Balsa wood is classified as a hard wood!
41
One cubic foot of gold weighs more than 1,200 pounds!
78
MIT has developed a camera that captures the speed of light at a trillion frames per second.
20
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Indoor pollution is 10 times more toxic than outdoor pollution.
62
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Pumice is the only rock that floats on water.
14
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17