Indoor pollution is 10 times more toxic than outdoor pollution.
62
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The average temperature at 40,000 feet above sea level is -60 F.
56
A single cup of gasoline, when ignited, has the same explosive power as five sticks of dynamite.
57
Kissing actually has the biological purpose of passing on biological information and chemical signals to assess mating possibilities and status.
9
The bark of an older redwood tree is fireproof.
65