Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Cold water weighs more than hot water.
93
Diamonds can be shattered with a hammer.
-104
Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
In zero gravity, a candle's flame is round and blue.
16