Dr. Universe

Ask Dr. Universe – French Fries

Dr. Universe: Why are French fries so good? – Emma, 8, Alaska

Dear Emma,

A good French fry starts with the right potato. My friend Rick Knowles is a potato researcher at Washington State University and told me all about the spuds.

It turns out there are certain kinds of potatoes that make the best fries. Two of them are the Clearwater Russet and Blazer Russet potatoes. These potatoes have a good texture and their long shape makes them great for cutting into fries.

If you took a bite of a raw potato, it probably wouldn’t taste very good. But when we cook a potato at just the right temperature, something called the Maillard reaction happens.

The Maillard reaction is a reaction in potatoes that happens between glucose, a kind of sugar, and amino acids, the building blocks of protein. Knowles explained that the Maillard reaction changes the flavors and odors of some foods that we cook.

“In the case of potatoes, we want a certain amount of Maillard reaction to give us the golden brown color and characteristic cooked flavor of the chips and fries, but not too much Maillard reaction,” Knowles said. “Otherwise we get dark colored fries that have a bitter, burnt flavor.”

You may have noticed the Maillard reaction doesn’t happen when we cook up mashed potatoes. That’s because we only boil the potatoes to around 212 degrees Fahrenheit. The Maillard reaction happens when foods like potatoes have just the right amount of glucose and amino acids and are heated to above 302 degrees Fahrenheit.

A big part of the flavor in fries also comes from the oil we use to fry them. A little salt also adds to the taste.

A lot of people in the food industry are very curious about flavor. In the lab here at WSU, Knowles and his team invite people to taste test French fries each year.

“We make them up right here,” Knowles said, when I visited him in the research building where he works.

Researchers in the Knowles lab study new potato varieties that they are growing in Oregon, Washington, and Idaho. They developed potatoes like the Clearwater Russet and Blazer Russet through a process called plant breeding. Plant breeding helps the researchers select the traits they want in a plant, like a certain shape, size, or a high amount of protein.

The team is helping farmers learn which potatoes people will buy and want to eat. In Washington state, we grow more than 9 billion pounds of potatoes every year and most of them will go on to become French fries.

You can also whip up some fries right at home with the help of a grown-up. My friends at WSU Extension even have a recipe for you to try: crispy potato wedges. Try out the science of cooking in your kitchen sometime, check out that Maillard reaction, and let us know how your potatoes turn out at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Sleep and Sounds

Dr. Universe: Can the sound of rain help us sleep? – A reader

Dear Friends,

All around the world, people fall asleep to different sounds. Maybe you hear a snoring dog, whooshing waves, noisy traffic, chirping crickets, a soft lullaby, or raindrops.

These kinds of sounds can actually help different parts of our body kick into gear, said my friend Devon Hansen. She’s a sleep researcher at Washington State University.

Her lab often investigates two of our body’s systems by hooking people up to a heart monitor. Monitoring a person’s heartbeat can help her see which of these two systems are active.

One system is the sympathetic nervous system. If you ever feel threatened, this system helps you decide whether to run away or confront the situation.

Another system is the parasympathetic nervous system. This one helps you stay calm, rested, and also digest your food–without even having to think about it. When you are in “fight or flight” your heartbeat speeds up. When the parasympathetic nervous system is active, your heartbeat is slower.

A fire alarm going off, a lion roaring nearby, or someone screaming might startle you and kick in that “fight or flight” system. You’re suddenly alert and awake to respond to danger. But the sounds of rain or ocean waves aren’t usually very threatening noises. They activate the parasympathetic nervous system and your body relaxes.

These kinds of soothing sounds can also muffle noises that might keep you awake or distract you, such as a howling dog or loud traffic.

Hansen said it’s important to remember that sound itself doesn’t make you fall asleep. It’s really that your parasympathetic nervous system is activated, which is what relaxes the body. Once the body is relaxed, it will naturally fall asleep.

You can try a sleep experiment of your own at home. Find a metal spoon or fork. Write down the time you go to bed. Then grab a metal tray and put it on the ground next to your bed. Once you are ready for bed, hold the utensil in your hand over the tray.

When your body and hand relax, you will drop the fork or spoon. The clatter will probably wake you up. Then write down the time you woke up. Subtract the time difference and you’ll see how long it takes you to fall asleep. You can try this while listening to different sounds, like the sounds of a forest, rain, or the ocean.

Hansen adds that putting on soothing background sounds can be helpful when falling asleep, but it’s not as helpful for staying asleep. If your speakers are on all night, they could be waking you up a lot without you realizing it. But it could explain why you might be tired the next morning. A good night’s sleep is important for humans, especially if you want to stay sharp and keep thinking up great science questions.

Sincerely,
Dr. Universe

Ask Dr. Universe – Why Cats Like Lasers

Dr. Universe: Why do cats like lasers? -Izzy, 10, MD

Dear Izzy,

Not only do I enjoy answering science questions from kids, but I also like naps, tuna fish sandwiches, and chasing lasers. I wasn’t entirely sure why I like chasing those little red dots. I asked my friend Leticia Fanucchi, a veterinarian at Washington State University.

“Cats like lasers because they are predators and like to chase or hunt anything that moves fast around them,” Fanucchi said.

A zipping red light that quickly switches directions might have a similar motion to a mouse or other critter. The light sort of mimics an animal scurrying around to escape its prey. Even though we cats know the laser is not an actual mouse, it triggers our predatory instinct.

An instinct is something hard-wired into animals—they don’t have to learn it, they just naturally know how to do it. For example, dogs drool when they see food. Birds build nests. These are all instincts and some can help animals survive.

As predators, cats also have a few other tools that are useful for survival: claws and sharp teeth. We also have good eyesight and hearing. Plus, we are pretty fast.

The house cat is actually descended from a wild species of cat, including the European and African Wild Cat. These cats were big hunters. While house cats are more domesticated, we still share that instinct to hunt.

Meanwhile, big cats like lions, tigers, and cheetahs have even bigger claws, teeth, and speed. Some of these animals show at least a bit of interest in laser pointers, too.

It turns out cats big and small aren’t the only ones who like to chase lasers. Other animals seem to be very curious about them. Dogs will chase lasers. Some insects go a little wild when they notice a laser moving. People have even recorded fish following the light in aquariums.

Biologists might call the laser a kind of superstimuli. It really draws in the animal’s attention because it’s so different from anything else going on in its environment. Unlike smart prey in nature who camouflage, the red laser point stands out.

While investigating all kinds of things about cats and lasers, I discovered that house cats haven’t been playing with lasers very long. The first cats were domesticated about 4,000 years ago in ancient Egypt. Some researchers think we might have been domesticated even earlier.

Lasers were only invented about sixty years ago. That might seem like a long time at first, but when you consider how long cats have been domesticated, only a small number of cats throughout history have ever played with a laser. That got me wondering how lasers work in the first place. We’ll save that question for another time.

Sincerely,
Dr. Universe

Ask Dr. Universe – Ancient Rain Filtering

Dr. Universe: How did people in ancient times filter water from rain? – Richard A., 11

Dear Richard,

Every day people around the world get their water in different ways. Some get water from a well, others turn on a tap, go to the store, and some walk many miles to a river. But no matter how we get our drinking water, it almost always starts with rain.

Rainwater is really clean, said my friend Julie Padowski. She’s a scientist at the State of Washington Water Research Center at Washington State University.

In ancient times, some people harvested rain in big containers, but many more people used water that had collected naturally in streams, rivers, and in the ground.

They could find groundwater rushing by in rivers, or bubbling up from underground through a spring. They could also dig deep into the earth to find water.

“What people did way back in ancient times is they looked for water that was flowing or they used groundwater,” Padowski said. “Groundwater from deep down in the earth is often safer to drink because it’s more protected from contamination.”

As cities grew up around the world, people had some new ideas for getting water. The Romans built big, bridge-like structures called aqueducts, which helped bring water from distant springs or mountains into the city. They also had different ways to filter the water. Padowski said we still use some of these ancient techniques.

For example, we let water sit, or settle, so particles fall to the bottom. Then we can strain off the particle-free water. We boil water to kill any bacteria. We also filter water through soil or sand. In ancient times, people actually built sand filtration columns. As the water slowly trickled through the column, it cleaned the water.

When using soil or sand as a filter, particles that might be bad for you get stuck in the little gaps, or pores. This small stuff gets trapped as the water continues to flow down. Tiny bacteria in the soil also eat up some of the particles. By the time the water moves through the soil, we have some very clean water.

We live on a wet planet—about 70 percent of the surface is covered in water. But only about one to two percent of that is water we can actually drink.

These days we have new technology and creative ways to filter some of the dirtiest water on our planet and transform it into clean drinking water. It allows us to tap into new techniques people in ancient times may not have been able to use, Padowski said.

Who knows, maybe one day you will also help us come up with innovative ways to make sure everyone has clean drinking water and that no one goes thirsty. Water is a precious resource and we can all do our part to take care of it.

Sincerely,
Dr. Universe

Ask Dr. Universe – How Land Affects the Weather

Dr. Universe: How does land affect the weather? – Isaac, 7, Baltimore, MD

Dear Isaac,

The surface of the earth is covered in all kinds of landforms. We have tall mountains, deep valleys, wide canyons, and scenic shorelines—I bet you could think of a few others, too. A little less than a third of our planet is land and the rest is mostly ocean. Both affect the weather, said my friend Nic Loyd, a meteorologist at Washington State University.

We get different weather patterns depending on a few conditions, such as how much sun the land gets, if the land is near mountains or ocean, and how air circulates through the atmosphere.

If you are out on the ocean, you might not feel a big temperature difference between night and day. But we do feel a bigger difference in temperature on land. Especially when conditions are clear and calm, the weather can be very warm in the afternoon and chilly by the morning. Loyd explains that land normally warms up and cools down more quickly than water.

You can test this out at home. Fill up one plastic tub with sand or dirt and fill up another plastic tub with water. Put them out in the sunshine. Using a thermometer, take the temperatures of the two tubs every ten minutes for thirty minutes. Record your results to find out which one heated up faster. You may want to try this a few times just to make sure your results are accurate. Water actually absorbs at least as much energy from the sun as the land does—but water just isn’t capable of warming up as fast as land, or in your case, sand or dirt.

The different types of land around the planet also impact the weather. One good example is mountains, Loyd said. The air is usually much colder if you are up high in the mountains. That’s also where we see a lot of glaciers, ice, and snow all year long. In the mountains, the air is thinner and it doesn’t trap in the heat very well.

Exactly what covers that land also influences the weather. Forests, cities, plains, or deserts can absorb a lot of the sunlight that reaches them, warming the air above the land. But when land is covered in snow, much of the sunlight is reflected away instead of being absorbed into the land. This also helps keep snowy areas colder.

