Science Sticks!!!

 - by KitchenPantryScientist

This morning my 9 YO came down the stairs and told me she does the soap science experiment every time she washes her hands.

“Which one?” I asked.


soap experiment cropped

“The one where the soap jumps!” she said, demonstrating for me by pouring a thin stream of liquid hand soap from one palm to the the other. “Sometimes it jumps clear out of the sink!”

Over a year ago, my daughter and some of her friends helped me do this “Kaye Effect” experiment  (shared with me by  Dr. Greg Gbur) for my book “Kitchen Science Lab for Kids,” but I had no idea that it stuck in her mind, or that she’d figure out a new way to do the experiment.

Lab 28 from Kitchen Science Lab for Kids

Lab 28 from Kitchen Science Lab for Kids

Maybe some day in the future, she’ll remember that shear-thinning fluids like soap can “jump” and it will help her solve a problem, or even create something new!

Here’s my original post on the Kaye Effect.

Sound Science

 - by KitchenPantryScientist

This week, I did some sound science experiments with the kids at my daughter’s school and it was literally a blast (of noise.) Here’s how it sounded (times 50.)

The kids had already done some cool experiments with their teacher, and told me that the sound we hear every day is energy that travels through air molecules as vibrations. We talked about the fact that you can’t hear sound in outer space, since there’s no air.

When I pulled out my trombone, the kids could see that the tube that carries the air from my lungs and the vibrations from my buzzing lips got longer when I extended the slide, making the sound lower. My daughter played her violin, and we heard how string instrument can make short sounds by plucking the strings and continuous sound when a bow makes them keep vibrating. We also saw that shortening the strings by pressing them down made the pitch higher as the string vibrated faster.

 

IMG_4294

The kids told me that 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.

We made a model “eardrum” out of a cup, saran wrap and sugar sprinkles, and then made two musical instruments: a straw “clarinet” and a kazoo from a comb and tissue paper. Finally, we made the sugar crystals on our model eardrums jump around using sound vibrations from our kazoos.

straw "clarinets"

straw “clarinets”

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!

 

Creative Science

 - by KitchenPantryScientist

If I give you glue, water and Borax, can you come up with a recipe for perfect polymer slime based solely on what you know about the science?

IMG_5874[1]

 

Last week, I did hands-on science with 150 third graders at Success Beyond the Classroom’s Creativity Festival at the University of Minnesota. As they came into the room, I asked them to draw a picture on chalkboard of anything related to science. They drew test tubes, trees, volcanoes, and even scientists!

IMG_5881[1]

Then we dug into the science. After doing my favorite large group hands-on experiment with purple cabbage juice to warm them up, I announced that we’d be making polymer slime, but that they would have to invent the recipe for the perfect goo.

To begin with, I talked about the science. We learned that one ingredient in the slime is glue (polyvinyl acetate), which is a polymer, or long chain of molecules. Then, we talked about the fact that adding water to the glue makes it less viscous, or thick. As usual, I had them repeat the vocabulary after me. Finally, I explained that the sodium tetraborate in Borax laundry detergent is a cross-linking substance that makes glue molecules stick together, and that we’d mixed up some Borax and water for them to use as a crosslinker for the slime.

IMG_5871[1]

Their challenge was to come up with one “recipe” to make a gooey, soft slime and a second recipe for a harder, rubber-like slime that could be rolled into bouncy balls. They each had a note card and pencil to keep track of their work, plastic teaspoons as measuring tools and paper cups for mixing slime. First, they’d stir up different proportions of glue and water, and then they’d add the Borax solution as a cross linker and mix it all together with a popsicle stick. To make it a little more colorful, they could add a drop of food coloring or some cabbage juice.

Needless to say, there were failures and successes and the kids had a blast.  We talked about the fact that experiments often don’t work on the first try, and each kid explained to the group how they’d made their perfect slime as they demonstrated how it bounced and stretched.

Try it!

