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Why do crickets make sound? – Carola, 7, Virginia

Dear Carola,

Have you ever read the book “The Very Quiet Cricket?” It’s about a young cricket who can’t chirp until he grows up.

My friend Rich Zack reminded me of that book when we talked about your question. He’s an insect scientist at Washington State University.

He told me only adult male crickets make sound. Sometimes they chirp to defend their territories. It’s how they tell other male crickets to stay away.

But the main reason they chirp is to find a mate. Cricket chirps are mating songs. That song will be different for different kinds of crickets—and the song changes when the female cricket shows up.

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I want to know how snake venom in the antidote makes sense? – Raagini, 10, New York

Dear Raagini,

One of my roommates is a corn snake named Buddy. He’s not venomous. But he’s a very private individual and really likes his space.

Buddy and I talked about your question with my friend Blair Perry. He’s a biologist at Washington State University. He’s an expert on snakes and venom.

Perry told me antivenom doesn’t contain actual snake venom. It’s made with antibodies to snake venom.

Antibodies are proteins. They’re part of your immune system. They travel in your blood to fight germs or dangerous molecules—like those in venom—that could hurt you. Sometimes we get vaccines to boost our antibodies so they’re ready when something harmful shows up.

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Do your eyeballs grow? – Ashlynn, 8, Utah

Dear Ashlynn,

I was the cutest kitten. I bet you were an adorable baby, too. Like me, you probably had a big, round head with chubby cheeks and huge eyes.

The fact babies have big eyes made some people think babies are born with adult-sized eyeballs. I talked about this with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

“It’s a very good question because there’s a lot of misinformation about it,” Johnson said. “Eyeballs do grow—but not very much compared with other parts of the body.”

He told me to … » More …

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Do insects have blood in their bodies? – Raman, 7, Washington

Dear Raman,

You probably don’t look like an insect. You don’t have feelers or wings. You keep your skeleton inside your body instead of on the outside. But what about blood? Do insects have blood like yours?

I talked about this with my friend Richard Zack. He’s an entomologist at Washington State University.

“Insects have hemolymph,” he said. “It’s very similar to blood.”

Zack told me hemolymph moves differently through the body, and it doesn’t do everything blood does.

Humans and other mammals have closed circulatory systems. That means their blood travels in blood vessels. A heart pumps the blood all over the … » More …

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How did our planet get to be the one with breathable air? – Jacob, 11, Idaho

Dear Jacob,

When I wake up from a cat nap, I stretch and take a deep breath. It feels good to fill my lungs with oxygen.

But that wasn’t always possible on Earth.

I talked about this with my friend Sean Long. He’s a geologist at Washington State University.

“The cool thing is the answer has to do with life,” Long said. “Early life forms on Earth gave us all the oxygen. They were single-celled bacteria.”

Our planet is about 4.5 billion years old. There’s been life on Earth for 3.5 billion years. The first life forms were made of just one cell. They were bacteria and their cousins called archaea.

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How do you tell if your betta fish is happy or depressed? – Neely, 10, Oregon

Dear Neely,

As a science cat, I handle going to the veterinarian better than most. I see it as a meeting of scientific minds. But I had no idea some veterinarians specialize in fish.

I learned all about fish medicine from my friend Nora Hickey. She’s a fish veterinarian at Washington State University. She works in the Washington Animal Disease Diagnostic Laboratory. She helps fish at zoos and hatcheries stay healthy.

Hickey told me you can watch a betta's behavior to see if it's happy. Happy bettas swim around. They interact with things in their tanks and act interested when you come close.

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What happens if you get sucked up by a black hole? – Amari, 10, North Carolina

Dear Amari,

I was fascinated by black holes as a kitten. I liked them because they were scary. But they’re also far away so I knew I was safe.

I talked about this with my friend Vivienne Baldassare. She’s an astronomer at Washington State University.

Baldassare told me a black hole is an area in space with lots of gravity. That’s the same force that pulls your body toward the Earth.

“If we want to send a spacecraft somewhere else in the solar system, it has to travel fast enough to escape the gravity of Earth—so the rocket doesn't just fall back down to Earth,” she said. “A black hole is a place where that escape speed is the speed of light. Nothing can move faster than the speed of light. So, nothing can escape from inside the black hole.”

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Are unicorns real? – Emma, 8, Minnesota

Dear Emma,

My favorite animated GIFs are the ones with cats riding unicorns. I’m delighted to tell you about a real unicorn that lived a long time ago: the Siberian unicorn.

The Siberian unicorn was bulky and furry. It had a big hump on its back. Its horn was three feet long. That’s as big as a human preschooler!

This real-life unicorn was a kind of rhino from Eurasia. But it was bigger than modern rhinos and probably galloped like a horse.

