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Ask Dr. Universe rcwebber

Dr. Universe: Why do microwaves hum? – T.J., Middle School, Ohio

Dear T.J.,

Long before humans invented microwave ovens, they had to rely on stoves or an open flame to heat up their food.

These days, we can warm up food in a matter of minutes, or even seconds. A lot of parts had to be invented to make that all happen. These parts help electricity flow through the microwave in lots of different ways.

One part called a transformer helps move the electricity from one area to another. As it does so, it may vibrate or shake a little, and that tiny movement can cause a humming noise.

Electricity is actually a big part of … » More …

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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: How do cows make milk? How do humans get milk from a cow? – John, 4, Colton, Ore.  

Quite a few things have to happen for a cow to make milk. First, the cow has to eat lots of food, such as hay, grass, or grain. You may have heard that a cow will regurgitate her food, or sort of spit it up, and then chew on it again.   A cow will chew this mashed up food, or her cud, so she can get all the good stuff out of it—protein, sugar, fat, vitamins, and other nutrients. Milk is actually mostly water, plus those good nutrients.   Read More ...

Why do we have eyebrows? -Zach, 11, Kettle Falls, Wash.

Dear Zach, Humans have hair on their heads, arms, and as you mention, even the face. If you feel your face, you might feel some small, fuzzy hairs on your cheeks and forehead. But the hair of your eyebrows is usually a bit thicker. I asked my friend Mark Mansperger why we have eyebrows. He’s an anthropologist at Washington State University. Eyebrows appear to serve two main purposes, he said. One of the purposes of eyebrows is to keep things like rain or sweat from rolling down your forehead and into your eyes. “It guards your eyes in that way,” Mansperger says. Read More ...

Dr. Universe: Why does the moon have phases? – Manahil, 14, Pakistan

When astronomers looked at the night sky long ago, they also wondered about questions just like this one. You know, I was also curious about why the moon looks so different at different times of the month. I visited with my friend Jose Vazquez, an astronomer at Washington State University, to learn more about it. He said that the way the moon looks to us has to do with two other objects in our solar system: our sun and earth. Read More ...

Dr. Universe: My mom says video games and too much TV rot my brain. What does that mean? How does that happen? Does my brain turn to slime? – Tree Family Kids, 3, 5, 7, Dundee, Michigan

If you play video games or watch too much television, you don’t have to worry about your brain actually turning to slime. But it is true that some video games and television shows can take away some of your energy without giving you much in return. When we are not being active with our bodies, too much screen time can wear us down. It not only wears down the brain, but also the body. And at the same time, some video games and stories can often help us learn better. That’s what I found out from my friend Jonah Firestone, a researcher at Washington State University who knows a lot about virtual reality, video games, and learning. Read More ...

Dr. Universe: What does it mean to go brain dead? – Noelle, 10, Sumner, WA

Let’s say we wanted to find out what kind of electrical activity was happening inside your brain at this very moment. Yep, you read that right: your brain is full of electricity. It actually generates enough electricity to power a lightbulb. In fact, the tiny cells in your body use electricity to send messages to each other. That’s part of what helps the brain and body communicate. I decided to visit my friend Samantha Gizerian, a neuroscientist at Washington State University, to find out more about our brains. She said if we wanted to observe activity in a human brain, we could do a test called an electroencephalogram (uh-lek-trow-uhn-seh-ful-luh-gram), or EEG for short. We’d attach some small discs with thin wires, or electrodes, to a person’s head. 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: Why do we have a tailbone? -Tyler, 15, East Liverpool, England

Dear 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.

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