 

 

 

Homemade Magic Orbs

 - by KitchenPantryScientist

My 8-YO loves Orbeez, those water-thirsty polymer balls that go from the size of cookie sprinkles to the size of marbles after a quick soak.

 

I wondered whether we could make something similar from gelatin or agar.

Homemade Magic Orbs- KitchenPantryScientist.com

Homemade Magic Orbs- KitchenPantryScientist.com (agar orbs on left, gelatin orbs on right)

A quick search online showed me that some chefs use a technique called oil spherification to make tiny round morsels using everything from balsamic vinegar to fruit juice, mixed with gelatin and agar.  It’s known to cooks as a “molecular gastronomy” technique, and takes advantage of the fact that water and oil don’t mix. Water-based droplets falling through chilled oil form  into perfect spheres due to surface tension, and gelatin and agar added to the mix are colloids that solidify as they cool.

 

Magic Orbs forming in cold oil (KitchenPantryScientist.com)

Magic Orbs forming in cold oil (KitchenPantryScientist.com)

We made some fun (inedible) orbs of our own, using the technique: standard orbs (from gelatin or agar and water), floating orbs (with agar and vinegar) and color-changing acid/base indicator orbs (from red cabbage juice and gelatin or agar.) Adult supervision is required for this project, since it involves hot liquids. The orbs may also be a choking hazard, so keep them away from toddlers. I demonstrated how to make them on Kare11 Sunrise News.

To make magic orbs, you’ll need

-unflavored gelatin or agar*

-water

-vinegar

-food coloring

-cold vegetable oil in a tall container. Chill oil in freezer or on ice for at least an hour, or until it is cloudy, but still liquid.

HINT: Orbs made with vinegar and agar shrink better than those made with gelatin (see floating orb recipe below!)

Standard colored orbs:

1. With adult supervision, dissolve 5 packets unflavored gelatin or 2 Tbs. agar in 1 cup hot water. Add 2 tsp. vinegar. Microwave and stir until completely dissolved.

2. Pour into smaller containers and add food coloring. When cooler, but not solid, add the melted, colored gelatin or agar to an empty glue container or squeeze bottle.

3. Drip gelatin or agar solution into the cold oil, a few drops at a time so it forms into marble-sized orbs and sinks. Drip two colors together to make multi-colored orbs! Allow to cool for 30 seconds or so and retrieve with a slotted spoon or strainer. Rinse with water and repeat, re-chilling the oil as needed until you have as many orbs as you want.

Making magic orbs on Twin Cities Live with Lindsey Brown and Steve Patterson (photo by Glenn Griffin)

Making magic orbs on Twin Cities Live with Lindsey Brown and Steve Patterson (photo by Glenn Griffin)

 

Lindsey Brown and Steve Patterson making orbs on Twin Cities Live (photo by Glenn Griffin)

Lindsey Brown and Steve Patterson making orbs on Twin Cities Live (photo by Glenn Griffin)

4. Rinse orbs with water. Dry them out by setting them on a plate overnight if you want to see them shrink and then re-hydrate them with water. Orbs can be kept in a plastic bag in the refrigerator. (Keep away from small children, since they may be a choking hazard.)

To make floating orbs, follow directions above, but make with 1 cup white vinegar and 2 Tbs. agar. They will sink and float when added to water with a few tsp. of baking soda mixed in as the vinegar and baking soda react to form carbon dioxide gas.

IMG_4056

To make color-changing orbs, dissolve 2 Tbs. agar or 5 packs unflavored gelatin in 1 cup red cabbage juice (magic potion) and follow directions for making orbs. Then drop them in vinegar to watch them turn pink or in water containing baking soda to watch them turn blue!

IMG_4048

 

Could you make homemade jelly beans using flavored gelatin using this same method? Try it!

*Agar, or agar agar flakes can be found in the Asian food section of many grocery stores!