Scientists have known about Siberian unicorns since 1808. For a long time, they thought the unicorns went extinct 200,000 years ago. Recently, that changed. Now they think the unicorns went extinct closer to 39,000 years ago.

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How does evolution work? – Aubree, 10, Kentucky

Dear Aubree,

When I thought about evolution, I always pictured big changes that happened over long time periods—like how birds evolved from dinosaurs.

But then I talked with my friend Jeremiah Busch. He’s a biologist at Washington State University. He told me evolution is happening all the time.

“As soon as you see that evolution is occurring around us, it changes the way you think about the world,” Busch said.

There are a few ways evolution happens. These include mutation, gene flow, genetic drift and natural selection.

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Do ants hibernate in the winter? – Garrett, 10, Illinois

Dear Garrett,

When most people think about hibernation, they picture bears snoozing away the cold winter in their dens. You’re right that other animals do that, too.

I talked about your question with my friend Laurel Hansen. She’s an entomology professor at Washington State University. Her specialty is carpenter ants.

“We think most ants in our temperate climate will have diapausing larvae and what I would call overwintering adults,” Hansen said.

Diapausing and overwintering are like hibernating but not quite the same. There are a few things to know about ants to understand what these terms mean.

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How many beetles are there in the world? – Tu, 12, Utah

Dear Tu,

If beetles seem to be everywhere, that’s because they are. Some beetles stand out because they’re colorful. Think about jewel beetles and ladybugs. Others play useful and weird roles in the ecosystem—like the poop-rolling dung beetle. Their ancestors probably even ate dinosaur poop.

Nobody knows exactly how many beetles there are, but scientists have some ideas. I talked about it with my friend Joel Gardner. He’s the collection manager for the insect museum at Washington State University.

When scientists find a new species, they describe what it looks like. They give it a name. They publish that information so other people know about it. That’s called describing a species. Scientists describe new insect species all the time.

Gardner told me scientists have described about 400,000 species of beetles so far. There are many more beetles we don’t know about yet. Altogether, there are probably between 1 million and 2 million beetle species.

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What is the difference between B cells and T cells in the immune system? – Tanveer, 11, California

Dear Tanveer,

Everyone who heard your question agreed that it’s a sophisticated one. To get my paws around the answer, I talked with my friend Phil Mixter. He’s an immunology professor at Washington State University.

He told me all living things need to protect themselves from microbes that could make them sick. These are called pathogens. They can be bacteria, viruses, fungi or parasites.

“Almost every organism I can think of—from plants to animals and beyond—has a defense system to handle the possibility that another organism might sneak in,” Mixter said.

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Did dinosaurs eat humans? – Brileigh, 10, North Carolina

Dear Brileigh,

If you looked inside a T. rex mouth, you’d see some 12-inch teeth. That’s longer than my tail!

I asked my friend Aaron Blackwell if dinosaurs used those big chompers on humans. He’s an anthropologist who studies human biology at Washington State University. He told me dinosaurs and humans didn’t live at the same time.

“Dinosaurs died out 65 million years ago—before there were even primates,” Blackwell said. “So, they could never have eaten a human or even a monkey.”

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What if there were no predators to eat the birds? – Katy, 10, Hawaii

Dear Katy,

Don’t let the lab coat fool you. I enjoy chattering at birds as much as the next cat. Staring out the window and vibrating my mouth to “chirp” helps me relax after a long day.

My wild cousins do take things a bit further—namely, predation. It’s not pretty, but it’s an important part of keeping life in balance.

I talked about predators with my friend Travis King. He’s a Ph.D. student at Washington State University. He studies big cats like lynx and jaguars.

“It's a balancing act between predators, disease, food and space,” King said. “If you take away predators, you lose one of the factors keeping an ecosystem in balance.”

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Who invented games? – Kinzie, 6, Ohio

Dear Kinzie,

Board games, video games, a long piece of yarn… I love them all. I took a break from batting around a catnip-filled mouse toy to talk about your question with my friend, Washington State University professor Jordan Clapper, who told me the answer is a mystery.

“That's almost impossible to know—for some really fun reasons,” Clapper said. “Every culture has games. It even extends beyond being human. If you've ever seen a dog or a cat play, they're playing a game. “

The earliest board game we’ve found is more than 4,600 years old. Archaeologist Leonard Woolley dug it up in a tomb from Sumer (modern-day Iraq). That tomb was in the Royal Cemetery of Ur, so he named it the Royal Game of Ur.

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Celebrate Black History Month

February is a great time to celebrate Black scientists who changed the world—and those transforming science right now.

I talked about Black History Month with Amir Gilmore. He’s a professor and associate dean in the College of Education at Washington State University.

“There are so many things that Black people have created that we just don't think about,” he said. “So, when I think about Black History Month, it gives me joy that other people made these inventions. Where would we be without refrigerated trucks or stoplights? Where would we be without telephone technology? I'm thankful that Black people thought about what the world needed and provided those things.”

