It’s Monarch season!
Go find some caterpillars, gather some Milkweed and watch an incredible transformation. The second video in this post tells you how to spot Monarch eggs and caterpillars and how to raise them into butterflies!
Here’s a short video on how to find and raise caterpillars, via my new book, Outdoor Science Lab for Kids.
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?
Seven weeks from today, my new book “Kitchen Science Lab for Kids: Edible Edition” hits shelves everywhere books are sold, and there are some great pre-order sales going on now! Kitchen Science Lab for Kids, Edible Edition gives you 52 delicious ideas for exploring food science in your own kitchen by making everything from healthy homemade snacks to scrumptious main dishes and mind-boggling desserts.
Here’s a sneak peek into the book….
When you step into your kitchen to cook or bake, you put science to work. Physics and chemistry come into play each time you simmer, steam, bake, freeze, boil, puree, saute, or ferment food.
Knowing something about the physics, biology, and chemistry of food will give you the basic tools to be the best chef you can be. The rest is up to you!
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?
Homemade pop rocks aren’t as fizzy as the ones you buy at the store, but they’re mighty tasty! Citric acid combines with baking soda to make carbon dioxide gas bubbles that get trapped in the candy. Adding extra citric acid and baking soda to the surface of the candy gives some extra fizz when you put them in your mouth. Trick your friends by adding a flavor that doesn’t match the color!
Warning: Ages 8 and up only. Extremely hot candy syrup. Adult supervision required.
2 cups sugar
1/4 cup water
1/2 cup corn syrup
a few drops of food coloring
1 tsp flavoring, like orange or cherry
1/4 cup citric acid + 1 tsp to sprinkle on in final step
1 tsp baking soda plus some to sprinkle on the candy
Step 1. Coat a the bottom of an inverted baking sheet with cornstarch.
Step 2. Boil sugar, corn syrup, and water, stirring until it reaches 300 degrees F.
Step 3. Remove the hot, melted candy from heat. Stir in food coloring, flavoring, 1/4 cup citric acid and 1 tsp baking soda.
Step 4. Very carefully, pour the mixture onto the baking sheet. Do not touch!!! Sprinkle 1 tsp. citric acid evenly over the surface of the candy.
Step 5. Let the mixture cool for at least 30 minutes and the break it into small pieces. Put some of the fragments in a plastic zip lock bag and use a hammer or rolling pin to crush them into tiny pieces or powder.
Step 6. Sprinkle on a little more baking soda and shake up in the bag.
Step 7. Enjoy the leprechaun pop rocks!
Does hand-washing really get rid of germs? Yes! Scrubbing your hands with soap and water for the length of time it takes you to recite the ABC’s will get rid of the majority of harmful microbes on your hands.
Here’s a video on how to make Petri plates for a hand-washing experiment, where you touch labeled sections of the plates with your fingertips before washing, after washing with water alone, and after scrubbing with soap or hand sanitizer. You can also use the plates to swab and grow microbes from around your house or school!
Find the recipe for Petri Plates in my book Kitchen Science Lab for Kids, or click here for a link to the recipe on my original blog post, where you can also read more about the science!
Most clear hard candy has what scientists call a glass structure. It’s a disorganized jumble of three kinds of sugar: glucose, fructose and sucrose, which can’t assemble into organized crystals, so it remains transparent when you melt it and allow it to re-harden.
To make stained glass for our gingerbread house windows, I adapted the crushed stained glass candy project from my book “STEAM Lab for Kids.” The challenge was figuring out how to create perfect rectangles. After some trial and error, I discovered that scoring the candy when it was still warm and soft created weak points, which allowed me to snap the candy into clean shapes once it had hardened.
-Jolly Ranchers, Life Savers or another clear, hard candy
-a baking sheet (spray or grease the baking sheet, if not using a silicon liner)
-a silicon liner for the baking sheet, if you have one
-a metal spatula or dough scraper
Safety tip: Adult supervision recommended. Hot, melted candy can cause burns. Don’t touch it until it has cooled.
What to do:
- Pre-heat the oven to 350F.
- Unwrap the candy and arrange the pieces on a baking sheet so that they’re close together, but not touching.
- Bake the candy for 7 to 8 minutes, or until it has melted.
- Remove the candy from the oven. Tilt the baking sheet, if needed, to fill gaps.
- Use the spatula to score (make lines in) the candy, creating whatever shapes/sizes you need.
- When the candy has cooled, snap it carefully along the lines you made. (See photo at the top of this post.)
- Eat your creations, or use them to decorate some edible architecture.
- Try crushing the candy before you melt it for different visual effects. What else could you try?
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.
To make a holidays version of the fizzing bath tablets in the video, we scented them with pumpkin pie spice and added a little more oil to incorporate the extra ingredients.
1 cup baking soda
¼ cup cream of tartar
3 Tbsp. coconut oil, melted to liquid
1 tsp. pumpkin spices
-Whisk together baking soda, cream of tartar and pumpkin spices. Slowly drizzle in coconut oil, mixing immediately. Stir for several minutes until you get a nice even mixture that holds together when you press it between your fingers. Add a little more oil if it is too powdery.
-Add a few drops of food coloring and mix again until the color is incorporated.
-Press the bath bomb mixture into a tablespoon and tap in on a tray to remove the bath tablet. If they don’t hold together, try adding a little more oil and mixing again. Dry the bath fizzies on a plate or cooking sheet and package them in cellophane bags or pretty baking cups for friends and family. Use the fizz bombs within a few weeks for maximum fizziness!
You can make larger “bath bombs” using molds for round ice cubes (which we found at Target.) Double or triple the recipes, gently press some mixture into each side of the mold, and mound a little extra on each side. Press the mold together to compress the bath bomb mixture into a single ball. Tap one side gently with the back of a spoon and gently open the mold to release that side of the sphere. Hold it in your palm and repeat with the other side to release the entire bath bomb from the mold.
The science behind the fun: The chemical name for baking soda is sodium bicarbonate , and cream of tartar is an acid called potassium bitartrate, or potassium hydrogen tartrate . When you mix them together in water, you create a chemical reaction that forms carbon dioxide gas bubbles! It’s interesting to note that at temperatures below 76 degrees F (25 C), coconut oil is a solid, but that at temperatures above this, it melts into a clear liquid. How does this affect your bath fizzies? Will they work in cold water as well as they do in warm water? Try it!