Take your summer food game up a notch using… science! Sorbet recipe below. Vinaigrette recipe is in the post below this one.
Simple Freezer Strawberry Sorbet (adapted from Epicurious.com)
30 minutes hands-on prep time, 8 hours start to finish
*Parental supervision required for boiling sugar syrup
a shallow dish
1 quart strawberries
1/3 cup lemon juice
1/3 cup orange juice
1 cup sugar
2 cups water
What to do:
- Make a sugar syrup by bringing 1 cup sugar and 2 cups water to a boil in a heavy sauce pan. Boil for 5 minutes.
- Puree strawberries in a blender or food processor until smooth.
- Add strawberries, lemon juice and orange juice to the sugar syrup.
- Pour mixture into a shallow dish and cool for 2 hours in the refrigerator.
- Put the chilled sorbet mix in the freezer for 6 hours, stirring every hour.
- Enjoy your sorbet!
The Science Behind the Fun:
In sorbet, sugar acts as an antifreeze agent, physically getting in the way of ice crystal formation to keep crystals small, so that you don’t end up with one big chunk of ice. Pre-chilling the mixture before freezing it allows it to freeze faster, which also encourages smaller crystals to form.
Looking for fun, creative summer projects? I showed off some projects from STEAM Lab for Kids this morning on WCCO MidMorning!
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!
I took some behind-the-scenes video when we were photographing my new book “STEAM Lab for Kids” last summer. Here’s a fun engineering project from the book! #summer #fun #balloon #rockets #STEAM #STEM
It’s hard to believe that my new book “STEAM Lab for Kids” is already in the Amazon book store! I studied both art and science in college, so this one was SO much fun to write!
Last summer, my publisher made a few videos of projects from the book for me to share with you. Here’s the first one, which features some sugar science!
Grab your coat and head outside to try this fun winter science project!
A large plastic zipper bag
Cotton kitchen twine
a toothpick or wooden skewer
a spray bottle
a squeeze bottle or syringe (optional, but helpful)
a very cold day (below 10 degrees F works best, but you can try it on any day when it’s below freezing)
Note: This experiment takes lots of playing around and results will vary depending on how cold it is outside. Remind your kids (and yourself) to be patient and try it on a colder day if it doesn’t work the first time around! If the bag leaks too quickly, try making one with smaller holes around the string.
What to do:
- Use a toothpick or skewer to poke 3 small holes in the bottom of a zipper plastic bag. Make one in the middle and one on each end.
- Cut three long (3 feet or so) pieces of kitchen twine and knot them at one end.
- Carefully thread the twine through the holes in the bag so that the knots are inside the bag to keep the strings from falling through. Try to keep the holes from getting too big, since the bag will be filled with water and you’ll want it to drip out very slowly around the string.
4. Attach two more pieces of twine to each top corner of the bag (above the zipper) to use for hanging the bag
5. Go outside and hang the bag from a low tree branch or railing.
6. Tie each of the three strings to something on the ground, like a rock, piece of wood, or the handle of an empty milk carton filled with water to weight it down. Arrange the objects so that the strings loosely radiate out at around a 45 degree angle. (See photo)
7. Add food coloring to some ice-cold water in a pitcher.
8. Fill the spray bottle with ice-cold water.
9. Add the cold colorful water to the zipper bag hanging outside. Zip the top of the back to slow the rate of leaking.
10. Immediately spray the strings with water to guide the leaking water down the strings.
10. Wait for the water on the strings to freeze. Use your syringe to add a little bit more water to the strings (same color) and wait for them to freeze again. Repeat until you have a nice layer of ice/icicles.
11. Refill the bag, using a different color of ice-cold water. Spray the strings lightly again. Repeat step 11.
12. Add layers of color to the icicles until you’re happy with the way they look!
The science behind the fun:
Icicles form when dripping water starts to freeze. Scientists have discovered that the tips of icicles are the coldest part, so that water moving down icicles freezes onto the ends, forming the long spikes you’ve seen if you live in a cold climate. When you add different colors of water to icicles in sequence, the color you add last will freeze onto the tip of the ice.
You’ll find more fun ice science experiments in my book “Outdoor Science Lab for Kids” and in my upcoming books “STEAM Lab for Kids” (Quarry Books April 2018) and “Star Wars Maker Lab” (DK- July 2018)
Gelatin is the substance that makes Jell-O jiggle. See what happens when food coloring molecules move, or DIFFUSE through Jell-O.
This creative science experiment that my kids and I invented lets you play with floatation physics by sprinkling glitter on melted gelatin, watch colorful dyes diffuse to create patterns and then use cookie cutters to punch out sticky window decorations. Water will evaporate from the gelatin, leaving you with paper-thin “stained glass” shapes.
-plain, unflavored gelatin from the grocery store or Target
–a drinking straw
*You can use the recipe below for two pans around 8×12 inches, or use large, rimmed cookie sheets for your gelatin. For a single pan, cut the recipe in half.
Step 1. Add 6 packs of plain, unflavored gelatin (1 oz or 28 gm) to 4 cups of boiling water. Stir well until all the gelatin has dissolved and remove bubbles with a spoon.