So yes, the land, as well as the water, affects the kind of weather we experience on our planet. But the weather can also affect the land. Just think of the rain that helps plants grow on farms. Or the sun that gives plants energy they need to grow. Can you think of other ways the weather might change the land? Can you think of how these changes might shape the land over a long period of time? Send your ideas to Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – How Trees Survive After a Wildfire

Dear Dr. Universe: How do some trees survive after being burned in a wildfire?
-S.P., Quilcene, WA

Dear S.P.,

While it might seem like wildfires only cause destruction, they are actually a natural and important part of keeping forests healthy. After many years, trees have adapted to their homes. Some are pretty invincible when it comes to surviving a wildfire.

There are a few ways they can survive, says my friend Andy Perleberg. He’s a forestry expert at Washington State University.

One thing that protects trees from wildfire is thick bark. In Washington state, the most common trees with really thick bark are the western larch and ponderosa pine. Ponderosa pine actually has jigsaw-puzzle shaped pieces of bark. Maybe you have seen these in your neighborhood. Some people call the pieces “scales,” Perleberg said. When on fire, these scales peel back and fall to the floor, taking the fire back to the ground.

The tree makes sugar—its food– through a process called photosynthesis. Under the bark is a very important part of the tree that helps the tree mobilize sugar called the phloem.

It helps move sugars around the tree and to the roots. The thick layer of bark also helps protect the tree’s food-processing system from fire and other damage so it can get the energy it needs to survive.

When a fire happens, some trees will release a kind of sticky, honey-like substance called sap, or pitch. The pitch will flow into cracks where fire could reach that very fragile phloem. It’s kind of like smearing putty over a crack in a wall, Perleberg adds. This leaves the tree with a fire scar, he says, but the tree survives and keeps growing.

Fire ecologists can use these fire scars to trace the patterns of historic fires and how often they happened. Sometimes, fires occur naturally through lightning strikes. Sometimes, fires are man-made, and Native Americans traditionally burned areas to help people survive, encourage certain plants and keep ecosystems healthy.

Some trees have also adapted to shed their lower limbs. As the tree grows higher and higher, some limbs don’t grow anymore. The fire can’t climb up the tree as quickly without the source of fuel to help it along.

After a fire, the trees left standing likely had thick bark or another one of these adaptations. Meanwhile, the rest of the dead trees will also have a new purpose in life.

Dead trees and old plants that turn into ash return important things, called nutrients, to the soil. The old trees also become habitats to some kinds of wildlife that live in the forest. Bark beetles like the weak trees and go in to eat the sugary layer beneath the bark. Other critters, like flying squirrels or tree frogs, might turn a dead tree into their new home in the forest.

Sincerely,
Dr. Universe

Ask Dr. Universe – Where Bees Sleep

Dr. Universe: Where do bees sleep? – Annalisa, 10, Middletown, NJ

Dear Annalisa,

Sleep is important for lots of the animals on our planet. Just like you need a good rest, so do bees. But, bee sleep is different than human sleep.

That’s what I found out from my friend Brandon Hopkins, a bee researcher at Washington State University. I asked him how you can tell if a bee is asleep.

“They don’t have eyelids, so you can’t just look for bees with their eyes closed,” he said. “By carefully watching bees, scientists have found that honey bees stop moving their antennae and in some cases fall over sideways.”

Sometimes other bees will try to help keep a bee from falling over. They actually hang onto the fellow bee’s legs so it won’t fall off the honeycomb. That’s some serious team work. The sleeping honey bee also relaxes its muscles so the upper body and rear-end droop a little. It’s wings may also rest on its body.

Exactly where a bee sleeps depends on where it lives. More than 20,000 known species of bees live on our planet and we find them in different places.

Honey bees work day and night and take shifts sleeping inside the hive. Their sleep patterns change as they grow up. Younger bees sleep a lot less than the older bees. The older foraging bees that collect pollen and bring it back to the hive have more of a regular sleeping pattern.

It’s a little hard to say how long they sleep, but these older bees catch between 30 minutes and an hour and a half each night. To get all that rest, they take little sleeps, or catnaps, of about 15 to 30 seconds at a time.

It’s very important that honey bees sleep, Hopkins explains. Researchers have found that older honey bees need sleep because it helps their memory. Yes, bees can learn and remember things, too. They need to have good memory to remember where they find pollen and nectar.

In studies where bees stayed awake for long periods of time, scientists also found that bees were poor dancers.

It’s ok if a human is a poor dancer, but honey bees dance to communicate with other bees and tell each other where they might find flowers.

“If they are sloppy dancers, the hive becomes less efficient and won’t be able to collect as much nectar and pollen,” Hopkins says.

Then again, not all bees live in live in hives or have a colony. Some are solitary bees, like the teddy bear bee. The teddy bear bee often bites into small branches and hangs there for the night. Other solitary bees will sleep in their nests or on plants.

Now that you know bees sleep, maybe you’ll spot one taking a snooze in your neighborhood. Just be sure and let it rest. In meantime, you can watch this short video of a sleepy bee catching some z’s.

Sincerely,
Dr. Universe

Ask Dr. Universe – Sticky Sand

Dr. Universe: How does sand stick together?– Kamrin, USA

Dear Kamrin,

Sand is actually made up of lots of different things. When we look at it under the microscope, we can see cooled lava, coral, seashells, and other kinds of wonderful, colorful rocks.

If you add just the right amount of water to sand, it transforms into a pretty good material for shaping towers, walls, and spires for a sandcastle. At first, I thought the wet sand stuck together because of a chemical reaction. But it turns out this interplay of sand and water creates what scientists call a physical reaction.

That’s what I found out from my friend and physicist Lauren Barmore, a graduate researcher at Washington State University who is very curious about matter and how things work on our planet.

She explained that if you had two rocks and put a bit of water in the middle, the water would be attracted to the rocks and form a kind of liquid bridge between them. One property of water is that it doesn’t like to touch the air. It has to do with its chemical make-up. Water would rather hang onto something else.

Sand is really just a lot of little rocks and some of those other solids. There are a lot of these tiny liquid bridges in a handful of wet sand. The sand particles aren’t sticking to each other, but are being held together by water.

A lot of these little bridges can make the sand stick together better. The water bridges are actually shaped like hourglasses, thin in the middle and thick at each end, Barmore explains. But as you add more water, the bridge gets weaker and that bond breaks. Then you end up with a soupier sand. On the other hand, if the sand dries out, the water bridges start to disappear and the sandcastle crumbles.

The force behind this is called surface tension. We see it when we fill a water glass to the top and it forms a curved edge. It’s also how some bugs can walk on water and why a bit of water forms into a droplet instead of spreading out.

Perhaps you can try some sandcastle investigations of your own at home or the next time you’re at a beach. Can you find the best recipe for sandcastle sand? Is it one part sand to a half cup water? One cup sand to one cup of water? A different combination? What happens if you use a different kind of liquid instead of water? Tell us what you discover or create at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

3 sandy facts from physicist Lauren Barmore and Dr. Universe

• Some engineers have found a way to make strong building material out of sand. They can layer up two materials that are not very strong on their own—sand and paper towel—to hold up a car. Watch a video about the engineering process.

• The water bridges that connect sand actually have a scientific name: interstitial water bridges.

• The Guinness World Record for the tallest sandcastle is 54 feet.

Ask Dr. Universe – Why Music Gives Us Chills – Part 2

Part 2: Dr. Universe: Why does music give us chills? -Nicole, 11, Spokane, Wash.

Dear Nicole,

It turns out that the experience of getting chills when we listen to music actually has a scientific name: frisson. That’s what I found out when I met up with Washington State University brain scientist Steve Simasko.

Simasko said he also experienced frisson last year when the moon passed in front of the sun and he saw the total solar eclipse. That made me realize we not only get the chills when we experience music, but also when we experience other kinds of art or wonders in nature.

It isn’t exactly easy to measure frisson, but Simasko said we can still make a few speculations about it based on what we know about the brain.

When we take in music we are using our limbic system. This is a system which helps us process emotions and memories. In the middle of the brain is the amygdala, which also plays a big part in processing emotions.

This emotional system helps us navigate the world. When you experience different emotions, sometimes a physical sensation comes along with it. Fear might give you sweaty palms, a racing heart, and desire to run away from something. This kind of response is helpful for survival.

We also have other kinds of responses. When you get nervous maybe you experience the sensation of butterflies in your stomach. This triggers a release of adrenaline in the body. That left me wondering: Why is frisson tied to this emotional system in our brain?

Simasko explained that human emotions are closely tied to the social part of people’s lives. Sound can actually be an important part of our social life from a very young age. Mothers often sing to their babies, and the babies often coo back. It is part of human bonding.

Emotions are not just important for survival, but also understanding norms, or the way things usually work in a group. Music is also tied closely to our culture—it’s something that we can use to connect and we can share with each other.

If someone grew up listening to opera in China, maybe they get goosebumps when they hear it as an adult. Maybe you live in another part of the world and don’t listen to Chinese opera. It might not have as strong as a connection to you and those around you. But maybe there is a different kind of music that reminds you of memories with your family and friends. Can you think of a kind of music that gives you the chills?

While music is an important part of people’s lives, the truth is, we still don’t know everything about why it gives us the chills. But we do know that a lot of people experience frisson. Perhaps we will learn more about it one day, but until then, keep asking great questions– and turn up the music.

Sincerely,
Dr. Universe

Ask Dr. Universe – Why Music Gives Us Chills – Part 1

Part 1: Dr. Universe: Why does music give us chills? -Nicole, 11, Spokane, Wash.

Dear 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.

The truth is I really wasn’t sure why music gives us chills, but I was determined to find out. My first stop was the Washington State University School of Music. That’s where I met up with my friend and music professor Greg Yasinitsky.

He played a few different notes on the piano in his office. He told me that if you play three or more notes at once, it’s called a chord.

Major chords tend to make us happy,” he said. “Minor chords are more ominous or sad.”

However, when the music tends to be sad people don’t always describe it as unpleasant, he adds. Just think of an emotional or dramatic part of a movie. Even if the music has more of a sad sound, sometimes it brings about a positive emotion.

Composers will sometimes mix around major and minor chords to play with a listener’s emotions. They also play with things like rhythm, the strong regular repetition of sound, and melody, or the sequence of notes that helps a song sound just right.

Yasinitsky said there seem to be two situations in which people will report feeling the chills. The first is when a listener hears something that is a surprise. Maybe a song has a pretty repetitive pattern, but then something happens that they weren’t expecting.

“That one little change suddenly has this immense importance and for a lot of people could send a chill up their spine,” Yasinitsky said.

Another situation where people might get the chills is when they hear something that is not a surprise. When they finally hear what they’ve been expecting, they might get goosebumps.

Of course, not everyone gets the chills—and different kinds of music may bring out the chills in different people. Either way, most people have an emotional connection to music.

“Pretty much every culture on the planet has music,” Yasinitsky said. “Even those that have outlawed music, they chant, they are still singing. We all need music.”

