Indoor pollution is 10 times more toxic than outdoor pollution.
62
A cubic yard of air weighs about 2 pounds at sea level.
31
Scientists are now able to grow 'beating' heart tissue in a lab!
162
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Sound travels about 4 times faster in water than in air.
408
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51