But Why: A Podcast for Curious Kids

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.