The Earth's atmosphere weighs about 5.5 quadrillion tons.
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The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
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Sound travels fifteen times faster through steel than through air.
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At room temperature, the average air molecule travels at the speed of a rifle bullet.
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Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
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A cubic yard of air weighs about 2 pounds at sea level.
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