The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
Research indicates that plants grow healthier when they are stroked.
173
Each day, up to 150 species of life become extinct.
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