Skip to main content Skip to navigation
Ask Dr. Universe

Dr. Universe looking through a microscope

A Special Announcement From Dr. Universe

Guardians can send Dr. Universe an e-mail with their student’s question about geology or plants for a chance to be featured in an upcoming program on Northwest Public Broadcasting. E-mail Dr. Universe at dr.universe@wsu.edu with the subject “Meet the Scientists.”

Episode 9: Handedness, Weighing Planets, Worms

Dr. Universe, a grey cat with a lab coat, looking through binoculars

Welcome back, young scientists. I’m Dr. Universe and if you’re anything like me you’ve got lots of big questions about our world. On this episode, we investigate questions like: Have you ever wondered why most people are right-handed? How did people learn how to weigh a whole planet? How worms help the soil? A big thanks to our kid narrator from Regional Theatre of the Palouse and to the scientists at Washington State University. Listen now or find other episodes on:

Apple podcast badge APPLE PODCASTS   Spotify podcast badge SPOTIFY   Stitcher podcast badge STITCHER

New Video: Do Bugs Have Hearts and Brains?

The Latest Questions and Answers

  • How do tiny seeds make huge trees?

    Dear Robin,

    If you’ve ever eaten a handful of trail mix, you’ve likely eaten quite a few seeds from trees. Some nuts, like cashews and almonds, are also seeds that can give us energy when we hike or play.

    Seeds actually store up their own energy in the form of something called starch, which is kind of like the food a seed needs to survive. The seed will use this stored up energy to start growing into a tree.

    Read Story
  • Why does it make noise when you snap your fingers?

    When I got your question, I snapped my fingers a few times to try and find the exact source of the sound. After a few tries, I decided to ask my friend Troy Bennefield, the director of Athletic Bands at Washington State University.

    While we may start a snap with the top of our thumb and middle finger touching, he said that the snapping sound actually happens when the middle finger hits the palm area at the base of the thumb.

    Read Story
  • Why are some berries poisonous?

    A lot of living things on our planet have defenses they use in the wild to help them survive. For some plants, being poisonous may help keep them from becoming someone’s dinner.

    Wendy Hoashi-Erhardt

    That’s what I found out from my friend Wendy Hoashi-Erhardt, a scientist who directs the Small Fruit Plant Breeding program at Washington State University.

    Read Story
  • Trees: Why do they grow so slow?

    When you eat food, you get a lot of important nutrients that help you grow. The trees that live on our planet also need some nutrients to grow.

    Trees use their leaves to help capture energy from the sun to make their own food. But as you may have noticed, a lot of trees lose their leaves during certain times of the year.

    Without leaves, they can’t make nearly as much food, and without those important nutrients, they can’t grow very fast.

    That’s what I found out from my friend Tim Kohlhauff, a certified arborist and urban horticulture coordinator at Washington State University. He is very curious about the lives of trees.

    Read Story
  • How do you learn something really, really hard?

    There are so many different things we can learn in our world, but that doesn’t mean learning is always so easy. Maybe you want to learn a process, like how to complete Rubik’s cube, code an app, design a solution to a problem or answer science questions.

    Read Story
  • Worms: How do they help the dirt?

    Worms can help the soil in a few different ways. One helpful thing worms do is move around different materials, such as leaves and grasses, and make holes in the soil.

    That’s what I found out from my friend Lynne Carpenter-Boggs, a soil scientist at Washington State University, who was happy to help with your question.

    Lynne Carpenter-Boggs

    “Worms are actually very strong,” Carpenter-Boggs said. “They can break through soil and make holes that allow air, water and plant roots to follow those channels.”

    Read Story
  • How do fish migrate and why?

    While a lot of fish swim from one region to another to find food or have babies, different fish species migrate in different ways.

    That’s what I found out from friend Steve Katz, a professor at Washington State University who knows a lot about our planet’s natural resources and has researched fish such as steelhead trout, tuna and seven-gilled sharks in the Pacific Northwest.

