Why are human babies so helpless compared to other mammals? — Ruby, 10, Florida
melissamayer
Walking upright reshaped the pelvis. Humans adapted by giving birth earlier, when the baby’s head is smaller. Read More ...
Ask Dr. Universe
Body and Brain
Why are giraffes’ tongues purple? — Winona, 6, Wisconsin
melissamayerDear Winona,
When I was a kitten, I visited a drive through zoo. A giraffe slithered its long, purple tongue through the open car window and licked my face.
It was awesome.
It turns out dark colors come from a pigment called melanin. That melanin makes a giraffe’s tongue purple, blue or black.
I asked my friend Cynthia Cooper about melanin. She studies pigments—the colorful stuff in animal cells—at Washington State University.
She told me melanin is also why human skin gets darker from being in the sun.
» More …
What determines the size and shape of someone’s belly button? – Isana, 16, Washinton state
melissamayerDear Isana,
My belly button is a subtle scar on my tummy. It’s covered by fluffy cat fur—and it’s not easy to see. But humans have obvious belly buttons. They come in different sizes and shapes.
I asked my friend Cindy Brigham-Althoff about that. She’s a nurse midwife and professor at Washington State University. She teaches student nurses about birth.
She told me the scientific name for a belly button is umbilicus. It’s what’s left of your umbilical cord.
Before you were born, a temporary organ called the placenta grew next to you. A cord connected the placenta to a spot in the … » More …
Read More ...Can humans live in space for a month? – Maya, 11, Seattle
melissamayerDear Maya,
I mostly keep all four paws on the ground. It’s hard to imagine living out in space.
I asked my friend Erica Crespi about it. She’s a biologist at Washington State University. She studies how animals tolerate stressors faced in the environment—including how humans can live and thrive in space.
Crespi told me that Valeri Vladimirovich Polyakov lived on the Mir Space Station for 437 days and 18 hours in the 1990s. So far, that’s the record for living in space.
Polyakov’s job was to test the effects of a long space flight—like maybe a trip to Mars. He handled … » More …
Read More ...Why do some humans like to do bad things? Is it the thrill or were they always born bad? – Leonel, 14, Texas
melissamayerDear Leonel,
I’ve met some naughty cats. I’ve also known some misunderstood ones.
I asked my friend Chris Barry why humans are sometimes like that, too. He’s a psychologist at Washington State University.
He told me we’re talking about behaviors that don’t align with social norms. They give most people bad feelings. That’s like feeling uncomfortable when someone does something violent or mean.
Sometimes those behaviors come from the person’s nature, or temperament. Sometimes they happen because the person enjoys taking risks. Or maybe they struggle to think before they act.
It could be all those things, even within the same person. Plus, temperament, … » More …
Read More ...Why does my tummy rumble when I’m hungry? – Jules 5, Maine
melissamayerDear Jules,
Sometimes my stomach growls so loudly that other people can hear it. It’s pretty awkward in meetings.
I asked my friend Ed Johnson why that happens. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
He told me the rumbling noise happens because of what’s going on inside your gut.
“The sounds you hear are the fluid and gas that’s in your digestive tract moving around,” Johnson said.
The digestive system cycles through a lot of fluid—about 9 liters every single day. That’s the same as four-and-a-half 2-liter soda bottles.
Some of that liquid comes … » More …
Read More ...Why do we age? – Ines, 17, Tunisia
melissamayerDear Ines,
I have gray fur. But sometimes I think it’s getting grayer—like my human friends’ hair does as they get older.
I asked my friend Jiyue Zhu about that. He’s a biochemist at Washington State University.
He told me it’s a mystery.
“We still don’t completely comprehend this,” Zhu said. “It’s an active area of research.”
Aging seems to be related to the way cells duplicate.
DNA is a set of instructions for making your body. You keep a copy of your DNA folded up inside each of your cells.
All those cells have different life spans. Some, like your skin cells, … » More …
Read More ...How does epinephrine work? – Annabelle, 15, Missouri
melissamayerDear Annabelle,
I love a peanut butter and tuna sandwich. But when I was a kitten, my school outlawed peanuts. My classmate was super allergic to them. So, we had a rule to keep our friend safe. I packed plain tuna fish instead.
I talked about that with my friend Travis T. Denton. He studies medicinal chemistry and neuroscience at Washington State University.
He told me that epinephrine is the medicine people use for a serious allergic reaction called anaphylaxis. It comes in an auto-injector, or EpiPen.
» More …
Why do we have germs on our hands? – Prince, 12, Georgia
melissamayerDear Prince,
Germs are tiny organisms—also called microbes. They’re so small you have to zoom in with a microscope to see them. They can be bacteria, viruses, fungi or other teeny things. Some microbes make us sick. Some don’t bother us at all. Some help us out.
I talked about all that with my friend Eric Lofgren. He studies infectious disease at Washington State University.
He said there are two main reasons we have germs on our skin. We pick up some microbes from the environment. Some live on our skin all the time.
“The world is full of microbes,” Lofgren said. “They’re very … » More …
Read More ...I would really like to make a better way to get a shot that doesn't hurt so much. – Jacob, 10, Cayman Islands
melissamayerDear Jacob,
I love vaccines. They keep us safe from germs that can make us sick. But I don’t love how much shots hurt. Sometimes I feel anxious before I visit the veterinarian for a vaccine.
I talked about that with my friend Roland Chen. He’s an engineer at Washington State University.
