Pumice is the only rock that floats on water.
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Sound travels about 4 times faster in water than in air.
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Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
Cold water weighs more than hot water.
93
There are more than 270 people cryogenically frozen in the hope that one day the technology will exist that can revive them and extend their lives.
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Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16