Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Pumice is the only rock that floats on water.
14
Sound at the right vibration can bore holes through a solid object.
134
Iron weighs more after it rusts.
68
The average temperature at 40,000 feet above sea level is -60 F.
56
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116