Painting Naturally

You need:

• Vegetable skins (carrots, radishes, beets)
• Whole vegetables (spinach, broccoli, peppers)
• 1 cup per plant
• Sturdy grinding sticks (and/or a knife, but only if a grown-up is helping you!)
• Water
• Teaspoon
• Paint brushes
• Coffee filters

1. Freeze the plants overnight.
2. Place each plant in a cup and thaw.
3. Grind, crush, and chop (if a grown-up is helping) each plant until each cup contains only pulp.
4. Add 5 teaspoons of water to each cup.
5. Let sit for 5 minutes.
6. Dip a different paintbrush into each cup and dab the mixtures on a coffee filter.  See what colours and images you can create!

Explanation:  

You made natural dyes!  The coloured dyes that you made are from pigments found in plant cells.  The pigments found in plants is what gives them color, just like the pigments in our bodies give our hair, eyes, and skin colour.  Freezing, chopping, and grinding the plant helps break the plant cells and release the pigments.

Nearly every plant will produce some kind of colour, whether we use leaves, bark, wood, roots, or fruit.  The colourfastness, meaning the likelihood that the color will fade or run, varies with the color of the plant.  Mant plant pigments can be extracted and used as dyes.  These dyes, with additives, can be made into inks.

Wind Finder

You need:

• Feather
• Straw
• Tape
• Scissors
• Straight stick that can fit inside the straw (like a barbeque skewer)
• Cardstock or blank cardboard (1 in. x 1 in.)
• Marker
• Compass

1. Cut the straw in half.  One half will be the wind finder and the other half will be its support.
2. Fit the feather into one end of the wind finder straw and tape it in place.
3. Use the marker to draw an arrow pointing away from the feather at the other end of the straw.
4. Balance the straw on your finger until you find its center of gravity.  (It should balance evenly and not tilt to one side.)  Mark this spot with the marker.
5. The second straw is your support straw.  Cut into the end of this straw to make 4 equal flaps, about 1/4 in. deep.
6. Peel back 2 of the flaps that are opposite from each other and lay the wind finder straw across the flaps so that the marked center of gravity is at the flaps.  The straws should form a "T" shape.
7. Tape the two straws together.
8. Write the letter "N" on the card stock.
9. Attach the stick somewhere outside high up and in the open, such as the top of a fence or gate post.  Make sure it is sticking straight up.
10. Fit the support straw onto the stick.  It should be able to turn easily.
11. Use the compass to find north.  Tape the card stock to the north side of the stick, below the support straw.  (Don't tape it to the straw.)
12. What happens when the wind blows?

Explanation:  

You just made a weather vane!  A weather vane is a tool used to tell which direction the wind is coming from.  Weather vanes are usually found on top of buildings so they can catch an open breeze.  The breeze turns the weather vane until both sides catch equal amounts of wind.  The part of the vane that turns toward the wind is usually shaped like an arrow.  The other end is wide, like your feather, so it catches the smallest breeze.  Directional indicators, such as your "N", are used to determine the wind direction.

Sharing the Swing

You need:

• Piece of string (3 ft.)
• 2 metal coat hangers
• 2 small paper cups
• Marbles or pebbles
• Masking tape
• Ruler
• 2 chairs

1. Pull one hanger into a long diamond shape.  The hook should be at the long end of the diamond.
2. Using the end of the hook, carefully poke a hole in the side of a cup, just above the bottom.
3. Slip the hook into the hole so the straight part of the hook rests along the outside of the cup, from bottom to top.  Tape the hanger in place on the outside of the cup.
4. Do the same with the other hanger and cup, making sure the hangers are stretched to equal lengths.
5. Tie the end of the hanger that is opposite from the hook to a spot 1 foot from one end of the string.  Tie the other hanger 1 foot from the other end.  The hangers will be 1 foot apart.
6. Stand the two chairs back-to-back about 2 feet apart.  Tie the ends of the string, or tape them securely, to the backs of the two chairs.  The hangers should be able to swing freely.
7. Fill the cups with equal amounts of marbles or pebbles.  You have made two pendulums!
8. Gently pull one pendulum back as far as you can without losing your marbles (so to speak) and let it go.
9. Observe what happens to the second pendulum.

Explanation:  

You created a coupled resonance pendulum!  A pendulum is a weight that swings back and forth from the support it's attached to.  As the pendulum swings back and forth, it tugs on the string connecting the two pendulums and starts the second pendulum swinging.

Like pushing someone on a swing, you need to push them at just the right moment for them to go higher.  If you push them at the "wrong" moment they'll slow down, then stop.

As the "right" and "wrong" moments of your two pendulums change, the swinging is transferred back and forth between the two, causing the pendulums to start and stop swinging or to swing together.

Soft Suds

You need:

• 2 cups of distilled water
• 1 cup of tap water
• 3 empty screw-top bottles
• Epsom salt
• Dish detergent

1. Fill two bottles with 1 cup of distilled water each.
2. Add 1 teaspoon of Epsom salt to one of the bottles.  Cap and shake the bottle until the salts have dissolved.
3. Add 5 drops of dish detergent to each bottle.  Cap and shake the bottles.
4. Which bottle formed suds?

Explanation:  

Suds are bubbles of air trapped in the liquid when it is shaken.  The detergent helps hold those bubbles together.

Water that is treated to remove chemicals is called soft water.  Soft water and hard water react differently with dish detergent.  This can be seen by the type of suds formed in the water.

Hard water usually contains the minerals calcium and magnesium.  When you added Epsom salt - which is magnesium sulfate - to the water, you created hard water.  The minerals in hard water react with the detergent and prevent bubbles from forming.

Now that you know how to test for hard water, try the experiment with tap water (but no Epsom salt).  How does it compare to your hard water and soft water samples? 

Balloon Kabob

 You need:

• A grown-up's permission to use pointy things!
• Balloon
• BBQ Skewer or Knitting Needle
• Petroleum Jelly or Baby Oil

1. Coat the skewer or knitting needle in petroleum jelly or baby oil.
2. Blow up the balloon until it is round like a ball and soft enough to squeeze gently.
3. Starting at the spot on the balloon where the color is darkest (this should be opposite to where the balloon is tied), slowly twist the skewer in one direction while gently forcing it into the balloon.
4. Keep twisting the skewer in the same direction until it pokes through the balloon.
5. Slide the skewer until the tip is touching the spot where the balloon is tied off.
6. Continue twisting until the skewer pokes out the other end!

Explanation:  

You skewered a balloon!  Balloons are made from a thin sheet of rubber called latex.  A latex balloon is like a stretchy ball because it is made of polymers, long, thin chains of molecules tangled together.  These polymers are attached by bonds called cross-links, which form a web that can be stretched and returned to its original shape.

The dark spots on the balloon are thicker than the rest of the balloon.  The balloon does not break when a sharp skewer is is forced through the dark spots because the polymers are pushed aside but remain bonded by the cross-links.  (The skewer will slide in easily and seal the hole if it is coated with oil or petroleum jelly.)  If you give the thin part of the balloon a quick, sharp poke with the skewer, the strands will break and the balloon will pop!

• Tarnished (brown) penny
• Ketchup
• Toothpick
• Paper towel
• Clock or watch