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Why do stink bugs stink?

brown stink bug on leaf

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. » More …

How do bees make 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. » More …

Why do puffer fish puff up?

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. » More …

Why do dogs have 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. » More …

How do cacti survive in such hot and dry environments?

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.

Dr. Universe

Part 3: Where does our garbage go?

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. » More …

Part 2: Where does garbage go?

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.

Melting down materials 

WIllustrated, cartoon cat with labcoate 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 part of 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.

Breaking it down with Dr. Zhang

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.

Dr. Universe

Part 1: Where does garbage go?

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. » More …

Why do bees have pointy 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. » More …