He’s working on brand-new needles that could make shots painless. They’re called microneedle arrays.
“You feel pain because the needle reaches the pain receptor,” Chen said. “Microneedles are much shorter than typical needles. They’re about one-third to half the size.”
Most vaccines are intramuscular injections. A trained healthcare provider gently slides … » More …
Read More ...Do video games rot your brain? – Joie, 10, Texas
melissamayerDear Joie,
After answering science questions all day, I like to play Mario. It’s relaxing to smash Goombas and zoom down pipes.
I asked my friend Dene Grigar if that’s wrecking my brain. She leads the Digital Technology and Culture program at Washington State University Vancouver.
She told me that sometimes people dismiss new things by calling them harmful.
That often happens with new technology or media. People reacted that way to railroads, telephones, cameras and television. People even freaked out about books. For a long time, books were hard to come by, and regular people couldn’t read. When that changed, folks worried about … » More …
Read More ...What is the likelihood that all your lysosomes could burst at the same time? Would you spontaneously dissolve? – Annika, 12, Pennsylvania
melissamayerDear Annika,
I’d love to read a creepy science fiction story where people dissolve.
I asked my friend Anders Omsland if that could happen. He’s a biomedical researcher at Washington State University.
He told me a lysosome is a specialized compartment in a cell. It’s like a little sack of digestive enzymes. Those are proteins that break stuff down. Our cells use lysosomes to help destroy germs or recycle old or messed up cell parts.
Lysosomes are basically the cell’s trash and recycling centers.
“I don’t think it’s possible for lysosomes to all pop at the same time,” Omsland said. “They don’t really explode … » More …
Read More ...Why do we lose our hearing when we get older? – David, 10, Wisconsin
melissamayerDear David,
I love visiting with my grandcat. But sometimes I have to talk loudly so she can hear me.
I asked my friend Christine Portfors why that is. She’s a biologist at Washington State University.
She told me it’s all about the hair cells inside our ears.
They aren’t really hairs. They’re sensory cells. Hair cells have tiny, bristle-like tufts that stick out—called cilia—that look a little bit like hairs.
Those hair cells are why we can hear.
First, sounds funnel into our ears. They bonk into the ear drum and make it vibrate. Then, three itty, bitty bones make those … » More …
Read More ...What’s the reason people are grumpy? – Braelyn, 13, Oklahoma
melissamayerDear Braelyn,
Everyone feels grumpy sometimes—even a cheerful cat like me.
Sometimes exhaustion makes us crabby. When we really need sleep, our brains struggle to do their jobs—like managing our emotions. Sometimes hunger makes us cranky. Our brains need a steady supply of sugar energy. When the available sugar drops too low, we feel terrible—or even hangry. Sometimes stress or problems like anxiety and depression make us grumpy.
In all those scenarios, anger lets us know we need to change something. We need to sleep, eat or get some help with our problems.
I asked my friend Anthony Lopez why we feel anger … » More …
Read More ...What are protons made of? – Dean, 11, Utah
melissamayerDear Dean,
There’s a pencil lying on my desk right now. It’s not much to look at, but what if I could zoom way in and see the protons and other itty-bitty stuff inside it?
My friend Ryan Corbin told me it would be like looking at a bubbling soup of fundamental particles. He’s a quantum physicist at Washington State University.
He told me that protons—along with neutrons—form the nucleus in the middle of an atom.
“Atoms make up all the stuff that we see,” Corbin said. “An atom has neutrons and protons in its nucleus. Protons have a positive electric charge. Neutrons … » More …
Read More ...How do sedatives work (like for endoscopy)? – Zara, 11, Colorado
melissamayerDear Zara,
I love visiting the vet. But, like many cats, sometimes I need medicine to keep me calm.
I talked about that with my friend Lais Malavasi. She’s a veterinarian at Washington State University.
She told me about two kinds of calming medicine. Vets and human doctors use them to reduce pain and fear.
Sedatives make patients feel relaxed and sleepy. But they’re mostly aware of what’s going on. When the medicine wears off, they’ll probably have fuzzy memories.
Anesthesia makes patients unconscious. They can’t feel pain or move. They aren’t aware of what’s going on. When they wake up, they won’t … » More …
Read More ...Why do we have two intestines? – Dru, 11, Illinois
melissamayerDear Dru,
When it comes to intestines, it sure seems like two are better than one.
I asked my friend Franck Carbonero why that is. He’s a microbiologist at Washington State University. He studies the bacteria that live inside the human gut.
He told me that the small intestine and the large intestine do different jobs.
Let’s say you sink your teeth into some pizza. You chew it up and swallow it. All those chewed up bits land in your stomach. They mix with digestive juices and start to break down. The broken-down food and digestive juices together are called chyme. After … » More …
Read More ...What happens when you get your wisdom teeth removed? – Lucy, 9, Rhode Island
melissamayerDear Lucy,
Cats like me don’t have wisdom teeth. So, imagine my surprise to learn some of my human buddies get extra chompers.
I asked my friend David Carsten about it. He studied biochemistry at Washington State University. Now he’s a dentist who teaches about dental sedation and anesthesia at Oregon Health & Science University.
Dr. Carsten told me that humans can get three sets of permanent molars. Molars are the big grinding teeth in the back of your mouth. The third set—also called wisdom teeth—usually come in when you’re between 17 and 21 years old. If you get them at all.
