But Why: A Podcast for Curious Kids

Why do bees pollinate? How do they make honey? Why do bees have stingers? Why do (some) bees die when they sting you? What's the difference between a bee and a wasp? Does honey have healing properties? Farmer and beekeeper John Hayden answers all of your bee questions! Download our learning guides: PDF | Google Slides | Transcript | Coloring Page Bees collect nectar from flowers. Nectar is the sweet liquid that entices the bees to the flower. The bees climb onto or into the flower and suck up the nectar with their straw-like mouth and collect it in a little sac called a crop. They also collect pollen on their legs. As they move from flower to flower, they leave a little bit of that pollen on each new flower they visit. That's called pollination and it’s how flowers reproduce. Bees take the pollen and nectar back to their hives and put it into the honeycomb (six-sided cells they have built out with wax). Pollen is like protein, one of the building blocks of animal bodies, and bees use that to feed their young mostly. To turn nectar into honey, bees spit it up into other bees’ mouths and eventually they spit the liquid into the honeycomb cells. Then they fan it with their wings to evaporate some of the moisture. Once it has reached the right consistency, they seal it off with wax to store it for later. So honey is just concentrated nectar. Bees keep the honey in storage for the winter months when there are no flowers. But they make more than they need, so beekeepers take the extra honey out of the hive and leave the bees enough to survive through the winter. Bees sting to protect their hive and defend their honey from potential predators. But honeybees don’t sting unless they have to, because after they sting, their stinger gets pulled out of their body and they die! Honeybees die when they sting because their stinger has a barb on it, like a fish hook. The stinger gets hooked into your skin and then when the bee tries to fly away the hook stays in and pulls out the bee's abdomen as it flies away. Honeybees are social insects who depend on their colony to survive. So they are willing to sacrifice themselves to make sure the whole colony can survive. Honeybees are far from the only pollinator. Bees are very important to our ecosystem and there are more than 4000 species in the US alone. Butterflies, hummingbirds, and bats also play important pollinator roles. Resources How do big plants grow from small seeds? How are babies made? Honeybee music video

Why do sharks have multiple sets of teeth? Why do sharks lose so many teeth? Do sharks eat fish? How do sharks breathe underwater? Do sharks sleep? Give a listen to this totally jaw-some conversation about sharks with Dr. Kady Lyons, shark researcher at the Georgia Aquarium! We also tackle: Why are dinosaurs extinct and sharks are not? Were megalodons the biggest sharks in the world? Do sharks have noses? How do sharks communicate? Why do sharks bite? Why are sharks dangerous? Download our learning guides: PDF | Google Slide | Transcript Sharks are a type of fish. They’ve been around for millions of years and their body plan hasn’t changed much in that time! Sharks’ skeletons are made of cartilage. They don’t have any calcified bones - so the only part of a shark that gets left behind in fossil records is their teeth! Megalodons were the biggest shark, but they are extinct (despite sensational TV shows that claim otherwise). The latest research suggests megalodons were bigger than modern day humpback whales! Sharks and other fish breathe by extracting oxygen from water by the use of their gills. Gills are made of very thin tissue. The blood inside the tissue picks up oxygen from the water and brings it into the organs in the fish’s body. Sharks evolved to have sharp teeth to grab slippery fish and other prey. If they break a tooth, they can regrow a new one, and they just drop the old one. Easily replacing a tooth that breaks off is a strategy that allows them to keep hunting. Their teeth grow continually through a shark’s life, moving forward in their mouth kind of like on a conveyor belt, maturing as they go. So when a tooth falls out a new one moves forward. Some sharks lose whole rows of teeth, like dentures, all at the same time. All sharks are carnivores, eating fish, seals, and sometimes other sharks. Some species, like whale sharks, filter feed, mostly on zooplankton but sometimes phytoplankton (sea plants) as well. Sharks have been known to attack humans, but humans actually aren’t great prey for them because we lack a thick layer of blubber or other energy the sharks are on the hunt for. Usually sharks attack when they mistake a human for something else, like a seal. Sharks go through periods of sleep or rest, reducing brain activity. Sharks have a fantastic sense of smell. It helps them find their prey.

How do popcorn kernels pop? How do salmon know where to return to spawn? How do rabbits change colors? Why does television fry your brain? How do zippers zip stuff? Who was the fastest runner in the world? In this episode, we'll tackle all of these questions! Download our learning guides: PDF | Google Slide | Transcript Inside the husk is a tiny little droplet of water surrounded by something called the endosperm. The endosperm is what you're actually eating when you eat popcorn. When you heat up popcorn, the tiny droplet of water gets hot and turns into steam. That steam pushes through the endosperm and turns it kind of soft and that endosperm builds up pressure and explodes through the husk. When it explodes, that soft gelatinous endosperm hits cooler air and it hardens up in whatever shape it has exploded into. So that's why popcorn has all those funny shapes and feels kind of like foam. Salmon are born in freshwater, but then spend their lives in saltwater. They return to the freshwater to spawn (lay and fertilize eggs) and die. Some salmon return to any body of freshwater to spawn, but some salmon have special ways of finding their way back to the place they were born. They use a kind of internal compass to head back to the spot. Other fish rely on their sense of smell to find their way back to fresh water. Animals that turn white in winter use the length of day as their cue to stop producing pigment in their fur. Their bodies can sense the hours of daylight, and when the daylight starts getting shorter, their hormones will tell the cells to stop producing melatonin. Hormones tell the cells what to do to shut off the production of pigment in the fall and to turn it on again in the spring. It's not because the days and the nights get colder or warmer. The fastest runner in the world is Usain Bolt. He's the fastest man who's ever been timed. He's a Jamaican sprinter, and he holds the world record for both the 100 and the 200 meter sprints. He has nine gold medals at the Olympics and 11 world championships. His record for the 100 meter sprint is 9.58 seconds. That is super fast. That's more than 23 miles an hour. Want to pop your own popcorn from kernels? Find a big pan with a tight-lid. Pour two tablespoons of cooking oil in the pan. Then add a half a cup of popping corn. Cover the pan and turn the heat to high. In a few minutes the popcorn will start to pop. Turn off the heat. Open the lid when the popcorn stops popping. Enjoy! How a zipper works Sounds Wild

Field trip time! Today we’re learning all about snakes while out on a search for timber rattlesnakes in New York with state wildlife biologist Lisa Pipino. Some of the questions we tackle: How do some snakes make venom? Why are some snakes venomous and others are not? Why do rattlesnakes have a rattle? How do snakes slither on the ground without legs? Why don’t snakes have legs? Why don’t snakes have ears? How do they smell with their tongues? Why do some snakes use heat vision? Do snakes sleep? Why do snakes stick out their tongues so much? Download our learning guides: PDF | Google Slide | Transcript Snakes are ectothermic - meaning they are cold-blooded and rely on their environment to regulate their body temperature. Snakes like to bask on warm rocks to stay warm. A rattlesnake’s first rattle segment is called a button. They shed their skin once or twice per year and each time they do, they get a new rattle segment. Rattle segments sit on top of each other, and when rattlesnakes shake their tail, the segments rattle. This noise is a warning to predators to stay away. Some snakes lay eggs. Others develop eggs that grow and hatch inside their body, meaning the snakes give birth to live young. Rattlesnakes give birth to live young but only stay with their babies for about a week. Those babies follow their mother’s scent trail back to the den for winter. Some snakes are venomous, but not poisonous. What’s the difference?! Venom is delivered through a bite or a stinger, while poison is usually inhaled, swallowed, or absorbed through the skin. Snake venom is a lot like saliva, except it’s toxic. Snakes create it using a special gland. They then use their venom to immobilize or kill their prey before they eat it. They sometimes use their venomous bite as a defense as well. Snakes do have nostrils and can smell through their nose a little bit. But they mostly use their tongues to smell and sense their environment. They stick out their tongues to pick up scents. And then they rub their tongues on a special organ at the top of their mouths, which sends a message about the scent to their brains. Timber rattlesnakes live in the Eastern US and are different from some of the other well-known rattlesnakes in the Western US. In much of the northeastern states they’re considered threatened or endangered. People shouldn’t try to look for these snakes because of the possibility of disturbing the snakes or their habitats.

Why do we feel pain when we get hurt? What is pain? Why do we cry when we get hurt? Why do we say ow or ouch? We’re learning about how pain works with Joshua Pate. He’s a physical therapist and author of a forthcoming children’s book series about pain. Download our learning guides: PDF | Google Slide | Transcript Pain happens when your body sends signals to your brain that something is wrong. And your brain sends signals to your body to feel pain! Pain is protective–it lets us know to stop doing something that is damaging or might damage our bodies. And it lets us know that something is wrong and we might need to get help from an adult or a medical provider. When you get hurt, like scraping your knee for example, the nerve cells in the knee send a message to the brain. Your eyes might see the scraped knee and send another message to your brain. Then your brain has to decide how much danger your knee is in. Pain is messaging that lets your brain know that something is not well. If you didn’t have that pain, you might keep scraping your knee over and over. Pain is biopsychosocial, meaning biology, psychology and social or environmental factors all play a role in what pain feels like for individual people. A lot of things can turn the feeling of pain up or down. Distraction, like listening to music or watching a video can help turn pain down. Staring at the source of pain can make it hurt more. Outside factors can also impact pain. In a study from several years ago, people were asked to hold a freezing cold rod. Scientists changed the colored lights in the room. When the lights were blue people felt less pain from the rod than when the lights were red. Normally, pain will recede when an injury heals. But not for everyone. Sometimes people suffer from chronic pain after an injury. We cry when we’re in pain as a way of letting others know that something is wrong. We also learn to use the words ow or ouch. Other languages have different words for pain.

Why do friends care about each other? How do you make friends? Can you have more than one best friend? How do you deal with a bully? We answer questions about friends and bullies with Dr. Friendtastic (also known as Eileen Kennedy-Moore), a psychologist and author of Growing Friendships: A Kids’ Guide to Making and Keeping Friends. And we get lots of advice from kids themselves about how to make friends and deal with bullies. Download our learning guides: PDF | Google Slide | Transcript Friendship is often about action. It's about what we do together, how we treat each other. The key to friendship is kindness. Best friends are nice, but the word “best” can make it feel like a contest. Most people have different friends and for different situations. So it’s okay to have several close friends instead of needing to identify just one best friend. Some people have lots of friends, but other people may just have a few close friends. People with more friends tend to put more effort into having more friends. It’s okay to have a lot of friends or just a few! To make friends, you have to show an openness to friendship. That can be as easy as smiling or saying hi. It’s also important to be kind to potential friends. And it also helps to identify people who have similar interests to you. Then, invite them to do something. Kids make friends by doing fun things with other kids. Don’t wait until you feel close to someone to invite them to do something; you become close by doing shared activities. Shy people might be unintentionally sending the message to potential friends that they don’t like them. Stop focusing on being uncomfortable and instead look the other kid in the eye (or the forehead if eye contact is hard for you), smile and say hello. Practice it with an adult. At recess or on the playground, bigger groups of kids will be more open to you joining than groups with just two or three kids. Research shows that instead of asking if you can play with a big group, hang back and watch for a few minutes to figure out the game the other kids are playing, and then just join in. If you ask “Can I play with you?” you risk interrupting the play. Bullying is deliberate (intentional) meanness directed at one person where there is an imbalance of power. For example, an older or more popular kid picking on a younger or less popular kid. It’s important to know the difference between bullying and meanness. Bullying requires adult intervention. If you’re having a problem with a friend that is not bullying, you may still want to talk that through with an adult, but it’s often possible to handle that conflict with your friend on your own.