    He said that steelhead trout often navigate through the water with help from a sense of smell. Steelhead trout use their nostrils to pick up on chemicals from rocks that have dissolved in the water. The differences in the scents of the water help them know which river or stream to follow.

    Read Story
  • Why are people most commonly right-handed?

    We don’t know exactly why so many people are right-handed, but one place we might look for answers is in the material that makes a person who they are: genes.

    The genes in your body help control all sorts of things from the color of your hair to your skin to your eyes. These traits can be passed down through generations—from grandparents to parents to you.

    My friend John Hinz, who is a right-handed professor at Washington State University, knows a lot about genes and the study of how organisms pass their genes through generations.

    Read Story
  • How did people figure out how much a whole planet weighs?

    About 300 years ago during another pandemic, there was a person named Sir Isaac Newton who spent a lot of time at home thinking about the universe.

    He was thinking about how objects fall and started to wonder if the same force that made objects fall also kept the moon in its orbit. He called this force gravity.

    That’s what I found out from my friend Guy Worthey, an astronomer at Washington State University. Gravity plays a big part in the answer to your question, and we’ll explore that in just a moment.

    Read Story
  • How do horses sense how you feel?

    When I got your question, I called up my friend and veterinarian Dr. Macarena Sanz who had just finished checking up on the horses at the Washington State University Teaching Hospital. She was happy to help.

    “It’s a hard question to assess scientifically,” Sanz said. “But I think everybody who has worked with horses can tell you that horses really do have a certain sense about humans.”

    Read Story
  • Why do we get sunburns?

    Humans need sunlight to help keep their bones, blood and other body systems healthy, but too much time in the Sun can sometimes leave people with a sunburn.

    Sunburns often strike when the body gets too much of a type of light, called ultraviolet light, from the Sun. As your body recognizes there is too much ultraviolet light, it turns on a defense system.

    The immune system, which responds to invaders like viruses and other harmful things like ultraviolet light, kicks in. Some people might see their skin get red or blistered. They might feel itchy or painful. But not everyone experiences sunburn in quite the same way.

    A big part of the answer to your question also has to do with human cells. My friend Cynthia Cooper, a researcher at Washington State University, knows a lot about cells and how they work.

    Read Story
  • How did Saturn’s rings form?

    We still don’t know exactly how the rings around Saturn formed, but scientists who study Saturn’s rings have come up with a couple of ideas.

    One common theory many scientists agree upon is that Saturn’s rings are made from the little leftover pieces of what used to be a moon.

    My friend David Atkinson is really curious about the solar system and told me more about it. He is a graduate of Washington State University and now works at the NASA Jet Propulsion Laboratory. He also worked on the Cassini-Huygens space research mission which helped us learn more about Saturn, Saturn’s large moon Titan, and the entire Saturn system.

    Read Story
  • How do trees give us air to breathe?

    Our planet is home to all kinds of different plants, and they help make a lot of the oxygen we breathe. To find out how plants make oxygen, I asked my friend Balasaheb Sonawane.

    Sonawane is a scientist at Washington State University who researches photosynthesis, or the ways plants use energy from the sun and make oxygen. He said that in a way, plants breathe, too.

    “They don’t have a nose or mouth,” Sonawane said. “They have tiny microscopic organs on their leaves called stomata.”

    Read Story
  • Dr. Universe: How does toothpaste clean your teeth? -Lucy, 10, Pullman, WA

    Dear Lucy,

    If you are anything like me, every day you squeeze a little toothpaste onto your toothbrush and brush your teeth. Toothpaste gets its cleaning power from a few different ingredients.

    My friend Mark Leid was happy to tell us about how they work. Leid spent part of his career teaching future dentists. He is also dean of the Washington State University College of Pharmacy and Pharmaceutical Sciences.

    First, he told me the outer covering of a tooth is called enamel. It’s the hardest tissue in the whole human body—even harder than bone—and it helps with things like chewing your food.