After chatting with Yasinitsky, I headed across campus to visit the WSU neuroscience department. That’s where I met up with our friend Steve Simasko. He told me more about music, emotions, and the brain. But we’ll explore that next week.

In the meantime, you can try making your own instruments at home. Collect different supplies like rubber bands, popsicle sticks, toilet paper tubes, or other kinds of materials to create your own sounds. Try making a coffee can drum or some maracas. If you are feeling really ambitious, try out a shoebox guitar. Maybe you can play a tune along with your friends. Let me know how it goes at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Sweet and Healthy Foods

Dear Dr. Universe: What food is sweet and good to eat? – Sophia, Pullman, WA

Dear Sophia,

There are quite a few foods that are sweet and good to eat. A lot of them are fruit, said my friend Pablo Monsivais. He’s an associate professor at the Washington State University Elson S. Floyd College of Medicine.

It turns out we grow quite a few of those fruits right here in Washington state. Farmers in our state grow more apples and blueberries than any other state in the country.

We also produce a lot of cherries. Humans have been eating cherries for a long time. Some cherry pits have even been found in Stone Age caves in Europe. Dark cherries and blueberries have a lot of chemical compounds that plants make and that our bodies need, Monsivais said. We call them phytochemicals.

Monsivais said these kinds of fruits also have antioxidants, chemicals that protect your cells from damage. They may also be helpful for fending off type-2 diabetes, a disease that affects how the body processes sugar. He adds that many people who are diabetic and want something sweet may choose to eat blueberries. The body is often able to process the sugar from blueberries more gradually, so blood sugar doesn’t rise too rapidly.

Pretty much all kinds of whole fruit contain fiber, a plant material you don’t digest, but that helps move food through your body’s digestive system. Most of us need more fiber in our diet, Monsivais said.

Whole fruit is also high in potassium, a mineral most of us could use more of as well. Some have Vitamin C, which is important for keeping our skin, bones, and blood vessels healthy.

A lot of fruit also has folate, a vitamin that helps us make our genetic material, or our DNA. It helps our body’s cells divide. Fruit is good, sweet fuel for our bodies.

One of my new favorite fruits is the Cosmic Crisp, a big, juicy and crunchy red apple developed at Washington State University. Apples have also been shown to help support health, especially when it comes to heart disease, cancer, type-2 diabetes and even asthma.

Finally, there’s chocolate. Like blueberries and cherries, dark chocolate also has a lot of phytochemicals that can benefit your health. But most of the benefits are in dark chocolate that has 70 percent or more cocoa powder. Some people find this type of chocolate kind of bitter.

However, Monsivais said how we taste sweets can change based on how many sweets we regularly eat. The more sweet foods and sugars you eat, the less sweet other stuff tastes. If you want things to taste sweeter, it might help to eat less sugar.

It’s also good to remember that it’s not just sweet foods that have sugars. They’re in a lot of the foods we eat, like sliced bread, salad dressing, and ketchup, too.

As kids get older, they tend to like sweet stuff less and less. Some researchers have even investigated this idea. They made a sugary solution of water and sugar. Adults like about as much sugar as is in a can of soda. Kids preferred at least twice that much.

That made me wonder, why do kids like sweets more than adults? Do you have an idea? Tell us at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Dogs’ Wet Noses

Dr. Universe: Why do dogs have wet noses? – Molly, NY

Dear Molly,

While we might not know all the reasons dogs have wet noses, I was able to sniff out a couple answers for you. I couldn’t have done it without some help from my friend Katrina Mealey, a veterinarian and researcher at Washington State University.

As a veterinarian, Mealey invented a medical test for dogs to make sure they get the medicine they need to stay healthy. She cares for all kinds of animals and knows a lot about dogs, including her own German shorthaired pointer, who also has a wet nose.

Dog noses come in all shapes, sizes, and colors, and pretty much all of them are wet. Most often a wet nose is a good sign that they are healthy, Mealey says. We do know that a wet nose helps dogs maintain a nice body temperature and helps them smell.

In fact, a wet nose can actually help increase a dog’s ability to smell. While you have wet boogers and mucus up inside your nose, dogs have something kind of like mucus on the outside of their noses. It’s called serous secretion and it comes in handy when they are sniffing around.

Maybe you can think of a few of your favorite and least favorite smells. All smells are really just a combination of chemicals, made up of building blocks called atoms. When the chemicals join up with each other in different arrangements, we smell different things.

The moisture created by the serous secretion that comes from the dogs’ noses can help them capture different chemicals in the air and smell better.

Dogs also have wet noses because they lick them. If you can make your tongue touch your nose, you are part of ten percent of the population that can do it. Go ahead and give it a try. Any luck?

It’s much easier for dogs to lick their noses. Dogs will use their tongues to spread the serous secretion around their nose and create even more moisture, helping them smell even better.

A dog probably smells all kinds of things we can’t even imagine, Mealey said. Dogs have more than 300 million little receptors in their nose that help them smell, while humans have only about six million. This great sense of smell makes some dogs really great trackers.

Mealey also said that dogs don’t sweat all over their body like humans do. Instead they have little glands on their paw pads and on their noses. These glands produce a little liquid that evaporate and cools their body.

Maybe you’ve experienced this when you got out of a pool on a sunny day and felt a bit chilly. The water was also evaporating from you and taking some of your body heat along with it.

“Evaporation on their nose helps cool them down a bit,” Mealey said. “We believe that’s one of the way they make up from not being able to sweat a lot.”

Along with panting, a wet snout can help a dog keep its body temperature just right.

Sincerely,
Dr. Universe

Ask Dr. Universe – Cacti

Dr. Universe: How do cacti survive in such hot and dry environments?
-Ravin, 11, London, England

Dear Ravin,

All plants need water to survive. Those that live in places where water is scarce use some interesting strategies to stay alive.

That’s what I found out from my friend Charles Cody, who manages one of the greenhouses at Washington State University. When I went to visit the greenhouse, he pointed out a few different cacti.

One was tall and cylindrical with big spines. Another was small and round with what looked more like little hairs. A rainforest cactus hung on the wall like a vine.

Cody explained that if we looked closely at a leaf of a plant we would find parts called stomata, which are kind of like little gates that let air and water in and out. Since cacti don’t have true leaves, their stomata are in the body of the plant, or the stem.

In most plants with leaves, the stomata open up during the day to take in a gas called carbon dioxide from the air. Plants can use this carbon dioxide plus sunlight and water to make their food. It’s a process called photosynthesis and it helps plants get the energy they need to survive.

When the stomata are open, the plant also lets out oxygen—the oxygen we all breathe. But at the same time, the plant can also lose water. It evaporates in the sun. You might already know about evaporation, if you’ve ever seen the water in a puddle seem to vanish on a sunny day. But stomata in the desert are a bit different.

Instead of stomata that open during the day, cacti have stomata that open at night. This helps them survive in extreme conditions. Cacti can still get the carbon dioxide they need to make their food without having their water supply zapped. They store up the carbon dioxide overnight and use it the next day to make their food.

Cody says cactus spines are actually a unique version of leaves. The spines provide a little shade to the cactus when they cast their shadow onto the stem. They can also collect dew, and when the dew drips to the ground, the roots take it into the cactus.

Spines also warn some desert critters to stay away and not eat the cactus. But sometimes if there is a long period of time without water, or drought, cacti like the prickly pear can offer a source of food to some desert critters.

Cacti can store a lot of water, too. When it rains a lot, the saguaro cactus takes in so much water it weighs up to about 4,800 pounds, or just a little less than a mini-van.
Life in the desert works out well for cacti, but I’m not quite adapted to that environment. I think I prefer a warm greenhouse where conditions are just right for a cat nap.

Sincerely,
Dr. Universe

Ask Dr. Universe – Sleepwalking

Dr. Universe: What is happening when we sleepwalk? -Daniel, 11, Easton, CT

Dear 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.

It’s almost like they are taking a little cat nap, said my friend Hans Van Dongen, a sleep researcher at Washington State University. Maybe you’ve experienced this if you’ve been daydreaming, lost your train of thought, or even just zoned out for a bit.

Van Dongen and his team observe lots of different sleep behaviors at the Sleep and Performance Research Center–that’s my kind of lab. He said there are really two main types of sleepwalking.

The first is when you are in a deep sleep. In a deep sleep, your brain isn’t thinking about much at all. It is actually recovering from the day before. During this time, the part of your brain in charge of different motions and movements is acting on its own.

There’s a chance that if you sleepwalk in this state, you will find yourself doing something you did during the day. You might walk down the hallway or to your table.

If you wake up someone who is doing this kind of sleepwalking, they will be pretty confused. It’s similar to that surprised feeling you wake up to at the sound of an alarm clock.

“It’s just a part of the brain forgetting that it is supposed to be asleep and carrying out an automatic program,” Van Dongen said.

The other type of sleepwalking happens in the same sleep state where most people remember their dreams. In this state, your eyes are at times moving very quickly while you are asleep—it’s called rapid-eye movement sleep. While scientists don’t exactly have evidence to show dreams have particular meanings, we do observe that dreams have storylines.

When you are in rapid-eye movement sleep, the brain turns off the muscles in your body. It’s called muscle atonia, and the brain does this so that when you are dreaming a storyline kind of dream, your body won’t act it out in real life. Sometimes muscle atonia happens while you are just about to fall asleep. This is known as sleep paralysis—and you may experience it as a feeling of falling or tripping when you are drifting off to sleep.

In some people, the brain sometimes starts dreaming, but it doesn’t turn off the muscles. That’s another reason why we see people sleepwalking. It isn’t supposed to happen, but sometimes the brain just doesn’t send the right message to the body.

A lot more kids sleepwalk than adults, too. While we don’t know exactly why, we do know the brain goes through some big changes as we grow and learn to walk, talk, think, and socialize.

“These are massive changes happening in the brain,” Van Dongen said. “The ever-changing brain doesn’t always get it perfectly right.”

Sleep is fascinating—and sometimes just thinking or writing about it makes me a little sleepy. I think it’s the perfect time for a cat nap.

Sincerely,
Dr. Universe

Ask Dr. Universe – Lizard Tails

Why do lizards lose their tails? -Bailey, Inwood, Iowa

Dear Bailey,

Our planet is home to all kinds of lizards. Maybe you’ve seen one climbing up the wall, scurrying through the grass, or at the pet store. Just the other day I saw a big green iguana when I visited the Washington State University Veterinary Teaching Hospital in search of an answer to your question.

Lizards hatch from eggs, have a backbone, scales, and depend on the environment to keep warm. They have four legs and claws, and a tail, which they sometimes lose and grow back. My friend Marcie Logsdon was taking care of the big iguana and several other exotic animals. She told me all about lizard tails.

Lizards have a series of small bones that run down their back. They are called vertebrae. Along the tail are several weak spots called fracture planes, Logsdon said. They are the places where the tail can detach.

