The Earth's atmosphere weighs about 5.5 quadrillion tons.
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Research indicates that plants grow healthier when they are stroked.
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Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
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Sound travels about 4 times faster in water than in air.
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One third of the electricity produced on earth is used to power electric light bulbs!
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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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A cesium atom in an atomic clock beats over nine billion times a second.
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