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Is it true that seven human years equals one dog year? – Cameren, 12, Kentucky

Dear Cameren,

Humans have kept dogs as pets for more than 14,000 years. That close friendship inspires scientists to explore questions like yours.

I talked about how dogs age with my friend Ryan Baumwart. He’s a heart doctor for dogs. He teaches in the veterinary hospital at Washington State University.

I asked Baumwart if a dog year is equal to seven human years.

“I think it's a good general rule,” he said. “But some larger breed dogs like bullmastiffs and Great Danes have a shorter lifespan of 6 to 8 years. So if you do the math, they get shorted. Then some small breed dogs like Chihuahuas seem to live forever.”

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How do animals teach their kids how to survive if animals can't talk? — Riley, 11, Texas

Dear Riley,

There’s really nothing cuter than baby animals. Many animal parents invest lots of time into caring for their young and teaching them to survive.

I talked about your question with my friend Amber Adams-Progar. She’s an animal sciences professor at Washington State University. She’s also an expert in dairy cow behavior. She told me that non-human animals learn in ways that are like how humans learn.

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If an animal has poison inside them, how are they not affected by their own poison? – Jad, 10, Georgia

Dear Jad,

From jellyfish to snakes to spiders, lots of animals use poison or venom. It helps them catch prey and defend themselves. Even the platypus and one very spicy primate called the slow loris use venom.

I talked about your question with my friend Blair Perry. He’s a biologist at Washington State University. He’s also a snake expert.

Perry told me the difference between poison and venom. They’re both toxic mixes of mostly proteins. But they get into your body in different ways. Poison is eaten, breathed in or absorbed through the skin. Venom is injected through a bite or sting.

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Why do you get acne? – Joey, 12, Illinois

Dear Joey,

Whether we call them pimples, spots or zits, acne is something most people experience. As many as 95% of people have some acne sometime. That’s nearly everybody.

I talked about acne with my friend Sarah Fincham. She has a clinical doctorate in nursing. She’s a nurse and a professor in the College of Nursing at Washington State University.

If you look at your skin, you’ll see tiny openings called pores. These pores connect to oil-producing glands under our skin. They’re called sebaceous glands, and the oil they make is called sebum.

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How is inflation caused? – Raymond, 12, California

Dear Raymond,

When I reached out to my friend Christopher Clarke with your question, he said, “That’s so cool that a kid is asking about inflation!” I agree.

Clarke is an economics professor at Washington State University. He told me inflation is the average rise in prices for goods and services.

So, what are goods and services? Let’s say you go to a restaurant and order enchiladas. The enchiladas are goods. You can see them, touch them and taste them. Services are the other parts of your dining experience. The people who take your order, cook your food and wash your dishes are all providing services.

The price you pay for goods and services changes over time.

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How long do you have to train to become a scientist? – Katelyn, Texas

Dear Katelyn,

Maybe you dream of pointing your telescope toward distant galaxies. Or zooming in on microscopic life on Earth. Being a scientist is an amazing job. You can also do science for fun—no matter your age or anything else about you. It belongs to everyone.

I talked about science training with my friend Kalli Stephens. She’s earning her bachelor’s degree in genetics and cell biology from Washington State University. WSU has a strong undergraduate research program. So, Stephens has been working as a scientist while going to school.

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Do animals have religion like humans? – Anna, 12, Hong Kong

Dear Anna,

When I read your question, I thought about elephants. There’s evidence that elephants have complex emotions—like grief when their relatives die or affection for humans who help them. Whales, dolphins, non-human primates and even dogs sometimes seem like they have complex emotions, too.

It makes us wonder if animals seek comfort and meaning the same ways humans do—like through religion. We truly don’t know the answer to your question. It’s something people have wondered about for a long time.

Exploring deep questions is the work of my friend Joe Campbell. He’s a philosopher at Washington State University.

We often think of religion as beliefs and behaviors. They relate to the supernatural—something beyond us and what we see in the natural world.

Campbell told me that underneath many religious beliefs and behaviors is a feeling: awe. It’s a proto-religious attitude. Proto means first.

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How do starfish eat? – Hailey, 7, Maryland

Dear Hailey,

Starfish might have the coolest—and strangest—way of gobbling up a snack.

I learned all about it from my friend Cori Kane. She studied coral reefs when she was a biology Ph.D. student at Washington State University. Now she works for the National Oceanic and Atmospheric Administration. She writes policies to help protect the ocean and the animals that live there.

“Sea stars are probably one of the weirdest creatures. I don't know any other organism that basically barfs out its stomach to eat,” Kane said.

Yes, you heard that right. She said sea stars barf out their stomachs.

