From surface tension to evaporation, science come into play every time you blow a bubble. Here’s some bubble science, along with a recipe for making giant bubbles from my book Outdoor Science Lab for Kids!
Water molecules like to stick to each other , and scientists call this sticky, elastic tendency “surface tension.” Soap molecules, have a hydrophobic (water-hating) end and (hydrophilic) a water-loving end and can lower the surface tension of water. When you blow a bubble, you create a thin film of water molecules sandwiched between two layers of soap molecules, with their water-loving ends pointing toward the water, and their water-hating ends pointing out into the air.
As you might guess, the air pressure inside the elastic soapy sandwich layers of a bubble is slightly higher than the air pressure outside the bubble. Bubbles strive to be round, since the forces of surface tension rearrange their molecular structure to make them have the least amount of surface area possible, and of all three dimensional shapes, a sphere has the lowest surface area. Other forces, like your moving breath or a breeze can affect the shape of bubbles as well.
The thickness of the water/soap molecule is always changing slightly as the water layer evaporates, and light is hitting the soap layers from many angles, causing light waves to bounce around and interfere with each other, giving the bubble a multitude of colors.
Try making these giant bubbles at home this summer! They’re a blast! (It works best a day when it’s not too windy, and bubbles love humid days!)
To make your own giant bubble wand, you’ll need:
-Around 54 inches of cotton kitchen twine
-two sticks 1-3 feet long
-a metal washer
1. Tie string to the end of one stick.
2. Put a washer on the string and tie it to the end of the other stick so the washer is hanging in-between on around 36 inches of string. (See photo.) Tie remaining 18 inches of string to the end of the first stick. See photo!
For the bubbles:
-6 cups distilled or purified water
-1/2 cup cornstarch
-1 Tbs. baking powder
-1 Tbs. glycerine (Optional. Available at most pharmacies.)
-1/2 cup blue Dawn. The type of detergent can literally make or break your giant bubbles. Dawn Ultra (not concentrated) or Dawn Pro are highly recommended. We used Dawn Ultra, which is available at Target.
1. Mix water and cornstarch. Add remaining ingredients and mix well without whipping up tiny bubbles. Use immediately, or stir again and use after an hour or so.
2. With the two sticks parallel and together, dip bubble wand into mixture, immersing all the string completely.
3. Pull the string up out of the bubble mix and pull them apart slowly so that you form a string triangle with bubble in the middle.
4. Move the wands or blow bubbles with your breath. You can “close” the bubbles by moving the sticks together to close the gap between strings.
What else could you try?
-Make another wand with longer or shorter string. How does it affect your bubbles?
-Try different recipes to see if you can improve the bubbles. Do other dish soaps work as well?
-Can you add scent to the bubbles, like vanilla or peppermint, or will it interfere with the surface tension?
-Can you figure out how to make a bubble inside another bubble?
Monday April 22nd is Earth Day, so get outside and show our home planet some love! Whether you’re picking up trash or visiting a park, it’s always fun to throw some science into the mix.
Here are some of our favorite environmental science experiments. Just click on the experiment names for directions and photos. You can find more fun outdoor experiments in my books “Kitchen Science Lab for Kids” and “Outdoor Science Lab for Kids“ (Quarry Books.)
Homemade Sweep Nets: Make a sweep net from a pillowcase and a hanger to see what arthropods are hanging out in your favorite outdoor spaces.
Window Sprouts: Plant a bean in a plastic baggie with a damp paper towel to see how plants need only water and air to sprout roots and leaves. Here’s a short video demonstrating how to make a window garden.
Homemade Solar Oven: Using a pizza box, aluminum foil, plastic wrap, and newspaper, you can harness the sun’s energy to cook your own S’mores!
Nature Walk Bracelets: Wrap some duct tape around your wrist (inside out) and take a walk, sticking interesting natural objects like leaves and flowers to your bracelet. It’s a great way to get outdoors and engage with nature. Bring a bag along so you can pick up any trash you find.
Carbon Dioxide and Ocean Acidity: See for yourself how the carbon dioxide in your own breath can make a water-based solution more acidic. It’s the same reason too much carbon dioxide in Earth’s atmosphere can be bad for our oceans.
