5 Backyard Science Experiments for Kids
Beat the winter blues by turning your lawn into a laboratory
Winter can be a bear for outdoor-loving parents with young children. Getting outside in cold weather requires serious logistics. Layers must be applied. Matching gloves must be found. Potty breaks have to be coordinated. Frostbite has to be avoided. Try squeezing naptime into those scarce daylight hours, and a parent can start to feel like a tethered animal. It’s tempting to pull up Daniel Tiger on Netflix, brew another cup of coffee, and slink back to your desk to maniacally refresh your email.
Winter needn’t be so grim. Get outside, for everyone’s sake, with these simple backyard science activities. Because science is about asking questions, asking questions cultivates wonder, and wonder is the best cure for cabin fever.
Build a Rocket
Of all the magical things that can happen when you combine baking soda and vinegar, my two favorites are this chocolate cake and a homemade rocket. My four-year-old, Theo, is obsessed with rockets and space, so I was pleased to find simple homemade rocket instructions in a science book at the library. Find a 35mm film canister (remember those?) at your local film store (or online here). The white Fuji canisters work best because the lids have a divot and seal tightly. Pack some baking soda into the divot in the lid. Fill the canister halfway with white vinegar. Find a safe launch site, put the lid on the canister, flip it upside down, step back, and watch it blast off.
Suck an Egg
My sister is a Montessori teacher, and she turned me on to Sergei Urban’s excellent YouTube channel, The Dad Lab. Start this activity by making a hard-boiled egg, and then teach your child how to tell if an egg is hard-boiled or not by spinning it on a cutting board and then stopping it with your finger. The uncooked egg will keep spinning, thanks to the centrifugal force of the liquid inside. Let your child peel the hard-boiled egg. Now, insert three birthday candles into the top of the egg. Find a glass bottle with an opening large enough for the candles to fit into, but not the rest of the egg. (I used a GT’s Kombucha bottle.) Light the candles and insert them into the inverted glass bottle. The candles will briefly burn in the bottle, expanding the air. When they go out, the air cools, contracts, and—POP!—sucks the egg into the bottle. When I did this with Theo, he couldn’t stop laughing. Here is The Dad Lab video.
One of the many things Isaac Newton left us with was a clear understanding of fluids and solids. But why so binary, bro? Some substances, like quicksand, can behave like a fluid and a solid at different times. Using a recipe I found online, Theo and I mixed up some backyard quicksand with cornstarch and water to create a non-Newtonian fluid known as “oobleck” among the youths. (The name comes from a Dr. Seuss book.) Simply put two cups of cornstarch into a bowl, then slowly mix in a cup of water until you get a paste-like substance that pours like a liquid but turns solid when you squeeze it. When I poured some into Theo’s hand, his first response was “yuck.” But then we both got carried away playing with it. According to YouTube, you can walk on a swimming pool filled with this stuff. You can also try hitting it with a hammer or a potato masher. It might seem really messy, but it cleans up easily with water.
Make an Eggshell Geode
When the ground is too frozen to hit the hills with a shovel and dig for your own geodes, these instructions on the handy website ScienceBob.com will teach you how to make geodes out of eggshells and common kitchen crystals. Start with some eggshells cracked as close to the tip as possible. Pour hot water into the empty shells, then clean out the inner membranes with your fingers. (This will be tedious, like many parenting tasks, but important—if the membrane stays in the eggs, it can mold and turn your crystals black, which feels inauspicious.) Boil some water in a pan, and then pour it into several cups—one for each egg. Into each cup, stir a different solid, such as sea salt, sugar, baking soda, borax, Epsom salts, or cream of tartar, until no more will dissolve. Add food coloring for effect. Pour the mixtures into the eggshells. Set them into an egg carton and allow the liquids to evaporate over several weeks. Compare the crystals that the different solutions make. Real geodes form in a similar way when mineral water seeps into cavities in rocks.
Build a Lava Lamp
Children are bizarrely preoccupied with lava. Theo is so taken with the stuff that we checked out a library book about Pompeii and spent the afternoon flipping through grisly pictures of 1,900-year-old Romans buried by ash, mud, and lava from Mount Vesuvius. I channeled that fascination in a happier direction by making Theo his own lava lamp, using a recipe I found in Jim Wiese’s book Weird Science: 40 Strange-Acting, Bizarre-Sounding, and Barely Believable Activities for Kids. Fill a clear jar three-quarters full of water. Stir in some food coloring. (Red and orange are the most lava-like.) Pour a quarter-cup of vegetable oil into the water and watch it float to the surface. Sprinkle a tablespoon of salt on the oil. Watch the salt pull the oil to the bottom of the jar and then dissolve into the water, sending the globs of oil floating back to the surface. Add more salt and see what happens. Then kick back, put on some Peter, Paul & Mary, and talk about life and the universe and stuff.