Search This Blog

Loading...

Thursday, June 28, 2007

The Mysteries of Water

In terms of rain, it has been a tough summer for the United States. Across the country, states are experiencing one of the driest summers in a very long time. In Georgia, where my family and I live, many cities and counties have established water rationing programs which severely limit the amount of water used. The drought has affect everything from wildfires in the Okefenokee Swamp to farmers’ crops to withering lawns. So, I couldn’t help but laugh to myself when I picked up this month’s issue of Science and Children. On the cover a girl in a bathing suit leaps gleefully through a spray of water from a lawn sprinkler (see above). I couldn’t help being a bit envious. After all, my lawn hasn’t seen water like that in months. All joking aside, summertime fun has always involved water, so it makes sense that the National Science Teachers Association (NSTA) would dedicate the July issue of Science and Children to the exploration of water.

According to an article at FastCompany.com, Americans spent more on bottled water last year than we spent on iPods or movie tickets - $15 billion. It’s clear that water is very important to us. Yet, we rarely take time to really think about water. Here are some interesting facts about water:

  • Approximately 65% of an adult’s body is made up of water. Water accounts for about 80% of a baby’s body weight.
  • You could survive about a month without food, but you could only
    survive 5 or 6 days without water.
  • Roughly 75% of the earth’s surface is covered with water. Did you know: Aquifers store most of the earth’s fresh water. 97% of the earth’s water is salt water found in oceans and seas.
  • Water is one of the world’s best solvents. It dissolves more substances than any other liquid. Wherever it travels, water carries chemicals, minerals, and nutrients with it.
  • The earth contains approximately 326 million cubic miles of water (1.4 billion cubic kilometers). Humans used about 0.3% of this water.
  • In the United States, the average person uses anywhere from 80-160 gallons of water per day. Two-thirds of this water your is used in the bathroom. Flushing the toilet uses the largest amount of water. The average five-minute shower uses between 15 to 25 gallons of water. Did you know: During medieval times, a person used only 5 gallons of water each day.
  • 300 million gallons of water are needed to produce a single day’s supply of newsprint in the United States.
  • The water on the earth today is the same as the water that was here when the Earth was formed and when the dinosaurs lived. As a result of the water cycle, we use the same water over and over and over.
  • Pure water (solely hydrogen and oxygen atoms) has a neutral pH of 7, which is neither acidic nor basic.
  • Unlike other liquids, water expands as it freezes.
  • Water weighs 8 1/3 pounds a gallon. It’s so heavy you can’t fill an 18-wheeler with bottled water (you have to leave empty space).

Of course, these tidbits don’t begin to uncover the fantastic properties of water. I encourage you to look for ways to explore water with your children. For example, how do we turn dirty water into clean drinking water? Your students can attempt to answer this question by building water filters. Perhaps, you can investigate some of the interesting properties of water; such as surface tension. How many drops of water do you think can fit on the face of a penny? Experimentation with mixtures and solutions is always fun! One of my favorites is super-saturated sugar water and the creation of rock candy. These are just a few of the many activities you can do with water. There are plenty more. I hope that you will take some time to discover them, and enjoy uncovering the mysteries of water!

Thursday, June 14, 2007

Farewell Mr. Wizard

One of my earliest memories of amazing science involves ping-pong balls, mousetraps and a man named Mr. Wizard. I don’t know if any of you remember this, but here’s how the demonstration worked. Inside a large plexiglass box were a bunch of mouse traps with ping-pong balls perched on top. Mr. Wizard drop a single ping-pong ball into the box. This single ball set off one of the mousetraps causing another ping-pong ball to be launched into the air. This second ball set off another mousetrap/ball combo and so on and so on. In a few moments the entire plexiglass box was filled with bouncing, ricocheting ping-pong balls. The entire demonstration took mere moments, but it created an impression on me that has lasted more than 30 years. That mere fact alone is a testament to Mr. Wizard and his work.

It wasn’t until adult years that I learned the true name of Mr. Wizard…Don Herbert. I continued to be a fan of his work and the kind of science teaching he promoted. Unfortunately, Don Herbert passed away on June 13, 2007 at his home in the Bell Canyon section of Los Angeles. He was 89. While I know that Mr. Wizard will be missed. I am positive that his work inspired many children to explore the world of science. As a result, today, there are scientists, science teachers, inventors, and tinkerers who can trace some aspect of their love of science to Don Herbert. I know that I can. I can only hope that the work that I do as a science teacher will have the same effect on the teachers and children that I connect with each day. Thank you for your contributions, Don Herbert.