    Read Story
  • Why do we get goosebumps?

    Dear Nolan,

    If you’ve ever been outside on a cold day, you may have noticed how your arm hairs stood up and you felt some goosebumps.

    Humans get goosebumps for different reasons and one of those reasons has to do with temperature.

    My friend Ryan Driskell, an assistant professor at Washington State University, is really curious about the innerworkings of skin.

    Read Story
  • How do touch screens work?

    Dear Nicholas,

    When I got your question, I decided to do a little experiment. First, I tapped my paw on a tablet and sent a message to a friend. Next, I put on a pair of wool mittens and started typing, but the screen did not respond. Finally, I used a banana to see if I could use it to swipe the screen. It actually worked.

    I wondered what exactly was going on here and decided to take our questions to my friend Praveen Sekhar. He’s an associate professor in the Washington State University School of Engineering and Computer Science.

    Sekhar told me our … » More …

    Read Story
  • Why do mirrors fog up when you breathe on them?

    Dear Zinnia,

    That’s a great observation. When you breathe out, you let a couple of different things into the air.

    Not only do you breathe out carbon dioxide, but you also breathe out teeny tiny droplets of water. These water droplets are so small we can’t see them with our eyes.

    Read Story
  • How do birds know where to migrate?

    Dear Jasmine,

    There are all kinds of different birds on our planet, and they migrate to different places.

    My friend Heather Watts, a researcher at Washington State University, is really curious about bird migration and told me more about how birds know where to go.

    Read Story
  • Why does oil on the street look like a rainbow?

    When it rains, sometimes we can see oil on the street rise to the top of puddles and spread out into a rainbow of colors.

    One of the main reasons we see color is because of light, said my friend Cigdem Capan, a physics instructor at Washington State University.

    She reminded me that when our eyes sense colors, we can trace those colors back to different wavelengths of light. Perhaps you can make some waves in the air with your hand. Make small, tight waves. Now make a big, wide waves.

    Read Story
  • How can you tell if a fish is female or male? Or if it is a kid or adult or teenager?

    Dear Hanaiah,

    There are more than 34,000 species of fish on our planet. It can be tricky to tell the age or sex of a fish, but biologists have come up with a few different ways to find out.

    My friend Paul Wheeler, a fish biologist at Washington State University, told me all about it.

    Read Story
  • Do flying squirrels really fly?

    Flying squirrels may not really fly, but they do have flaps of skin on their bodies that act like parachutes and help them glide through the air.

    My friend Todd Wilson told me all about it. He’s a wildlife biologist with the U.S. Forest Service in Oregon and graduate of Washington State University who researches Pacific Northwest ecosystems and the animals that call them home— including flying squirrels.

    Read Story
  • Why do cats and dogs spin around before they sit?

    Dear Antonio,

    That’s a great observation about cats and dogs. Even I wasn’t sure why cats spin around before they sit down, so I took your question to my friend Dr. Jessica Bell.

    She is a veterinarian at the Washington State University Veterinary Teaching Hospital and has seen quite a few cats and dogs walk in a little circle before they sit down.

    “It’s a common thing we observe as veterinarians, but we can’t talk to cats and dogs and ask them ‘why,’” she said. “From a behavioral standpoint, it probably stems back to their wild instinct.”

    Read Story
  • Why do some cheeses stink?

    When you take a whiff of stinky cheese, that smell is coming from one of its very important ingredients: microorganisms.

    Microorganisms are so small, you’d need a microscope to see them, but sometimes they give off a big stink. To find out more about stinky cheese, I talked to my friend Minto Michael.

    Michael is a professor of dairy science at Washington State University and told me microorganisms do a few different jobs to help make cheese.

    Read Story
  • Why does frost make shapes like flowers and ferns?

    Dear Grace,

    You’re right: frost can sometimes form patterns that look like the ferns or flowers we find in nature.