Wisdom … » More …
Read More ...Insects are scary to me. Should I be afraid of bugs? Can you help me not be afraid please? – Devyn, 6, Ohio
melissamayerDear Devyn,
I love insects, but—between you and me—I’m a little scared of spiders. I’ve been nervous around them ever since I was a kitten.
I talked about our fears with my friend Paul Strand. He’s a psychologist at Washington State University.
He told me that anxiety about insects or spiders is common. Some people even have phobias of them. That’s an intense fear that causes distress.
Many common fears involve things that were probably dangerous to our ancestors—like snakes, the dark, heights and social rejection.
Strand told me that being afraid of insects is similar.
“It’s almost like a double whammy,” he said. … » More …
Read More ...Why do people have allergies? – Hailey, 11, Washington state
melissamayerDear Hailey,
Under my lab coat, I have a splendid fur coat. That can be a problem when I work with someone who’s allergic to cats.
I asked my friend Ed Johnson about it. He teaches classes about the human body at Washington State University.
He told me that allergies happen when your immune system overreacts to a normal thing it perceives as a threat to your body. That thing can be pollen, dust, food, medicine, insect venom or something else. It can be bits of fur and shed skin called cat dander.
“The immune system evolved to protect the body,” Johnson said. … » More …
Read More ...Why is snot green? – William, 7, United Kingdom
melissamayerDear William,
There are lots of unpleasant things about being sick. Leaking slimy green snot is near the top of my yuck list.
I talked about it with my friend Linda Eddy. She’s a nurse for kids. She runs the nursing program on the Vancouver campus of Washington State University.
She told me that snot is normally clear. It turns yellow or green when our bodies fight germs that can make us sick.
Snot is also called mucus. It’s a thin, slippery liquid that covers many of the surfaces inside our bodies. You can find mucus in your nose, mouth and eyes. It … » More …
Read More ...How do glasses work? – Prisha, 8, Pennsylvania
melissamayerDear Prisha,
I got glasses as a kitten. I put on my new spectacles and was floored by the crisp details. I had no idea you could see individual leaves on trees. I thought everyone saw a green blur.
I talked about that with my friend Dr. Rachna Narula. She’s an eye doctor—called an optometrist—at Washington State University.
She told me that glasses help direct light to the correct spot in the eye so we can see.
“If someone's eyeball is too short or too long, glasses help focus the image on the retina because that’s where the person can see,” Narula said.
Read More ...What happens to the pill capsules after you swallow the pill? – Avery, 11, Illinois
melissamayerDear Avery,
I think it’s really cool when a clear pill has teeny tiny balls of medication inside it. My paws itch to bat it around—but I know medicine isn’t a toy, so I sharpen my claws on my desk and then get back to answering your questions.
I asked my friend Damianne Brand-Eubanks what happens after you swallow one of those capsules. She teaches in the College of Pharmacy and Pharmaceutical Sciences at Washington State University. She’s an expert on medication.
She told me that the outside of a pill capsule is usually made of gelatin. That’s the same stuff that’s in jello or gummy candy.
“Just like with food, you swallow the pill, and it goes down the esophagus into the stomach, where there's a whole bunch of acid,” Brand-Eubanks said. “That acid breaks down the gelatin capsule.”
Read More ...Why are heart attacks so dangerous? – Jack, 8, England
melissamayerDear Jack,
When I go to the veterinarian for a checkup, one of the first things they do is listen to my heart. They want to make sure it’s healthy because it pumps blood to my whole body.
I asked my friend Zhaokang Cheng about heart attacks. He’s a scientist at Washington State University. He works on new medicines to help people who have heart attacks or heart disease.
He told me that a heart attack happens when a big blood vessel that delivers blood to the heart gets blocked. Those blood vessels are called coronary arteries.
They get blocked when fatty gunk and other stuff build up on the walls of the arteries. Over time, the buildup can get thicker and harder. It can make the space inside the artery very narrow, so there isn’t much room for blood to get through. Or it can block the artery completely.
Read More ...What happens if we drink too much water? – Joseph, 7, United Kingdom
melissamayerDear Joseph,
As an early-rising science cat, I always lap up a bowl of coffee in the morning. After that, I drink fresh water from a cat fountain I keep near my desk.
But what if I drink too much of that thirst-quenching liquid?
I asked my friend Karen Anders if that can happen. She teaches nursing at Washington State University.
She told me that drinking too much water can cause a rare condition called water intoxication.
It’s rare because it doesn’t happen very often. Even if you guzzle lots of water, your kidneys can probably process it. You might feel sloshy and waterlogged. You might throw up, but then you’d just pee the excess water out of your body.
Read More ...Why do we get fidgety when we're bored? I have ADHD, and a lot of other people in my school do, too, so I’ve always wondered this. – Amelia, 11, Utah
melissamayerDear Amelia,
Sometimes when I’m in a boring meeting, my tail starts twitching. Or I gently rock my office chair.
I asked my friend Amanda Stueber why that helps me. She’s a psychologist at Washington State University. One thing she studies is attention-deficit hyperactivity disorder (ADHD).
She told me that boredom happens when you have less stimulation. That means you don’t have much information coming in from your senses. Like what you see, hear, smell, taste and feel.
When there's no new or interesting info coming in, you start to feel bored and tired. The less stimulation you have, the sleepier you get.
But you can’t just fall asleep wherever you are! So you might play with your hands, bounce your legs or shift your whole body. You may doodle, click your pen or twirl your hair.
That’s your body’s way to keep you awake.
