Washington State University. Wasabi is a plant that mainly grows in Japan in the cool, running water of mountain streams and springs.

Illustrated, cartoon cat with labcoat» More …

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Dr. Universe: Why do cats like lasers? -Izzy, 10, MD

Not only do I enjoy answering science questions from kids, but I also like naps, tuna fish sandwiches, and chasing lasers. I wasn’t entirely sure why I like chasing those little red dots. I asked my friend Leticia Fanucchi, a veterinarian at Washington State University.

“Cats like lasers because they are predators and like to chase or hunt anything that moves fast around them,” Fanucchi said.

A zipping red light that quickly switches directions might have a similar motion to a mouse or other critter. The light sort of mimics an animal scurrying around to escape its prey. Even though we cats know the … » More …

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Dr. Universe: How does land affect the weather? – Isaac, 7, Baltimore, MD

The surface of the earth is covered in all kinds of landforms. We have tall mountains, deep valleys, wide canyons, and scenic shorelines—I bet you could think of a few others, too. A little less than a third of our planet is land and the rest is mostly ocean. Both affect the weather, said my friend Nic Loyd, a meteorologist at Washington State University.

We get different weather patterns depending on a few conditions, such as how much sun the land gets, if the land is near mountains or ocean, and how air circulates through the atmosphere.

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Why do lizards lose their tails? -Bailey, Inwood, Iowa

Dear Bailey,

Our planet is home to all kinds of lizards. Maybe you’ve seen one climbing up the wall, scurrying through the grass, or at the pet store. Just the other day I saw a big green iguana when I visited the Washington State University Veterinary Teaching Hospital in search of an answer to your question.

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Dr. Universe: How do cacti survive in such hot and dry environments?

-Ravin, 11, London, England

Dear Ravin,

All plants need water to survive. Those that live in places where water is scarce use some interesting strategies to stay alive.

That’s what I found out from my friend Charles Cody, who manages one of the greenhouses at Washington State University. When I went to visit the greenhouse, he pointed out a few different cacti.

One was tall and cylindrical with big spines. Another was small and round with what looked more like little hairs. A rainforest cactus hung on the wall like a vine.

Cody explained that if … » More …

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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.

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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 … » More …

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Dr. Universe: Do you have any experiments you can 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 … » More …

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Can video games help us learn? - Isaac, 12, Clyde, N.Y.

Dear Issac,

All kinds of games can help us learn, including some video games. They can be a fun and useful way to help you remember what you learn, too.

Our brains work hard each day to take in and process information. Ever since video games were invented, people have been asking if and how they might change our behavior and brains.

For example, people once thought that video games left players with poor eye-sight and poor attention. Some scientists decided to actually test out these ideas. Their studies have shown that some video game players … » More …

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

[caption id="attachment_2942" align="alignleft" width="592"] Dr. Universe examines a gray hair.[/caption]

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.

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Dear Dr. Universe: How does a light bulb work? When one bulb in a string of lights goes out, why do they all go out? – Molly, 8

Dear Molly,

Just the other day I was taking down a string of lights from my lab, when I discovered the bulbs were burnt out. I visited my friend Aaron Crandall, an engineer at Washington State University, to see if I might get them working again.

Crandall explained when you plug in a string of lights to a power source, like an outlet, an electrical charge flows into the wires. A lightbulb works when an electrical current runs through thin metal wires in the bulb and electrical energy gets converted to heat and light. We can get this current of electricity to follow different paths, … » More …

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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.

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Dr. Universe: How do planes fly? -Tahira, 12, India

Dear Tahira,

Planes are very heavy, yet they stay up in the air kind of like a bird in the sky. They can get us across the world in less than a day. Humans went from learning how to fly a plane to putting a man on the moon in a little over 60 years.

But the answer to your question goes even further back. It goes all the way back to the 1700s and actually started not with air, but with water.

That’s what I found out from my friend Michael Allen, a physics and astronomy professor at Washington State University. He thought you … » More …

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Hello Dr. Universe, may I ask how fish breathe? - Nghi, 11, Vietnam

Hello Nghi,

Cats, humans, and fish all breath for the same reason. We need oxygen. Oxygen is one of the things our bodies use to make energy.

Just like the hungry feeling you get when you haven’t eaten, your body uses oxygen to keep everything running. Unlike the breaks you take between meals, the breaks you take between breathes are much shorter. Most people take about 12 breaths per minute.

While it may seem like we breath only oxygen, there are lots of other gasses in the air. When we breath in, our lungs fill up with all this gas. The lungs take the oxygen … » More …

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Dr. Universe: Why do birds have feathers? –Karthikeya, 7

Dear Karthikeya,

Bird feathers are interesting. There are so many types, shapes, and colors. My friend Daniela Monk is a Washington State University professor who studies avian ecology, or the study of birds.

She told me about why the birds we know today have feathers and how they got them. Researchers believe that birds evolved from dinosaurs a very long time ago.

“One lineage of dinosaurs gave rise to birds,” Monk said.

Researchers around the world are finding dinosaur fossils that contain feathers. A fossil is the remains of a very old animal or plant that is preserved in a rock. From these fossils they … » More …

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