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How do gems form underground? – Jett, 11, Kansas

Dear Jett,

When I was a kitten, I loved collecting rocks and gems. So, I was very excited to talk about your question with my friend Johannes Haemmerli. He studies minerals in the School of the Environment at Washington State University.

Minerals are solids that form from non-living elements in nature. They have a very specific structure for how those elements are arranged. Haemmerli told me that nearly all gems are minerals or sometimes mixtures of minerals.

You’re right that gems form underground. A diamond forms when the element carbon is buried nearly 100 miles deep inside the Earth. It’s super-hot and there’s tons of pressure down there. Eventually the pressure pushes the carbon atoms together to form the mineral we call diamond. Above ground, where there is much less pressure, the same carbon can come together and form a mineral we call graphite. That’s the “lead” of your pencil.

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Who invented books? – Nicole, 6, Washington

Dear Nicole,

Some people only like paper books. But I love the library app on my phone. It’s like having stacks of library books in my pocket.

To learn more about books, I talked with my friend Greg Matthews. He’s the rare books librarian at Washington State University. “The short answer would probably be the Romans,” Matthews said. “But Rome was a really vast empire. So, it could have been a Roman in North Spain. It could have been a Roman in Egypt.”

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What are microorganisms? –Trystan, 11, North Carolina

Dear Trystan,

One of my favorite things to do is look at pond water with a microscope. I love to see all the teeny tiny critters zooming around in a single drop.

I talked about microorganisms, also called microbes, with my friend Claire Burbick. She’s a microbiologist at Washington State University. She told me the key trait for microbes is size. Microbes are micro—which means extremely small.

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Do animals feel home-like in wildlife sanctuaries? – Haniya, 8, Pakistan

Dear Haniya,

There are lots of things that make a place feel like home. Your home is probably full of sights, sounds and smells that feel familiar and cozy. Those things are important for animals in captivity, too.

To find out more, I talked with Charles Robbins, a wildlife biologist at Washington State University. He started the WSU Bear Center. It’s the only grizzly bear research center in the United States.

“The most important thing to bears and probably most animals is a feeling of safety—that they’re not being hurt, and the food is good,” Robbins said. “Probably all the same things that … » More …

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When was the first bee made? – Henry, 7, Illinois

Dear Henry,

It’s easy to love bees. They’re furry and buzzy. Along with other insects, birds and bats, they pollinate about one-third of the plants we eat.

I talked about how long bees have been buzzing around Earth with my friend Silas Bossert. He’s an evolutionary biologist in the Department of Entomology at Washington State University.

“The oldest bee fossil that is really without doubt a bee is between 65 and 70 million years old,” Bossert said.

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How does the brain transfer signals to each body part to move? Yulissa, 11, Virginia

Dear Yulissa,

Your brain weighs less than 3 pounds but has the power to move your whole body. That’s because it’s part of your nervous system.

Your brain and the spinal cord that runs down your back make up your central nervous system. You also have a peripheral nervous system made up of nerve cells. These connect your brain and spinal cord to all the other parts of your body.

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How did life begin? Kelsey, 10, Texas

Dear Kelsey,

The universe is a big place. Thinking about how we fit into it is part of what makes humans (and cats like me) special.

I talked about your question with my friend Afshin Khan who studied astrobiology and environmental science at Washington State University. Astrobiologists explore how life began. They also look for signs of life outside Earth.

Khan told me your question is a huge mystery.

“We have very good ideas about what could have happened,” she said. “In different labs around the world, we’ve gotten very close to simulating some of those conditions. But simulations can only get so … » More …

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How does honey last forever? Gillian, 7, Illinois

Dear Gillian,

Archaeologists exploring ancient Egyptian tombs sometimes find honey. It’s thousands of years old, but you could still safely spread it on your toast!

I talked to my friend Brandon Hopkins, professor in the WSU department of entomology, about why honey lasts so long. He told me honey is one of the only foods that never spoils.

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How was the moon formed? - Barbara, 10, Texas

Dear Barbara,

Why do moon rocks taste better than Earth rocks? They’re a little meteor! In all seriousness, your question is something humans wondered about for a long time.

I talked to my friend Michael Allen, astronomy professor at WSU about how the moon formed. He told me we figured out the answer in 1972. That’s shortly after humans visited the moon for the first time.

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Dr. Universe: Why does the sky turn darker in winter? - Alex, 6, Cincinnati

Dear Alex,

As winter gets underway here in North America, you may notice we don’t feel the sun’s rays for quite as many hours as we did in fall and summer.

To find out why this happens, I talked with my friend Vivienne Baldassare, an astronomer at Washington State University.

She said the reason we get fewer hours of daylight in the winter has to do with how Earth rotates. As our planet goes around the sun, it is always rotating. This rotation is also why we have day and night.