    Those frosty shapes we see on the surface of windows start out as water in the air, said my friend Kai Carter. Carter is a meteorologist with Washington State University’s AgWeatherNet team.

    Kai Carter, Field Meteorologist

    If you’ve ever had a glass of ice water, you may have noticed droplets formed on the outside of the glass. The droplets actually came from water in the air. This water condensed from the air onto the surface of your cup, which means it turned from a gas to a liquid.

    Read Story
  • Can a shadow make a shadow?

    Dear Aven,

    When we look around our world, we can find all kinds of shadows. One way we can explore the answer to your shadow question is with a little experiment.

    My friend Anya Rasmussen, a physics professor at Washington State University, told me all about it.

    First, you will need to cast your shadow on a wall. Rasmussen reminded me shadows form when an object—such as your body— blocks light and keeps the rays from reaching a surface—like a wall.

    Read Story
  • Why do we have seasons?

    Dear Bella,

    It turns out seasons can be quite different depending on where you live. But no matter where you live, the reason for the seasons has to do with the way the Earth rotates.

    To find out exactly why we have seasons, I talked to my friend Vivienne Baldassare, a physics and astronomy professor at Washington State University.

    Read Story
  • Why does water in ponds not get soaked up by the dirt at the bottom?

    That’s a great observation. If we investigated the bottom of a pond, we might find a few different things.

    Read Story
  • Dr. Universe, a grey cat with a lab coat, looking through binoculars How many black holes are in the universe?

    Dear Krisha,

    While we can’t see black holes with our eyes, astronomers have figured out how to spot these objects in our universe.

    One astronomer who is really curious about understanding black holes is my friend Sukanta Bose, a researcher at Washington State University.

    First, he told me there are different kinds of black holes. Supermassive black holes can be millions to billions of times the mass of the Sun. We have a supermassive black hole in our own Milky Way galaxy called Sagittarius A*, which is pronounced as Sagittarius A-star.

    Read Story
  • Illustration of smiling apples Why do trees have sap?

    Just as blood moves important stuff around the human body, sugary sap moves important things around a tree.

    My friend Nadia Valverdi told me all about it. She’s a researcher at Washington State University who studies how apple and cherry trees survive in different environments.

    When we eat food, like a delicious apple or a handful of cherries, we get important nutrients.

    Read Story
  • How does stained glass get its colors?

    Dear Emily,

    Ever since humans discovered they could use sand to make glass, they’ve been experimenting with it. They even learned how to control the colors.

    My friend Dustin Regul is a stained glass artist and painter who teaches fine arts at Washington State University. He told me more about where glass gets its color.

    “It’s actually metals that help change the color of the glass,” he said.

    Read Story
  • Why does the internet go down?

    The internet has helped many people connect with classmates, friends and family during the pandemic. But you’re right, sometimes the connection gets lost.

    My friend Dingwen Tao, an assistant professor of computer science at Washington State University, said we can think about the internet like a highway of information.

    You may remember from our question about how the internet works that information, like the data that makes up your favorite cat video or science website, travels through electronic signals we cannot see with our eyes.

    Read Story
  • How do you make cider?

    We can make cider with juice from apples. There are many different kinds of apples and a few different ways to squeeze out the juice.

    My friend Bri Valliere told me all about it. She’s a food scientist at Washington State University who knows a lot about cider.

    The first step is to pick out the apples. Honeycrisp apples will make a sweet cider. Granny Smiths are more acidic and will make a tart cider.

    “We could make a single batch of one kind, or we could mix different kinds of apples together and see how it turns out,” she said. “No matter what, it’s going to taste good.”

    Read Story
  • Why do mushrooms grow in rings?

    When you see a ring of mushrooms, it’s likely they are exploring for food under the ground.

    Giant mushrooms in your backyard are not animals or plants. They are part of another class of living organisms called fungi. But like you and me, they do need food to survive.

