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Do you have any experiments you can recommend?

Dr. Universe: Do you have any experiments you can recommend? Thanks! -Etta, 7, Milwaukee

Dear Etta and Friends:

You can try all kinds of fun experiments at home. It really all depends on what you are curious about. Lately, I’ve seen some really great sunsets and started wondering what gives them their colors.

I decided to ask my friend Tom Johnson, who leads fun physics demonstrations for kids visiting Washington State University. I asked him if he had any simple ideas for an experiment I could try out in my lab, or even the kitchen. One idea he had was to create a sunset in a cup.

Maybe you can try it, too. You’ll need a flashlight, a transparent cup or two, water, and some milk. We cats have a reputation for liking milk. But it really isn’t so great for our digestion. So instead, I like to use it for science.

Once you’ve collected all your supplies, you’ll want to fill your glass about 2/3 of the way with water. Then, you’ll want to add milk until the liquid gets pretty cloudy. Be sure and stir it up well.

Turn on your flashlight and turn down any other lights in the room. Now you can shine the flashlight down into the water and look through the side of the glass. What color do you see?

This time, shine the flashlight through the side of the glass while looking at it from the opposite side. Any changes? Then hold your glass up off the table. Shine the flashlight up through the bottom of the glass and look down into the liquid. What colors can you see now? Perhaps the colors are looking more like those you’d see during a sunset.

Milk in the water scatters the light from the flashlight. It’s similar to the way different molecules and dust in our atmosphere scatter light from the sun.

Light travels from one end of the glass to the other and then up to your eyes. The further the light has to travel through the water, the more blue light gets scattered. That leaves more red light for your eyes to pick up.

Now that we’ve started to get an idea of how light scatters, runs into particles, and travels long distances, you can really get to experimenting.

What happens when you use less or more milk? Will you see any changes if you use a different kind of flashlight, like an LED? What kind of milk gives off more orange or reddish colors? Two percent? Whole milk?

Does the shape of the glass change anything? Why do you think that might be? Make a prediction and give it a try sometime. I’d love to hear more about your experiments and how your own sunset in a cup turns out. E-mail: Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

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How do we get our personality?

Dr. Universe: How do we get our personality? – Jamie, 11

Dear Jamie,

Everyone is different. Maybe you are adventurous, shy, outgoing, funny, or kind. Before you were even born, your unique personality was beginning to take shape. » More …

Why do cows moo?

Why do cows moo? -Sam, 11, Gahanna, Ohio

Dear Sam,

If you’ve ever been near a herd of mooing cows, it might have sounded like all their moos were the same. But just as each person’s voice is a little different, so is each cow’s moo. » More …

Can video games help us learn?

Can video games help us learn? – Isaac, 12, Clyde, N.Y.

Dear Issac,

All kinds of games can help us learn, including some video games. They can be a fun and useful way to help you remember what you learn, too.

Our brains work hard each day to take in and process information. Ever since video games were invented, people have been asking if and how they might change our behavior and brains.

For example, people once thought that video games left players with poor eye-sight and poor attention. Some scientists decided to actually test out these ideas. Their studies have shown that some video game players actually have better attention than non-players. Other studies have shown how some video game players also have sharper vision.

When it comes to learning new things, being able to focus and quickly process visual information can be helpful. But those aren’t the only things that help with learning.

That’s what I found out from my friend and Washington State University education researcher Raed Alsawaier. He studies how different elements of games can help us learn in our classrooms or other settings outside of the virtual, video game world.

“Almost all of us grow up learning through playing,” he said.

Just think back on a time when you played a game with friends. Maybe you worked with as a team. Maybe you used some creativity and imagination to face a challenge or solve a problem.

It appears that there are two elements to video games, in particular, that can really help us learn, Alsawaier said. One of these elements is collaboration. Learning through video games often happens when you are working with others to reach a goal. This can happen in the game or outside the game.

For example, some games like Minecraft help kids learn to read and write. But the game itself doesn’t actually require you to read or write. The game also doesn’t come with a lot of instructions. Players read other people’s experiences online and write about their own.

The other element of learning through video games is, well, fun. When playing video games, people use a lot of their senses during the experience; sight to watch the screen, hearing to listen to their fellow players, and touch when using the controller.

Our senses and experiences are also tied closely to our memory, Alsawaier explains. Not only can video games give us skills that help us learn, but there’s evidence that they can help us remember what we learn, too.

We still have a lot to learn about different video games and how they affect us, but we can say, at least in part, that the answer to your question is yes.

Now that you know about few elements in video games that can help us learn, what kind of video game would you design? Tell me about it sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Why does hair turn gray?

cat dressed in lab coat examines one of her hairs up close
Dr. Universe examines a gray hair.

Dear Dr. Universe: Why does hair turn gray? –Darae, 10

Dear Darae,

Hair comes in lots of different colors. There’s black, medium brown, auburn, light brown, strawberry blonde, and copper, to name just a few. But in the end, almost everyone will have hair that’s gray or white. » More …

Why do we get fevers?

Dr. Universe: Why do we get a fever when we are sick? – Marcelina, 11, Ovid, N.Y.