How are crickets so loud? Why do they chirp at night? How are they different from grasshoppers? We’re talking crickets today with Karim Vahed, a cricket and katydid expert and entomologist (bug scientist) at the University of Derby in the United Kingdom. Professor Vahed also takes on some of your pressing insect questions: Do insects have bones? What do baby bugs like to do? Do insects drink water? Why are bugs so important? Download our learning guides: PDF | Google Slide | Transcript There are over 9,000 known species of crickets on the planet. These insects are best known for singing and hopping! Insects are divided into different orders depending on what kind they are. Crickets are in the order known as Orthoptera, which contains grasshoppers, locusts, crickets and bush crickets, and katydids. Crickets and grasshoppers are different! For one thing, most grasshoppers make noise by rubbing one of their legs against one of their wings. But most crickets make sound by rubbing their two forewings (their front wings) together. One wing is jagged, like a little row of teeth. And the other wing kind of scrapes up against it, making a sound. The number of teeth on the scraper, the speed of the rubbing and how frequently they make the chirps differ depending on the species. So there are lots of different cricket songs. Try an experiment: Get a comb and run your fingernail across it. See if you can make a sound. If you have more than one comb, or a comb with two differently sized/spaced teeth, see if they make different sounds. Does the size of the fingernail make a difference in the sound? Try giving your comb to an adult and find out! In most cricket species, the males chirp to attract a female. And they mostly sing at night to help avoid predators. But Karim Vahed says some studies have shown that predators like domestic house cats follow the chirps of the crickets to find and eat them! Imagine a cricket the size of a hamster! A cricket so big it would cover the palm of your hand if you were holding it. The giant wētā [say it: WEH-tah] is that insect! There are several species of giant wētās. They all live in New Zealand and most of them are protected because they’re quite rare. Insects are the most diverse group of animals on the planet. There are more than a million known species (about 80% of all known animals). But scientists estimate anywhere from 10 million to 80 million insect species have yet to be discovered!

That’s just one of the questions we answer in this week’s episode, which also includes instructions on how to easily make your own ice cream at home! We’ll also tackle the why and how of melting ice cream and why some flavors tend to melt faster than others! Our expert in this episode is ice cream entrepreneur Rabia Kamara, of Ruby Scoops in Richmond, Virginia. It's going to be sweet! Download our learning guides: PDF | Google Slide | Transcript After listening, if you're ready to try making ice cream at home, here's Rabia's easy recipe. INGREDIENTS: 2 cups of heavy cream 1 14oz can of sweetened condensed milk Optional additional flavorings: a splash of vanilla pinch of salt And whatever else you might want to add! (Chocolate chips, cookie crumbles, etc.) INSTRUCTIONS: Use a hand mixer to beat the heavy cream until it is the consistency of whipped cream, with peaks that hold their shape. Fold any additional ingredients into the sweetened condensed milk and add the mixture to the heavy cream and fold them together using a spoon. Put into a freezer safe container. Let freeze for about 8 hours. Enjoy!

The Washington Mystics of the WNBA join us in this episode to answer all of your questions about the sport of basketball and what it’s like to be a professional athlete. How many basketballs does the team have? Why do balls spin when you bounce them? Who invented basketball? Why are basketballs orange with black lines? Why do men and women play on separate teams? How do injuries impact professional careers? And do you have to be tall to play hoops? Download our learning guides: PDF | Google Slide | Transcript Resources Basketball Games for Kids Learn More About the WNBA

For the past 50 years, visitors to the Smithsonian National Zoo in Washington, D.C. have been able to observe giant pandas. It’s one of the few places in the United States to see these black and white bears. For our latest episode we took a field trip to the zoo to visit the three pandas currently living there and answer panda questions with zookeeper Mariel Lally. We tackle: Why do animals live in the zoo? Why are pandas black and white? Do pandas hibernate? How can we save the pandas? And check out our social media pages for lots of pictures! Download our learning guides: PDF | Google Slide | Transcript Three pandas live at the National Zoo: adults Tian Tian and Mei Xiang and their cub, Xiao Qi Ji. Zookeepers are never in the same space as the pandas. Even though they are herbivores, pandas are still wild animals with sharp claws and big teeth, so it’s important for people to stay safe. Researchers at the National Zoo have worked with colleagues in China on a breeding program for both captive and wild pandas. That research has helped pandas go from endangered to vulnerable. They’re still at risk of extinction, but doing better than they were just a few decades ago. Pandas eat 100 pounds of bamboo per day! The National Zoo cuts bamboo from sites around the D.C. area, including at some local private homes. Researchers aren’t sure why pandas are black and white, but the leading theory is that the white color provides camouflage in their snowy natural habitat and the black fur helps them blend in when they hide in shady bamboo forests. Panda cubs do have predators in the wild. Pandas do not hibernate, but they spend their time eating or sleeping. They have a period of deep sleep, similar to the torpor of reptiles. Keepers say they try not to wake sleeping pandas because they get very grumpy! (So the saying, “Never wake a sleeping bear” is especially true for pandas.) Zoo pandas get daily training to make their care easier. For example, they learn their names and they are taught to open their mouths and show a paw so they can more easily receive medical care. Zoos used to display animals primarily for human enjoyment. Now, most zoos focus on species conservation, research and educating the public about animal species. Resources National Zoo’s Panadriffic Pack (games and coloring pages) Panda Cam

What is climate change? What is causing climate change? How do you cool down the earth? How is climate change affecting the oceans? Kids are hearing about climate change and they have lots of questions. In this episode we explain the science of climate change and look at how humans will adapt to a rapidly warming planet. We speak with Dr. Claudia Benitez-Nelson, oceanographer at the University of South Carolina and Dr. Jola Ajibade, a geographer at Portland State University. This certainly isn’t a comprehensive look at the issue, but it’s a good way to start a conversation about this issue for families and teachers. Download our learning guides: PDF | Google Slide | Transcript Climate is the long-term trend of temperatures and weather. You can think of the difference between climate and weather like a dog walking down a sidewalk: The dog might go from side to side of the sidewalk - that’s kind of like the weather - it varies. But the general direction of the dog is forward - that’s the climate. Since the 1800s we’ve had a lot of changes in technology that mean humans are burning a lot of fossil fuels like oil, gas and coal, to power engines, run our cars, heat our homes and create electricity. That puts a lot of greenhouse gasses and carbon dioxide into the atmosphere. The atmosphere is like a blanket around the earth. The increase in greenhouse gasses means that the blanket is getting thicker, making the earth warmer. Think of the earth like a human body: when a fever increases our body temperature by a few degrees, it can make you feel really sick (sometimes really hot, but other times with cold shivers). It’s the same thing for the earth! Even one or two degrees difference in average global temperature can make a big difference, including changing the amount of rainfall that a region gets or the overall temperature of the ocean, throwing our systems out of balance. Climate change can increase sea levels. As polar ice caps melt because of increasing temperature, the water levels rise, which can cause higher tides and more flooding. A good experiment you can do to visualize this is to grab a mixing bowl and turn a smaller bowl upside down inside of it (like an island). Pour some water and several ice cubes into the big bowl and see how high the water goes up the side of the smaller bowl. (You might need to weigh the smaller bowl down so it doesn’t float up.) As the ice melts, observe how the water level rises up the sides of the small bowl. Increased water temperatures are bad for coral reefs and other ocean animals. The best way to stop climate change is to stop burning fossil fuels. People will respond to climate change through coping mechanisms, including migration and relocation. The people most affected by climate change are the people least responsible for greenhouse gas emissions. If you’re concerned about global warming, find ways to consume fewer resources and to burn fewer fossil fuels. And lobby your government officials to make policies that benefit the environment and those most vulnerable to climate change. Resources NASA’s Climate Kids NASA’s Kids’ Guide to Climate Change National Geographic Kids Climate Change Explainer Take Action: Young Voices for the Planet Science Moms

Why do flowers bloom? How do flowers grow? Why are flowers different colors? Why do people find flowers beautiful? How are seeds made? Why do plants grow from seeds? Why do we put seeds in the garden? We’re answering your questions about seeds and flowers with garden writer Charlie Nardozzi and Hannes Dempewolf from The Crop Trust. Find more answers to plant questions in two of our older episodes: How Do Big Plants Grow From Such Small Seeds? and Are Seeds Alive? Download our learning guides: PDF | Google Slide | Transcript New seeds are made through pollination, plant reproduction. Pollen makes its way to the ovary of a flower in various ways. Sometimes it is spread from one flower to another by a pollinator, like a bee or hummingbird. Some flowers are called “perfect”, meaning they can reproduce with their own pollen–not the pollen from another plant. But they still need a way for their own pollen to drop onto their egg. A gentle gust of wind, or the jostling of the plant by a gardener's hand can do the trick. The flower will create the seed and then the flower structure will fade, leaving behind a seed. Sometimes it’s in a pod, sometimes it’s in a fruit or other structure to protect it. Seeds are alive, but dormant. They contain all the nutrients needed to make a new plant. That seed will wait for the right conditions to germinate and create a new plant. Some seeds only need a little moisture to germinate, others need to be submerged in water. There are many different kinds of seeds and they have different necessary conditions. Flowers can be many different colors. They use those colors to attract pollinators. Those colors are created by pigments, natural colorings, in the plants. Some plants only flower once per year, others can bloom multiple times. Some plants flower in spring, others in summer, and some in fall. There is a lot of diversity in plants and the way they reproduce. That benefits all of us because if some plants aren’t thriving in certain conditions, other plants may do better. Resources Seed sprouting experiment Window gardening for kids Webinar: Gardening with Kids

Why are some people right-handed and some are left-handed? And what’s up with some people being ambidextrous (equally good with both hands)? Why, in the past, did some people try to make left-handed people use their right hands? We talk with Chris McManus, professor and author of the book Right Hand, Left Hand: The Origins of Asymmetry in Brains, Bodies, Atoms, and Cultures. We’ll even find out how common left-handedness (or left-pawedness) is in other animals! Download our learning guides: PDF | Google Slide | Transcript Why do we prefer one hand over the other? McManus says it probably pays to specialize. It’s better to do something with one hand over and over and get really good at it, as opposed to doing it sometimes with one hand and sometimes with the other. For example, it takes years to develop your handwriting, so it would take twice as long to develop good handwriting with both hands! How do we pick which hand? We chose the hand that feels more normal to us, and then we practice with that hand. Try a simple experiment: bring your hands together quickly and entwine your fingers like you’re holding hands with yourself. Which thumb do you have on top? Now switch which thumb is on top. It probably feels a bit wrong. 90 percent of people use their right hand more. Our brain is asymmetrical (different on the right and left sides), and most of us use the left half of our brain to talk. Our heart is also on the left side of our body for most humans and vertebrates. There must be an advantage to being left-handed or we wouldn’t have left-handed people, but no one is sure exactly what that advantage is. What about people who say they’re ambidextrous? McManus believes there’s no such thing. He says people who say they’re ambidextrous are generally good at different things with each hand, but aren’t actually equally good at everything with both hands. McManus calls these people mixed-handers. Many animals also have handedness. But while right-handedness is dominant i people, animals tend to split down the middle. (So, for example, half of cats are right-handed, half are left-handed. Same goes for dogs and mice etc. in the 19th century, when people wrote with pens dipped in inkwells, writing with your left hand was messy business, as left hands would smear ink across the page. But as people have shifted to mostly typing, the hand you write with matters less. For every five left-handed boys, there are only four left-handed girls, and scientists have no idea why.