Plant Transpiration: See how trees “sweat” in this survival science experiment.
Earthworm Experiment: Do you know what kind of earthworms are living in your back yard?
Composting: Be a composting detective. Bury some things in your back yard (away from power cables) and dig them up in a few months to see how they look. Composting reduces methane gas emissions (a greenhouse gas) from dumps.
Diffusion and Osmosis: See for yourself how the chemicals we add to water, put on our streets to melt ice, and spray on our lawns and crops can move into our soil, ground water, rivers, lakes and oceans.
Solar Water Purification: This project illustrates the greenhouse effect and is a fun “survival science” experiment. Requires hot sun and some patience!
Citizen Science: Don’t forget about all the real environmental research projects you can participate in through Citizen Science programs all around the world!
For mores activities and games, check out NASA’s Climate Kids website, to see a kid-friendly diagram of the water cycle, click here, or just get outside and enjoy the beautiful planet that sustains and nurtures us.
Love basketball? Think you’re pretty good? Try taping some coins to a basketball, or covering one eye and shooting the ball. The coins change the ball’s center of mass, making it harder to shoot, and covering one eye messes with your depth perception! Try it!
I had fun thinking up these new basketball experiments that we tested on TV this week. Can you come up with one of your own? What could you try?
Get ready to make some noise! Read on to find instructions for making two simple experiments.
The sound we hear every day is energy that travels through air molecules as vibrations. In fact, you can’t hear sound in outer space, since there’s no air.
When I play my trombone, air travels from my lungs to my buzzing lips, which make vibrations inside the horn. The vibrations travel through the trombone, and the tube the vibration travel through gets longer when I extended the slide, making the sound lower. My daughter plays the violin, which, like other string instruments, can make short sounds by plucking the strings or a continuous sound with a bow that keeps them vibrating. Shortening the strings by pressing them down makes the pitch higher as the string vibrated faster.
We have a “drum” in our ears called an eardrum, or tympanic membrane that picks up sound vibrations in the air and transfers those vibrations to tiny bones in the middle ear, which then move them on to our inner ear, sending a message to our brain.
You can make a model “eardrum” out of a cup, saran wrap and sugar sprinkles that jump when you make a loud noise right next to it.
It’s also fun to make two simple musical instruments: a straw “clarinet” and a kazoo from a comb and tissue paper. Use the instruments to make the sugar crystals on a model eardrum jump around!
Click on this link to learn how to make straw “clarinets.”
To make comb kazoos, fold a piece of tissue paper in half the long way (see photo), place it over a comb with the teeth towards the fold, and place your lips on the tissue paper. Sing doo doo doo doo into the paper (don’t blow.) The vibrations from your voice will make the thin paper vibrate and buzz. It will tickle if you’re doing it right!
Use science to make your holidays shine! Here are a few fun ornaments adapted from projects in my book “STEAM Lab for Kids.” Basic instructions can be found below. Buy your own copy of “STEAM Lab for Kids” anywhere books are sold to learn more about the “Science Behind the Fun!” Happy Holidays!
LED Ornaments and Jar Globes:
To make LED ornaments, buy plastic jars or ornaments with removable bases. Use sculpting clay (the kind that won’t harden) to design a scene and add LEDs connected to a coin-cell battery to light your creation. LEDs can be ordered online. See images below.
Epsom Salt Crystal Ornaments:
(Warning: Hot liquids require adult supervision.) To make the Epsom Salt crystals, dissolve 3 cups of Epsom salts in 2 cups of water by heating and stirring until no more crystals are visible. This creates a supersaturated solution. Allow the solution to cool slightly. Hang pipe cleaners formed into snowflakes in jars or hollow ornaments and pour the solution in. When long, needle-like crystals have formed, remove the pipe cleaners from the jars. You can leave them in the ornaments, and drain the liquid.
With a few simple technology and art supplies, you can put together a simple kit that lets kids design and build bristle bots, art bots and light-up creatures.
The Science Behind the Fun: Hooking an unbalanced spinning toy motor to a brush sends vibrations through the bristles. The vibrating bristles move the brush, and anything attached to it, around on a flat surface. Make a disc robot by attaching toothbrushes to a CD and attaching a motor, or make a drawing robot with legs made of pens.