The main reason a lizard loses its tail is to defend itself. When a lizard detaches its tail, the tail whips around and wiggles on the ground.

Nerves from the lizard’s body are still firing and communicating with each other. In fact, sometimes the tail will keep moving for upwards of a half hour. This distracts a predator and gives the lizard plenty of time to escape.

When the lizard’s tail grows back, it’s a bit different than it was before. Instead of a tail made of bone, the new tail is often made out of cartilage, the same stuff that’s in your nose and ears. It can take quite a while for the cartilage to form, too.

The small green anole has a tail that is only about four inches long, but it takes about two months to grow back. Meanwhile, a longer iguana tail might take more than a year to grow back.

Most lizards can only lose their tails so many times before they can’t regrow them anymore. Of course, there are the exceptions. The crested gecko is one lizard that can lose its tail, but it doesn’t grow back.

Like lizards, some squirrels also lose their tails to escape predators. But their tails also don’t grow back. In nature, we see other animals that regrow different parts. Some worms split into pieces can grow into new individual worms. Sea cucumbers can do this as well. Some spiders can even regrow missing legs or parts of legs. Some salamanders can also shed their tails.

You know, tails can come in handy. Some lizards can wrap their tails around vines or branches. Others use their tails as a kind of propeller to help them move through the water. Tails are also useful for balance. And for some lizards, being able to ditch their tail might just save their life.

Sincerely,
Dr. Universe

Ask Dr. Universe – Glaciers

Dear Dr. Universe: What is a glacier? – Addison, Pullman, WA

Dear Addison,

When snow piles up and compresses into a thick mass of ice, we call it a glacier. But a glacier is really more than ice and snow.

“People think of them as these big blocks of ice where nothing could live,” said my friend Scott Hotaling, a biologist at Washington State University. “For a long time that was the idea, that glaciers were devoid of life.”

Hotaling spends a lot of time visiting glaciers, where he’s on the lookout for small, black creatures that live there: ice worms.

Can you imagine living in a giant block of ice? For ice worms, it’s the perfect habitat. Hotaling is curious about how animals and plants have adapted to live in such extreme environments. The ice worm is also a source of food for migrating birds, like the snow buntings and rosy finches, that fly from Alaska to the lower U.S.

Hotaling is also curious about animals that live in the icy water that melts from glaciers. One of these is the threatened meltwater stonefly.

Understanding more about these animal habitats and how they survive can help us protect the species that call glaciers home.
Glaciers are also a source of water for animals and humans.

About ten percent of the land on Earth is covered in glaciers.
Washington state has more glaciers than any other state in the U.S., besides Alaska. In our state, melting glaciers produce 470 billion gallons of water each summer. Humans rely on meltwater for farming, hydropower, and drinking.

“As we use up more and more of the fresh water on Earth, existing sources become increasingly important,” Hotaling said. “Glaciers are the biggest fresh water resource there is.”

If you were to visit a glacier, you might hear quiet trickles of water moving through the ice or a rushing torrent cascading from the end of the glacier. Or perhaps you would hear a loud boom and crack as a piece of ice broke away and became an iceberg.

Glaciers are really heavy and slide down the sides of mountains, carving and shaping different features along the way.

Glaciers in Washington’s Cascade and Olympic Mountains helped sculpt the landscapes we see in Olympic National Park, the North Cascades and even around Mount Rainier.

On the Palouse in eastern Washington, we can also see the history of glaciers. During the last Ice Age, huge floods carried glacial meltwater and pulverized rock, called glacier flour, into the state. When it dried, the very fine dust blew across the land and fell to help form the rolling hills of the Palouse.

A glacier is connected to many parts of life on earth from providing drinking water, to icy habitats, to shaping the environments where we live.

Sincerely,
Dr. Universe

Ask Dr. Universe – Stink Bugs

Dr. Universe: Why do stink bugs stink? – Lily Z., 11, Oregon

Dear Lily,

You’re right, stink bugs give off quite a stink. To find out exactly what that smell is all about, I visited my friend Elizabeth Beers. She’s a researcher at Washington State University who works with insects, including a kind of stink bug.

You may remember smells are really just a combination of elements. An eggy smell, for example, often comes from a combination of two elements, hydrogen and sulfur. These elements come together to form a compound.

A stink bug releases its own compounds from a small gland located on the middle section of its body, or the thorax. Different kinds of stink bugs may give off different smells as they release different compounds into the air. Each person’s nose may pick up on the smell in a slightly different way, but most people agree the smell is pretty unpleasant.

Adult stink bugs don’t have many predators, in part because of their size and their smell. They can be attacked by spiders, praying mantises, and assassin bugs. The smelly compounds are a defense mechanism, Beers adds. Even if the stink bug might actually taste good to another bug, the predator just can’t get past the smell and may leave its prey alone.

In the U.S., we have more than 200 different species of stink bugs crawling around. Some of them made their way here from other countries. We call them an invasive species.

One invasive stink bug that has moved into Washington state is the brown marmorated stink bug. Recently, Washingtonians were starting to see a lot of these in their houses and yards. This species is reported to smell a bit like cilantro.

Beers and her fellow scientists at WSU got a lot of messages about the stink bug sightings—and the reports continue to pour in, she says. The bugs pose a challenge for farmers.

We grow a lot of fruit trees in Washington state. Do you have a favorite fruit? Farmers work hard to bring us the best apples, pears, and cherries. But stink bugs can be a real pest.

They stick their long tube-like proboscis down into the fruit and damage it. Beers and friends at WSU are working on ways to help manage stink bugs so farmers can keep growing delicious, healthy fruit.

If you have friends in Washington state, you can let them know they can report stink bug sightings to our researchers. You can identify a brown marmorated stink bug by its six legs, two antennae with white stripes, and its shield-shaped body. Here’s a photo.

After you find one, snap a photo and include it in an e-mail with your name, the date you found it, and where you found it. You can send your findings to tfrec.reportbmsb@wsu.edu. Have fun practicing your stink bug sleuthing skills, citizen scientists.

Sincerely,
Dr. Universe

Ask Dr. Universe – Earth’s Garbage – Part 3

Part 3/3
 
Dear Dr. Universe: What happens to the world’s garbage? -Presley, 8, Spokane, Wash.
How do you recycle an object into another object? -Brianna, 12, New York

Dear Presley and Brianna,

So far, we’ve investigated how recyclables like plastic, aluminum, and paper can end up in the trash. If our clothes get damaged, or we simply outgrow them, we might toss them in the trash, too. Or send them to a thrift shop. Either way, they often end up buried in a landfill.

But my friend and Washington State University researcher Hang Liu imagines a different future for our used clothes. In her lab, she and her team are coming up with creative ways to recycle cotton into a new fiber.

My own lab coat is made of cotton. If you look at the tags on your clothes, maybe you’ll see some of them are also made from cotton. Cotton comes from a plant and is a natural fiber made up of lots of different parts that we call molecules.

As we learned last week, we can use heat in the recycling process to break down materials. However, the molecules that make up cotton stand up to heat really well. This has made it hard to recycle cotton in the past. Instead of using heat, Liu and the team created a mix of environmentally-friendly chemicals to dissolve the cotton fabrics.

Using a machine they built in the lab, they can transform those molecules back into a new fiber that can be woven into new clothes. The machine in their lab has five holes that spin out tiny fibers. But one day this method could be used in even bigger machines to create even more fiber for clothes.

Liu even showed me a spool of blue cotton made out of denim from an old pair of jeans. Denim is just one of many cotton products that can be recycled with this new process.

In the U.S., an adult discards about 68 pounds of textiles, cloth or woven fabric, every year. About at least 75 percent of that eventually reaches a landfill.

Liu and her team are excited to be able to recycle old cotton materials like clothes, sheets, and towels into new fiber— over and over again. Their invention will help keep more waste out of landfills.

Liu reminds me that finding new ways to recycle clothes is important if we want to meet the needs of people today while also making sure the next generations have what they need in the future.

One question that remains is what to do with the zippers and buttons on these recycled cotton clothes, Liu says. Who knows, maybe you can help come up with a creative way to recycle clothes or fabric. After all, recycling never goes out of style.

Sincerely,
Dr. Universe

P.S. Thank you to all our generous Dr. Universe readers who inspired future scientists and engineers by donating items to the first-ever Science Rules STEM Supply Drive! The donations will support science education in local classrooms, libraries, and after-school programs.

Ask Dr. Universe – Earth’s Garbage – Part 2

Part 2/3
 
Dear Dr. Universe:
What happens to the world’s garbage? -Presley, 8, Spokane, Wash.
How exactly do you recycle an object into another object? -Brianna, 12, New York

Dear Presley and Brianna,

While a lot of our trash goes in a landfill, we can also recycle all kinds of stuff on our planet. Depending on what the object is made of, we might grind it up, mix it up or melt it down before we turn it into something new.

Let’s start with paper. When you recycle paper, it usually ends up at a recycling center where it gets washed with soapy water and mixed into a huge, thick slurry.

Sometimes we add a few other ingredients if we want a specific kind of product, like cardboard or printer paper. The slurry is poured out onto a big table and flattened with big rollers. After it dries, it can be cut into different sizes and shipped to stores. Recycling is a great way to help us make new paper without cutting down more trees.

We can also recycle things like glass, plastic and aluminum. A lot of these materials are mixed together in a recycling bin, so the first step when they arrive at a recycling center is to wash and sort them. Engineers have built conveyer belts and equipment to help divide up the different items into groups.

Once they are divided up, they can be melted down, cooled and shaped into flat sheets or new objects. A glass bottle might become a jar, a plastic bottle might become recycled clothing and a soda can might become another soda can.

While different objects go through different recycling processes, most of the time we break them down before we build them up into something new. But some materials that we want to recycle don’t break down quite as easily.

While most of us put smaller items into the recycle bin, we also have lots of really huge stuff we need to recycle, too. Things like airplane wings and giant blades from windmills often end up in landfills. My friend Jinwen Zhang, a scientist at Washington State University, is helping research ways to recycle the lightweight materials and keep these big objects out of landfills.

This kind of lightweight material, carbon fiber plastic, they work with in the lab can’t melt down like a lot of other things we recycle. Zhang and his team figured out a different way to break them down using just the right environmentally-friendly chemical mix.

Exactly what kinds of objects those wings and blades will become is a question that we are still looking to answer. It will inspire more research and help us understand how to recycle things that couldn’t really be recycled before we learned to break them down.

These are great questions you ask, Brianna and Presley. Thank you for being curious. We can help make the planet a safer and healthier place to live when we recycle.

Sincerely,
Dr. Universe

Ask Dr. Universe – Earth’s Garbage – Part 1

Part 1

Dear Dr. Universe: What happens to the world’s garbage? -Presley, 8, Spokane, Wash.