Why do pigs snort? And why do we call their snorts “oink” in English? We’re taking our exploration of animal noises in two directions today. First we’ll learn about why we use different words to describe animal noises, depending on what language we’re speaking. And then we’ll examine what animals are actually saying when they oink or tweet or moo! Our guests are linguist and author Arika Okrent and bioacoustic researcher Elodie Briefer, of the University of Copenhagen. Other questions we tackle in this episode: Do cows make different amounts of “moos” to say different words? Why do ducks make loud noises? Why do roosters cockadoodle-do in the morning? PLUS, so many kids sent us animal noises in different languages and we’ll hear them all! Download our learning guides: PDF | Google Slide | Transcript Bioacoustics is the study of sounds made in nature. Scientists like Elodie Briefer study how animals make sounds and what information we can find in those sounds. Scientists will record sounds and use computers to measure and analyze what they hear and use observational skills to help determine what the sounds might mean. Animals speak in emotion, not in words. Pigs have contact calls as well as positive and negative calls. Researchers have found that pigs will make longer calls when they are unhappy. Scientists and animal welfare advocates hope to use this information to eventually develop an app that farmers can use to improve animals’ lives on farms. With words like moo, oink and cockadoodle-do, we are giving a name to a sound. But we’re not just trying to mimic the sound. Most of us can make the sound of a pig snort but we need words like oink because we don’t want to stop using our language to make a pig snort in the middle of a conversation. Human voices are capable of millions of sounds but a language only uses a subset of those sounds. Our animal noise words will use the sounds available in our individual languages. Words that sound like the sound they are describing are called onomatopoeia. An animal has to have some cultural importance for a language to create a word for its call. That’s why we don’t have words in English for the noise a camel or a sloth would make. In Turkish there is no word for a pig call because that culture doesn’t keep pigs on farms.

We’re bringing back an episode from the archives, all about the moon: Why does the moon change shape? How much does it weigh? What color is it? Why does the Earth only have one moon? Why does it have holes? Where does it go when we can't see it? Why do we sometimes see it in the daytime? And why does the moon look like it's following you when you're in the car? Answers to your moon questions with John O'Meara, chief scientist at the W.M. Keck Observatory. Download our learning guides: PDF | Google Slide | Transcript | Coloring Page We can see the moon during the day for the same reason we see the moon at night. The surface of the moon is reflecting the sun's light into our eyes. But we don't see the moon all the time during the day, and that's because of where the moon might be in the sky. There are times where the moon is on the other side of the earth so we can’t see it. We see the moon in the sky when it’s in the right spot and it’s reflecting enough light to be brighter than the background of the sky. The moon is a satellite. A satellite is something that moves or rotates around a planet, the earth in this case. The moon is 239,000 miles away. That's far, but it's way closer than any of the other stars or planets you can see in the night sky. That's why the moon looks so big compared to other celestial objects even though the stars are actually much bigger. The moon weighs 100,000,000,000,000,000,000,000 pounds. That’s a lot! But it’s such a big number it’s hard to imagine how much that weighs. Instead, think about how much the moon weighs compared to the Earth. It turns out that the moon is about 1% percent the mass of the earth. That’s a lot! When you’re in a car and it feels like the moon is following you, what you’re actually seeing is an optical illusion. The moon is very far away, compared to anything else you see when you're driving — like the telephone poles that appear to fly past your car as you're going down a highway. But the moon is so far away that its size and shape in the sky doesn’t change, so it feels like the moon is following you.

The invasion of Ukraine has been the top story in the news for the last few weeks, and kids around the world are asking questions about what is happening and what it means for them. In this episode we ask Erin Hutchinson, Assistant Professor of Russian History at the University of Colorado Boulder, to help us understand the history behind this conflict. Adults: we don’t go into detail about what war looks like on the ground, but we acknowledge war is a scary topic. You may want to preview this episode ahead of time to make sure it's right for your kids. Download our learning guides: PDF | Google Slide | Transcript We have collected some resources for parents/caregivers about how to talk to kids about war and ways families can help. How to talk to kids about war Meet the Helpers Common Sense Media News Sources for Kids from Common Sense Media NAMLE Parent’s Guide to Media Literacy Ways To Help Save the Children UNICEF Eurasia Foundation Donations for refugees in Moldova

Violet, 5, wants to know: what was life like before refrigerators? And Ellinor, 6, asks: how did they make ice in the old times? In this episode, we learn about the history of ice harvesting and the industry that built up around it, where ice cut from lakes in New England was shipped to as far away as India and the Caribbean. We hear more about this history from Gavin Weightman, author of The Frozen Water Trade. And we visit Rockywold-Deephaven Camps in New Hampshire, where ice is still harvested each winter from Squam Lake and used to keep old fashioned ice boxes at the camp cool all summer long. Download our learning guides: PDF | Google Slide | Transcript Before refrigeration, people stored food in a lot of different ways. Food would be smoked, dried, salted, fermented or pickled. It would also be kept in root cellars or pits underground. Wealthy people who lived in cold climates were more likely to have an ice pit or later an ice house where they would keep ice for use in warm months. In the 1800s, a Massachusetts man named Frederic Tudor thought he could get wealthy by shipping ice to warmer climates. After trying and failing many times, he finally succeeded in convincing people that there was a market for ice and wound up shipping ice around the world, as far away as India. The ice was kept cold by insulating it with straw and sawdust and stored in warehouses until it was time to be used. People cut ice from lakes using hand saws. Eventually they started using horse drawn machinery to cut ice, but it was still hard and dangerous work. People in cities also became accustomed to ice as an everyday necessity, and eventually, naturally harvested ice was eventually replaced by ice made in factories. In cities, “ice men” would deliver ice to butchers and fishmongers, and to individual houses, where people would use them in their ice boxes. Ice boxes were wooden or metal chests with a compartment in the top where a block of ice would be placed. Cold air falls and cools the food below it. Ice boxes needed more ice every day or two. The electric refrigerator was invented in the early 1900s and became popular by 1940. Resources Ice Harvesting Video

Why is the heart a symbol of love? Why do people draw hearts when they love someone? Why do we draw hearts the way we do when they're nothing like the hearts inside of your body? And do we need a heart to love or does the brain do it? We’re learning all about hearts and symbolism with Thomas and Stephen Amidon, authors of The Sublime Engine: A Biography of the Human Heart. Download our learning guides: PDF | Google Slide | Transcript No one really knows where the heart symbol comes from, but there are theories. One is that the heart shape comes from the shape of the leaves of a now-extinct plant called silphium, which was considered a key component of a love potion in the time of the Romans. Another theory is that St. Valentine used the symbol when arranging secret marriages. Another is that it was simply a guess of what the human heart looked like. Love and other emotions are actually regulated in the brain, not the heart. Specifically, a part of the brain called the amygdala. People might partly associate the heart with strong emotions like love because when we get excited to see someone, our heart sometimes beats faster, and we notice our heartbeat. We aren’t really aware of what’s happening in our brain. The human heart pumps blood to all parts of your body. The heart beats once a second. If you live to the age of 70, your heart will have beat about 2 billion times! Resources How the heart actually pumps blood - TEDEd Your Hardworking Heart and Spectacular Circulatory System by Paul Mason Heart and Circulatory System Activities

The U.S. Mint is producing a new series of quarters featuring American women. The first one, featuring poet Maya Angelou, has just been released. We're learning about coins are made and how images are chosen for money around the world. The US has a law preventing any living person from appearing on its money. Kenya has a new rule preventing any individual people on their money at all. Meanwhile, many countries with kings or queens have those leaders on their money while they’re still in power. Questions we tackle in this episode: How are coins made and how do they get their logos? How are presidents chosen for coins? Why does Lincoln have his shoulder in the picture while other presidents don’t? Why are coins different sizes? What are coins made of? We learn more from Rodney Gillis of the American Numismatic Association and Leigh Gordon of the Royal Australian Mint. Download our learning guides: PDF | Google Slide | Transcript Some people like learning about coins so much they collect them! A coin collector is called a numistmatist! Numismatics is the study or collection of coins, paper currency, and medals. The U.S. Mint makes coins for the United States. There are four facilities in the US where our coins are made: San Francisco, Denver, Philadelphia, and West Point, New York A new image on a coin requires approval from Congress. Australian coins feature kangaroos, koalas and native plants. U.S. Coins mostly feature former presidents, but some non-presidents have appeared on coins including Susan B. Anthony, Sacagawea and Ben Franklin. The reverse side of quarters changes frequently. There are quarters for every state. Over the next four years the U.S. Mint is releasing quarters featuring 20 notable American women. US law says no living person can be pictured on our money. Today, the smallest US coin is a dime. But there used to be something called a trime! It was a tiny 3-cent coin and it was so small and thin that it often got bent in people’s pockets. Resources Coins for A’s U.S. Mint Collector’s Corner How Coins Are Made

What causes wind? How is wind created? Why does the wind blow in different ways? How does the wind start blowing and what makes it stop? Why is it windy by the ocean? Why does it get windy when the weather is changing? How is it you can you feel and hear the wind but not see it? Why is the wind sometimes strong and sometimes cold? Answers to all of your wind questions with National Weather Service Meteorologist Rebecca Duell. Download our learning guides: PDF | Google Slide | Transcript Wind is just the air around us moving. The atmosphere always wants to be in balance. Some areas of the atmosphere have more air pressure than others. When there’s a pressure imbalance, the higher pressure air moves to fill a vacuum left by lower pressure air. The wind starts blowing when that balance is off - when one area is heated more than another area. That heat comes from the sun. Warm air will rise and cold air will sink. When one area is heated that warm air will start to rise. Air at the surface will be rushing to fill that area where the air is rising. Wind near the ocean is called a sea breeze. The land is absorbing more heat from the sun than the ocean water absorbs. As the less dense warm air over the land starts to rise and the cooler, the more dense air over the ocean rushes in to fill the space. If there’s enough moisture in the air when it rises, it will cause rains, which is why you often get afternoon rain and thunderstorms in places like Florida. The wind can be hot or cold depending on where that air is coming from. The northern winds will be colder, winds from the south will be warmer. (In the northern hemisphere. It’s opposite in the southern hemisphere.) Related Episodes What’s What With The Weather? How Do Meteorologists Predict the Weather? Experiment One way to see the wind is to put some steam or smoke into the air. Which way is it blowing? Be sure to have an adult help you! Or you can look at a smokestack or chimney. Which way is the smoke blowing? Are there other ways you can see the wind?

