Iron weighs more after it rusts.
68
For every gallon of sea water, you get more than a quarter pound of salt.
45
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
A cesium atom in an atomic clock beats over nine billion times a second.
43
Diamonds can be shattered with a hammer.
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Columbia University has developed an artificial tree that passively soaks up carbon dioxide from the air using "leaves" that are 1,000 times more efficient than true leaves that use photosynthesis.
15
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.
5