Dear Presley,

If you’re anything like me, maybe one of your weekly chores is helping take out the trash or making sure all your tuna cans get into the right recycle bin. The truth is, I wasn’t entirely sure where the garbage goes either, so I decided to ask my friend Karl Englund.

Englund is a research engineer at Washington State University and studies all kinds of different materials in our world. He is really curious about how we can take materials and give them a new purpose. Our garbage can end up in a few different places, he says.

The average human who lives in the U.S. creates about 4.83 pounds of trash each day. As you can imagine, it piles up pretty quick. Many people don’t really see much of it, though.

Englund explained that after sanitation workers pick up the trash in their big trucks, they often drive to a landfill. A landfill is a place where we bury garbage underground.

Some garbage will break down pretty fast in a landfill. Something like a banana peel will become part of the soil again in about a week or so. Some people even let these organic things break down into something called compost and use it to help their gardens grow. But then there are other items we throw out that don’t break down as easily, such as plastic water bottles. A plastic water bottle can remain in the earth for hundreds of years.

A plastic water bottle may not break down in the dirt, but it can be pretty easily made into new plastic materials if we simply recycle it. That’s why it can be helpful to learn about what different materials are made of and how we can dispose of them in a way that helps the environment.

You could also repurpose something like a plastic water bottle. If you cut it in half, it might make a nice little container to grow some small plants, Englund says. Or if companies take the bottle and grind it up, they can make things like carpet or even a playground. It takes some science mixed with a lot of creativity.

In Englund’s lab, scientists are working with materials from old airplane wings to create a kind of pavement.

When it rains, a lot of dirty storm water often puddles up on roads and flows into the streams and rivers. But pavement made with recycled materials lets water flow straight down into the soil. The soil acts as a natural filter and the pavement keeps toxic things from running off the road into the water. This is really important to the fish and other animals that call the water home.

With Earth Day just around the corner, we’ll keep exploring more questions about ways we can use science and engineering to help our planet. Stay tuned for next week’s big question.

Sincerely,
Dr. Universe

Ask Dr. Universe – Broccoli

Dr. Universe: How come broccoli is good for you? -Zack, 10, San Lorenzo Valley

Dear Zack,

You aren’t alone if you’ve ever heard someone at the dinner table say, “you’ve got to eat your broccoli.” Broccoli is one of nature’s superfoods, so it’s no wonder we are often encouraged to eat those little green trees.

As I cat, I don’t eat too much broccoli. So, I decided to visit my friend John Clarke, a professor of pharmacy at Washington State University. Broccoli is what got him a PhD, he says. Clarke studied how broccoli can help fight off toxic things in our bodies and may even have cancer-fighting properties.

He’s happy to help with your question and says broccoli is what we call a cruciferous vegetable. Whether it’s broccoli, cabbage, radishes, or bok choy, the veggies in this family all share a similar chemical makeup.

If you’ve explored the periodic table of elements, you know that there are a lot of different elements that make up things in our world. When two or more elements come together, they form a compound.

When we chew or cut broccoli, we damage the plant tissues and a new compound forms. It’s actually this compound in broccoli that gives off that, well, unique broccoli smell. Scientists have also discovered how this same compound can help fight off toxins in your system.

“The plant has components that can act like coffee in a tired person,” Clarke said. “It stimulates some of the body’s detoxifying bodyguards to stay awake and get rid of bad toxins in the body.

There are lots of ways to eat broccoli, too. You might steam it, fry it, roast it—maybe even sprinkle a little cheese on top. But I also found out that cooking broccoli actually reduces some of those bodyguard compounds.

“It is still good for us,” Clarke said. “It’s just that it is better to eat the whole food.”

You’re right, Zack. Broccoli is good for us– and it’s best raw.

Broccoli is also packed with vitamin C, which can be good for fighting off infection. If you are ever feeling under the weather, you might just consider having a little broccoli along with your chicken noodle soup. It also has fiber. When we get enough fiber from our food, it can help with both heart and blood health.

The chlorophyll that gives broccoli–and a lot of other plants–its green color can also be good for us. It has all kinds of nutrients and is the source of vitamins and minerals our body needs to grow strong.

Maybe sometime soon you can help make dinner at your house and see if you can find a creative way to use those little green trees.

You can learn more about all kinds of vegetables and try out these recipes from my friends at WSU Extension. http://extension.wsu.edu/skagit/harvest-of-the-month/ Tell us how it goes sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Bees’ Behinds

Dear Dr. Universe: My daughter is asking, why do bees have pointy behinds? -Asma, Pakistan

Dear Asma and Friends:

Lots of bees have pointy behinds, but not all of them. The ones that do have a pointy behind, or a stinger, can use it to help defend their homes, food, and fellow bees. That’s what I found out from my friend Megan Asche, a graduate student at Washington State University who studies honey bees and takes super close-up photos of insects.

Asche explained that when a honey bee adult emerges, it chews through one of the waxy hexagon cells in the hive before pushing itself out into the world. For the first two days of the bee’s life, it can’t sting. The bee has a pointy behind, but the venom-releasing organs attached to her stinger are still growing. She needs to walk around and eat before the stinger fully forms.

If you get stung by a bee, it’s going to be a female. Males don’t have a stinger.

Female bees’ ancestors used to lay eggs inside plants or animals using a kind of shovel-shaped thing on their rear end called an ovipositor. After a while, they didn’t need their ovipositor, so it stopped being used for laying eggs and instead became a stinger bees can use to help defend their home.

When a new queen honey bee hatches, she will use her stinger to damage the wax cells where her rival queen bees are growing. She also has to look for a mate. Once she has found a mate, she doesn’t need her stinger anymore. If there’s any stinging to be done, that’s the job of the worker bees.

In one of the photographs Asche took in the lab, you can see that a honey bee stinger has lots of tiny sharp parts, or barbs. The little barbs on a honey bee stinger are long enough to stick in your skin. Bees don’t want to hurt you, but sometimes they will sting if they feel threatened. Once a honey bee stings you, it dies. That’s because its stinger is attached to important organs inside of the abdomen.

“They are essentially making the greatest sacrifice,” Asche said.

When you get stung, the bee will release a pheromone, or a chemical. The bees are basically flagging you. Other bees can sense this pheromone in the air and may show up on the scene. Their stingers may be tiny, but they sure can use them to protect their fellow bees.

“Worker bees are defending their sisters,” added Asche. “They are protecting their home and their food.”

In the end, a pointy stinger can help a family of bees survive. That’s really important for humans and other animals, too. Bees are pollinators. We rely on them to help plants grow and reproduce so that we can have oxygen, food, and a healthy planet.

Can you think of other ways insects might defend and protect themselves in nature? Tell me about it sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Puffer Fish

Dear Dr. Universe: How do puffer fish puff up? Do they fill with water or air? Why do they get so big? Thank you. – Ben, 6, Madison, WI

Dear Ben,
You’re right, a puffer fish can get pretty big. In fact, some of them can even inflate to the size of a balloon or a beachball.

My friend Wes Dowd is an associate professor in the School of Biological Sciences at Washington State University who currently studies mussels and tiny crustaceans called copepods in tidepools. Much of his training was with fish and he has always been curious about life in the ocean.

In fact he said he’s shared your fascination with puffer fish ever since he was a kid himself, fishing for the Northern puffer fish on the waters of the Chesapeake Bay.

He remembers these fish were a lot different than the bass or flounder he usually caught. The yellowish puffer fish had spines around its body, puffy cheeks, and a little beak-like mouth.

One idea scientists have about the pufferfish is its puffiness is a defense against predators, Dowd explained.

If puffer fish are swimming, they gulp water into a special sack near their belly. But if they are frightened while in the air, perhaps while being fished out of the water, they will also gulp in air.

“In the fish world, dinner is often consumed in one bite,” says Dowd. “So making yourself as big around as possible minimizes your chances of being eaten.”

Being able to puff up while also having lots of spines on your body is also a great way to ward off predators.

Even if a predator is big enough to eat a puffer fish whole, it will be in for a big surprise. Some pufferfish also have another potent way to defend themselves: tetrodotoxin. It blocks the ability for an animal’s nerves to communicate with each other, causing paralysis or death. However, some puffer fish like the ones Dowd caught as a kid aren’t toxic.

Believe it or not, the puffer fish is just one of more than 200,000 known species of animals that live in our oceans—and there are likely millions more we don’t even know about yet. Who knows Ben, maybe one day you’ll discover something about the puffer fish or other kinds of life out there in the ocean.

Sincerely,
Dr. Universe

Ask Dr. Universe – Bees Making Honey

Dr. Universe: How do bees make honey? – Nisi, 10, Nampa, Idaho

Dear Nisi,

All around the world bees are busy turning nectar from flowers into sweet, golden honey. That’s what I found out from my friend Brandon Hopkins, a honey bee researcher at Washington State University.

When a bee sucks up nectar from a flower, the sugary liquid flows into its honey stomach. Unlike the stomach where its food goes, the bee uses this tiny compartment just for carrying honey. It can haul about one-third of a bee’s body weight in nectar.

Once the bee’s honey stomach is full, it heads to the hive, where it is greeted by housekeeping bees who are ready to help with the next step.

The full-bellied bee spits up, or regurgitates, the nectar. It passes the nectar to some of the housekeeping bees then heads back outside to fill up again. Meanwhile, the housekeeping bees get to work. They pass the regurgitated nectar to other bees in the hive and it is eventually put into the hexagon-shaped honeycomb cells.

Hopkins said sometimes the nectar has too much water in it for the bees to make honey, so the bees fan the nectar with their wings to help some of the water evaporate.

After the bees get rid of the moisture it is ready for storage. Using a gland in their body, the bees produce small flakes of wax. They can use their jaws, or mandibles, to move it around and shape it. Finally, the bees create a wax cap for the honeycomb cell to seal in the honey.

Bees are quite the honey-making machines. They are also important for helping plants and flowers survive. While sipping nectar, they also move around tiny grains of pollen from flower to flower. This process helps flowers reproduce. The pollen is also food for the bee.

Bees are not only good for plants, but also for any humans who like to eat dinner. Bees help pollinate fruits, nuts, and all kinds of other food sources. Of course, we also eat the honey they make. Honey has been part of the human diet for a long time.

Archeologists have actually found old pots full of honey in tombs from ancient Egypt. It had crystalized into more of a solid, but could be melted back into liquid. Even though the honey was put in ceramic pots thousands of years ago, it was still good to eat. Honey has the longest shelf life of any food out there, Hopkins adds.

There are lots of bees that make honey and there are lots of different kinds of honey to try.

The flavor often depends on what plant nectar the bee used to make it—clover, berries, trees, or whatever flower the bee happened to visit. Send an e-mail with the subject “honey” to Dr.Universe@wsu.edu this month and you’ll be entered into a raffle for a jar of honey from WSU. The winner will be announced the last week of June.

