Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Sound travels about 4 times faster in water than in air.
408
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
3