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Dr. Universe: What’s the purpose of baking soda? What’s the purpose of baking powder? What’s the difference between the two? - Kyle, 9, Florida

When I got your question, I headed straight to my kitchen cabinet. I grabbed some baking soda and baking powder from the shelf and made some observations. Not only did the baking soda and baking powder look similar to one another but both contained an ingredient called sodium bicarbonate. Read More ...

Dr. Universe: What are cells made of? – Lela, 10, Bogart, GA

Dear Lela, You have all kinds of cells in your body that do lots of different things. In fact, there are about 200 different types of cells in the human body—from blood cells to skin cells to bone cells. To find out exactly what all those cells are made of, I visited my friend Deirdre Fahy. Fahy is a scientist at Washington State University who is curious about how and why things work, including our cells. She reminded me the human body is made up of billions of cells. You might think about each cell as if it were a tiny room. But this room, or cell, is so small, you’d likely need a microscope to see it. Read More ...

Dr. Universe: How do worms help protect the dirt? -Fisher, 7, Palouse, WA

Dear Fisher,

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 More ...

Why are people most commonly right-handed? Who/what deicides if we are left-handed or right-handed? Are you left-handed or right-handed? Mya, 8, Alexandria, VA

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 More ...

Dear Dr. Universe: How did people figure out how much a whole planet weighs? They could not have just put it on a scale! How did they do it? – Angel, 14, California

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 More ...

Dr. Universe: How do horses sense how you feel? –Taylor, 11, New Zealand

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 More ...

Dr. Universe: How were Saturn’s rings made? -Amelia, 9, Washington State

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 More ...

Dr. Universe: How do trees give us air to breathe? – Jamar, 11, Vineland, New Jersey

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 More ...

Dr. Universe: Do flying squirrels really fly? - Gwendolyn, 9

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 More ...

Dr. Universe: Why do dogs and cats spin around before they sit down? – Antonio, 10, Richmond, Va.

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 More ...

Dear Dr. Universe: Why do some cheeses stink? – Cody, 11

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 More ...

Dr. Universe: Can a shadow make a shadow? – Aven, 7, Palouse, WA

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 More ...

Dr. Universe: Why do we have seasons? -Bella, 9, North Carolina

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.

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Dr. Universe: How many black holes are in the galaxy and the universe? -Krisha, 9, New Jersey

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 More ...

Dr. Universe: Why does the internet go down? -Mia, 11, Sheridan, Wyoming

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 More ...

Dr. Universe: How do you make cider? -Julianna, 7

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 More ...

Dr. Universe: Why do mushrooms grow in rings? We have a lot of giant ones in our yard right now! - Layne, 8, Spokane 

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 More ...

Dear Dr. Universe: I heard a little bit about how COVID-19 started, but I don’t know much about it. What happened?  - Colleen, 10, Louisa, VA 

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 More ...

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 More ...

Dr. Universe: Why do apes walk on their knuckles? - Sam, 10, Benton, Arkansas

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 More ...

Dr. Universe: With the coronavirus why is it effective to wear a mask? How does it make life safer? - Marin, age 12, in Ohio

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 More ...

Dr. Universe: Why do we need to eat and drink? -Victoria, 7, MN

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 More ...

Dr. Universe: What are bees’ wings made of? -Natalia, 13, Kennewick, WA

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 More ...

Dear Dr. Universe: I am wondering if birds can smell because I have chickens and have seen their nostrils! –Lila, 9, Philadelphia, PA

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 More ...

Dr. Universe: Why does soap get bubbly? Samuel, 9, East Peoria, IL

When you wash your hands with soap and water, a few different things happen to make bubbles. Just like you, water and soap are made up of parts called molecules. Water molecules really like to stick together. If you’ve ever jumped in a puddle or a pool, you may have even observed how water splashes in the shape of little drops. As water sticks together, it likes to form spheres. Read More ...

How are vaccines made? - Sibagh, 7, New York City, NY

It might seem strange, but a small piece of something dangerous can protect you against something much more dangerous. This idea has been around for a long time—and it works. To learn more, I talked to Guy Palmer at Washington State University. As a scientist who studies infectious disease, Palmer likes learning about how to protect both human and animal health. Vaccines are one way to accomplish this. Read More ...

Dr. Universe: Why do we have spines? - Jessie, 10, Covina, Calif.

Dear Jessie,

Your spine is more than just a long line of bones. It’s the secret to jumping for joy, the base for all your best dance moves. Every time you run, climb, walk, and play, your spine is right there with you.

“Without a spine, our ability to move would be completely different,” Edward Johnson said.  Johnson teaches Human Anatomy in the School of Biological Sciences at Washington State University. He is very curious about how all the parts of your body work together.

All creatures with spines are called “vertebrates,” including humans. They get this name from their vertebrae: the special bones that make up the spine. Your vertebrae are different shapes and sizes, but they all connect together.

