Indoor pollution is 10 times more toxic than outdoor pollution.
62
In zero gravity, a candle's flame is round and blue.
16
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Aluminum used to be more valuable than gold!
84
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Nearly 50% of the world's scientists are assigned to military projects.
71