Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
In zero gravity, a candle's flame is round and blue.
16
Scientists have developed a microparticle filled with oxygen that can be injected into the blood stream, enabling us to live without breathing.
21
Diamonds can be shattered with a hammer.
-104
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Each day, up to 150 species of life become extinct.
-23