In zero gravity, a candle's flame is round and blue.
16
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Sound travels fifteen times faster through steel than through air.
134
Out of all the senses, smell is most closely linked to memory.
146
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
The smell of freshly cut grass is actually a plant distress call.
31
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