Step 2. Allow gelatin to cool to a kid-safe temperature. Pour the liquid gelatin into two large pans so it’s around 1-1.5 cm deep. It doesn’t have to be exact.
Step 5. In the pan with no glitter, use a straw to create holes in the gelatin, a few cm apart, scattered across the surface. It works best to poke a straw straight into the gelatin, but not all the way to the bottom. Spin the straw and remove it. Then, use a toothpick or skewer to pull out the gelatin plug you’ve created. This will leave a perfect hole for the food coloring. Very young children may need help.
Step 6. Add a drop of food coloring to each hole in the gelatin.
Step 7. Let the gelatin pans sit for 24 hours. Every so often, use a ruler to measure the circle of food coloring molecules as they diffuse (move) into the gelatin around them (read about diffusion at the bottom of this post.) How many cm per hour is the color diffusing? Do some colors diffuse faster than others? If you put one pan in the refrigerator and an identical one at room temperature, does the food coloring diffuse at the same rate?
Step 8. When the food coloring has made colorful circles in the gelatin, use cookie cutters to cut shapes from both pans of gelatin (glitter and food coloring), carefully remove them from the pan with a spatula or your fingers, and use them to decorate a window. (Ask a parent first, since some glitter may find its way to the floor!) Don’t get frustrated if they break, since you can stick them back together on the window.
Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
When they’re dry, peel them off the window. Are they thinner than when you started? Why? Can you re-hydrate them by soaking the dried shapes in water?
The Science Behind the Fun:
Imagine half a box filled with red balls and the other half filled with yellow ones. If you set the box on something that vibrates, the balls will move around randomly, until the red and yellow balls are evenly mixed up.
Scientists call this process, when molecules move from areas of high concentration, where there are lots of other similar molecules, to areas of low concentration, where there are fewer similar molecules DIFFUSION. When the molecules are evenly spread throughout the space, it is called EQUILIBRIUM.
Lots of things can affect how fast molecules diffuse, including temperature. When molecules are heated up, they vibrate faster and move around faster, which helps them reach equilibrium more quickly than they would if it were cold. Diffusion takes place in gases like air, liquids like water, and even solids (semiconductors for computers are made by diffusing elements into one another.)
Think about the way pollutants move from one place to another through air, water and even soil. Or consider how bacteria are able to take up the substances they need to thrive. Your body has to transfer oxygen, carbon dioxide and water by processes involving diffusion as well.
Why does glitter float on gelatin? An object’s density and it’s shape help determine its buoyancy, or whether it will float or sink. Density is an object’s mass (loosely defined as its weight) divided by its volume (how much space it takes up.) A famous scientist named Archimedes discovered that any floating object displaces its own weight of fluid. Boats have to be designed in shapes that will displace, or push, at least as much water as they weigh in order to float.
For example, a 100 pound block of metal won’t move much water out of the way, and sinks fast since it’s denser than water. However , a 100 pound block of metal reshaped into a boat pushes more water out of the way and will float if you design it well!
What is the shape of your glitter? Does it float or sink in the gelatin?
Here’s a video I made for KidScience app that demonstrates how to make window gellies
Credit: My 11 YO daughter came up with the brilliant idea to stick this experiment on windows. I was just going to dry out the gelatin shapes to make ornaments. Kids are often way more creative than adults!
It’s fun to make a rubber-band powered car from cardboard, straws, and wooden skewers!
-glue (a glue gun works best)
-a plastic straw
-a CD (or a compass)
-pipe cleaner (optional)
Hints: Parental supervision recommended for hot glue gun use.
Here’s what you’ll be building:
What to do:
- Wrap cardboard around a large spice bottle so you can see how it bends. Cut a piece of cardboard about 9 inches (22cm) long to wrap around the bottle. Trim off the excess cardboard and tape it to create a tube.
- Trace a CD or use a compass to make 8 circles that are around 4 and 1/2 inches (12 cm) in diameter. Use a ruler to make a square around each circle and then diagonal lines to mark the center of each circle. Cut them out and glue two circles together until you have four wheels. Use skewers to poke holes through the center of each wheel.
- Poke skewers through each end of the cardboard tube, about 1 and 1/2 inches (4 cm) from the end of each tube. Make sure that the skewers are parallel and that they line up when you look through the end of the tube.
- Use a screwdriver to make the holes larger.
- Cut 4 pieces off of a straw that are about 1/2 inch (1.5cm) long. Glue them to the outside of each hole in the tube. Use a skewer to help align them. The skewer should spin freely.
- One at a time, put wheels on the skewers and glue the OUTSIDE of the wheel to the skewer. Make sure that the wheels are parallel to the car, and to each other as they dry. Cut off excess skewer.
- Poke a skewer down the center of one end of the car, parallel to the wheels so that it’s sticking out about 1 inch (3 cm.) See image above.
- Decorate the car!
- Tie three thin rubber bands together and hook them over the skewer that’s sticking out. If you have a pipe cleaner or wire, hook it onto the other end of the rubber bands. Drop the rubber bands down through the center of the tube.