Dear Marcelina,

Lots of warm-blooded animals get sick, including cats. I’ve had a fever before, but I wasn’t entirely sure why we warm up when we get sick. I decided to ask my friend and professor Phil Mixter at Washington State University. » More …

How does a string of lights work?

Dear Dr. Universe: How does a light bulb work? When one bulb in a string of lights goes out, why do they all go out? – Molly, 8

Dear Molly,

Just the other day I was taking down a string of lights from my lab, when I discovered the bulbs were burnt out. I visited my friend Aaron Crandall, an engineer at Washington State University, to see if I might get them working again.

Crandall explained when you plug in a string of lights to a power source, like an outlet, an electrical charge flows into the wires. A lightbulb works when an electrical current runs through thin metal wires in the bulb and electrical energy gets converted to heat and light. We can get this current of electricity to follow different paths, depending on how we wire up the lights.

When the electricity reaches the first bulb in a string of lights, it flows up a tiny vertical wire inside the bulb. Here, it crosses a tinier horizontal wire, which acts kind of like a bridge, for the electrical current. The current follows another tiny vertical wire down and out the bulb. The current moves on, powering up the other lights, until it gets back to the power source. It’s all part of a looped pathway.

My string of lights is on one long path, or circuit— if one of the lightbulbs goes out, they all go out. Usually this happens when the tiny wire bridge that connects those two vertical wires inside the bulb melts or breaks.

Crandall said in some sets of lights you can gently shake the bulb to try and get the tiny horizontal wire to reattach to the vertical ones. I attempted this with my broken lights, but didn’t have much luck. I decided to pick up a new set of lights. This newer set has individual loops, or circuits, for each light. It also requires more wire to work.

You might think of this type of circuit like the monkey bars on a playground. Imagine the view from the top. There are two parallel bars that connect to rungs (the part you swing from). Let’s say you and a few friends are lightbulbs. You each hang from your own rung.

A circuit called a series circuit would be kind of like if you and your friends (the lightbulbs) were all holding hands and the current was flowing down the line. If one friend left, it would break the connection.

But on the monkey bars you aren’t holding hands. You have your own connection (rung) to the lines the electricity is flowing along (the parallel bars). In this kind of design, each light or a series of lights has its own loop, or circuit. If one route along the electrical pathway is not working or blocked, the rest of the bulbs can still light up.

I’ll put up my new lights next year, but I think I’ll break apart my old set of lights to do some experiments with circuits. With some help from an adult, you can check out how to make your very own circuit with old holiday lights. Tell me how it goes sometime at Dr.Universe@wsu.edu.

Sincerely,

Dr. Universe

 

Why do some animals live in groups?

 

Dr. Universe: Why do some animals live in groups?

– Mrs. Rubert’s students, Foothill Knolls STEM Academy of Innovation, Upland, Calif.

Dear Mrs. Rubert and Students,

Fish swim in big schools. Baby ducks waddle in a straight line. Ants and bees divide up labor. The world is full of animals that live in groups and they do it for a few different reasons. » More …

Glass: How is it made?

Dr. Universe: How is glass made? And, what is it made out of? What about thick glass like they are putting up on the Space Needle? – Tali, almost 8 years old, Seattle, Wash.

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. » More …

How do planes fly?

Dr. Universe: How do planes fly? -Tahira, 12, India

Dear Tahira,

Planes are very heavy, yet they stay up in the air kind of like a bird in the sky. They can get us across the world in less than a day. Humans went from learning how to fly a plane to putting a man on the moon in a little over 60 years.

But the answer to your question goes even further back. It goes all the way back to the 1700s and actually started not with air, but with water.

That’s what I found out from my friend Michael Allen, a physics and astronomy professor at Washington State University. He thought you asked a great question and was happy to tell me all about how planes can fly.

Around 300 years ago, a scientist from Switzerland named Daniel Bernoulli was experimenting with water pipes, like the ones under your sink at home. When water (or anything) moves through a small space, like the inside of a pipe, it puts pressure on that container (the pipe.)

The more air you push into a smaller space, the greater the pressure. Allen told me that Bernoulli found out that the faster the water moved through the pipe, the less pressure the water put on the pipe.

This idea has come to be known as Bernoulli’s Principle. This principle doesn’t only apply only to water, it also applies to air that passes over the wings on an airplane.

Allen told me that wings on an airplane are flat on the bottom and curved on the top. Allen said that as the wing moves through the air, some air goes over the top of the wing while some goes under the bottom of the wing.

However, the air that goes over the top of the wing has to go over a longer distance than the air under the wing because of the curve. Allen also said the air has to get past the wing at the same time, meaning the air above must travel faster, just like the water moving quickly in the pipe.

Since this air above the wings travel faster, there is less pressure above the wing than below the wing, which pushed the wings and the plan up into the air, causing the plane to fly.

Thanks for your question. It was a great one and I’m happy that you have such a big interest in airplanes. Have you ever thought about becoming a scientist or engineer that works on planes one day? Maybe you could make the next spacecraft that takes a person to the moon or Mars.

Sincerely,
Ian Smay and Dr. Universe

 

Ianb Smay contributed this article. He is a student in the Edward R. Murrow College of Communication at Washington State University.