Sincerely,
Dr. Universe

Ask Dr. Universe – Worms

Dear Dr. Universe: Why do worms come out when it rains? -Courtney, Moscow, ID

Dear Courtney,

That’s a great observation. When it rains, worms sometimes leave their home in the soil and wiggle their way up to the surface, where we see them on sidewalks and roads.

Worms come to the surface to move around, but exactly why they do it or where they are headed remains a bit of a mystery. Still, scientists have some interesting theories about it.

That’s what I found out from my friend Tarah Sullivan, a scientist at Washington State University who studies the living soil. Soil is very much alive, she reminds me.

It’s not only home to worms, but also all kinds of plants, insects, and billions of tiny living things called microbes. The different kinds of life in the soil depend on water to survive, so rain is quite often a really good thing.

One theory for why worms come to the surface is so they don’t drown, Sullivan says. But worms breathe through their skin and they can actually get some of their oxygen from water. They also need a wet environment to live and breathe, so it seems like there would need to be a lot of rain for this theory to work out, she adds.

Another idea scientists have is that rain creates some pretty good travel conditions for worms. Imagine you were trying to move through a big tunnel of soil. It would probably be hard to move around with all kinds of dirt clods, roots, and other things in your way.

Yes, worms can wriggle and squirm through the soil. But it’s still going to be easier for them to travel, and faster, if they are moving around in the more open space on the surface. They may be able to find other worms easier, too. This is especially helpful if they happen to be looking for a mate or trying to find a new home.

Worms like to avoid light and don’t want to get fried in the sun, so moving when it’s rainy or cooler outside can make for safer travel conditions. If you see worms on the sidewalk, it’s best to not disturb them. They have some important work to do and have to continue on their journey.

Worms can help soil stay healthy, which is especially important to us because we need healthy soils to grow the food that we eat.

Maybe the next time it rains in your neighborhood you can go out and make some worm observations. How many worms can you count? How long was it raining and what were their travel conditions? Are they headed in a certain direction?

Tell me about it sometime at Dr.Universe@wsu.edu. Keep asking great questions and maybe one day you’ll be helping us answer big questions about the living soil that supports life on earth.

Sincerely,
Dr. Universe

Ask Dr. Universe – Recommended Experiments

Dr. Universe: Do you have any experiments you 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

P.S. Science rules! Join Dr. Universe for a STEM Supply Drive to support local schools, libraries, and after-school programs on the Palouse. Visit askDrUniverse.wsu.edu/ScienceRules to find a list of supplies and drop-off sites.

Ask Dr. Universe – 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.

Part of the answer to your question is that some of your personality comes from your parents. Just as parents pass down physical traits like hair and eye color to their offspring, they can also give them different personality traits. They’re in your genes, the information passed throughout generations.

But your personality isn’t set in stone from the beginning. There are a few other things that go into it.

That’s what I found out from my friend Chris Barry, a psychologist at Washington State University. He studies personality in young people, including how people express themselves on social media. He was really excited to hear about your question.

Even as little babies, people start to express their own personalities, he said. Maybe you were a really fussy infant. Maybe you laughed or smiled a lot. As you grew up and learned how to communicate, your personality started to grow, too.

You’ve had a lot of different life experiences and those play into your personality, too. Barry reminded me that humans are social animals. He explained that as the brain develops, you become much more aware of the world around you.

For example, when you were little, you could run around with spaghetti all over your face and no one would think much about it. But now that you are an 11-year-old, running around with spaghetti on your face could be a little embarrassing.

Perhaps your family and friends would suggest you find a napkin. Barry explained that as you get older you are not only more aware of different social situations, but also your own personality.

Humans are often looking for information from other humans to figure out how to navigate the world. Meanwhile, an almond-shaped brain structure called the amygdala is especially helpful as you figure out these new situations and emotions.

You may notice that your family, friends, or others may react to the way you behave. You might learn to change your behavior depending on their reactions. While everyone has their own personality, in a way, other people are helping shape it, too.

Humans have all kinds of words to describe each other’s personality traits. In fact, some researchers have come up with a list of more than 600 characteristics.

Barry explained that we still have a lot of unanswered questions to explore when it comes to understanding personality. He said that while your personality develops a lot as you grow from a baby into a kid, it probably won’t change too much once you become a grown-up.

Based on your question, it appears that you are very curious. That can be a great personality trait. Have you ever thought about become a scientist or researcher one day? Keep asking great questions and you’ll be well on your way.

Sincerely,
Dr. Universe

Ask Dr. Universe – Mooing Cows

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.

Human ears might not always pick up the small differences in moos, but cow ears sure can. In fact, cows have great hearing. They can even tell that different moos mean different things.

That’s what I found out from my friend Amber Adams-Progar, an animal scientist at Washington State University who studies cow behavior. She learns a lot about how we can better care for cows and spends time visiting our herd out at the Knott Dairy Center in Pullman, Wash.

Adams-Progar explained that before humans domesticated cows and started raising them on farms, these animals lived in the wild. In nature, mother cows go off on their own to find a spot to have their baby.

Sound is a big part of how a mother and baby cow bond. While a calf might send out one kind of moo when she is hungry, another moo might mean she’s lost.

“Sometimes a calf will go running off and the mom will look around. All of a sudden you hear her moo and then somewhere in the distance you hear a little moo respond back,” Adams-Progar said. “It’s kind of cute.”

Some cows will also moo when they are looking to find a mate. Finding other cows in the herd is part of why these animals moo, but there other reasons, too.

In the wild, cows are prey animals. Sometimes mooing attracts predators, but sometimes cows can also use their moos to help keep each other safe. They can use their moos and their great sense of hearing to let other cows in the herd know there might be danger afoot.

While mooing can help cows find and protect one another, they also use other kinds of behaviors to communicate. Sometimes cows will grunt. Usually when we see cows grunting, they are pretty content, like when they are eating. They may also use their grunts when they are defending themselves or letting other cows know about their rank in the herd.

A wag of their tail can also help communicate to animals around them. When its tail is between its legs, the animal may be cold. A wagging tail could also mean it is in pain or just irritated. Cows also use their tails to swat away flies and sometimes calves wag their tails when they are nursing.

It’s a great question you ask, Sam. Maybe the next time you drive by a herd of mooing cows you can think about all the different communication that is going on out there in the pasture.

In fact, your question leaves me with even more questions about animal communication. Why does a bat screech? A bee buzz? Or an elephant trumpet? What is your favorite animal? What sounds does it make to communicate? Tell me about it sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – 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.

Ever since you were born, different cells have been working on your hair. Each hair sprouts from a follicle, a sort of little hair-making factory under your skin. Here, some of your cells are making your hair and others are coloring it.

The cells that color your hair are called melanocytes. They produce a pigment, or natural coloring matter, called melanin. This is the same pigment that gives your eyes and skin their color, too.

I decided to visit my friend Cynthia Cooper, a biologist and researcher at Washington State University, for help answering your question.

A close-up look at cells

Cooper and the other scientists in her Vancouver, Wash., lab are really curious about cells. They are investigating questions about how some cells end up becoming the kind that produce skin pigment.

As people get older, she said, the pigment-producing cells in their hair follicles gradually die. They can no longer make enough pigment to keep coloring their hair.

If we took out all the pigment from your hair, it would be totally white.  So when melanocytes stop producing melanin altogether, your hair turns white.

“Why hair follicle melanocytes die over time, and are not replaced, we don’t entirely know,” Cooper said. “Our skin doesn’t turn gray, so the biology is quite different,” she adds.

While Cooper works on pigment in skin, she said some scientists are also working on other big questions about the pigment in hair, too. These scientists are especially curious about the inner-workings of the cells and how gray hair is part of people’s DNA.

Perhaps, you’ve heard someone say their kids are giving them gray hair. But scientifically, if anyone is giving someone gray hair, it’s likely their own parents. Those that come before us pass down their hair color to us through the genes we inherit from them. It’s the same with graying hair.

Scientists have even pinpointed specific genes and parts of cells that are involved in growing gray hair. The new knowledge is helping us put together a better picture of how pigment works. Still, there’s a lot more to discover.

Maybe as you get older and find that first gray hair, you’ll remember some of the science that’s at the root of it all. If you have a cat or dog, maybe you’ll notice that they’ll go gray around their muzzles, too.

I’ve actually had gray and white hair ever since I was a kitten. I think it’s pretty great. Our pigment, or lack of it, help make us all unique.

Sincerely,
Dr. Universe

Ask Dr. Universe – Fever

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.

Mixter is curious about the germs, or microbes, that we all carry around with us. In fact, scientists estimate that humans carry more than 100 trillion of these tiny microbes with them wherever they go. Not all of these microbes are bad, but some of them can make you sick.

Thankfully, a lot of animals—from starfish to cats to humans—also have an immune system that helps them fight off bad germs. In humans, fevers are one way your body helps fight back.

It’s sort of like that story about Goldilocks and the three bears, Mixter said. In the middle of your brain is a control center, the hypothalamus, which helps your body know if it’s too hot, too cold, or just right.

Maybe the last time you went in for a check-up the doctor took your temperature and told you it was somewhere around 98.6 degrees Fahrenheit—or 37 degrees Centigrade for readers outside the United States. That’s a pretty normal temperature for humans.

Cats run a little warmer, with temperatures around 100 degrees Fahrenheit. As we go about our day, sometimes our body temperatures will rise or fall just a little. But if germs come on the scene, things can really heat up.

When your immune system realizes something unusual is going on, some of your white blood cells will release a substance into your blood stream. The substance is made up chemicals that your brain can detect. When the hypothalamus receives the chemical message, it sends an alert back out to the body: Turn up the heat! We’ve got to slow down these germs.

Many microbes that make us sick do best in an environment that is about 98.6 degrees F. The temperature is just right. When we get a fever, the heat helps slow down these troublemakers. You might feel sweaty and hot on the outside, but the microbes are also getting too hot. The heat helps keep them from multiplying rapidly.

One thing a fever can’t really tell us is what kinds of germs are in our system. Sometimes there might be something else going on and we might need to visit with a doctor.

A fever may not make us feel great, but it’s usually a good sign that our body’s immune system has kicked into gear and that we’ll get better real soon.

Sincerely,
Dr. Universe

Ask Dr. Universe – Glass

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.

In fact, sand is one of the most important ingredients we use to make glass. We may also use things like seashells, salt, and other chemicals. That’s what I found out when I visited my friend John McCloy, an engineer at Washington State University. McCloy and graduate student Jose Marcial were testing out different materials to make glass in the lab.

Marcial explained that glass is made of molecules—think of them as building blocks—arranged in a pretty random order. Most of the time we think of glass as a solid. But the way its molecules are arranged actually allows it to act as both a solid and a liquid. When we heat up the mix of sand, seashells, salt, and other chemicals, it can become molten, kind of like lava.

