One ragweed plant can release as many as one billion grains of pollen!
51
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Pure water (H2O) does not conduct electricity on its own.
46
One 75-watt bulb gives more light than three 25-watt bulbs.
57
In zero gravity, a candle's flame is round and blue.
16
Nearly 50% of the world's scientists are assigned to military projects.
71
A cubic yard of air weighs about 2 pounds at sea level.
31
Research indicates that plants grow healthier when they are stroked.
173