 

Frozen: Crystallize Your Holidays

 - by KitchenPantryScientist

IMG_4144

With the touch of her bare hands, “Frozen’s” Elsa coats the world with ice. It takes a little longer, but with your imagination, you can use alum crystals to make ordinary objects extraordinary with science!

IMG_4142

We coated pipe-cleaner snowflakes, styrofoam snow people and even an evergreen branch with gorgeous ice-like alum crystals. We demonstrated how to make these on Kare11 Sunrise News.

Here’s how to grow your own alum crystals:

Ingredients: alum (spice section of grocery store. 3 small containers for half recipe, 5 containers for 4 cup recipe. Alum is relatively expensive, so you might want to cut the recipe in half and crystallize smaller items! See below.) glue, water, paintbrush,small items you’d like to coat with crystals.

1. Using a paintbrush, brush glue on the surface you want to “freeze”. One option is to twist 3 pieces of pipe cleaner together to make a snowflake. If you have beads, add them to your snowflake before crystallizing!

2. Before the glue dries, sprinkle the object with alum. These are your seeds for crystallization. Allow object to dry.

IMG_4100

3.With adult supervision, dissolve about  1 1/4 cup alum in 4 cups in hot water (we use the microwave), reserving some alum to sprinkle on other objects you may want to make later. (One 1.9 oz. container of alum is around 1/4 cup, so you’ll need 5 of them.) Liquid will be cloudy and some crystals will sink to the bottom. This is your supersaturated alum solution.

4. Allow liquid to cool.

5. Suspend objects in alum solution until crystals are the size you’d like them to be. This may take an hour for small crystals or overnight for large one.  Remove the crystals from the jar and dry your crystallized object. We grew big crystals on our snowflakes and then scraped them off the beads, but left them on the pipe cleaners.

IMG_4102

6. To crystallize more objects, reheat alum solution, stir up crystals to dissolve as many as possible, and cool before adding the next thing to be “frozen.”

The Science Behind the Fun: Some crystals, like alum, will form from supersaturated solutions, like the one you used in this experiment. A supersaturated solution is one that is forced to hold more atoms in water (or another solute) than it normally would.  You can make these solutions using heat or pressure.  Crystals can form when a supersaturated solutions encounters a “seed” atom or molecule, causing the other atoms to come out of the solution and attach to the seed.

What else can you think of to crystallize?

Give Kids The Gift of Science

 - by KitchenPantryScientist

At home science offers an opportunity for kids to have fun and be creative thinkers. This holiday season, help your kids take a break from screens with an activity they’ll love, like blowing up balloons with baking soda and vinegar!

Wrap up Kitchen Science Lab for Kids (available wherever books are sold) with a box of baking soda, a bottle of vinegar and some balloons for an instant holiday hit.

IMG_4598[1]

 

 

 

 

IMG_1732

 

 

 

 

 

Better yet, put together a homemade science kit for the kids on your list and let them choose and experiment a day to do over break. (Many of them are easier than baking cookies.)

 

 

Put kids in charge of the experiments. Let them try whatever they want, as long as it’s safe, even if you don’t think it will work. We learn to be creative when we’re given freedom to make mistakes and go beyond the instructions.

Homemade Holiday Window Stickies (A Density, Diffusion, Evaporation Experiment)

 - by KitchenPantryScientist

I’m creating a fun new holiday experiment for 2014, but thought I’d re-post this experiment that my kids and I made up last year, since we love it so much. Try it!

What happens when food coloring molecules move, or DIFFUSE through gelatin, the substance that makes jello jiggle?

IMG_3674

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.

You can watch us making them on Kare11 Sunrise News by clicking here.

You’ll need

-plain, unflavored gelatin from the grocery store or Target

-food coloring

-a drinking straw

-water

-a ruler

-glitter

*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 3. Sprinkle glitter on the gelatin in one pan.  What happens?
IMG_3623
Step 4. Allow the gelatin to harden in both pans.

