Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
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Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Sound travels about 4 times faster in water than in air.
408
4.5 pounds of sunlight strike the Earth each day.
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Scientists have developed a microparticle filled with oxygen that can be injected into the blood stream, enabling us to live without breathing.
21
Cellophane is not made of plastic. It is made from a plant fiber, cellulose, which has been shredded and aged.
44
Iron weighs more after it rusts.
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