When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Columbia University has developed an artificial tree that passively soaks up carbon dioxide from the air using "leaves" that are 1,000 times more efficient than true leaves that use photosynthesis.
15
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
In the 60s, a scientist gave LSD to dolphins in an attempt to teach them English.
17
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
A cubic yard of air weighs about 2 pounds at sea level.
31
Most dust particles in your house come from dead skin.
48