Your heart was about the size of a walnut when you were born. Now your heart is about the size of your fist.

Materials:

• white carnation
• scissors or knife
• 2 glasses
• water
• red and blue food coloring

1. Get a white carnation with a long stem.
2. With help from an adult, very carefully cut the carnation's stem lengthwise, from the bottom to about halfway up to the flower.
3. Now fill 2 glasses with water.
4. Use food coloring to color the water in one of the glasses dark red.
5. Color the water in the other glass dark blue.
6. Put the glasses right next to each other.
7. Check the carnation a day later, and 2 days later.
8. Can you tell that the carnation has been drinking the water? You'll notice that the water travels up the tubes into the stem to reach the other parts of the plant.

The equator measures 24, 912 milesa round. It would take 25 million people holding hands to circle it!

Materials:

• soft leather scraps
• block of wood
• stapler
• marker
• sunscreen
• baby oil
• water

1. Take 4 scraps of leather and staple them to a block of wood.
2. Use a marker to label the strips "Suncreen", "Baby Oil", "Water", and "Natural".
3. Then rub a thick layer of sunscreen across the top of the sunscreen strip, baby oil over the baby oil strip, and water on the water strip. Don't put anything on the natural strip.
4. On a very hot summer day, take the strips of leather outside and let them bake in the sun. The next hot, sunny day, reapply the sunscreen, baby oil, and water and repeat the process.
5. Keep doing this every hot, sunny day.
6. At the end of the summer, closely examine how the strips of leather held up. Now imagine that the leather is your own skin!
   

Our blood always travels around your body in the same direction. It takes about 45 seconds for one trip.

In one day, you breathe enough air to fill about 500 party balloons !

Since the moon's orbit is elliptical, its distance varies from about 221,463 miles (356,334 km) at its closest approach to Earth to 251, 968 miles (405,503km) at its farthest point, with the average distance being 238,857 miles (384,392km).

Materials

• Paper
• Plastic comb
• Cloth (wool, polyester, or nylon)

1. Tear a sheet of thin paper into small pieces
2. Rub a comb with a cloth to give it a charge
3. Hold the comb near the pieces of paper, and watch as they cling to the comb.
4. Play a version of the game jacks called Static Cling jacks with a friend of by yourself.
5. Put the pieces of paper in a pile.
6. Rub the comb a little so that it picks up a single piece of paper
7. Rub the comb a little more so it picks up exactly 2 pieces of paper
8. Then try for 3 pieces of paper
9. Keep going until you pick up more or less than the correct number.
10. When it is your turn, you start with 1 piece of paper again.
11. Can you work your way up to 8 pieces of paper?

The U.S. government authorized Yellowstone National Park on March 1, 1872.

The center of the sun is about 27,000,000 degrees F. The surface, or photosphere, of the sun is about 10,000 degrees F.

Materials:

• Toothpick
• Lemon juice
• Paper
• Heat source
• Vinegar or milk

1. Dip the tip of a toothpick into lemon juice
2. Then use it to write a secret message on a piece of paper
3. Use lots of lemon juice for each letter you write
4. Allow the paper to dry until you can’t see the writing anymore
5. Now move the paper back and forth over a heat source, such as a lightbulb or iron
6. As the ink gets warm, your message is revealed!

The acid in the lemon juice breaks down the cellulose of the paper into sugars. The heat supplied tens to caramelize the sugars, making them brown and revealing the secret writing. Repeat this with vinegar or milk to find out which makes the best invisible ink!

The speed of rainfall varies with drop size and wind speed. A typical raindrop in still air falls about 600 feet (182) per minute or about seven miles (11 kilometers) per hour.

Materials:

• Sugar
• Measuring cup
• Nonstick pan
• Stove
• Large wooden spoon
• Water

1. Measure ½ cup sugar into a deep nonstick pan
2. Place the pan on the stove over low heat
3. Continuously stir the sugar as you gradually increase the heat
4. Remove the pan from the heat when the sugar is yellowish
5. Slowly add ½ cup of water to the caramel
6. Place the pan back on the stove over low heat, and stir the mixture until the caramel dissolves in the water
7. When it has cooled, taste the mixture!

Caramel is a combination of sugar and carbon. The sugar has been converted to caramel through a chemical reaction. If you heat the sugar too long, it will turn the dark brown color of carbon and lose all of its sweetness- an interesting chemical change but not very tasty!

John Brower Minnoch (1941-1983) of Bainbridge Island, Washington, weighed 976 pounds (443 kilograms) in 1976 and was estimated to have weighed more than 1,387 pounds (630 kilograms) when he was rushed to hospital in 1978 with heart and respiratory failure. Much of his weight was due to fluid retention. After two years on a hospital diet, he was discharged at 476 pounds (216 pounds). He had to be readmitted, however, after reportedly gaining 197 pounds (87 kilograms) in seven days. In 1983 when he died, he weighed 798 pounds (362 kg).