Read More ...What is cancer? – Austin, 9, New York
melissamayerDear Austin,
I love a predictable schedule. Knowing when to eat, sleep and answer your questions keeps me chill.
That how the cells that make up our bodies work, too. They grow and die on a predictable schedule. Our bodies constantly make new cells to replace the ones that die. They grow for a set time and then die, too.
But sometimes cells grow out of control. They may grow faster or for a longer time than normal cells. They ignore the signals that tell a cell it’s time to die. They can even spread to other parts of the body and start growing there. That’s cancer.
Read More ...Why can’t we tickle ourselves? – Malcolm, 3, Washington
melissamayerDear Malcolm,
I was surprised the first time I saw a human transform into a tickle monster. They curled up their fingers and rhythmically poked someone else’s armpits. That is something a cat would never do.
I asked my friend John Wright about it. He’s a retired psychology professor at Washington State University.
I learned that there are two kinds of tickling.
The first is the light tickle you feel when someone gently brushes your skin. Like when someone uses a feather to barely touch the inside of your arm. Scientists call that knismesis.
It turns out you can totally tickle yourself that way. But the feeling will be much more tickly if someone else does it.
Read More ...What makes pee so bad that I have to get rid of it? – Jeff, 14, Michigan
melissamayerDear Jeff,
The worst thing about being an anthropomorphic cat is that I have to scoop my own litter box. It’s a real drag.
I asked my friend Henry Mroch why we need to pee in the first place. He’s a doctor at Washington State University. He teaches medical students about the organs that make urine—called kidneys.
He told me that most people have two kidneys. Each one is about the size of your fist. They sit near your back, right under your ribcage.
Each kidney attaches to a tube called a ureter. Those tubes take urine to a storage pouch—called the bladder. When you pee, another tube called the urethra moves the urine from the bladder out of your body.
Read More ...How do we get muscles? – Jalane, 10, Ohio
melissamayerDear Jalane,
I’ve always been a bookish cat. I spend most of my time in the lab rather than running, prowling and pouncing like most felines.
But I still have super strong muscles. They’re way bigger than when I was a kitten.
I asked my friend Edward Johnson how I got so buff. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
He told me that muscles are made of muscle cells. They’re also called muscle fibers or myocytes.
We usually think cells are way too small to see with our eyes. But muscle cells can be some of the longest cells in your body. They’re shaped like long tubes or hot dogs. Each muscle cell is as long as the muscle it’s part of. So a muscle cell in a grownup’s thigh muscle could be 14 inches long!
Read More ...How does sunscreen work? – Seth, 6, Virginia
melissamayerDear Seth,
Since I’m a fluffy cat, my fur protects me from the sun. But my hairless cat and human friends use sunscreen when they go outside.
I asked my friend Michael Smerdon how it works. He’s a biochemist at Washington State University.
He told me that the sun puts out different kinds of light. Some light is visible to humans. Some is invisible—like UV light.
Read More ...What is the human brain made out of? – Trevor, 9, Illinois
melissamayerDear Trevor,
Everything we do and think is thanks to the 3-pound organ tucked into our skulls. But what is it made of?
I asked my friend Samantha Gizerian. She’s a brain scientist at Washington State University.
She told me the brain is surprisingly soft and mushy.
“We think about our other organs and tissues, and they’re squishy in a very solid way,” Gizerian said. “Like when you go to the grocery store and get a carton of meat. You can squish on the steak, right? Our other organs are mostly like that as well. But the brain is very, very delicate.”
She told me it’s more like the ground up burger people use to make meatballs. Or like soft tofu or a Jello square.
The brain is extra soft because it’s about 60% fat.
Read More ...Why do people get voice cracks? – Jade, 12, Montana
melissamayerDear Jade,
Have you ever heard cats yowling? It’s expressive, that’s for sure. Sometimes when I yowl or sing, my voice cracks a little bit.
I asked my friend Alisa Toy why that happens. She’s a professional singer who teaches in the School of Music at Washington State University.
She told me it has to do with the muscles that move the larynx. That’s sometimes called the voice box. It’s a hollow tube that’s important for breathing and talking.
When you talk or sing, you push air from your lungs up through your larynx. The air passes through an opening made by your vocal folds. Those are incredibly thin tissues in the middle of your larynx. They vibrate as the air whooshes past them. That vibration makes the sound that becomes your voice.
Read More ...Why do we need to hydrate? – Victor, 9, Ohio
melissamayerDear Victor,
Is there anything better than lapping up cool water on a hot day?
I talked about why we need to hydrate with my friend Ed Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
It turns out that up to 60% of an adult human’s body is water. A kid’s body contains even more water than a grown up. When you were a baby, you were about 78% water.
Humans use that water for all kinds of things. It keeps you cool when you sweat. It removes waste when you pee. It moves important stuff around inside your body. It even cushions your brain and spinal cord.
But staying hydrated is really about your cells.
Read More ...How does your voice make sound? – Bianca, 6, California
melissamayerDear Bianca,
Think about all the ways you use your voice: talking, singing, whispering, shouting, yodeling. Humans make so many sounds with just their voices.
I talked about how it works with Alisa Toy. She’s a professional singer who teaches in the School of Music at Washington State University.
She told me that the human voice is the smallest instrument in the world. The parts that make the sound—called the vocal folds or vocal cords—are about as long as your thumbnail.
So, where are those tiny vocal folds and how do they do it?
