Nylon is made from coal and petroleum.
42
In zero gravity, a candle's flame is round and blue.
16
A cubic yard of air weighs about 2 pounds at sea level.
31
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
The average home creates more pollution than does the average car.
33
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55