Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
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Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
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Your brain is 80% water.
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4.5 pounds of sunlight strike the Earth each day.
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If the chemical sodium is dropped into water it will immediately and violently explode.
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It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
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