The average temperature at 40,000 feet above sea level is -60 F.
56
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
Rafflesia Arnoldii is the largest flower in the world and can grow as big as an umbrella.
42
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
Nearly 50% of the world's scientists are assigned to military projects.
71
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17