We asked our listeners: if you could invent anything what would it be? And we got so many fantastic ideas from kids all over the world: a solar cooler, a chimney that changes carbon dioxide to oxygen, a slide that gives you an ice cream cone at the bottom, and more. Some kids would like to invent robots that do their chores, flying cars, teleporting devices to take them back in time, and even a bully behavior zapper. This episode is all about creativity! But how do you take a great idea and turn it into reality? We’ll get advice from teenage brothers Ayaan and Mika’il Naqvi, who invented, patented and now sell Ornament Anchor after Ayaan came up with the idea in fourth grade. Download our learning guides: PDF | Google Slide | Transcript What would you invent? Inventors are often driven by a desire to create something that would help solve a problem. Our listeners are interested in ways to tackle climate change, clean up the environment and to make life easier or more fun for all. Once an inventor has an idea, they can get something called a patent. A patent protects the idea and means that no one else can take that concept and start selling a product without permission from the inventor. Once someone has a patent, there are a lot more steps required to actually start a business. People who start businesses are sometimes called entrepreneurs. They need to find a way to manufacture (make) and sell the product. Some companies will do research to figure out how well a product will sell and who will buy it. Learning Resources Little Inventors Cloudy with a Chance of Meatballs U.S. Patent and Trademark Office Resources for Kids Camp Invention

Why do seasons change? Why does it get darker earlier in the winter and why is there more daylight in the summer? Why are some seasons warm and some are cold and icy? Why do some places not have seasonal changes at all? We’re learning about solstices, equinoxes and seasons in this episode of But Why. Our guide is John O’Meara, Chief Scientist at Hawaii’s Keck Observatory. And kids around the world tell us what they like best about their favorite season. Download our learning guides: PDF | Google Slide | Transcript The solstices are on December 21 and 22 and June 20 or 21, those are when the earth is leaning as far away from the sun or as close to the sun as it gets. Whether the solstice is your winter or summer solstice depends on whether you are in the northern or southern hemisphere. The two equinoxes - when both hemispheres are getting about the same amount of solar energy are on March 21 or 22 or September 22 or 23. If you want to visualize the solstice, John O’Meara has an experiment. Find a ball and a flashlight. Have someone hold the flashlight; you hold the ball. Spin the ball around and around, the way the earth would rotate in a day. You can even draw a dot on the ball to mark where you are. Now lean the ball a little bit away from the light and keep spinning. Remember the earth is tilted on its axis (23.5 degrees to be exact!). Observe how the light falls differently on the dot. It forces the sunlight to be brighter on some spots and darker in others even during the day because of the way the light falls on the earth. In some parts of the world there aren’t big seasonal changes. Those places are near the equator. The equator is a line around the middle of the earth, where the sphere is at its fattest or widest. While the poles get more or less light because of the tilt of the earth, the middle stays centered, so people near the equator have about the same length of daylight all year and don’t have as many seasonal shifts in light and temperature. The amount of sunlight in any given location makes a big impact on how cold or hot it is. But there are other factors that determine the climate (long-term weather trends) where you live, too. Differences in the landscape, global wind systems, proximity (how close or far you are) from the ocean, and precipitation patterns also determine what the seasons will feel like where you live.

How are babies made? We speak with Cory Silverberg, author of What Makes A Baby, for answers to questions about how we all come into the world. This is a conversation that welcomes all kinds of families as we answer questions about why babies don't hatch out of eggs, why boys have nipples, why girls have babies but boys don't and why some people look more like one parent more than the other. Later in the episode we also explore how we get our last names and how two people can have the same last name when they're not related. We made this episode with our youngest listeners in mind, but parents may want to preview this episode on their own or listen with their kids. Download our learning guides: PDF | Google Slide | Transcript "How are babies made?" - Wade, 7, Charlottesville, Va. In his book What Makes a Baby, Cory Silverberg begins by reminding kids and grownups that there are really two questions: what makes a baby in general, and then the more specific question that is unique to you--where did you come from? That's a question that only your parent or parents or the adults who love you can answer. While there are lots of ways that babies join families, some things are true for all of us. “For all humans to be born we need three things. We need to start with an egg; we need to start with a sperm; and those come from two different bodies. And then we need a third body part which is called a uterus. That's where we grow, where this tiny, tiny thing grows into a baby, which is the thing you are when you are born," Silverberg explains. Book recommendations from Cory Silverberg Books Geared to Kids 4 - 7 (ish) What Makes a Baby By Cory Silverberg and Fiona Smyth A book about where babies come from that works for every kind of family, regardless of who is in it and how the child came to be. What's the Big Secret: Talking about Sex with Girls and Boys By Laurie Krasny Brown and Marc Brown A simplified and clear introduction to reproduction, genitals, and touch. Leaves out a lot of kids and families, but better than most. Who Are You? The Kid's Guide to Gender Identity by Brook Pessin-Whedbee and Naomi Bardoff Also simplified, but a good introduction on gender identity written and illustrated for younger children. Books Geared to Kids 7 to 10 (ish) The Care and Keeping of You: The Body Book for Younger Girls By Valorie Schaefer and Josee Masse Only for girls, and not trans inclusive, but still one of the best books to cover a range of sexuality and puberty related topics. It's So Amazing! A Book about Eggs, Sperm, Birth, Babies, and Families By Robie Harris and Michael Emberly Covers reproduction including intercourse gestation and birth, with a focus on heterosexual, gender normative parents and kids. Sex Is a Funny Word By Cory Silverberg and Fiona Smyth Covers body parts, boundaries, touch, and an extensive gender section for kids and families of all identities and orientations. Stacey's Not a Girl By Colt Keo-Meier, illustrated by Jesse Yang A picture book about a kid who knows they aren't a girl, but isn't sure if they are a boy.

Why is the Burj Khalifa so tall? That’s what 5-year-old Simon wants to know. The Burj Khalifa is the tallest building in the world and it’s located in Dubai. 6-year-old Isabel, who lives in Dubai, visited the tower and gives us the bird’s eye view in this episode! Plus, Janny Gédéon, architecture educator and founder of ArchForKids answers lots more questions about tall buildings: How are tall buildings built? How do they stay up? Why are so many buildings squares or rectangles? How do they make buildings that are taller than cranes? Resources Architecture workshops and online learning: ArchForKids Download our learning guides: PDF | Google Slides | Transcript Why is the Burj Khalifa so tall? - Simon, 5, Chicago The Burj Khalifa is 160 stories tall. It measures over 2,716 feet tall – or if you think in metric that’s 828 meters. “If you put 450 grown ups stacked on top of each other, that would be the height of the building,” Janny Gedeon says. Architecture is the science of designing buildings. Architects consider the purpose of the building and what it will be used for and then they design that space. Square and rectangular buildings are less expensive to build, but architects do like to design buildings in interesting shapes. Check out the Lipstick Building in New York or the Gherkin in London, or the Sydney Opera House. Tall buildings are more common in cities because they allow more people to live in a smaller space. They have to build vertically to fit more people in a small area. “The footing, the space that the building takes is not that big, so they have to build up,” Janny says. The footing is like your footprint, the amount of space you take on the ground. Manhattan is built on a very strong rock, so it can support those tall buildings. Buildings stay up in much the same way humans stay up. There are footings--think of them like feet--that go into the ground. Buildings have a skeleton, called a structural frame, kind of like bones in a human. And on the outside, they have a cladding, aluminum or glass or other materials, kind of like our skin. Wind is a big consideration for architects building tall buildings. They design the buildings to sway. If buildings are too brittle they will break, they are designed to sway. Most skyscrapers get narrower toward the top. In earthquake prone areas, buildings sometimes have footings on a track so they can move. Activity Try making the tallest tower you possibly can, just using paper. (Newspaper works great if you have some newsprint lying around. But printer paper or construction paper is fine, too.) You should focus on making it strong and stable. Strong means that it can hold something. Stable means that if it’s pushed to the side it can stay upright. You can use cardboard for the base, but otherwise, see how you can do with just paper. Need a hint? Janny says to think about the ways you’d stay stable when playing sports.

Squirrels are everywhere. Three hundred or so species of these often adorable rodents live on every continent except Antarctica. No matter where you live, city or country you’re bound to have squirrels nearby. How much do you know about our bushy-tailed neighbors? How fast do squirrels and chipmunks run? Why do squirrels have big bushy tails? Do squirrels get sick? Why do they like nuts better than berries? How do squirrels eat acorns? How do squirrels sleep? Are squirrels nocturnal? Answers to your squirrel questions with Ben Dantzer, scientist at University of Michigan. Plus some observational activities you can do to learn more about squirrel behavior! Download our learning guides: PDF | Google Slides | Transcript Submit your squirrel observations to iNaturalist How do squirrels climb up trees? -Rachel, 5, Alabama Squirrels have long nails and they have five digits (fingers or toes) on their paws just like us. And squirrels are expert climbers. “Some tree, or arboreal, squirrels are really well adapted to climb up trees whereas ground squirrels also have nails or claws, but they use them primarily for digging and not for climbing,” explains Ben Dantzer. “Tree squirrels have this especially long middle digit that helps them climb up and down trees.” So an extra long middle finger and they can do something else that humans can’t. “The most helpful thing they can do is when they climb down a tree, squirrels can turn their back feet around when they’re climbing down head first. They turn their rear feet entirely around so they can use those claws to hang down from a tree and walk down easily.” What? Tree squirrels can turn their feet all the way around so they’re backwards when the squirrel is climbing down a tree?! Time to go outside and see if you can observe that in the wild!

