Indoor pollution is 10 times more toxic than outdoor pollution.
62
Pumice is the only rock that floats on water.
14
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
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
Hot water can freeze faster than cold water.
181
Some toothpastes and deodorants contain the same chemicals found in antifreeze.
38
Cold water weighs more than hot water.
93
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89