Here is a gravity experiment from Bayer's Everyday Science Web site. Everyday Science is a public radio program sponsored by Bayer.
Gravity keeps our feet planted on the ground as well as keeps everything, including water, from floating in air. Find out how you can create an anti-gravity environment.
- One small baby food jar
- One straw
- Red or blue food coloring
- Clay -- a piece the size of a marble
- Press the clay against the inside of the bottom of the jar.
- Fill the jar one-half full with water.
- Add three or four drops of food coloring to the water and stir.
- Slowly lower the straw into the colored water.
- Push the bottom end of the straw into the clay. The straw can now stand in a vertical position.
- Quickly turn the jar upside down over a sink.
- Turn the jar right side up and set it on a table.
- Observe the liquid level inside the straw, if any.
What this means:
Colored water remains in the straw. The height of the water in the straw is the same as that of the water before it was poured out. Water molecules are attracted to each other. At the surface of the water, the molecules tug on each other so much that a skin-like surface is produced. The air in the straw pushes up on the water when the jar is inverted and water molecules are pulling from side to side. These forces are greater than the downward force of gravity; thus the water remains in the straw.