In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
The bark of an older redwood tree is fireproof.
65
One barrel of petroleum holds 42 gallons.
20
The average home creates more pollution than does the average car.
33
One cubic foot of gold weighs more than 1,200 pounds!
78
Pumice is the only rock that floats on water.
14
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108