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Dr. Universe: What is inside a blade of grass and why is it green? Green is my favorite color. We really like reading your articles in our newspaper. – Luke, 5, Ogden, Utah

Dear Luke,

I’ve been wondering the same thing lately.  Every time I go on walks, I notice new splashes of color. Watching bugs in the grass, I pretend they’re crawling through a jungle. Everything is bright and bursting with green.

When I saw your question, I knew Michael Neff would know the answer. Green is his favorite color, too. (In fact, when we talked over video, he wore a green Hawaiian shirt.) Neff researches plants at Washington State University, and he is especially curious about grasses.

If you chopped a piece of grass and looked at it with your eyes alone, you might not see much. But if you looked at it under a microscope, you’d see tiny structures containing even tinier parts.

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How does the Internet actually work? I know you can type in most anything and it just pops up and all that, but how? - Eden, 8, Oregon

Dear Eden,

If you wrote me a physical letter, it would take a few days to reach me. You put the letter in your mailbox. A postal worker picks it up. Then it travels between different post offices on its journey from you to me.

But within seconds of you sending this question over the Internet, it was sitting in my inbox. How can this be?

The whole Internet works like the mail system—but much faster. That’s what I learned from Adam Hahn, an Assistant Professor of Computer Science at Washington State University.

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How do viruses form? Since the coronavirus has been all over the news, I've been wondering this question for a long time. - Samantha, 12, N.C.

Dear Samantha,

Viruses are strange things. They’re not alive like you or me. But they behave somewhat that way—spreading, growing, appearing in new forms. How can this be?

There’s a lot scientists don’t know yet about the new coronavirus. But they do know a lot about how viruses work and make people sick.

To learn more, I talked to Sylvia Omulo, a scientist specializing in infectious diseases at Washington State University.

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Dr. Universe: how do sleeping darts work? (e.g. for elephants) - Jonathan, 7, Pullman, Wash.

Dear Jonathan,

Some people get nervous when they go to the doctor. Maybe you’re one of them. You may not enjoy all of the visit, but you understand the doctor wants to help you. (And that a treat might await you at the end.)

But if an elephant gets sick, they can’t understand a doctor’s words. They may get confused and scared, until it’s too dangerous to help them.

That’s why sleeping darts—also known as tranquilizer darts—help so much.

“It’s safer for both the humans and the elephant because the humans aren’t right next to a wild animal, and the animal isn’t being chased to try to catch it,” Dr. Tamara Grubb said. She is a veterinarian at Washington State University who specializes in anesthesiology, drugs that make animals calm, sleepy, or unable to feel pain.

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Why do I like buffalo wings and not broccoli? - Joe, 10, New York City, NY

Dear Joe,

You’re not alone—cats don’t like broccoli much either. As a carnivore, I think a nice, meaty buffalo wing sounds great.

But humans are omnivores, meaning they eat both plants and meat. They’ve developed a taste for all kinds of things growing and living all over the world. So where do individual people’s preferences come from?

To find out, I visited Carolyn Ross, a professor of Food Science at Washington State University. Like you, she is very curious about why people like the foods they like.

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How do you make submarines? - Luke, 5, Western Washington

Dear Luke,

The next time you’re in the bathtub, turn a cup upside down on the water. Push down on it as hard as you can. See if you can get it to sink below the water.

It’ll be difficult to do! The air inside the cup makes it lighter than the water. But what happens if you turn the cup on its side, allowing water to rush in? You’ll see it’s easier to push underwater.

Those same basic forces make a submarine work.

That’s what I learned from Ian Richardson, an engineer at Washington State University. He is very curious about how liquids and solids interact. He has even helped NASA work on a submarine to someday go to Titan, one of Saturn’s moons.

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How was popcorn discovered? - Jalen, 12, Benson, N.C.

Dear Jalen,

There’s nothing like popcorn in progress: the snapping kernels, the warm buttery smell, and the knowledge that a delicious snack will be ready in minutes. It gives you some good time to think and wonder: how did humans first start doing this?

To find out where popcorn came from, I visited my friend Erin Thornton, an archaeologist at Washington State University. Archaeologists study how humans lived in the past—including the things they ate.

To learn the story of popcorn, we have to trace the history of maize.

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What is a sinkhole? What causes one? - Kathrine, 12, Calgary, Canada

Dear Kathrine,

Sinkholes can be scary to think about. They don’t happen too often, but when they do, they can take people by surprise. The solid ground disappears, and a hole suddenly appears.

It might seem like sinkholes appear out of nowhere. But they actually need specific conditions to form.

To have a sinkhole, you first must have a cave.

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How are seashells formed? And why are they different colors? Can seashells live or die? - Caroline, 9, Crestwood, Ky.

