When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
In zero gravity, a candle's flame is round and blue.
16
German chemists made a replica of a trophy the size of one molecule.
68
The only letter not appearing on the Periodic Table is the letter "J".
180
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The average temperature at 40,000 feet above sea level is -60 F.
56
Sound travels fifteen times faster through steel than through air.
134
A cubic yard of air weighs about 2 pounds at sea level.
31