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?