Dear Caroline,

Seashells come in an astounding variety. Some are curved and round, others long and tube-like. Some are smooth, others bumpy. Some are large, others small. Plus, they come in a rainbow of colors: red, green, brown, purple, pink, and more.

All that variety comes from the same source: little animals called mollusks, with a mighty muscle called a mantle.

I found out all about them from my friend Richelle Tanner, a scientist at Washington State University. She is very curious about the ocean and knows a lot about mollusks, a type of animal with a soft, moist body.

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Where does the universe end? - Oriah, 8, Pullman

Dear Oriah,

When you look up at the night sky, it can feel like the universe is a big blanket of stars above you. But unlike a blanket, the universe doesn’t have corners and edges. Far beyond what humans can see, the universe keeps going. As far as humans know, it never stops.

When I saw your question, I went straight to my friend Michael Allen to learn more. He is a Senior Instructor of Physics and Astronomy at Washington State University.

The universe is bigger than the biggest thing you’ve ever seen. It’s bigger than the biggest thing this cat can imagine. It’s so big that even your question has more than one very big answer.

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Why are bears called bears when they can be called anything else, not just a bear? - Natallia, 8, Yakima, Wash.

Dear Natallia,

You’ve noticed something very important: there’s no natural reason for the words humans use. Any sound could be used to describe a big mammal that eats berries and salmon.

But people who speak English choose “bear.” People who speak Spanish use “oso.” People who speak Maricopa say “maxwet.” They’re all different, but they’re all correct.

That’s what I learned from my friend Lynn Gordon, a linguist at Washington State University.

“Why do we call bears ‘bears’?” she said. “Because we’ve agreed to.”

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Dr. Universe: Why are brains mushy? – First Graders, Waller Road Elementary, Puyallup, Wash.

Dear First Graders,

You’re right, brains are quite mushy. It turns out the three-pound organ between your ears is mostly made up of water and fat.

I found out all about brains from my friend Jim Peters, a neuroscientist at Washington State University.

“It’s gooey. It really is squishy,” he said. “When it is warm, it is kind of like butter.”

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Dr. Universe: Do babies have ways of communicating? –Jalen, 12, North Carolina

Dear Jalen, Babies can communicate in a few different ways. For the most part, they use their emotions. Humans come into the world crying, but that’s actually a good thing. In a way, babies start communicating from the moment they are born. Of course, it can be hard for their caregivers to know exactly what they mean with all those cries. Read More ...

Dr. Universe: Why are evergreen trees green all year? – Emily, 10, Silverdale, Wash.

Whenever I go for a hike in the woods, I can’t help but admire the tall evergreen trees. No matter what time of year it is, the pines, hemlocks, cedars, and spruces are usually all green. My friend Bert Cregg is also very curious about the lives of trees. He graduated from Washington State University and is a professor at Michigan State University. Read More ...

Dear Dr. Universe: How do people name continents or places on earth? Thank you. - Lila Grace, 8, Virginia

Our world is full of so many different places. They get their names in lots of different ways. One way a place might get a name is from the person who explored it. The Americas are named after an Italian explorer, Amerigo Vespucci. But Amerigo wasn’t the first person to explore these continents. There were already people living there when he arrived. Still, “America” was named after Amerigo. For the most part, people name things because they are claiming possession of a place. Because of that, sometimes the original names of places are lost or erased. That’s what I found out from my friend Theresa Jordan, a history professor who teaches a geography course at Washington State University. Read More ...

Dr. Universe: If snakes smell with their tongues, what do they do with their noses? – A.J., 5, Kennewick, WA

You’re right, snakes have an amazing sense of smell. They can use their tongues to pick up on all kinds of scents in the air. Whenever we smell something in the air, we are actually sniffing tiny building blocks called molecules. These molecules are what make up the scents of everything around us—things like baked bread, fresh-cut grass, and warm cookies. If you were a snake, you might sniff out the scent of a slug or mouse. You’d use your tongue to pull the molecules from the air into your mouth. Read More ...

Dr. Universe: How did the first horse change into the horses of today? -Ava, 7, Kennewick, Wash.

We can learn a lot about animals of the past from fossils, the imprints or remains we find in rocks. One fossil found in the Bighorn Basin, Wyoming helped us learn about the oldest known horses. These horses are called Sifrhippus (siff-RIP-us). They had four toes on each foot and were very small. Believe it or not, these tiny horses weighed only about ten pounds. That’s just a bit heavier than your average house cat. According to the fossil records, Sifrhippus lived somewhere between 54 and 30 million years ago. When I went to visit my friend Lane Wallett, she told me all about the history of horses. As a veterinarian and a paleontologist at Washington State University, she is very curious about both horses and fossils. Read More ...

