Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
A cubic yard of air weighs about 2 pounds at sea level.
31
Cellophane is not made of plastic. It is made from a plant fiber, cellulose, which has been shredded and aged.
44
4.5 pounds of sunlight strike the Earth each day.
27
The average home creates more pollution than does the average car.
33
For every gallon of sea water, you get more than a quarter pound of salt.
45
In the 60s, a scientist gave LSD to dolphins in an attempt to teach them English.
17