The FDA recently gave emergency use authorization to the Pfizer-BioNTech vaccine for kids age 5 to 11. With all the news and conversation about this development, kids are curious to know more about the Covid vaccine--and vaccines in general! So in this episode we answer questions from kids and parents, including: Why does it have to be a shot? How do vaccines work? How does a vaccine trial work? Should an 11.5yo get the shot as soon as it’s available or wait until age 12 to get the larger dose? We speak with Sofia and Nico Chavez and their parents. The kids took part in the vaccine trial at Stanford University. We’re also joined by Dr. Jenna Bollyky, an investigator in the Stanford trial site, and Dr. Mark Levine, Vermont’s Health Commissioner. Download our learning guides: PDF | Google Slides | Transcript Strategies to prepare kids for shots Vaccine Info from the CDC. “Why do they have to use needles for shots?” - Nina, 6, Maryland “In general, vaccines are a way to train your immune system without having to get sick,’ explains Dr. Bollyky Your immune system is how your body works to fight off sickness from things like viruses. Most vaccines use a small protein from the virus you want to fight, or from a similar virus – and they put that little protein in your body in a very small and weakened or changed amount to help your body learn how to fight the real invader. But giving the vaccine as a drink or a pill wouldn’t work, because of your stomach acid! “Whenever we want to give a protein or something that your body turns into a protein, the acid in the stomach does a really good job of breaking down that protein. So it’s really hard to get a vaccine that comes as a pill,” Bollyky says. “Why can’t we drink medicine to keep us safe from the virus, instead of shots? - Eloise, 5, Texas In order to get that vaccine into your muscle, where it needs to go, a doctor or a nurse uses a thin needle. They do have to poke you, but that doesn’t mean they like it. “If we could give it as a pill we would,” Dr. Bollyky promises! While that poke might hurt, sometimes the anticipation of the shot is worse than the real thing. The reason your arm sometimes aches after getting a shot is that the immune cells are coming to be educated. “The cells around where the medication was delivered, they’re doing their job, they’re taking in the information they need and are starting to train your immune system,” Dr. Bollyky assures us. “So that immune response is exactly what you want to teach your body to fight the infection should you encounter the real virus later.” It’s normal to feel a little tired or run down after some vaccines, including the COVID vaccine. But if you feel very ill, you should contact a doctor or health care provider.

Why do apples have stems? Why do fruits start out as flowers? How did the first apple grow when no one was there to plant its seed? Why can you make a seedless grape and not a seedless apple? Why are apples so juicy? How is apple juice made? Why are apples hard and pears soft? In this episode we take a field trip to Champlain Orchards in Shoreham, Vermont to learn more about apples. Our guides are 10-year-old Rupert Suhr, his father, Bill, and apple expert Ezekiel Goodband. Download our learning guides: PDF | Google Slide | Transcript Flower to Fruit Image Why are some fruits a flower before they’re fruit? - Grayson, 8, San Jose, California Actually ALL fruits start as flowers (but not all flowers turn into fruit). Growing fruit is a way that some plants reproduce. Fruit is the nice ripe container that holds the seeds, which humans or animals will eat and then spread around (often through their poop), allowing new plants to grow. But that process begins with a flower. The outer part of the flower often has beautiful colors and shapes and smells—and that’s all part of the way the plant tries to attract a bee or other pollinator: “The flower has an ovary at the base of the petals. The petals are enticing a bee to come with the pollen from another blossom that it’s visited and there’s some nectar that the bee can collect and while the bee is doing that it’s shedding some pollen,” explains Ezekiel Goodband. “That pollen completes the information that the apple needs to start growing. So the flower is to attract the bee.” That ovary at the base of the flower will start to grow and that will become the apple that you eat. If you look at the bottom of an apple—the opposite end of where the stem is attached to the tree—you can actually see where the flower used to be. It even kind of looks a little bit like a tiny flower.

We’re exploring a part of the world that not much is known about—in fact, you could be one of the people who help us understand and learn more about this very important, and very large, part of our earth. The land underneath the ocean is as varied and interesting as the terrain up on dry land—with mountains and canyons, plains and forests. (That’s right, forests! There are kelp forests where the kelp is as much as 150 feet tall!) In this episode, what’s known--and unknown--about the bottom of the ocean. How deep IS the deepest part of the ocean? And how was the Mariana Trench formed? We get answers from Jamie McMichael-Phillips and Vicki Ferrini of Seabed 2030, a global collaboration designed to map the sea floor, by 2030. Resources Download our learning guides: PDF | Google Slide | Transcript Seabed 2030 Visual: What Lurks In The Depths Of the Ocean? (CBC Kids) “How deep is the deepest part of the ocean?” –Freya, 8, Wellington, New Zealand The deepest part of the ocean is the Challenger Deep, 11,034 meters in the Mariana Trench. It’s about seven miles deep! How did the trench get so deep? The same processes that formed canyons and mountains on dry land also formed the depths of the ocean and the islands that peek above the water. In the case of the Mariana Trench, it was formed by the process of subduction—when one tectonic plate slides under another. A tectonic plate is a gigantic piece of the earth’s crust and the next layer below that, called the upper mantle. These massive slabs of rock are constantly moving, but usually very slowly, so a lot of changes to the earth’s structure take place over a long time. But sometimes something like an earthquake can speed that process up. A trench is formed when one plate slides or melts beneath another one. The Mariana Trench is the deepest trench in the world—farther below sea level than Mount Everest, is tall!

Kala wants to know why we say soccer in the United States, when the rest of the world calls the game "football." In this episode we hear from people who make their living in the game: professional players, coaches and commentators. Download our learning guides: PDF | Google Slide | Transcript “Why is soccer called 'soccer,' instead of being called 'football?'” - Kala, Colchester, Vt. "It's an interesting question because so many people around the world play the game of football," said David Saward, now-retired men's coach at Middlebury College. "What happened with the words soccer and football goes back to the 1800s when the game was developed. There were two groups of people in Britain who got together to set the rules of two different games, one that was known as rugby football, and another that was known as association football. From those two first words: 'rugby' and 'association,' came two very separate games. Rugby was abbreviated to the word 'rugger.' And out of the word 'association' came 'soccer.' That's the root of where the two differences came." So although these days you probably won't hear many Brits calling the sport "soccer," the word actually originated there. Americans brought the nickname to the US, and as the sport became popular, soccer stuck. "When you look around the world," says Coach Saward, "there are all sorts of different forms of football: American football, Australian rules football, Gaelic football, rugby football and association football. I think for the clarity of everyone over here when we say the word football, we think of people running around with helmets and pads on; so soccer is a very clear distinction."

In this episode of But Why we visit a credit union to learn what money is all about. And Felix Salmon, Anna Szymanski and Jordan Weissman from Slate Money answer questions about why money plays such a big role in modern society. How was money invented? Why can't everything be free? How do you earn money? How was the penny invented? Why are dimes so small? Download our learning guides: PDF | Google Slide | Transcript Related Episodes: What Is The Biggest Number? Resources: How To Talk To Kids About Money, Million Bazillion podcast Who invented money? - Luca, 9, Ashland, Ore. There's no first person we can point to who invented money. The idea of money has evolved as human society got more complicated. In the early days of humankind, people mostly bartered. Bartering is essentially trading. But over time people realized they needed to have a system for dealing with things when there wasn't an easy trade. If you have something I want but I don't want anything you're offering because I really need something else, how do we work it out? That's where the earliest forms of money emerged. First they were things like shells or rocks. Then pieces of clay with symbols or faces pressed into them. These things don't have much value by themselves, but if everyone agrees that they're going to use them as a symbol of value, you can trade them and start a system of payment. Eventually these objects became more formalized, turning into coins and paper dollar bills, like the ones we use today. These days there's another method of buying and selling: the credit or debit card.

Five-year-old Odin in Wyoming is about to start school and he sent us this question: If I’m terrified about kindergarten do I have to go? What should I do if I’m scared? What if kids are mean to me? In this episode, tips and suggestions from our listeners for kids returning to school, along with answers from guidance counselor Tosha Todd and National Teacher of the Year Juliana Urtubey. Download our learning guides: PDF | Google Slide | Transcript Related Episodes: Why Do We Have To Go To School? First day of school book recommendations from Tosha Todd First Day Jitters Night Before Kindergarten Miss Bindergarten Gets Ready for Kindergarten The Kissing Hand Back to school tips Make a hug button! Draw a heart on the inside of your hand. Draw a heart on your parent’s hand. Squeeze them together to charge your hug button. If you feel nervous at school, push the hug button and it will send you a hug. - Tosha Todd, school guidance counselor Keep a picture of your family in your backpack. You can share with your teacher the things your family does for fun. That will help your teacher understand your family. - Juliana Urtubey, National Teacher of the Year If you're nervous try to have fun and try to make some friends and the school year will be a lot better.- Zoe, 10 Colorado Remind yourself that you are brave and confident. - Clarissa, 8, Ontario Get into a school routine now. Pick out your clothes the night before. Maybe pack your lunch too. - Tosha Todd When I start school I feel nervous, but when I step in I feel ok. For the first few days I play by myself. When those first few days are done, I play with others. - Julius, 8, Ontario Take a deep breath, be kind to someone and they'll be kind to you. - Zoe, 6, California Get everyone's names and if you forget them it's ok to ask again. - Lucy, Vermont Say hi to all the kids. - Ben, 6, Michigan You're going to make friends, and your mom and dad will pick you up; they're not going to leave you there forever. - Sly, 7, New York

Have you ever been threading one leg through a pair of pants in the morning and wondered…why do we wear pants anyway? Or wondered why pockets in clothing designed for girls are sometimes smaller than the pockets in clothing designed for boys? In this episode we’ll tackle your questions about clothes with fashion historian and writer Amber Butchart. Download our learning guides: PDF | Google Slides | Transcript “Why do we have to wear clothes?” - Bhakti, 9, Australia Many people think we started to wear clothes for practical reasons of warmth and protection. “We don’t have fur like other animals, so when modern humans started moving into colder parts of the world, we needed to protect ourselves somehow if it’s cold and snowy. This is one answer, that we wear clothes for protection,” said Amber Butchart. Butchart is a dress historian, author and broadcaster. She studies how the clothes we wear are connected to where we live and what kind of culture we grow up in, and what time period we’re growing up and living in. Butchart says, while the protection theory explains why we have to wear something—to cover our skin from the elements, there are a lot of other answers that help explain the style of clothes we wear, or don’t wear. These have to do with culture and society, and ideas about modesty as well. In this case modesty means what’s considered proper, broadly accepted as not being too wild or “out there.” A lot of how we dress comes down to what is considered appropriate in our current culture. “The idea is that these cultural codes built up across millennia and centuries and centuries, ideas that parts of our body should be covered up,” Butchart explained. “We have these social ideas to do with what parts of the body should and shouldn’t be on display, but we also have that combined with this need, especially in colder parts of the world, for protection from the elements.” But when it comes to fashion, what you wear communicates something about you to the outside world, and clothing has gone through many changes throughout history. Listen to the episode to learn more! Support But Why | Newsletter Sign-Up

