Hans-on science:

Science World, April 5, 2004

Check out these hands-on experiments after you've read "Tomorrow's Weather (p. 8) and Buy a (p. 16), They're fun and foolproof!

PERSONAL RECYCLE MILL

In "Buy a Better Earth" you learned recycling saves trees. Find out what kind of paper is easiest to recycle.

YOU NEED:

3 pages each: newspaper, white paper, and glossy magazine paper * blender * measuring cup * warm water (1 gallon) * pan--at least 8 cm (3 in.) deep * screen or nylon mesh that fits inside the pan * 3 entire newspaper sections * rolling pin

TO DO:

1. Shred three pages of newspaper and drop into a blender. Add five cups of warm water. Cover, and blend into a mushy pulp.

2. Pour about 3 cm (1 in.) of water into the pan. Then place the screen inside the pan.

3. Pour 250 ml (1 cup) of pulp over screen. Spread evenly.

4. Lift the screen and let the water drain into the pan.

5. Unfold a newspaper section. Place the screen with pulp onto one half of it and fold the other half over the screen.

6. Flip the newspaper so the screen is on top of the pulp. Remove the screen, leaving the pulp.

7. Roll out the excess water with the rolling pin.

8. Open the newspaper and let dry for up to 24 hours.

9. Clean the blender, pan, and screen. Repeat Steps 1-8 using the white and magazine paper.

10. When the paper is dry, peel it off the newspaper.

CONCLUSIONS:

Which type of paper was easiest to make into recycled paper?

MINI GREENHOUSE

You read in "Tomorrow's Weather" that greenhouse gases absorb the sun's energy and cause Earth to warm up. Build your own greenhouse to see this warming.

YOU NEED:

2 clear plastic soda bottles (2-liter) * maker * scissors * 2 thermometers & clay * sunlight or a lamp * clock

TO DO:

1. Clean the soda bottles and remove their labels.

2. Label one bottle "A," and the other "B."

3. Use scissors to cut three slits (2 cm by 6 cm, or 1 in. by 2.5 in.) in bottle "A." Note: Handle with care.

4. Insert a thermometer into the mouth of each bottle. Secure it at the mouth of the bottle with a piece of clay.

5. Put both bottles in direct sunlight, or 15 cm (6 in.) from a lamp. Make sure both bottles are an equal distance from the light.

6. Record the starting temperature. Note: It should be the same for both bottles.

7. Continue to record the temperatures every 5 minutes for 20 minutes or longer.

8. Make a double-line graph with your data.

CONCLUSIONS:

In which bottle did the temperature change the most? Why? Which bottle best models the greenhouse effect?

Mini Greenhouse

1. The temperature changed the most in bottle "B." In bottle "B" the air couldn't circulate to the outside. Instead, the sun's heat was trapped inside the bottle and the air kept getting warmer. As the temperature increased inside bottle "A," however, the warmer air was replaced with the cooler air outside of the bottle.

2. Bottle "B" best modeled a greenhouse. In both bottles the sun's energy passed through the clear plastic walls. But in bottle "B," its sealed plastic sides--like Earth's greenhouse-gas layer--trapped this heat inside.

Personal Recycle Mill

Find out how your paper-making project compares with the way a paper mill recycles paper on a larger scale. This Web site also has a Kid's Page, which includes fun recycling games and projects: http://marcalpaper.com/default.cfm?SiteMenu=Editorial&PageID=181

Visit the Environmental Protection Agency's Municipal Solid Waste Web site to learn more about the recycling process, recycling facts, and useful Internet links: www.epa.gov/epaoswer/non-hw/muncpl/recycle.htm