    That’s what I found out from my friend David Wheeler, an assistant professor at Washington State University, who knows a lot about fungi.

    He said the mushrooms are just one part of fungi. The other part that explores the soil for food actually lives under the soil.

    Read Story
  • How did the COVID-19 pandemic start?

    It turns out scientists around the world are investigating this very question.

    It’s likely the coronavirus that causes COVID-19, SARS-CoV-2, started in an animal before jumping to humans. But exactly how it all happened is still a kind of mystery.     

    That’s what I found out from my friend Michael Letko, a researcher at Washington State University who studies viruses and how they cross different species.

    Read Story
  • How does exercise help us? What is the best exercise?

    When we exercise, it helps the body and mind in so many different ways.

    One important muscle that benefits from exercise is the heart. Maybe you’ve felt your heart beat harder and faster when you run or climb at the playground.

    As the heart gets stronger, it also gets better at pumping blood around the body. That’s really important because your blood is full of oxygen you need to help fuel all your body’s systems.

    That’s what I found out from my friend Chris Connolly, an associate professor at Washington State University who knows a lot about the science of exercise.

    Read Story
  • Why do we get tears when we yawn?

    You’re right, a lot of people get tears when they yawn. When you yawn, you actually use lot of muscles in your face. Maybe you can feel the stretch in your jaw, cheeks and eyes.

    As the muscles in your face contract, they can put a lot of pressure on the plumbing system that is in charge of making your tears.

    That’s what I found out from my friend Karin Biggs, an adjunct professor at Washington State University who teaches anatomy.

    Read Story
  • Why do apes walk on their knuckles?

    Dear Sam,

    A lot of apes walk on their knuckles. Gorillas, chimpanzees and bonobos use their knuckles for stability and balance.

    That’s what I found out from my friend Nanda Grow, an anthropologist and wildlife biologist at Washington State University who studies primates.

    “Gorillas and chimpanzees both do knuckle walking, but they do different kinds,” she said.

    Read Story
  • Why do we get pins and needles when we don’t move for a long time?

    If you’ve ever had a leg or an arm “fall asleep,” the nerves in your brain and body were sending you an important message.

    That’s what I found out from my friend Darrell Jackson, a researcher at Washington State University who studies how drugs affect the nervous system.

    The nervous system is made up of bundles of nerve fibers that help humans think, feel and navigate the world. These nerves also help people sense things like temperature, vibrations, pressure and pain.

    Read Story
  • Why do garden spiders hang upside down in the middle of their webs?

    Dear Abree,

    That’s a great observation. Garden spiders and other orb-weaver spiders can crawl all around their webs, but we often see their heads pointing down toward the ground.  

    My friend Todd Murray, an entomologist at Washington State University, told me about a group of scientists that had a question a lot like the one you’ve asked.

    These scientists used mathematical models to learn about orb-weaver spiders and how they move around the web. They discovered spiders that wait with their head down for prey can reach prey faster than spiders that wait with head up for their prey.

    While there are exceptions, … » More …

    Read Story
  • Why is it effective to wear a face mask?

    Dear Marin,

    Whenever I go out and about, I make sure to wear my face mask. Like you, I wanted to find out exactly how they work.

    First, I talked to Marian Wilson, an assistant professor and nurse at Washington State University who is curious about how face masks protect people.

    “When we talk, sneeze, sing, or laugh, we spread droplets into the air all the time,” she said. “With the COVID-19 pandemic going on, we know people may have virus in their droplets.”

    Read Story
  • How are gummies made?

    Gummies can come in all different shapes and flavors. Maybe you’ve had gummy worms, gummy bears, or peach rings.

    It turns out that gummies require just a few simple ingredients. That’s what I found out from my friend Connie Remsberg, a pharmacist at Washington State University.

    She said making gummies requires a little gelatin, water, a mold, and some help from a grown-up.

    Read Story
  • Why do ants build hills?