Inside your throat you have two tubes. The esophagus … » More …
Read More ...Why do we have nose hairs? – James and Zion, 10, Virginia
melissamayerDear James and Zion,
Despite being a curious science cat, I must confess I haven’t spent much time looking up human noses. But I have noticed that human nostrils can be a bit…furry.
I talked about what’s inside your nose with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
He told me that nose hairs only grow in your nose’s vestibule. That’s the inside of the part of your nostrils that you can flare out. The nose hair’s job is to filter the air you breathe in through your nose.
Read More ...Why do we change our minds? – Stella, 10, Tennessee
melissamayerDear Stella,
As a science cat, I’ve changed my mind a lot over the years. I used to wear a fancy neck scarf called a cravat all the time. Now I’m comfy in my lab coat.
I talked about that with my friend Makita White. She’s a graduate student in the psychology department at Washington State University.
She told me that we change our minds when we get new information or insight that tells us we need to make a different choice.
It turns out that we have lots of opinions and beliefs. They’re also called attitudes. We have attitudes about what we like to eat or wear. We have attitudes about other people and how the world should be.
White told me that having attitudes helps us out.
Read More ...Do babies open their eyes when they are in their mom's tummy? – Neela, 6, Washington state
melissamayerDear Neela,
My litter mates and I were born with our eyes closed. It takes a week or more for newborn kittens to open their eyes and see the world. But newborn humans can open their eyes and look around right away.
I talked about your question with my friend Cindy Brigham-Althoff. She’s a nurse midwife and professor at Washington State University.
She told me that whether unborn babies can open their eyes depends on their fetal age, or how close they are to being born.
Most babies are ready to be born after about 38 weeks of growing and developing. (Or 40 … » More …
Read More ...Why does milk cure the spicy feeling in your mouth after you eat something spicy but water doesn't? – Eloise, 10, Minnesota
melissamayerDear Eloise,
My work as a science cat has introduced me to human foods—like chips and salsa. I love the spicy taste of salsa, but I always keep a saucer of milk handy.
I talked about why milk calms the spicy feeling with my friend Emily Cukier. She’s a chemistry librarian at Washington State University.
She told me that the spicy feeling comes from something called capsaicin. The amount of capsaicin in a pepper determines how hot it is.
Read More ...How do people get ear infections? – Lydia, 9, Illinois
melissamayerDear Lydia,
Ear infections aren’t fun. They can make your ears hot, itchy or painful. They can cause lots of pressure or make it harder to hear. Sometimes fluid leaks out of your ear.
I asked my friend Bevan Briggs why that happens. He’s a nurse practitioner and professor at Washington State University.
He told me people usually get outer ear or middle ear infections.
Your outer ear includes the flappy part attached to your head—called the auricle or pinna. It also includes the ear canal. That’s the tunnel that goes into your head. At the end of the ear canal, there’s a thin, flexible barrier of tissue called the eardrum. That’s the boundary between your outer ear and your middle ear.
Read More ...Why do some people just seem so much smarter than others, no matter how hard I try to be good at studies? – Alexa, 12, Hong Kong
melissamayerDear Alexa,
As a science cat, I talk to some of the smartest scientists on the planet. It can be intimidating. Especially when I talk with people who are experts at things that are hard for me.
I talked about what it means to be a good student with Kira Carbonneau. She’s an educational psychologist at Washington State University.
She told me that everyone grows and learns at different rates. Just like people learn to walk or talk or ride a bike at different rates.
Read More ...How does your body heal cuts and scrapes? – Liam, 11, California
melissamayerDear Liam,
Did you know your skin is the largest organ in your body? The average 5th grader has more than 6 pounds of skin. Whoa.
Skin protects the inside of your body from the dirty outside world. It keeps your insides from drying out and ensures a steady body temperature. It lets you feel things you touch.
Your skin also has the incredible ability to heal itself. I talked about that with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
“Skin is the point of contact between you and everything in your environment,” Johnson said. “So, it's evolved the ability to regenerate.”
Read More ...How does hair grow? – Aidric, 9, Ohio
melissamayerDear Aidric,
My whole body is covered in thick, glossy cat fur. Humans look mostly furless. But people grow hair on every part of their bodies except the palms of the hands and soles of the feet. Most human hair is just super fine and hard to see.
That’s what my friend Edward Johnson told me. He teaches classes about the human body in the School of Biological Sciences at Washington State University.
He also told me hair grows from follicles. Those are special organs in the top layer of the skin. Everything you need to grow hair is inside the follicle.
Read More ...Why do we get rashes on our skin? – Claire, 9, Virginia
melissamayerDear Claire,
I’ve been allergic to fleas ever since I was a kitten. Flea bites give me an itchy, red rash.
I talked about why that happens with my friend Bevan Briggs. He’s a nurse practitioner and professor at Washington State University. Nurse practitioners are nurses with advanced training. They diagnose illnesses, order tests and prescribe medicine.
Briggs told me that often rashes happen when the immune system gets turned on. The immune system is the body’s defense system.
“It's the way our body tries to protect us from germs and poisons,” he said. “Rashes happen because your immune system identifies something as foreign—either an infective agent or some kind of toxin.”
Read More ...Why do babies cry? – Camren, 7, Indiana
melissamayerDear Camren,
I was a very quiet kitten. I only cried when I needed something. But some kittens in my litter cried all the time.
