Dear Louis,

That’s a great observation about numbers. Whether you start counting backwards or forwards, numbers never seem to end.

To find out more about these mysterious numbers, I took your question to my friend Kevin Fiedler. He’s an assistant professor of mathematics at Washington State University.

He reminded me that there are a lot of different rules mathematicians follow. For instance, if you think of a number, you could always add one to it.

Dear Amari, 

There are many different ways germs can enter the body. Sometimes they find a way in through an opening like the mouth, nose, eyes or a cut in the skin.   

Most of these germs—what scientists call viruses and bacteria—are so small we’d need a microscope to see them.

My friend Leigh Knodler is a researcher at Washington State University who works with a particular kind of bacteria called Salmonella.  

Salmonella can sometimes live on food, such as undercooked chicken or unwashed fruits and vegetables. It typically enters the body through the mouth when someone takes a bite of food.  

If we followed Salmonella through the body, it would pass through the esophagus, the stomach and finally into the intestines.

Dear Hanaiah,

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

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

Dear Tyra,

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

Dear Christian,

If you’ve ever eaten a chili pepper, you know it can make you feel really hot. You might start sweating, get a runny nose, or even cry.

Dear Daniel,

We don't just use our ears to hear music. A big part of hearing also has to do with our brains. Our ears certainly are necessary to help us hear, but it is our brain that helps interpret the sounds in our environment.

Dear Shayli,

Maybe you’ve heard a little voice in your head say “ba-da-ba-ba-bah, I’m lovin’ it!” when you saw a sign for McDonald's or thought “snap, crackle, pop” when you crunched on a spoonful of Rice Krispies cereal.

Dear Addi,

As a cat, I’ve often wondered the same thing about my whiskers. I asked my friend Jennifer Slovak about it. She’s an Assistant Professor of Small Animal Internal Medicine at Washington State University who knows a whole lot about whiskers.

Dear Theo,

That’s an excellent observation. If we drew an imaginary line straight down the middle of the human body, it would look pretty similar on each side.

Dear Tali,

We can make glass in factories and we can find it in nature. Some volcanoes make glass. When they spew out lava, it often cools into obsidian, a black glass. Glass can also form on sandy beaches. Small tubes with smooth glass on the inside may appear after super-hot lightning strikes the sand.

Dear Brody,

It’s a snowy morning and the thermometer reads 20 degrees Fahrenheit. You grab a jacket and a pair of mittens for your paws. It’s going to be a cold day.

Dear Jada,
If you were to travel around the world, the word “science” might look or sound very different. In Spanish, it’s ciencia. In Japanese, 理科. In German, wissenschaft! And in French…well, it’s also science. But with an accent. 

Whether it comes from trees or is made by scientists in a lab, rubber can really bounce. Well, a rubber band or rubber on your shoes might not be very bouncy. But a super bouncy rubber ball? It can really catch some air.

Dear Rahman,

Our animal kingdom is full of different eyes. The human eye weighs less than an ounce. That’s about as heavy as 11 pennies. But I suppose the answer to your question really depends on which eyeballs you are curious about. Perhaps you are looking for an answer about the biggest animal eyes on our planet.

Dear Bhayana,

The very first roller coaster at Coney Island amusement park cost only a nickel to ride and was a big thrill for visitors—even if it did only go 6 mph.

 
Dear Ravin,

No matter how much you flap your arms or I flap my paws, gravity keeps us pulled to Earth. But when birds use their strong muscles to start flapping their wings, something amazing happens.