Dr. Universe: Why do people have different accents? Why do we have them and need them? -Florrie P., 9, UK

Whether you say hello, ‘ello, hey ya’ll, toe-may-toe or toe-ma-toe, we all have a kind of accent that often comes from where we live or who lives around us. That’s what I found out from my friend Nancy Bell, a Washington State University professor who is really curious about the way language works. She told me more about why we have accents and why we need them. There are a lot of different accents. You might have friends who speak English but have a Scottish, Irish, Australian, or French accent. Even in the U.S., there are many accents from the east to the west to the mid-west to the south. In those regions, people also speak many types of English such as Chicano English, African American English, or Indian English. Read More ...

Dr. Universe: Why are dogs important to humans? Stephani R., 9, Washington State

Dear Stephani, Dogs are important to humans in all kinds of ways. The connection between the two goes back thousands of years. A long time ago, wolves would trail along after humans on hunting trips and eat any scraps they could find. Eventually these wolves evolved into dogs that helped protect the hunters and gatherers. Read More ...

Dr. Universe: What are shooting stars made of? – Erin, 11, Arkansas

If you are anything like me, you probably like watching for shooting stars in the night sky. A shooting star, or a meteor, is usually a small rock that falls into Earth’s atmosphere. When I went to visit my friend Michael Allen, a senior instructor of astronomy and physics at Washington State University, he told me a lot of shooting stars are no bigger than a pencil eraser. Read More ...

Dr. Universe: What’s the best story ever made in the world? – Jada, 13, New Jersey

Humans have been telling stories for thousands of years. At first, they told these stories out loud, then they started to write. There are more than a hundred million published books on our planet now and to find out which one is best, I visited my friend Matthew Jockers. He’s a professor at Washington State University who combines his love of stories with computer science to research what makes some books bestsellers. Read More ...

Dr. Universe: Back when cell phones weren’t a thing, how could you place a call from across the ocean? Were there wires under the ocean? -Tali, 9, Seattle, Wash.

Long before telephones, if you wanted to say “hi” to friend across the ocean you’d probably write them a letter and send it over on a ship. But in the last hundred years or so, we’ve been able to connect across the ocean much faster. And yes, it often required thousands of miles of wires, or cables, deep in the sea. That’s what I found out from my friend Bob Olsen, a professor of electrical engineering at Washington State University, who told me all about the telephone. Read More ...

Dr. Universe: What can I do to help stop ocean pollution? -Hailey, 10

It’s great to hear you want to help our oceans. After all, they do a lot for us. Life in the ocean provides much of the oxygen we breathe and is also a source of food for many animals, including humans. One of the most important things we can do to prevent more pollution is to keep our garbage, especially plastic, out of the ocean. That’s what I found out from my friend Richelle Tanner, a marine biologist and researcher at Washington State University. While a lot of plastic ends up in the ocean, it actually started under the Earth’s surface in the form of oil, leftovers of plants and animals that died long ago. Read More ...

Dr. Universe: How many peas would fit in the sun? -Keegan, 8

Our sun is so massive, you could fit more than one million earths inside of it. To find out how many peas would fit inside the biggest object in our solar system, I decided to ask my friend and mathematician Kimberly Vincent at Washington State University. Vincent and her students said that to figure out how much of something can fit inside the sun, we need to know the volume of the sun. The volume is how much space something takes up. Read More ...

Dr. Universe: Why do gadgets need batteries? How do they work? -Shereen and Jasmine, 8, Florida

Dear Shereen and Jasmine, Batteries can power up all kinds of gadgets. To find out how batteries work, I decided to visit my friend and materials engineer Min-Kyu Song. He makes batteries in his lab at Washington State University. As you might know, materials are made up of atoms—and atoms have tiny parts called electrons. If you’ve ever felt a spark when you touched a doorknob, you’ve felt electrons making the jump from your body to the door. Read More ...

Dr. Universe: Why do we get morning breath? -Stephanie, 10

Dear Stephanie, If you’ve ever caught a whiff of someone’s stinky morning breath, or even your own, you know it can be pretty rotten. We can trace the smell back to tiny culprits that live in our mouths. They are called microbes and they live around your gums, between your teeth, and on your tongue. Read More ...

How do volcanoes erupt? –Miles, 10, Tampa, FL

Wherever we find a volcano on the surface of our planet, we can find the source of an eruption beneath it. That’s what I found out from my friend John Wolff, a volcanologist at Washington State University. Our planet is home to all kinds of volcanoes that erupt in different ways. Some eruptions are quiet and continuous, with a slow flow of lava. Other volcanoes erupt explosively and can spew ash and lava hundreds of feet up into the sky. All of this lava has its start underground in the form of something called magma. Wolff said that scientists used to think there were large pools of hot liquid beneath volcanoes. Now we know it isn’t quite that simple. Magma is not really a liquid, but rather a kind of sludge or slurry. It helps to think of it kind of like honey. 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 ...

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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