    Ants build mounds in all shapes and sizes. Beneath those piles of dirt, ants are building their underground homes.
     
    That’s what I found out from my friend Rob Clark, an entomologist who studies bugs on plants. His job is to figure out if bugs make a plant sick or help the plant grow.
     
    He told me ants are one of the most diverse insect families. Scientists know about nearly 13,000 species—and each ant species makes a different kind of nest.

    Read Story
  • Do robots have their own language?

    Robots do have their own language—and yes, there’s a translator.

    That’s what I found out from my friend Manoj Karkee, an engineer at Washington State University who is also really curious about robots.

    Karkee and his team work on lots of robots that help farmers do important jobs. They can program robots to do different tasks such as pick apples or pull weeds.

    Read Story
  • How are coins made?

    In the United States, pennies, nickels, dimes, quarters, and other coins are made through the U.S. Mint. It turns out, they’ve been making a lot more coins than usual during the global pandemic. But more on that in a moment.

    It takes both science and art to make coins. Coins are made from metals that have been mixed together. We call these kinds of metals alloys. The very first coins in the world were made thousands of years ago in Turkey from electrum, an alloy of gold and silver. A penny is made from an alloy of copper and zinc.

    Read Story
  • Can dogs tell time?

    Dear Sam,

    Dogs might not use clocks to tell time like humans do, but they are pretty good at following a schedule. They often know when it is time for a walk, dinner, or sleep.

    Read Story
  • How many microbes are there in the world?

    There are lots of tiny living things on our planet that we call microbes. They live in the soil, water, air, your gut, and on your face. You’d probably need a microscope to see them.

    While we can’t exactly count all the microbes on the planet, we do know there are about a billion microbes in a teaspoon of soil.

    Read Story
  • Why do we need to eat and drink?

    Just like a car needs gas to run, food is the body’s fuel. Food gives us energy, or the power to do work. It helps us run, jump, think, and do all kinds of things.

    That’s what I found out from my friend Alice Ma, a dietician at Washington State University.

    When you take a bite of food it goes down your throat, or esophagus, and down into your stomach. In the stomach and small intestine, things like bile, acid, and enzymes help digest, or break down your food so your body can absorb the parts it needs.

    Read Story
  • What are bee wings made of?

    Dear Natalia,

    Bee wings may be small, but they are really strong. I learned all about bee wings from my friend Melanie Kirby, a honey bee researcher at Washington State University.

    Kirby said you can think about bee wings as if they were a kite. If you make a kite out of thin tissue, it might rip. But if you make it out of a strong plastic film it will be stronger.

    Bee wings are made of a material called chitin (KITE-IN) and it’s a lot like keratin, the material that makes up your fingernails. Chitin is what makes up the wings on each side of the bee’s body.

    Read Story
  • Can birds smell?

    Birds have nostrils, or nares, on their beaks that can help them smell all kinds of things.

    That’s what I found out from my friend Dave Oleyar, a scientist with HawkWatch who recently taught a course on ornithology at Washington State University.

    He said that when an animal breathes air, they can also breathe in different scents or combinations of molecules.

    The nose has receptors that pick up on scents and send information to the brain, including a part called an olfactory bulb. It’s all part of the olfactory system. You have an olfactory system, too. This system can help animals navigate the world through a sense of smell.

    Read Story
  • Why do birds make different sounds?

    That’s a great observation. Birds make all kinds of sounds and for lots of different reasons.

    When I got your question, I called up my friend Jessica Tir, a graduate student at Washington State University who studies songbirds.

    She said one of the main reasons a bird will make a loud sound is to attract a mate. When the birds find each other, they can make a nest for their eggs and wait for babies to hatch.

    Read Story

 

An important video message from Dr. Universe

 

Got Cat Mail?

Sign-up for the weekly e-newsletter to get the latest answers, activities, and videos!



Grown-ups can follow Ask Dr. Universe on

Twitter and Facebook