What is the cleverest thing hippos can do? This week we’re answering seven quirky questions about animals! Why do elephants like peanuts? Why do cows put their tongues up their noses? Has anyone ever ridden a tiger? How do woodpeckers cling to trees? Why is some bird poop black and some is white? Why do people make animals like sharks and bears sound way scarier than they are? Answers from Keenan Stears of the University of California, Santa Barbara, Christine Scales of Billings Farm & Museum; shark researcher Kady Lyons and the Bird Diva Bridget Butler. Download our learning guides: PDF | Google Slide | Transcript Related Episodes: Why Do Elephants Have Trunks? Why Do Things Seem Scary In the Dark? Resources: Hippopotamus facts, Cornell Lab of Ornithology, Online Birding With Bird Diva What is the cleverest thing a hippo can do? – Elliot, 8, England We turned to Keenan Stears of the University of California, Santa Barbara for some help with this tricky query. “The first thing that comes to mind that highlights the intelligence of hippos,” he told us, “is the ability to identify hippo friends from hippo enemies by the smell of their dung.” Dung is another word for poop. “Dominant male hippos use dung middens to mark their territories. A dung midden is a place where an animal repeatedly goes to drop their dung. The dung middens act as a way that hippos can keep track of the other hippos in the area. So when moving through the environment, hippos can sniff out areas where their hippo friends live, versus areas where their hippo enemies live and they can do all of this just by smelling the dung in middens.” Bet you didn’t think the cleverest thing hippos can do would involve poop! And just in case it wasn’t totally clear, a midden is basically a waste pile. So a dung midden is kind of like a toilet or an outhouse. It’s where the hippos go repeatedly to poop. But, as Stears told us, it also serves another purpose. While humans can’t tell their poop from someone else’s, other animals can sniff out individuals this way, and use dung or urine—pee—to mark their territories. Hippos aren’t the only animals to use dung middens this way, by the way. Rhinoceroses do this too! Other animals, like dogs, cats, rabbits and monkeys also sniff feces and urine as a way to learn about their fellow species, but they don’t always leave their “messages” in the same place. Support But Why | Newsletter Sign-Up

What are fireworks made of, why are they bright and loud, and how do people make them? And, why do Americans celebrate the 4th of July with fireworks? We learn about pyrotechnics with licensed fireworks professional John Steinberg. And David Chavez, an explosives expert at Los Alamos National Laboratory tells us how changes to the materials used in fireworks can make them better for the environment and unleash new, more vibrant colors in the night sky. We also address firework safety and how to impress your friends by knowing what kinds of metals are in the fireworks you’re watching or the sparklers you’re playing with. NOTE: We know not all kids (or adults) enjoy the noise of fireworks. We do play the sound of fireworks at the very beginning and very end of the episode. And John Steinberg offers some advice to people who dislike fireworks in the middle of the episode. Download our learning guides: PDF | Google Slide | Transcript Related episodes: Why Is Fire Orange? and How Do You Make Paint? Resources: celebratesafely.org, Sparkler Safety Video, Fireworks Colors Why are fireworks bright? –Dash, 4, Omaha, NE Steinberg told But Why that the brightness is the main purpose of fireworks. “You’re painting the in sky with light. It has to be bright enough to create the color and the effect you want to in the sky. Second, fireworks are explosive. You can’t be right up in front of it like a painting in an art gallery. You have to be some distance away, so the fireworks have to be bright enough for you to appreciate it,” he said. Fireworks are created by burning materials that shine brightly when burned. Those fires are very hot! “The types of things we burn in fireworks burn very brightly, and they’re chosen for those properties,” Steinberg said. Fireworks are created by a combustion in the sky – a combustion is something that burns. “You need a fuel and you need something to burn that fuel,” Chavez said. “An example of a fuel would be gasoline or wood in a fireplace. In fireworks, the fuels are the chemicals that we use to make the firework itself. The oxidizer is another chemical. When those two things burn, they burn very hot. And those high temperatures excite the coloring agents that we have in fireworks.” The coloring agents are metals. “Anytime you see red, that’s strontium. If you see a pinkish-purple, that’s potassium. Yellow is from sodium. Orange comes from calcium. The green is from barium, but now you can use boron. Blue is from copper. And these can be mixed to make other colors. “You need a really hot fire to be able to excite these atoms, to make them give off their color. But when they are that hot, it makes the colors come out really bright.” Chavez and other scientists have found ways to change the fuel source of fireworks to create less soot. Those changes also allowed them to replace barium, which can get into water sources, with boron, a greener way to create those green fireworks. Support But Why | Newsletter Sign-Up

This week, we're revisiting one of our favorite older episodes from the past. We’re going to learn a little bit about the history of noodles--and how to make them! We’re joined by Jen Lin-Liu, author of the book On the Noodle Road: From Beijing to Rome with Pasta and Love. And we also get an exciting hand-pulled noodle demonstration from Tony Wu, who was the executive chef at M.Y. China, a restaurant in San Francisco’s Chinatown, when we originally recorded this audio in 2019. Wu can hand-pull 16,000 strands of noodles from one lump of dough in just two minutes...while blindfolded! Narrating this noodle-pulling exhibition is celebrity chef Martin Yan, who owned the restaurant. (M.Y. China closed during the pandemic.) Download our learning guides: PDF | Google Slide | Transcript | Video The first written references to noodles or pasta can be found in Chinese texts dating back about 3200 years. Author Jen Lin-Liu says it's likely that pasta developed in China and in the Middle East within a couple hundred years ago. But what likely didn't happen was the often repeated idea that Italian explorer and trader Marco Polo "discovered" noodles during his two decades traveling in east Asia and then introduced them to Italians upon his return. "Probably what happened," Lin-Liu told But Why, "was they were invented in China and they were also invented somewhere in the Middle East a little bit later, probably a few hundred years later. And there were two parallel cultures of noodles that developed separately. "And then," Lin-Liu continues, "because of the interactions between cultures later on, they started merging. So they were probably eating noodles in Italy and China at separate times and they didn't have much to do with each other at the beginning." On mobile? Click here to watch the video. As for how noodles are made, the ingredients are pretty basic: just flour and water. Sometimes eggs are used in place of water in Italian pasta. They can then be turned into noodles or pressed into different shapes. Sometimes they're filled with meat and cheese or other ingredients and turned into dumplings or tortellini or other filled-pasta shapes. Making pasta takes skill, both to get the consistency right and to make the perfect shapes. At Martin Yan's San Francisco restaurant M.Y. China, executive chef Tony Wu puts on a weekly show for diners, displaying his ability to hand-pull 16,000 strands of noodles from one lump of dough in under two minutes. Yan calles him a "human pasta machine," and we get to experience the excitement in this episode. Support But Why | Newsletter Sign-Up

Are seeds alive? What are they made of? Here in Vermont it's planting time, and we've been getting a lot of questions about seeds from kids around the world. In this episode we'll explore the importance of preserving seed diversity with Hannes Dempewolf of the Global Crop Diversity Trust. Crop Trust manages a repository of seeds from around the world at the Global Seed Vault in Svalbard, Norway, above the Arctic Circle. Plus, ethnobotanist and Abenaki scholar Fred Wiseman shares a little bit about a project called Seeds of Renewal, which aims to find seeds traditionally grown by Abenaki people in our region and return them to cultivation. Download our learning guides: PDF | Google Slide | Transcript More Plant Episodes: How Do Big Plants Grow From Such Small Seeds? The Svalbard Global Seed Vault contains an enormous wealth of seeds from around the world. Unlike other seed banks, the vault is designed not to be used unless there are no other options in other seed banks. Seed banks are places where seeds are stored for future use in case of a disaster or crop failure, and are sometimes given out to help establish new populations of heritage or rare plants and crops. Seed banks also promote genetic diversity by keeping many varieties of seeds from many different plant species. "Are seeds alive?" - Evie, 5, Hawaii Yes, seeds are very much alive! At least the seeds that we use to grow food are alive. Seeds can die if they're not properly cared for, if they get too hot or cold or wet. But under the right conditions, they're just dormant. "It means they're sleeping basically," Dempewolf says. "Seeds are dormant and they need to be activated to grow. They need light to grow, along with humidity and warmth, that's the conditions that allow seeds to grow." "Different species of plants have very different kinds of seeds and different types of seeds also need very different conditions to grow. Some grow with very, very little humidity with very little wetness, and some need a lot. Some need to be submerged in you know under water for a while until they can grow. Some need to be frozen first before they can grow. Some seeds are made that they have to first be eaten by an animal and then pooped out again, so they can grow. Some grow with very, very little wetness, and some need to be submerged underwater for a while until they can grow. Some need to be frozen first before they can grow. Seeds are amazingly complex." Support But Why | Newsletter Sign-Up

Our guest this week is a lexicographer. That's someone who studies words and, in this case, edits dictionaries. Emily Brewster is a senior editor at Merriam-Webster and host of the podcast Word Matters. Emily answers a question from 8-year-old Emma in Kentucky, who wants to know how words are added to the dictionary. But before we can answer that, we'll tackle 7-year-old Julia's question, "How are new words created?" Join us for an episode about how words are created, when they've reached a critical level of use to get their own dictionary entry, and when words are removed from the dictionary. Get ready for some word nerdery! Download our learning guides: PDF | Google Slide | Transcript More Word Episodes: Who Invented Words? But Why Live: Words and Language Why Are Some Words ‘Bad’? "How do words get added to the dictionary?" - Emma, 8, Kentucky Lexicographers like Emily Brewster read and listen a lot and pay attention to the new words that people are using. They collect these examples and determine how many instances there are of the word and what different kinds of sources are using the word. "If all the examples are only appearing on TikTok, then that tells us one thing about the word. But as soon as they're also appearing in, you know, a magazine that you would see at the dentist's office, then that tells us something else about the word's status," Emily explains. "So we are always looking for information, for evidence, of how words are being used by the people who speak the English language. And when we have enough evidence that the word is really part of the language, that it's a word that most people already will recognize when they hear it, that's when we know that it's ready to be added to the dictionary." For example, the word COVID-19 was a word created by the World Health Organization about a year and a half ago. "It got into our dictionary faster than any other word in the history of the dictionary has ever been added. Because what we knew immediately was that this word was not going away, that everybody was talking about this word," Emily says. Sometimes dictionary editors update the definition of words that were already included. For example, the definitions of "pod" and "bubble" were updated this past January to include a new meaning: people you might have grouped up with when you weren't seeing other people because of the pandemic. Other new words recently added to the dictionary include: "makerspace," where people get together in a common area and often share tools to make their own projects; "BIPOC," an abbreviation for Black, Indigenous and People of Color; and "second gentleman," in reference to Vice President Kamala Harris's husband. Once it's been established that a word is in widespread use, an editor will carefully read through evidence of the word in use and formulate a meaning in very careful language. Another editor will determine how old a word is and its earliest usage, another will look at the word's history, and the word will get a pronunciation. Then it's ready to be added to the dictionary. Merriam-Webster updates their online dictionary with new words or new definitions of words a few times a year. Emily says words don't usually get taken out of dictionaries, but editors do make choices about which words appear in print dictionaries. Support But Why | Newsletter Sign-Up

How do people whistle? How does whistling make a sound? Why does your tongue change a whistle higher or lower? Can you get a trophy for whistling? Can people with laryngitis whistle? Get ready, we learn all about whistling with musician and champion whistler Emily Eagen and musician Yuki Takeda. And who whistles our theme song? We'll hear from musician Luke Reynolds, and a kid whistling chorus from our listeners! Download our learning guides: PDF | Google Slide | Transcript How do you whistle? - Aurelia, 6, New York Emily says the first thing you should do is lick your lips or use lip balm. "If your lips are dry when the air passes it doesn't feel good," she says. Then you'll make your lips kind of into a pucker, circle your lips tightly. Next, stick your tongue touching your bottom teeth. Then you make kind of a yuh, yuh, yuh sound. "But instead of saying the words, make it with a little stream of air. You want to let air pass over the top of your tongue and out your lips. You're making a tiny little instrument by curling your tongue." "I like to think about between your nose and your lips, that's a little body part called a philtrum. I like to pretend that my whistle is coming out of that. That helps me make the sound have a little focal point," she says. Emily says it helps to make little sounds when you practice. "Pretend your sipping tea with that little tiny space there. You don't want to push too much. If you blow too much air it won't work. You have to be really gentle." Once you find your first whistle, it's all about practice and playing around to see what sounds you can make. "If you move your tongue forward, the notes go up, and if you move your tongue down, the notes go down," she says. If you can make a variety of notes, then you can start putting them together to make music!