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.
IMG_3628
Step 6. Add a drop of food coloring to each hole in the gelatin.
IMG_3640
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.
IMG_3641
Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
IMG_3688When 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?
IMG_3691The 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!

Blundering Into Innovation

 - by KitchenPantryScientist

I was thrilled to see the words “In Praise of Failure” emblazoned across the New York Times Magazine innovation issue Sunday morning and to read stories that illustrate that there is no substitute for trial, error and risk-taking in the process of invention. It reminded me that I’ve been meaning to write about a fantastic kids’ science competition (Young Scientist Challenge) and an online kids’ show (Annedroids) that both embrace the idea that you have to make mistakes to create something great.

Two of the Young Scientist Challenge finalists talk about their Rube Goldberg machine.

Two of the Young Scientist Challenge finalists talk about their Rube Goldberg machine.

Each year, 3M teams up with Discovery Education to host an innovation competition called the Young Scientist Challenge. At the finals this year in St. Paul, ten smart, articulate kids presented original inventions they’d been working on all summer with 3M mentors. (Check out their videos on the website to see the amazing things they’ve invented!) The competition encourages kids to create innovations that address problems they see in the world around them, test their ideas using math and science, and present their projects, along with obstacles they faced along the way.

As one fun part of the competition, I got to watch the finalists frantically finish up Rube Goldberg machines they’d assembled from Legos, marbles, baking soda, vinegar, Mousetrap, and various other materials as teams. As judges looked on, some machines worked, and some marbles never made it into the mousetrap, but it was clear that process trumped perfection as the kids explained their ideas, the science behind them, and how they’d worked together to create their machines.

My kids are already looking forward to entering next year’s competition!

annedroids-2

The kid inventors on Annedroids (Amazon)

Kids get inspired in all kinds of ways, so I was thrilled when my 8YO switched things up from pink ponies to Amazon’s invention series Annedroids. I’m sure that she loves that  the main inventor is a girl, and as a science educator, the first episode had me at “we didn’t fail, we just discovered another way of doing it wrong.” The entire series is free if you have Amazon Prime, but the first episode is available at no cost everyone.

As for me,  I’ll be setting up a family holiday Rube Goldberg competition (and not just for the kids!)  We have Legos, baking soda, vinegar, and plenty of old toys in the basement, so I just need to pick up a Mousetrap game or two!

*Innovation Story: When 3M hired a young, banjo-playing engineering student named Richard Drew in 1920, they had no idea that he would revolutionize the entire company. At the time, 3M’s wildly popular new invention (and sole product) was abrasive particles stuck to paper with adhesive (sandpaper) and Drew’s job was to take samples to auto shops, where they could try it out on cars they were prepping to paint. Hanging around and observing the process of sanding and painting, Drew discovered that the tape they were using to do two-tone paint jobs was pulling fresh paint off the cars and decided to try to make a better tape. 3M gave him a lab and some materials, and he got to work experimenting, eventually introducing the world’s first roll of masking tape in 1925. As the company grew,  innovation continued to be an integral part of the culture, with every employee encouraged to spend 15% of their time working on their own projects. Now they make everything from the reflective material on street signs to multi-layer optical films and paper-thin microbial growth surfaces.

 

 

All About That Base

 - by KitchenPantryScientist

In addition to some of my neighborhood friends,two awesome chemist friends helped me out with this song: the amazing Dr. Raychelle Burks (with the Bronsted-Lowry line) and bassist Ryan Williams, who happens to have a PhD in Chemistry, with his awesome bass-playing.

The video quality isn’t top-notch, but you’ll get the idea, and hopefully learn a little chemistry!

Physics! Biology! Chemistry! Yeah!

 - by KitchenPantryScientist

I got together with some friends this weekend to do a quick iPhone recording of a chemistry song (on my Kitchen Pantry Scientist YouTube channel soon) and these awesome kids were nice enough take a break from playing to sing the Science Song with me. They had me laughing so hard that I could hardly get the words out!

Can you make up a song about science?