We refer to our planet as “planet earth,” but we should probably call it “planet ocean.” It is, after all, 70% covered with water, mostly saltwater. Water is essential to all life. Without it, plants and animals could not exist. In fact, most living organisms consist primarily of water. Humans are about 60% water and jellyfish are about 95% water. That is the same water content of a cloud!
We do not “lose” or “gain” water. It is simply recycled. Some water has been lost from the earth as a result of man’s space explorations. But, that accounts for very little loss. And we don’t have a pipeline coming to earth from some far away planet to replenish our water. So the water we now wash our hands with is the same water Pilate used to wash his hands. We drink the same water that Napoleon drank.
Water is water. It is used and then recycled as it evaporates from the earth and then returns in some form of precipitation. Vast quantities of water evaporate from seas and lakes to form clouds that move over the earth, rise, cool, and condense back into a liquid to be released onto the earth.
This is “fresh” water since it contains no salt. It falls to earth, soaks into the ground, and eventually runs back into the seas. We will never run out of water. We have all the water we could ever use. But there is one little problem with ocean water – it contains about 3.5% salt. We cannot use it until all the salt has been removed. And desalinating water can be very expensive.
To teach students to conserve water and use it wisely, we make a “water cycle bracelet” to illustrate the recycling principle.
Supplies Needed: Elastic cord or string and two beads of each color listed below.
Directions: Thread one set of beads onto cord in the order listed. Repeat to represent the water cycle repeating over and over. Tie knot in cord and trim excess.