- Grab the rubber bands from the end opposite where they are attached to the car. Remove the pipe cleaner hook and wind them around the skewer to create tension in the rubber bands. Wind them until they’re tight.
- Set the car down and let the wheels start to spin to see what direction the car will go. When you’re ready, let go!
- Measure how far the car traveled.
Enrichment: How can you make the car go faster or farther. Try using different kinds and numbers of rubber bands. How could you redesign the car to make it work better?
The Science Behind the Fun:
In this experiment, you use your body’s energy to twist rubber bands around the wooden skewer axle of a cardboard car. The energy is stored as elastic energy in the tightly-stretched rubber bands. When you let the car go, the rubber bands apply enough force on the axle to turn the wheels on the car and elastic energy is transformed into the energy of motion, which is called kinetic energy.
Yesterday on Twin Cities Live, I demonstrated some fun botanical science projects for learners of all ages, including Vegetable Vampires and Leaf Chromatography.
This fun art/science project lets you transfer plant pigments to cloth, creating beautiful prints of your favorite leaves and flowers. It’s especially great for fall, when there are so many colorful leaves around.
-Fresh leaves and flowers (Dry leaves won’t work.)
-A hard, smooth pounding surface, like a wooden cutting board or carving board
-Wax paper or plastic wrap
-Mallets or hammers
-Untextured cotton cloth, like a dishtowel. Heavy cloth works better than very thin cloth.
-*Alum and baking soda to treat cloth (This is optional. I don’t pre-treat my fabric, but the treatment step will help bond and preserve color, if you want to frame your prints. You can also buy fabric that’s pre-treated for dyeing.)
Safety tips: Protective eye wear is recommended. Young children should be supervised when using mallets and hammers.
What to do:
*If treating cloth: The day before you do the project, add 2 quarts water to a large pot. Add 1 Tb alum and 1 tsp baking soda to the water. Add the cotton and bring to a boil. Simmer for 2 hours, turn off heat and soak for at least two hours. Let fabric dry.
The next steps are the same, whether you’re using an untreated piece of cotton or treated cloth.
- Take a walk to collect colorful leaves and flowers. Choose plants that can be flattened. Flowers with huge centers, like coneflowers don’t work as well, but petals may be removed and pounded.
- Cover the pounding surface with waxed paper or plastic wrap.
- Cut a piece of cloth that will fit on the pounding surface when folded in half. Iron the fold.
- Open the cloth and lay it on the pounding surface. (See image above)
- Arrange leaves and flowers on the cloth.
- Fold the cloth over the plants and pound it with the hammer or mallet. If you’re using a hammer, pound more gently.
- Pound until you can see the forms of the leaves through the fabric. As the pigment leaks through, you’ll see the outlines of what you’re smashing. Hint: Hammers work better than mallets for fall leaves. For juicy leaves and flowers, use a mallet or hammer gently.
- When you’re finished pounding, unfold the fabric to reveal the print you created. Remove the leaves and petals.
- Label the image with plant names, enhance it with paint or markers, or leave nature’s design to speak for itself.
The Science Behind the Fun:
Pigments are compounds that give things color, and many of them are found in nature. Flowers, leave, fruits and vegetables are full of brilliant pigments. In this experiment, we transfer plant pigments to cloth by bursting plant cells using pressure from a hammer or mallet.
The green pigment found in leaves is called chlorophyll. In the fall, many trees stop making chlorophyll, and the red, yellow and orange pigments inside the leaves become visible.
Although you create a mirror image of leaves and flowers, you’ll notice that the color may be more intense on one side of the print. A waxy covering called a cuticle covers leaves, and is sometimes thicker on the top than on the underside of the leaf. It may affect the transfer of pigment to the cloth, making it easy to see structures like veins on the leaf print.
What parts of the leaf can you identify in the print you created?
With a brush, some batteries, a small motor and a few wires, it’s easy to create a robot that spins, bumps and buzzes around on any smooth surface.
-a small brush, like a vegetable brush or a cleaning brush
-two AA batteries
–battery holder for 2 AA batteries (optional)
-a small toy motor with lead wires and pencil eraser or small rubber stopper (or vibrating motor)
–battery clip (optional)
-zip ties (optional)
-electrical tape or duct tape
Make your bristlebot!
- Attach the motor to one end of the top of the brush. If it’s not a vibrating motor, stick a eraser or rubber stopper onto the spinning post to make it vibrate. Use a zip tie or duct tape to secure it. Make sure the spinning parts can rotate freely.
- Attach the battery holder to the top of the brush near the motor.
- Insert batteries in motor.
- Twist wires around the motor terminals and secure with tape. (These may be the wires on the battery clip, if you have one.)
- To start the motor, attach wires directly to the battery terminals, or to the battery clip and snap it onto the batteries.
- Place your robot on a smooth surface to see what happens.
Enrichment: Try different brush shapes, sizes and angles to see how they move. Does your robot spin in the same direction as the motor, or the opposite direction?
The Science Behind the Fun: In this experiment, you complete a battery-powered electrical circuit to spin a vibrating motor. The vibrations traveling through the bristles of the brush move your robot around on the floor.