I talked about this with my friend Masha Gartstein. She’s a psychology professor at Washington State University. She studies how babies develop different temperaments. That’s how you relate to the world around you in a way that’s unique and fairly consistent.
Gartstein told me babies cry because they’re helpless. They need a way to signal that they need something.
“Babies are born into this world needing a lot of assistance—and without a lot of communication tools,” she said. “Crying is a very powerful communication tool.”
Read More ...Do your eyeballs grow? – Ashlynn, 8, Utah
melissamayerDear 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 …
Read More ...What is the difference between B cells and T cells in the immune system? – Tanveer, 11, California
melissamayerDear 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.
Read More ...How does sleeping charge us up? -Joaquin, 10, Illinois
melissamayerDear Joaquin,
I love curling up under a pile of blankets at bedtime and waking up refreshed in the morning. You might be surprised to hear that scientists aren’t sure why sleep makes us feel that way.
I talked about how sleep works with my friend Marcos Frank. He’s a brain scientist who works in the Sleep and Performance Research Center at Washington State University.
“Without sleep, we do poorly on a lot of tasks, and our brains and bodies don't work as well,” Frank said. “But why is not entirely clear.”
Read More ...Why do you get acne? – Joey, 12, Illinois
melissamayerDear 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.
Read More ...How does the brain transfer signals to each body part to move? Yulissa, 11, Virginia
melissamayerDear 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.
Read More ...Dr. Universe: Why does time fly when we are having fun? – Isaac, 7, Australia
Larry Clark
If you’re having a great time playing at the beach or camping with your family this summer, the day might zip right by. But the long drive to get to your fun destination might seem to take forever.
To understand why time seems to change based on our activities, I asked my friend Alana Anderson, who just earned her Ph.D. at Washington State University. Anderson studies how people, especially babies and little kids, manage their behaviors and emotions. Read More ...
Dr. Universe: Why do we get sleepy when we study? - Sadaf, 12, Pakistan
Larry ClarkDear Sadaf,
Like many good students, you’ve probably noticed that when you study, especially late in the day, you feel sleepy. Scientists don’t know exactly why, but they have a few clues.
The human brain is packed with tens of billions of cells called neurons, which process and store information that helps us observe, understand and make decisions about the world.
My friend Hans Van Dongen, director of the Sleep and Performance Research Center and a professor of medicine at Washington State University, said you might think about neurons as workers in a huge company. Each neuron is an expert in a piece of information, and neurons work together to share what they know and build new connections in the brain.
Read More ...Dr. Universe: Why do we have toenails and fingernails? – Chloe, 12, Texas
Larry Clark
Dear Chloe,
Maybe you like to paint your toenails beautiful colors or admire the dirt under your fingernails when you come in from playing outside. But you’re right to notice that nails must be more than just decoration.
To learn more, I talked to my friend Edward Johnson, an assistant professor of anatomy and physiology at Washington State University.
Johnson reminded me that humans are primates, just like gorillas or orangutans. If you look closely at a primate’s hand or foot, you’ll see their nails look a lot like yours. They’re wide and flat at the ends of their fingers and toes.
Read More ...
Dr. Universe: Why does sleep feel so short? - Brooklyn, 12
rcwebber
That’s a great observation. When my friend Ashley Ingiosi was a kid, she remembers how napping in the car during a four-hour drive to her grandparents’ house seemed to make the time fly by. Maybe you’ve had a similar experience.
As a researcher at Washington State University, Ingiosi is really curious about what goes on within the human brain during sleep. She was happy to help with your question. Read More ...
Dr. Universe: What are cells made of? – Lela, 10, Bogart, GA
rcwebber
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: Why do we have to blink? - Michael and Virgil, 3 and 5, in Sioux Falls, SD
rcwebber
Dear Michael and Virgil,
If you’ve ever had a staring contest with a friend, you may have felt your eyes start to get tired and dry. Eventually, you just had to blink.
Blinking helps our eyes stay healthy, and my friend Dr. Karen Janout, a clinical assistant professor at Washington State University, told me all about it.
She said that with each blink, your eyelids help spread tears over the surface of your eyes—and you actually do this a lot. Humans blink an average of 15 to 20 times a minute, which adds up to somewhere around 5.2 to 7.1 million blinks a year. 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
rcwebber
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 ...
Dr. Universe: How does toothpaste clean your teeth? -Lucy, 10, Pullman, WA
rcwebber
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 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
rcwebber
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?
rcwebber
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 we have spines? - Jessie, 10, Covina, Calif.
jaime.chambersDear 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.
Read More ...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.
jaime.chambersDear 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.
Read More ...Dr. Universe: how do sleeping darts work? (e.g. for elephants) - Jonathan, 7, Pullman, Wash.
jaime.chambersDear 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.
Read More ...Dr. Universe: Why do people have different fingerprints? - Mary, 12, South Carolina
jaime.chambersDear Mary,
Did you know even identical twins have different fingerprints? It can be hard to tell twins apart, but a close look at their fingertips can reveal who’s who. The reason lies partly in their genes, but mostly from the unique way everyone’s skin grows before birth.
That’s what I learned from my friend David M. Conley, a professor at Washington State University’s Elson S. Floyd College of Medicine.
“The reason fingerprints are unique is the same reason individual humans are unique,” Conley said. “Variation is the norm, not the exception.”
Read More ...Dr. Universe: Why are brains mushy? – First Graders, Waller Road Elementary, Puyallup, Wash.
jaime.chambersDear 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.”
