When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Aluminum used to be more valuable than gold!
84
A ball of glass will bounce higher than a ball made of rubber.
73
Each day, up to 150 species of life become extinct.
-23
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
One cubic foot of gold weighs more than 1,200 pounds!
78
In zero gravity, a candle's flame is round and blue.
16