How are rocks made? Why are some rocks hard and others soft? How do rocks shine? How are geodes and crystals made? Why do some rocks have gems in them? Answers to your rock questions with Hendratta Ali, rock doctor! Ali is a geologist who studies and teaches at Fort Hays State University in Kansas. Download our learning guides: PDF | Google Slide | Transcript

Is it OK to do something that you were told not to do and then never tell anybody? In this episode we tackle that thorny question from 10-year-old Finn from Seattle. We'll also wrestle with the question, "Why do people make really bad choices and want other people's lives to be harder?" Download our learning guides: PDF | Google Slide | Transcript We're tackling some ethical dilemmas in this episode and we're letting kids give the answers! We also get a response from ABC Radio's Short & Curly, a podcast devoted to ethics for kids. Here's how some of our young listeners answer the question about whether it's ever okay to break a rule and lying about it: "No, because it usually just means you get in trouble." - Juniper "I think so. If you're protecting somebody or keeping a surprise." - Camille "It depends who told you. Like if your parents told you, then you shouldn't do it. Or if you do it, you should tell them you did it. But if it's like a mean person you met on the street it's ok. And it depends what it is. Because if it's a bad question, you shouldn't do it either way if it's a bad thing. If it's a good deed you should do it. And if you did that, why wouldn't you tell anyone?" -Sylvie "No, not really. If you don't tell anyone about it. It's mostly the doing it and then not telling anybody about it. Mostly what isn't the good thing about it. It's a little bit worse, if you don't tell someone you might get a feeling where you feel kind of embarrassed. And you don't tell anybody and it just sticks with you the rest of your life." - Piper

Have you ever felt competitive with a friend or a sibling? Competition comes up in a lot of different ways in life. Maybe you're running a race with a friend and you want to beat them! Maybe you're trying to play a song without making a mistake and you're competing against yourself. Sometimes competition feels good and fun. It can make you want to do better, and make a game more enjoyable. But not always. Sometimes competition feels bad. Like it's too much pressure, or takes away from the fun of being with your friends. Some people really don't like competition at all. 3-year-old Kai from Tokyo, Japan asks: "Why do we need to compete with other people, especially friends, for example on a sports day or at gym class?" In this episode we discuss competition with anthropologist Niko Besnier. And we'll hear from 12-year-old Harini Logan, a competitive speller from San Antonio, Texas, and 10-year-old Del Guilmette, an athlete from Monkton, Vermont. Download our learning guides: PDF | Google Slide | Transcript We put Kai's question to Niko Besnier, anthropologist at the University of Amsterdam. One of his books is called The Anthropology of Sport, written with Susan Brownell and Thomas F. Carter. He says there are two reasons that people take part in competitions: "One is that sports are fun. It's fun to play with your friends and classmates, to run, jump, play ball. We've all experienced this rush of pleasure and fun doing these things. But the other aspect that's contradictory to the fun part is that it enables us to measure our strength, our speed, our physical ability against those of other people. It's the competition part of sport, and competition can become extremely serious. Frequently, the fun part of sport gets lost." Besnier says when competition gets out of hand it can lead to hurt feelings, and on a larger scale, competition can lead to things like war and inequality. But with the right attitude, competition, especially when we compete against ourselves, can help us get better at sports and academics. That's how it is for Harini Logan. She's a competitive speller who has made it to the Scripps National Spelling Bee twice! "Competition teaches you a lot, whether it's the preparation leading up to that competition or the outcome," Logan says. "It can teach you a lot about not only your abilities, but also new things that can change the way you look at life. When you're preparing for a competition you can learn how to work hard, and how not to give up on something. And during the competition you learn teamwork. That's one thing you learn in spelling bees, because you want to be with your community, your friends. One thing to learn if you win: sportsmanship! You don't gloat about it, you still appreciate yourself but you don't overdo it so others don't feel bad. And if you don't win it doesn't matter. [You just say:] I'm going to try harder next time." Competing also helps us get better. That's how 10-year-old Del Guilmette views it. He likes to play against tough teams when he plays sports, because that's how you get better. "The best players at the game, whatever sport it is, they didn't get better because they played teams that they knew they were going to beat. They played those teams that were better than them. They got better and they practiced!" Listen to the full episode to hear more about how these mature young competitors think about the value of competition.

In the ice age, megafauna roamed North America: mammoths, saber-toothed cats, even giant land sloths! What happened to them? In this episode we answer questions about the ice age: What was it? Did birds live during that time period? How about giraffes? Did people live with woolly mammoths? Why did mammoths go extinct? We'll answer your questions with Ross MacPhee, senior curator at the American Museum of Natural History and author of End of Megafauna: The Fate of the World's Hugest, Fiercest, and Strangest Animals. And we'll hear from Nathaniel Kitchel, a Dartmouth researcher who used carbon dating to discover the age of a mammoth rib. Plus, John Moody, of the Winter Center for Indigenous Traditions in Norwich, Vermont, on how mammoths appear in the oral history of the Abenaki people. Download our learning guides: PDF | Google Slide | Transcript "What was the ice age?" -Karen, 5, Wilmington, Delaware In the Pleistocene era, which lasted from 120,000 years ago to 15,000 years ago, ice covered the landscape in much of the northern hemisphere. Ice covered all of Canada down into the Northern United States and all of northern Europe. And there were smaller ice sheets in Russia. How did this happen? Scientists think it was a buildup of ice over time. "The theory is that the winter never ended," explained Ross MacPhee. "You would have snowfalls in the winter and it never really got warm enough to get rid of it completely. The next year that would be built on, built on and built on. And the thing about snow is that it kind of makes its own weather. If you have snow it gets very cold! And that preserves the snow pack for a very long time." The weight of that snow would compact into ice, eventually covering parts of the world in great sheets of ice. It might help to think of the process as a little bit like what happens when you have a favorite sledding hill: the snow is light and fluffy when you start, but if you sled down it enough times (and walk up the hill, too), eventually the paths get icy from the footsteps and sleds continually packing the snow down. It wasn't just ice sheets that were a feature of the ice age. All of that water caught up in the ice made sea level drop 300 feet lower than it is now. That exposed lots of land that is now covered in water, including a land bridge connecting Alaska and Russia! This land bridge allowed a number of species to move into North America from Asia, like bison. And some North American animals went into Asia, like camels and horses! Bear species traveled in both directions. Humans also used the land bridge to migrate into North America, though scientists think some early humans probably used boats too. Mammoths also migrated over that land bridge! They originated in Asia and came into North America. But there were other species of megafauna that roam the landscape as well, like giant condors, saber toothed cats and even giant sloths. These species went extinct at the same time as mammoths, as the ice age was ending. Listen to the episode to learn more about the theories of why so many large animals went extinct around the same time.

In 2019, we answered a question about the Great Pacific Garbage Patch, a huge mass of plastic and other trash swirling around in the Pacific Ocean. Mary James heard that episode and was so inspired, she created a device to help clean up the plastic in the ocean. In this episode of But Why, we learn about her invention, the mermicorn! Download our learning guides: PDF | Google Slide | Transcript Listen back to Why Is There A Big Patch Of Garbage In the Pacific Ocean? Kids: we'd like to know what you think could be done about all the garbage in the ocean. Download our learning guide above to draw a picture or describe an invention you would make to help clean it all up. Mary James sent her picture of the mermicorn to the Little Inventors competition, for Canadian children. See Mary's entry here. Her invention has been chosen from among hundreds of other submissions to be turned into a prototype, a model of what the real thing might look like. There are Little Inventors competitions in the UK as well, and lots of countries and organizations sponsor design challenges for kids. See if you can find one where you live!

On Thursday, February 18th, a robot called a rover is expected to land on the surface of Mars, and begin collecting information scientists hope will help us learn if life ever existed on that planet! We answer your Mars questions with Mitch Schulte, NASA program scientist for the Mars 2020 mission. Download our learning guides: PDF | Google Slide | Transcript NASA has a number of ways that you can watch the landing live on February 18th at 11:15 a.m. PST / 2:15 p.m. EST / 19:15 UTC. The rover is called Perseverance, which means not giving up, continuing to work toward a difficult goal even when challenges are placed in your way. And it is quite a challenge just to get to Mars! The rover was launched on a rocket from Cape Canaveral in Florida more than 6 months ago, by NASA, the U.S. Space Agency. And it has been traveling through space ever since, on a path to Mars. And now, people all over the world are eager to watch it land on Mars and get to work. And it’s not just Perseverance that is going to land on Mars. There’s also a helicopter, called Ingenuity, which means cleverness, creativeness and resourcefulness all rolled into one. Ingenuity, the helicopter, is basically a drone—there’s no one inside driving it around, just as there are no people onboard the rover. But ingenuity is the first helicopter to ever test-fly on another planet!