Read More ...Dr. Universe: Why do we have a tailbone? -Tyler, 15, East Liverpool, England
rcwebberDear Tyler,
At the very bottom of the human spine is a bone that sticks out a bit called the coccyx (cox-ix). We sometimes call it the “tailbone,” but it is actually made up of several different spinal bones.
In some animals that actually have tails, those different bones at the bottom of the spine help them move their tail around. But in humans, those bones partially fused together.
Read More ...Dr. Universe: Why do we have nightmares? -Kourtney, California, 10
rcwebber
You are running through the woods and a bear is chasing you, when all of a sudden you wake up in your bed and realize it was just a scary dream. Our nightmares can sometimes feel super scary, even if what’s happening isn’t real.
Fear is a natural part of being a human. In fact, you may have even felt shaky or sweaty after waking up from a bad dream. It’s all part of something we call the fight or flight response.
When humans are faced with something scary, this response helps them decide if they should face their fears and fight or run away by taking flight. This fight or flight response works even when you are asleep. Read More ...
Dear Dr. Universe: How do we talk? – Emmy, 7, Wash. State
rcwebber
Dear Emmy,
When you were a little kid, maybe you played Peek-a-Boo or sang “Itsy Bitsy Spider.” These kinds of games and songs have a lot of the different sounds we make when we are first developing speech.
A lot of humans start out playing with speech through cooing and crying. At about six months old, this cooing and crying turns to babbling. A baby might make sounds such as ma-ma, pa-pa, or ba-ba. Read More ...
Dr. Universe: Why are dogs important to humans? Stephani R., 9, Washington State
rcwebber
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: How do bags form under your eyes? –Sophia Ivy, 7, New Providence, NJ
rcwebber
Dear Sophia Ivy,
If you’ve ever stayed up late and woke up really early, you may have noticed a little puffiness or swelling under your eyes.
When I asked my friend Devon Hansen about the answer to your question, she said that we first have to know a bit about how sleep works. Read More ...
Dr. Universe: Why do we get morning breath? -Stephanie, 10
rcwebber
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 ...
Dr. Universe: Why do we have a belly button? – Jane, 9, Kennewick, WA
rcwebber
Whether you have an innie or an outie, pretty much all us mammals have a belly button. But before you had a belly button, there was actually a different bit of anatomy in its place.
While you were still growing inside of your mother, a small, bendy tube on your tummy connected the two of you. This tube is how you got pretty much everything you needed to grow before you were born into the world. Read More ...
Dr. Universe: Why do we have five fingers and five toes? -Eli, 11, Edinburgh, Indiana
rcwebber
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 ...
Dr. Universe: Why does music give us chills? -Nicole, 11, Spokane, Wash.
rcwebberDear Friends,
If you are anything like me, maybe you’ve suddenly felt a chill while listening to music. Perhaps, you got goosebumps and saw your arm hairs stand on end. Maybe you even teared up.
Read More ...Dr. Universe: What is happening when we sleepwalk? -Daniel, 11, Easton, CT
rcwebberDear Daniel,
Our brains work hard to help us move, talk and think. They also help us sleep. When we rest, some parts of our brain are active. When we are up and moving around, parts of our brain are actually at rest.
Read More ...Why do feet smell? -Jose, 10, Costa Mesa, Calif.
rcwebberDear Jose,
We live in a world filled with all kinds of smells. Take off a pair of tennis shoes after a long day and you might even get a whiff of something pretty stinky. You can blame it on your bacteria. Millions of these tiny things live on your feet.
Read More ...What causes a mirage? –Georgia, 10, Wash.
rcwebberDear Georgia,
Imagine you’re riding in the car on a very hot day, when you look out the window and see a shimmering puddle of water up ahead. As you get closer, you find there’s not really anything there. It’s a mirage.
Read More ...Dr. Universe: Why are there different blood types? - Sarah, Tacoma, Wash.
rcwebberDear Sarah,
At this very moment, several quarts of blood are circulating through your body at nearly 4 mph. But as you’ve pointed out, not everyone’s blood is the same.
Your question made me wonder exactly what we mean when we talk about blood types. I decided to ask my friend Amber Fyfe-Johnson, a researcher at Washington State University who studies cardiovascular diseases--diseases of the blood vessels-- in kids.
Read More ...Why do people grow hair under their nose? Why does it grow down instead of up? –Riley, 11, Prior Lake, MN
rcwebber
Dear Riley,
Humans have hair all over their bodies, including above the upper lip. Of course, not all hair is quite the same. A lot of people have very fine hairs on their faces. Others can sprout a thick beard or mustache.
Read More ...Why do we have different feelings? - Charan and Aishwarya V., 10 & 8, Rutherford, New Jersey
rcwebberDear Charan and Aishwarya,
Imagine you are playing a game of soccer and your best friend is on the opposing team. The sun is out, you are having a great time, and you score the winning goal. You’d probably feel pretty happy and so would your team.
Read More ...How do viruses affect animals? -Gianni, 10, Cayman Islands
rcwebber
Dear Gianni,
Our planet is home to more than seven million amazing animal species. While we have our differences, we also have something in common: We are all made up of a bunch of cells.
Read More ...Why do we have blood? Where does it come from? –Norelle, Olympia, Wash
rcwebberDear Norelle,
Our bodies have many living parts, like skin, muscle, brain and bones. Blood helps keep these parts alive and healthy. The system that moves our blood around the body is sort of like a city’s postal service, said my friend Astrid Suchy-Dicey.
