The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
For every gallon of sea water, you get more than a quarter pound of salt.
45
Iron weighs more after it rusts.
16
The average temperature at 40,000 feet above sea level is -60 F.
56
Columbia University has developed an artificial tree that passively soaks up carbon dioxide from the air using "leaves" that are 1,000 times more efficient than true leaves that use photosynthesis.
15
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101