How is chocolate made? Why can't we eat chocolate all the time? Why is chocolate dangerous for dogs? Why do adults like coffee? In this episode, we tour Taza Chocolate in Somerville, Massachusetts to learn how chocolate goes from bean to bar. Then we visit a coffee roaster in Maine to learn about this parent-fuel that so many kids find gross! And we'll learn a little about Valentine’s Day. Download our learning guides: PDF | Google Slides | Transcript "How is chocolate made?" - Samarah, 8, Johnson, VT "Chocolate actually comes from cocoa beans--which is no bean at all--they are seeds of the cacao trees," says Ayala Ben-Chaim of Taza Chocolate. Taza is a "bean-to-bar" chocolate maker. That means starting with raw cocoa beans and going all the way through the process to turn those beans into a chocolate bar you can buy in a store. (Some chocolatiers get chocolate that's already mostly made and they just add stuff to it and shape it.) The tree that those cocoa beans come from is called the Theobroma cacao tree, which grows in warm tropical parts of the world--within 20 degrees of the equator. Taza Chocolate sources (buys) cocoa beans from farmers in the Dominican Republic, Haiti, Belize and Bolivia. It takes about five years from when it's planted for a cacao tree to produce cocoa pods. "Cocoa pods are a little bit funny to look at. They look like a gourd growing off of the tree, or like a lumpy tiny American football. The cocoa pods grow off of the branches of the tree like apples, but they also grow right off of the trunk of the tree," Ben-Chaim explains. "The next step in the process is fermentation. Fermentation is so important in chocolate making. And this is one of the things that is so surprising about chocolate making. After the beans ferment, they spend a week drying in the sun on wooden planks. At this point they look like almonds. Next, they are packaged and shipped to wherever they'll be made into chocolate. The first thing the chocolate maker will do is roast the beans at 200 degrees for about an hour, which gives them a nice toasted flavor. "We also start to separate the thin outer shell that surrounds the inner part of the cocoa bean. Our next step is to separate that shell from the inner part of the bean, called the nib. We do this by winnowing the cocoa beans, using a machine," says Ben-Chaim. "At Taza Chocolates we use a traditional Mexican milling style using a molino - or mill - to grind the cocoa beans down," Ben-Chaim says, demonstrating. "Over time, those cocoa nibs will be turned into a cocoa liquor, which is smooth and chocolaty. Imagine a chocolate waterfall. It looks beautiful, it smells chocolaty and delicious and yet it is not very tasty because we're missing a really important ingredient, and that is sugar." Sugar is added to the chocolate liquor, then the sweetened chocolate is ground again, and other ingredients are sometimes added, like spices or coffee or fruit. At this point some chocolate makers will conche the chocolate, which blends and mixes the chocolate at a high temperature over many hours, which makes it smooth and creamy. Taza doesn’t conche their chocolate. The next step is tempering. Tempering the chocolate makes it glossy and brittle. Then the chocolate is poured into molds and cooled. Then it's wrapped up and ready to take home. Also in this episode: we visit 44 North Coffee to learn more about the mysterious beverage that so many adults like to drink--coffee!

What makes a cactus a cactus? And what are you supposed to call a group of these plants--cacti, cactuses, or cactus?! We'll find out in today's episode, as we learn more about the cactus family with Kimberlie McCue of the Desert Botanical Garden in Phoenix, Arizona. She'll answer kid questions about why cactuses are spiky and how they got those spikes, as well as why teddy bear cactuses aren't actually cuddly! Download our learning Guides: PDF | Google Slide | Transcript Those prickly spines that are so characteristic of the cactus family are actually modified leaves! Cactuses don't have the kind of leaves like a maple or oak tree. But they might have had leaves that were at least a little more like that way way back in the past. Over time, those leaves evolved into the spiky spines we see on cactuses today because they help the plants survive in hot, dry environments. Why are cactuses spiky? -Noah, Iowa "They can be a defense mechanism to discourage herbivores - animals that eat plants - from eating the cactus. But, also, spines create shade!" explains Kimberlie McCue. "When you're covered in spines, as the sun moves across the sky, those spines are casting shadows on the body of the cactus. They're little shade umbrellas!" All cactuses are native to desert environments, and some live in places where it never rains at all. So how do they get water to survive? Well, Kimberlie tells us that these plants grow not too far from the ocean. "Early in the morning, there will be fog that comes off the water. Those spines provide a place for the water to condense, form little droplets of water that run down the spine, to the body of the plant, down to the ground and to the roots." Cactuses are also extremely important parts of their desert environments, as they hold soil in place and provide shelter for birds and other animals. Those insects and birds in turn help pollinate the cactus flowers. Cactuses are also an important local food source for humans. Unfortunately, cactuses are in danger from people who poach (illegally take) wild plants from their environment. Kimberlie McCue says one way to help make sure cacti stay healthy and plentiful is to be careful when you buy cactus plants. Check to see where the plant seller got the cactus and make sure they're taking care to be ethical stewards of these plants before you buy.

Why are whale sharks called whale sharks? Why are guinea pigs called pigs if they're not pigs? Why are eagles called bald eagles if they're not bald? You also ask us lots of questions about why and how animals got their names. So today we're going to introduce you to the concept of taxonomy, or how animals are categorized, and we'll also talk about the difference between scientific and common names. We'll learn about the reasoning behind the names of daddy long legs, killer whales, fox snakes, German shepherds and more! Our guests are Steve and Matt Murrie, authors of The Screaming Hairy Armadillo, and 76 Other Animals With Weird Wild Names. Download our learning guides: PDF | Google Slide | Transcript There are some animals whose names don't really seem accurate-like daddy long legs...which certainly aren't all daddies! Or bald eagles that very clearly have plenty of feathers on their heads. Or guinea pigs, which aren't actually pigs! And then there are animals with awesomely silly names. Have you ever heard of the umbrella bird? How about the sparklemuffin peacock spider! Or the monkeyface prickleback, the sarcastic fringehead, and the white-bellied go-away bird! How do animals get their names? Well, there are two types of animal names: Scientific names and common names. Scientific names are used as a way to categorize all living things, so even if you don't know a lot about an animal, you can learn a lot about them by knowing their scientific name. There are eight different levels that living things get grouped into: domain, kingdom, phylum, class, order, family, genus and species. The broadest category is called the domain. There are three domains: archaea, bacteria, and eucarya. Bacteria and archaea are both categories of micro-organisms. All animals and plants belong in the eucarya domain. Below domain is kingdom. There's a kingdom for animals called Animalia and a kingdom for plants called plantae. (And a few others as well.) As you go through the classification system it gets more and more specific. So, take humans: we belong to the eucarya domain, the animalia kingdom, the chordata phylum (because we have a backbone), the mammalia class (because we're mammals), the primate order, homonidae family, homo is our genus and homo sapien is our species name. All species have two official scientific names, kind of like how you have a first name and a family name. So the species name for humans is homo sapien. The species name for a common black rat is rattus rattus. An Asian elephant is elephas maximus. Those names sound fancy, and originally the scientific names of animals were in Latin or Greek, but they don't have to be Latin or Greek anymore, they just have to sound like they are! But we don't typically call all animals by their scientific names. We often refer to them by their common names, which are kind of like nicknames! Common names can be different in different languages. Like, the scientific name for a wolf is canus lupus. That would stay the same no matter what language you're using. But in English we tend to call it a wolf; in Spanish you'd call it un lobo, and in Welsh it would be blaidd (pronounced "blythe"). Even within the same language, an animal can have lots of common names. Here in Vermont, where I live, we have an animal called a groundhog. But most people around here call it a woodchuck. And others call it a land beaver, or a whistle pig! Common names were often in use long before animals go their specific scientific names.

As the new year dawns, what are you hopeful for in 2021? Even though the change of the calendar year is mostly symbolic, New Year's Day is often a time for looking back on the year that just passed and setting goals for the year ahead. We asked you to share your hopes and dreams for 2021, from the end of the COVID-19 pandemic to your own personal goals. In this episode, more than 100 kids from around the world offer New Year's resolutions. We'll also hear from Johns Hopkins University epidemiologist Jennifer Nuzzo, climate activist Bill McKibben and Young Peoples Poet Laureate Naomi Shihab Nye. Download our learning guides: PDF | Google Slide | Transcript Here are just a few of the hopes and dreams you sent us: "My environmental wish for 2021 is that we can stop so much pollution. My personal wish is to learn Urdu and to convince my brother to get a cat or dog!" - Maya, Toronto, Ontario "My wish for 2021 is that the coronavirus will stop and the vaccine will come out and we can do things we haven't done this year and we can have our birthday together this year!" -Zain "I want to learn how to ride my bike by myself. - Adelaide, 6, California "What I want to happen for the new year is that I want people to start being responsible and no coronavirus. I want people to stop polluting. I want people to wear more masks. I want people to be kind to animals." - Jedi, 8, Ohio "I hope in 2021 more people think about and believe in climate change." -Evelyn, Albany, New York "Next year I would like more electric cars!" - Kyrav, 6, Geneva, Switzerland "My hope for next year is that we don't use as much plastic as we do now and that coronavirus will stop so we're able to do the things we like to do." - Tejas, Canberra, Australia "My hope for 2021 is that everyone gets health care." - Mikal, 7, Georgia My new year’s resolution is for sloths to take over the world and for people to use less plastic. - Sloan, 7, Wisconsin

Lots of people are afraid of the dark, including many kids who have shared that fear with us. In today's episode we explore the fear of the dark with Daniel Handler, better known as Lemony Snicket, the author of the Series of Unfortunate Events books, and a picture book for young kids called The Dark. Download our learning guides: PDF | Google Slide | Transcript | Coloring Page Then we go on a night hike with Vermont Fish and Wildlife biologist Steve Parren, to talk about ways to embrace the darkness. We practice our night vision by not using flashlights and we think about how our other senses can help us navigate. Steve also answers questions about how animals see in the dark and why it sometimes look like animals' eyes are glowing back at us in the darkness. This episode features coloring pages by Xiaochun Li. Download and print My Flashlight And Me, and Hiding Under The Covers. You can color as you listen!

Why are babies small and grownups big? Why are babies so helpless, instead of little versions of adults? Do babies know they're babies? How do babies grow? How do babies learn to talk? Kids have been sending us lots of questions about babies! This week we’re learning more about the development of the human brain with Celeste Kidd, professor of psychology and primary investigator at the Kidd Lab at the University of California Berkeley. Download our learning guides: PDF | Google Slides | Transcript It seems like a really bad idea, right? Human babies rely on adult humans for everything, while babies of some species never meet their parents and are able to take care of themselves as soon as their born! Why is that? While researchers aren’t sure on this one, Celeste Kidd says there are a lot of theories. “Because we are very intelligent, we need bigger brains to account for all the things we can do that other animals can’t do. If you have a big brain and you’re born via live birth – meaning you aren’t born from an egg – then there’s an upper limit on how big your head can be when you go through the birth canal,” she explains. In other words, we need those big brains to do all the things humans do, but a human head with a fully developed brain can’t fit through the birth canal. “The bigger your head needs to be ultimately, the more immature you need to be born,” Celeste says. So we have to develop and grow outside of the womb. We’re born with some of our brain power, but our brains keep growing long after we’re born, well into our 20s. And there are some advantages to that long period of childhood. “If you require dependence on your parents for a really long time, which humans do, that creates a lot of opportunity for you to learn a lot of stuff about your culture and the other people that you’re being raised with. We have a lot of knowledge that is unique to us as a species, and that’s unique to us as social groups,” Celeste says. The long childhood allows for a lot of cultural transmission – learning about tools, language, manners and arts. Some of these exist in other species, but the human systems are a lot more elaborate and take more time to learn!