Scientists have become the bearers of the torch of discovery in our quest for knowledge.

— Stephan Hawking, Physicist.

Every time you fill your glass with water you are filling it with a liquid that has been on this earth longer than you or me.

Water is recycled over and over again generation after generation water keeps going around in the natural phenomenon known as the water cycle.

The sun causes a large amount of water to evaporate from the oceans and other bodies of water. This vapor rises into the atmosphere, cools, condenses and forms small water droplets.

The small water droplets then start to combine with other water droplets and the droplets become bigger and bigger, until they can no longer be held in the air so they fall. This can be in the form of snow, sleet, hail and of course rain drops and then the water cycle start all over again.

Investigation: Where does rainwater comes from?

What you will need:
3 cups of water, 1½ tablespoons of salt, plastic wrap, cup, mixing bowl, small rock.

Instructions:
1. Pour the water into the mixing bowl, add in the salt, and stir until it has dissolved.

2. Put the cup or small bowl into the mixing bowl without letting any salt water get into the cup.

3. Place the plastic wrap over the bowl and seal the edges. Place the small rock on top of the plastic wrap in the middle of the surface. The plastic should slant slightly toward the cup in the middle of the large bowl.

4. Place the setup under a hot sunny area for one hour. Water drops should start to form underneath the plastic. The water drops will flow into the middle of the bowl and fall into the cup.

5. After a few hours, remove the plastic. The cup should now have a sizeable amount of water in it.

What’s happening?
The heat from the Sun should form water vapor from the salt water in the large bowl on the under side of the saran wrap/cling film.

The vapor then condenses on the saran wrap/cling film that happens to be colder and drips as fresh water into the cup in the middle of the bowl.

When the water evaporated it left behind its impurities such as salts and metals. That’s why rainwater does not taste salty even though a lot of the water comes from the oceans.