In the lab, Marcial poured a mixture of solid materials into a tiny metal cup. He heated it way up until the mix turned to something in-between a solid and liquid, similar to a thick honey. It was so hot that as Marcial poured it out onto a table, the molten material started glowing orange. As the mix cooled down, the molten liquid turned to a solid piece of glass right before our very eyes.

Marcial said that in factories, glass is made in a similar way. We take sand, add in different chemicals, heat it up, and pour it out onto a bed of molten metal. Just as oil sits on top of water, the lighter, liquid-like glass material floats atop the metal.

As everything cools down, the metal stays molten, but the glass on top solidifies. The glass might end up in a pair of eyeglasses, a computer screen, fish tank, or window. The big pieces of glass you see in buildings or observation decks are often made up of thinner layers of glass that have been combined.

As you’ve observed, the Space Needle is getting a big renovation. According to friends at the Space Needle, more than 10 types of glass will be used to renovate the landmark. They will also bring in 176 tons of glass during construction—that’s more than twice the weight of a NASA space shuttle.

As you can see, glass is made in lots of different ways. Believe it or not, you can also make something very similar to glass in your kitchen. Instead of grains of sand, salt, and seashells, you can use tiny grains of sugar.

With the help of a grown-up you can make your own edible sugar glass by mixing together ingredients like sugar, corn syrup, water, and cream of tartar. Try it out sometime and let me know what you learn at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Animal Farts

Dr. Universe: Do all animals pass gas? Do cats fart? 
Hasandi, 11, Jeddah; Harrison, 10, Albany, Ore.

Dear Hasandi and Harrison,

If you’ve ever been near a cat or dog when they tooted, the smell might have sent you running right out of the room. A lot of animals pass gas. But believe it or not, some animals do not.

First, let’s talk about the gassy ones. When us cats and humans eat food, we are also swallowing air, or gas. It’s made up of elements like nitrogen and oxygen. The gas travels down into our digestive system and can take up space in our stomach and intestines. In our digestive systems, we also find tiny living things called bacteria.

You might blame the dog for your farts, but the real credit goes to your bacteria. Not all bacteria are bad. In fact, a lot of bacteria are helpful. Some of them help break down your food into its simplest form, like proteins and sugars that you can use for energy and growing. Some get rid of waste. But as they do their different jobs, they produce a bit of gas.

That’s what I found out from my friend Kristen Johnson. She’s a researcher at Washington State University who has tackled some big questions about how cow gas impacts the environment. She explained that while each bacterium makes a small amount of gas, there are millions of them doing it. It really adds up.

This gas needs to leave your body somehow, so you can release it either as a burp, a fart or by breathing. But if you were a clam or other mollusk, you wouldn’t toot. If you were a sea anemone, you wouldn’t fart, but you could probably burp.

Last year, a bunch of researchers listed which animals they studied farted. According to their list, it appears that some worms don’t pass gas either. Then there are some animals that scientists aren’t sure about, like spiders and parakeets. One researcher even found that some millipedes have hard valves on their rear ends that silence their toots. It would be nice if some other animals I know had those.

Birds have the equipment to fart but apparently don’t. Some scientists have found that a lot of them don’t usually carry the same kinds of gas-forming bacteria in their guts that humans and other mammals do.

As it is, humans toot around 20 times a day, producing enough gas to fill up about half a two-liter bottle of soda. A lot of the time these farts don’t smell. But sometimes your bacteria release sulfur and other things that can get pretty stinky. It might not always be pleasant, but it’s totally normal. Silent or deadly, a fart is usually a sign that our bodies are healthy.

Sincerely,
Dr. Universe

Ask Dr. Universe – Cold in the Mountains

Dear Dr. Universe: Why is it so cold up in the mountains if heat rises and it’s closer to the sun? –Andrea, 11 

Dear Andrea,

You’re right. If we took a trip into the mountains, we would find that it felt a lot colder. It all has to do with our atmosphere. We may not always think about it, but we are basically living in a giant ocean of air.

“It’s a big part of what makes Earth livable,” said my friend Shelley Pressley. She’s an environmental engineer at Washington State University’s Laboratory for Atmospheric Research. “Without gravity and our atmosphere, all the oxygen we breathe would fly out into space.”

Our atmosphere contains small building blocks, or gas molecules, that make up the air we breathe, she said. We can’t always see or feel how much gas there is, but we can measure it. We can calculate the mass of gas, or the number of molecules there are in a certain area.

Air is actually pushing down on us all the time, even if we can’t really feel it.

“Imagine you are standing on Earth’s surface,” Pressley said. “There’s a column of air above your head that stretches up to the top of the atmosphere. The column of air is pushing down on your head. This is pressure.”

“Now, climb the tallest mountain you can find and stand on it,” she adds. “The column of air pushing down on your head is shorter. It has less mass than the column in the first spot.”

The air pressure is greater when you are closer to the level of the ocean’s surface. Here, the building blocks or molecules are pretty squished together. When the gas’ pressure is greater, temperature increases.

Maybe you’ve heard people say the air is thinner up in the mountains, where there is less pressure and the molecules or building blocks are more spread out. When the pressure of a gas decreases, so does temperature.

Pressure is a big part of the answer to the first part of your question. The other part of your question involves the sun. Our sun is about 490 billion feet away from the surface of the Earth.

While a mountain might seem tall, it’s pretty puny in comparison to the distance between Earth and our sun. It actually doesn’t make a huge difference in temperature.

Pressley said that pressure and our sun also have a lot to do with weather. When sunlight travels through the atmosphere, it heats the surface of the planet. When the surface gets warmer, it sends heat back up to air molecules near the surface and warms them up. The molecules of air rise. As they do, they expand and cool.

Somewhere else, air over a mountain that is even colder actually starts to sink. This sinking air gets compressed, squished together, and heats up. This mixing of air is called convection and is at the heart of our weather. This system also keeps the surface of our home planet warm enough to live—from the colder mountains to the warmer beaches around our world.

Sincerely,
Dr. Universe

Ask Dr. Universe – Parasites

Dear Dr. Universe: What can you tell me about parasites? -Brianna, 12, Eastern Wash.

Dear Brianna,

A parasite is an organism that steals resources from another organism in order to survive. Our planet is home to all kinds of parasites and organisms that host them.

My friends Kevin Zobrist and Lisa Shipley, scientists at Washington State University, told me about a few holiday-inspired parasites. After all, ‘tis the season.

The first parasite is a type of plant that people often smooch under around the holidays: mistletoe. There are a lot of species of mistletoe, explains Zobrist, a forester at WSU.

An example in the Pacific Northwest is hemlock dwarf mistletoe, which explosively releases sticky seeds during the summer. The seeds can fly up to 50 feet and stick to tree branches they fall on. When the seeds land on trees like western hemlock (the state tree of Washington), the mistletoe starts to grow.

Some kinds of mistletoe have leaves they can use to take in sunlight and help make food. But they still aren’t able to get enough food on their own. They have to feed off trees. Dwarf mistletoes don’t have any leaves. They get everything they need from their host.

In the process, this little mistletoe parasite causes trees to form weird clumps called “witch’s brooms” that can ultimately end up killing them. While the trees might die and become snags of dead wood, this can actually be a good thing for the forest ecosystems.

Zobrist explained that some animals, including some endangered species, will use witch’s broom branches or the insides of dead trees to make their habitat or nest. Even though the parasite takes life from the tree, it’s not all bad for life in the forest.

While some parasites live off plants, other parasites need animals. Lisa Shipley, a WSU professor who works with animals in the deer family, said some reindeers are host to a parasite that is so small we’d need a microscope to see it. It’s a kind of nematode more commonly called a brain worm.

Before the nematode finds the reindeer host, it lives in a different animal. When it’s young, it will go into the slimy bottom part of a snail, called its foot.

As snails slide along leaves of plants, reindeer that are munching on leaves will sometimes eat a snail, too. When they eat the snail, they eat the young nematode. The young nematodes move through the body and are eventually pooped out. But along the way, they can lay eggs and cause damage to the reindeer’s brain.

“The worm can be treated with parasite medications, so if you have your own reindeer—like some people in the North Pole do—you can give them medicine,” Shipley said.

Mistletoe and nematodes are just two of many parasites. Other parasites like ticks or fleas rely on hosts like us cats to get their food. Parasites can be inconvenient and even deadly, but to them, it’s all about survival.

Sincerely,
Dr. Universe

Ask Dr. Universe – Grasshoppers

How do grasshoppers survive the winter? –Lucy, 9

Dear Lucy,

There are a lot of different grasshoppers living on our planet. In fact, scientists have discovered more than 11,000 species. Exactly how these grasshoppers spend their winter depends on what kind of winter they experience.

That’s what I found out when I went to visit my friend Laura Lavine. She’s an entomologist at Washington State University and was happy to help with your question. Let’s hop to it.

Lavine explained that in places with colder winters, such as Washington State, grasshoppers spend the winter as eggs. That means that their mothers will have buried them deep in the ground.

The grasshopper mom has an egg-laying organ, called an ovipositor, that’s shaped like a knife or sword. It’s really handy for digging in the soil.

“The ovipositor has a hard external skeleton and the grasshopper digs into the ground to lay her eggs below the surface,” Lavine said.

Some Pacific Northwest grasshoppers, like the red-legged grasshopper, will lay about 20 eggs at once. The mother will cover them all with a gummy coating.

The coating hardens and binds the eggs together so they can survive the harsh winter conditions. The mother grasshoppers will also bury them.

Lavine explained that some grasshoppers will lay their eggs in other safe, warm places such as plant roots, wood, or even cow manure.

“They hatch in the spring when the weather warms up and the sun comes out,” she said. Spring is a great season for us cats to chase these little hopping insects around. I must say it’s pretty entertaining.

While a lot of grasshoppers overwinter as eggs, some will survive the winters in a different stage of life. Between their egg stage and adult stage, grasshoppers are juveniles, or nymphs. In winter, nymphs will find a nice warm spot to hide. They probably won’t move or hop around much at all until it warms up again.

Of course, not all winters are so cold and harsh. For example, the giant grasshopper that lives in South America experiences a pretty warm habitat. It will still lay eggs underground to keep them safe, though.

“In warm places, grasshoppers are more active in the winter because the temperature is good and there are plenty of plants around to eat. So, they can spend the winter as eggs, as nymphs, and even as adults,” Lavine said.

Here are a few activities you can try at home to learn a little bit more about grasshoppers: Draw a grasshopper or make one out of a toilet paper tube and label its anatomy. Don’t forget to include the five eyes.

If you are feeling up to the challenge, you can also play around with some geometry in this grasshopper origami project. Have fun and tell us what else you learn about grasshoppers sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe

Ask Dr. Universe – Cold

Hi Dr. Wendy Sue: Me and my brother had a little bit of an argument about the point that there is no such thing as cold. He said liquid nitrogen produces cold, which I think is absurd, but lack the knowledge to explain it. Can you please explain to us why there is no cold? 
– Brody, 12

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.

