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.

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 !

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

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).