Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Nylon is made from coal and petroleum.
42
The inventor of the Super Soaker squirt gun was a NASA Scientist who also helped develop the Stealth Bomber and the Galileo mission to Jupiter.
7
Pumice is the only rock that floats on water.
14
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5