We might use the word “cold” to describe what that feels like, but you’re right: there isn’t actually something called “cold.” Not scientifically speaking, at least.

My friend Jake Leachman is an engineer at Washington State University and was happy to help with this question. He said that a long time ago people thought heat was a kind of fluid. The idea was that this fluid was inside different objects and it could move around to make something hot or cold. It wasn’t until a person named Count Rumford was making some cannons that a better idea came about.

Rumford’s oxen were helping turn a large tool that carved out the insides of cannons. He noticed that as long as oxen were doing work to move the tool, the inside of the cannon would get super-hot and could even boil water. The work from the oxen was being converted into heat by friction on the inside of the cannon barrels. That’s much more heat than you could make by rubbing your paws together to keep them warm.

Rumford realized that if heat was some fluid coming out of the cannon barrels, it would eventually run out, but that wasn’t the case. As long as the oxen worked, more heat would be produced.

Then there was James Joule, who used thermometers to show that even water falling over a waterfall warms after the fall. Rumford and Joule were some of the first to help us realize energy isn’t created or destroyed.  Energy is converted between things such as work and heat. And heat, not “cold”, can transfer from object to object.

As you may remember, molecules are the building blocks of pretty much everything in our world. The motions of molecules are also related to heat, or thermal energy. We measure the movement of the molecules, also known as temperature, using thermometers.

Leachman explained that heat, like time, actually has direction. It always flows from something with higher temperature to something with lower temperature.

“Yes, something feels cold because your thermal energy is flowing from you, the warmer thing, to the thing at a lower temperature,” Leachman said.

Leachman explained that for nitrogen to be in a very cold liquid state (-321°F!), the nitrogen molecules must be moving very slowly.

They are moving so slowly that they can rest right on top of each other and any energy, or heat, transferred from room temperature is enough to cause nitrogen molecules to move very quickly.

They can no longer exist as a liquid and boil to become a gas. It’s just a process of slow-moving molecules being sped up—heated—by faster moving molecules.

Now, maybe your brother is also thinking about something like this: If energy is only converted between objects and heat only goes from hot to cold, how does a refrigerator work to keep things cold? Stay tuned for the answer.

Sincerely,
Dr. Universe

Ask Dr. Universe – Eyeballs

Dr. Universe: How much does an eyeball weigh? – Rahman, 10, Tollygunge, India

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.

An elephant’s eye is about the size of a golf ball, but there are even bigger eyes. A gray whale’s eyes are about the size of a baseball. But they still aren’t the biggest eyes. Those belong to the giant squid.

I decided to ask my friend Kirt Onthank exactly how much giant squid eyes weigh. He studied cephalopods, which include squid, as a student at Washington State University and now teaches biology at Walla Walla University.

“I don’t know the exact answer,” Onthank said. “But we can get a really good estimation.”

He said the largest giant squid was actually measured from a photograph. No one actually weighed it. But we do know its eye had a diameter of 10.5 inches, which is just a little bigger than a basketball.

While human eyes are made up of a more jelly-like material, a squid’s eyes are pretty much all seawater. Knowing this, we can estimate its weight.

After a little math, it comes out to about 22.7 pounds—more than 3,000 pennies.

“That is one really big eye,” Onthank said.

Colossal squid have even bigger eyes that weigh in at about 25.3 pounds. Even though their eyes are much bigger than yours, they still have some of the same parts.

Both squid and people have a lenses, irises, pupils to let light in, and retinas to capture the light and help send a message to your brain. One thing squids don’t have is eyelids.

Exactly why colossal squid need the world’s biggest eyeballs is a question some scientists are still investigating. The best theory is that their eyes are geared to see sperm whales, Onthank said.

Sperm whales have eyes that are only 7 centimeters in diameter. They are super tiny compared to their 40-foot-long bodies. They depend on sound waves that bounce off things to figure out where they are and to find food. And their favorite food is squid.

A squid’s big eye helps it detect very dim light deep in the ocean. It turns out, there are also some bioluminescent creatures in the deep waters. Bioluminescent creatures make their own light through a chemical reaction that allows them to glow in total darkness. If there was a sperm whale around, it would disturb some of these creatures who give off light.

The squid can use its big eyes to take in the light and receive a signal that might just help it avoid becoming a sperm whale’s lunch.

Sincerely,
Dr. Universe

Ask Dr. Universe – Directions in Space

In space, which way is up? –Pablo, 10, Spokane, WA

Dear Pablo,

We might not always think about it, but every day gravity keeps us pulled to the Earth. It’s what brings us back down when we jump on a trampoline. It’s why a Slinky tumbles down stairs.

Now think about what it would be like to live in a place with very little gravity. Let’s say you were 200 miles off the ground, orbiting earth in the International Space Station. Here, the idea of up and down really gets flipped around.

On Earth, the human balance system  helps the head figure out how move up and down under the force of gravity. It’s what helps people figure out to look up to the ceiling or down to the floor. If you are floating around in space, up and down is different.

I decided to visit my friend Afshin Khan to find out more about it. She is a researcher and astrobiologist at Washington State University.

Khan explained that even things in space have a little gravity, and whichever object is being pulled toward another due to stronger or larger gravity is what we call “down.” The opposite is what we call “up.” We use these words to help us navigate.

But in reality, there really are no true directions, Khan said. There is no up and down in space.

It’s kind of like when we look at a globe, she explains. If you are trying to get to Japan from the U.S., you can see it is both east and west of the U.S. It depends on the direction you want to travel. If you want to cross the Atlantic Ocean, you go east. If you want to fly over the Pacific Ocean, you go west. It’s all relative.

Inside the International Space Station, the ceiling might as well be the floor. The walls might as well be the ceilings. It’s enough to make your head spin.

In fact, researchers at NASA are asking big questions about what happens to the human brain when it can’t figure out which way is up or down. They are curious how it changes the activity of the brain.

Some scientists have even tackled questions about how to help plants “grow up” in these environments with very little gravity. To help plants grow upright, scientists have developed little plant pillows. The pillows are full of dirt, water and plant food to help the plants stay grounded. Otherwise, their roots would grow out in all different directions.

As the concept of direction may be different in space, engineers and scientists have to think about it when they are designing tools to help us navigate the universe. Who knows, maybe one day you’ll come up with a great idea that can help us explore, too.

Sincerely,
Dr. Universe

Ask Dr. Universe – Rain and Water Pollution

Where does rain go? –Finn, 8, New Zealand
How does pollution effect the world’s water? – Emily, 13

Dear, Finn, Emily, and friends,

When a raindrop falls from a cloud, there are quite a few places it could end up.

We might follow that raindrop into a stream, river or ocean. If it’s in the ocean and it gets warm enough, it might evaporate into even tinier droplets of water to form clouds. It’s part of the water cycle.

Clouds can only hold so much rain before they get saturated. Then it starts to rain again.  Maybe this time the raindrop falls into soil and helps a plant grow. Or perhaps the raindrop falls onto the sidewalk, street, or highway. If it falls on the pavement, it could flow into a drain and back into the streams and oceans.

Lots of these raindrops make up what scientists call storm water. But it’s not just water. Along the way, water can pick up other things on the road. It might sweep away something like leaves. It also picks up things that aren’t very good for our planet, like oil, animal waste, metal from car brakes, or other kinds of chemicals and pollutants.

We can’t always see these pollutants with our eyes, but they can really threaten animals who call the streams, rivers, and ocean home. Pollution can create a toxic environment for fish. As a researcher at Washington State University, my friend Michelle Chow studies some of the fish that get sick from pollutants in storm water.

Coho salmon that live in the Pacific Northwest of the U.S. will often die if they are in this polluted water for a couple of days. But Chow and other researchers at WSU are working on ways to help save the salmon.

It turns out soil is really great at filtering toxic stuff out of water. If you are curious how it works, check out this video, “Polluted Puddles.” One thing people can do to help clean up the environment and help save salmon is to plant a rain garden. When the rain comes down, it gets filtered through the garden’s soil instead of running off into the road. You can find out how to plant a rain garden in your community with the help of friends at WSU Extension.

Another way researchers are helping is by developing a kind of pavement that looks a bit like a Rice Krispies Treat. It’s called permeable pavement and is designed to let water go straight through the pavement down into the soil. That way, it doesn’t run off and carry pollutants to nearby bodies of water.

Chow said there are other ways we can also help keep pollutants out of our environment. Can you think of something you might be able to do? I might just walk to work or ride my bike. Helping find solutions is good for salmon who live in the water and good for animals who like to eat them, too. Together, we can help improve and restore healthy water habitats.

Sincerely,
Dr. Universe

Ask Dr. Universe – Feet

Why do feet smell?
-Jose, 10, Costa Mesa, Calif.

Dear 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.

While bacteria are too small to see without a microscope, sometimes you can just smell them doing their job. They like dark, damp, warm places, where they can eat dead skin and drink sweat. Inside your shoes and socks, for example.

There are more glands that produce sweat on your feet than any other part of the body. As bacteria eat there, they also turn your dead skin and sweat into chemical products that can really reek.

It might just make you want to plug your nose. But at least you’ll know the system that helps you smell, the olfactory system, is working well. Your brain, nose, and a bunch of smell receptors work together to help you figure out what you are smelling.

Maybe it’s stinky feet. Or maybe it’s fresh-baked chocolate chip cookies. Do either of these bring back any memories for you? Scientists have found that our sense of smell is tied pretty closely to our memories—and there are more than 10,000 different kinds of smells, or aromas.

Sniffing out chemical combos

Smell is a really important part of our daily life, said my friend Sindhuja Sankaran, a biological engineer and researcher at Washington State University. The ability to smell can also help us identify spoiled foods, find quality foods, and even remind us to take out the trash.

She said that knowledge of the way humans smell has allowed us to develop electronic devices that can help pick up on these different combinations of chemicals.

Scientists like Sankaran can use a kind of sensor, you might call it an electronic nose, to study the quality of foods and sniff out any problems bacteria might be causing when food is in storage. She even uses this technology to study what chemicals released by plants can tell us about whether they are infected by a disease or attacked by an insect.

For example, some kinds of plants can release chemical combinations into the air to warn other plants that a particular predator is around. Some evidence points to the idea that plants can sense some chemical messages in their roots, too.

Lucky for them they can’t smell stinky feet. What kinds of things have you smelled lately? Keep exploring all the aromas around you. You might even try to find out what combinations of chemicals give things like fresh cut grass, garbage and bacon their smells.

Sincerely,
Dr. Universe


And now for 3 smelly facts with Dr. Sankaran

  1. Humans have about 5 million receptor cells in their olfactory system to help them smell.
  2. Dogs noses are about a thousand times more sensitive than humans. They have around 220 million olfactory sensors.
  3. A pair of feet can have about 250,000 glands for making sweat.