I’ve included ideas for items to put in a kit, along with a tech supply list and photos of the robots from STEAM Lab for Kids. Use your imagination for art supplies! Pair the kit with a book, like STEAM Lab for Kids (Amazon.com), which has instructions for making bristle bots, art bots and light-up creatures, or let tech-savvy kids take the reigns and start building!
LEDs, alligator clip test leads, toy motors and batteries let kids assemble simple circuits. (Supply list below photo)
Basic 3mm and 5mm through-hole LEDs (Art Bot, CD Bot, Light-Up Creature)
Small alligator clip test leads (Art Bot, CD Bot, Light-Up Creature)
AA battery holders (Art Bot, CD Bot )
AA batteries and 9V batteries (Art Bot, CD Bot )
9V battery clip snap-on connectors (battery snaps)
3V coin cell batteries (Light-Up Creature)
Mini electric motor for DIY toys (1500 rpm) for Art Bot, CD Bot
(Find these supplies at your favorite bricks and mortar location, like Axman Surplus stores, or get them online at Amazon.com or another tech retailer.)
Paper and plastic cups, brushes, toothbrushes, duct tape, zip-ties, and CDs all make great building supplies, and a glue gun always comes in handy.
Use your imagination for the art supplies.
And if you’ve got a kid who likes to sew, it’s fun to add supplies to make sewable circuits!
Sewable electronics: coin cell battery holders, sewable LEDs, snaps and conductive thread
Here are instructions for building a simple bristle bot.
Turn your kitchen table into the coolest mad science lab in the neighborhood. Click on the project name for a link to instructions and the “Science Behind the Fun.” Several of these projects can be found in my book “Kitchen Science Lab for Kids,” if you’re looking for a gift for your young mad scientist!
1. Frankenworms– Bring gummy worms to “life” using baking soda and vinegar.
2. Alien Monster Eggs– Make creepy, squishy monster eggs.
3. Oozing Monster Heads– Combine science and art to create Halloween fun.
4. Bag of Blood– Amaze your friends with this magical science trick.
9. Magic Potion– Make a color-changing, foaming potion using red cabbage and water.
10. Halloween Soda Explosion– Halloweenize the classic Diet Coke and Mentos explosion
11. Foaming Alien Blood– Bring the X-Files to your kitchen with this creepy green fake blood
12. Mad Scientist’s Green Slime– Because everyone loves slime
13. Homemade Fake Blood– It’s simple to make non-toxic fake blood in your kitchen.
14. Fizzy Balloons– Draw scary faces on balloons and blow them up using baking soda and vinegar.
Sound waves are formed when air molecules are compressed (pushed together), creating pressure waves.
It’s fun and easy to play with sound waves! Here are some ideas for you:
Have fun experimenting!
Combine science and art to engineer and decorate a custom water bottle jacket as unique as you are. Test different every-day insulators to see what works best to to keep water cold all day long!
-a washable plastic water bottle
-flexible insulating material, like craft foam, bubble wrap or fabric batting
-decorating materials, like stickers, ribbons or foam stickies
-a thermometer (optional)
-4 disposable empty water bottles or cans that are the same size (optional)
What to do:
(Optional) Test insulators by insulating each of the empty cans or bottles with different material. Fill each of them with the same amount of hot tap water and check the temperature of each periodically to see which material does the best job of slowing cooling of the water. The one that keeps water hot the longest is the best insulator, since it slows the movement of heat from one area to another.
Use the best insulator to build an insulating case for your water bottle. Make it big enough so that your bottle will slide out for washing. We used thick craft foam and covered it with adhesive craft foam. Shipping folders made of bubble wrap work well too! Here’s how we built ours…
Add some ice water to the bottle and you’re good to go! Just remove the jacket when you wash the bottle.
Robots took over the driveway last summer when we were photographing my new book “STEAM Lab for Kids: 52 Creative Hands-On Projects for Exploring Science, Technology, Engineering, Art and Math”
With a few supplies from your junk drawer and a few inexpensive tech supplies available online, kids can easily make their own CD Bots! Grab a copy of “STEAM Lab for Kids” for easy instructions, or figure out how to do it yourself by attaching a toy motor (connected to a battery) to a CD with toothbrushes glued to the bottom!