Read More ...Does science get harder every year or is that just me? -Keegun, 8th grade, E. Wash.
rcwebberDear Keegun,
We’ve got about three pounds of brain in our heads that help us look for answers and solve all kinds of problems. But it isn’t always easy. Sometimes an experiment doesn’t go the way I expect or I get stuck on a particularly tricky science question.
Read More ...Dear Dr. Universe: Do you know how human and animal interactions help our mind grow? Does it help us? Does it do nothing? This has fascinated me for a very long time. - Gabby G., 11, Berlin, VT
rcwebberDear Gabby,
Our brains are pretty busy. They are constantly thinking, feeling, and sensing our world. One thing that can help some people relax is spending time with an animal friend. You might play fetch with a dog, sit with a cat, brush a horse, or even watch a goldfish zip around its bowl.
People who spend a lot of time with animals might tell you that something special seems to be going on here. But scientists are looking for evidence and want to find out for certain just what is going on. They want to know … » More …
Why do we have water in our bodies? –Angelika, 12, Cathedral City, CA
rcwebberDear Angelika,
Believe it or not, we are mostly water. Of course, you may have noticed we aren’t sloshing around and spilling everywhere.
Read More ...Dear Dr. Universe: How do our ears work? -Aryana, 11, Ohio Dear Aryana,
rcwebberThe chirps of birds. The squeaks of mice. The barks of dogs. In a world full of different sounds, our ears take in almost everything. But it takes more than just our ears to hear.
Read More ...Why do cows burp methane? -Silas, 10, Seattle, WA
rcwebberDear Silas,
There are more than a billion cows on our planet and they all need to burp. Just like us, they burp to get rid of extra gas in their stomachs.
Read More ...Dear Dr. Universe: Is it possible that we are growing every second? - David, 9, Camas, Wash.
rcwebberDear David,
When I was a kitten, I used to keep track of my growth. Every now and then, I’d make a little pencil mark on the wall right above my ears.
Read More ...Dear Dr. Universe: Why do animals hibernate? -Jarrett T., 10, Edinburgh, IN
rcwebberDear Jarrett,
Animals can get through winter in all kinds of ways. Us cats like to curl up on a cozy couch. Some penguins huddle in groups to create heat. A lot of birds fly south to warmer weather. Perhaps you put on mittens and a coat.
Read More ...Dear Dr. Universe: How does digestion work? -Abi, 12, U.S., Megha R., 11, Dubai
rcwebberDear Abi and Megha,
All around the world, animals are eating all kinds of different foods. Our foods might be different, but one thing is true for all of us: We have to digest.
Read More ...Dear Dr. Universe: Why do we find some things scary? -Jack H., 8, UK
rcwebberDear Jack,
While our fears might be different, we all get scared sometimes. Vacuums, dogs, and even cucumbers make my hair stand on end. Perhaps for you it’s spiders, the dark, or the thought of monsters under your bed.
My friend Michael Delahoyde is really curious about what freaks us out. As an English professor at Washington State University, he’s even taught a course about monsters.
Read More ...Dear Dr. Universe: How do we remember stuff? -Aidan, 11, Franklin, Indiana
rcwebber
Dear Aidan,
Our brains have an incredible ability to help us remember all kinds of stuff. Of course, memory isn’t perfect. Sometimes we forget our homework or where we left our favorite cat toy.
Read More ...Why do we hear the sea in a seashell? -Steve, Minnewaska School, Minnesota
rcwebber/strong>
Dear Steve,
Whenever us cats go to the beach, we tend to keep a safe distance from the water and like to explore the shore. I once stumbled upon a big, beautiful pink and white seashell.
Read More ...Why do we feel pain? -Sara, 11, Moscow, Idaho
rcwebberDear Sara,
Pain is unpleasant, but we need it for survival. Just the other day I was out exploring when I stubbed my paw and let out a big meow. My nervous system was doing its job.
Read More ...How many colors can we see? -Andrew P., 12
rcwebber-
Dear Andrew,
The human eye can see millions and millions of colors. But believe it or not, some colors exist in our world that the human eye can’t see.
Read More ...Are there creatures on Earth with one eye? -Elena, 7, Vancouver, Canada
rcwebberDear Elena,
The animal kingdom is full of amazing eyes. And yes, there are actually creatures on our planet that have just one.
Read More ...Why do we have earwax? -David, 10, Albany, Oregon
rcwebberhttps://www.youtube.com/watch?v=as4TWgC4xxA
Dear David,
The other day I was scratching my ears when I noticed some yellowish-brown gunk on my claw. It was pretty gross, but it also made me very curious.
Read More ...Why do we get brain freezes -Hannah, 9, Monroe Elementary
rcwebberDear Hannah,
You’re enjoying some ice cream, when suddenly you feel a pain in your head that hurts a whole lot. It’s like it came out of nowhere, and in a matter of seconds, it’s gone.
Read More ...Dear Dr. Universe, Why do we age? -Logan, 12, Pullman, WA
rcwebberDear Logan,
It’s usually later in life that we see the more dramatic signs of aging, like gray hair, wrinkles, and lots of birthday candles on our cake. But we really start growing older from the time we are born.
Read More ...Dear Dr. Universe, Do kids' brains work better in the morning or in the afternoon? -Grace, Spring, TX
rcwebberDear Grace,
Hang on tight because the human brain keeps you on a 24-hour roller coaster.
Read More ...