Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
No matter how cold it gets, gasoline will not freeze.
107
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
Iron weighs more after it rusts.
68
A cesium atom in an atomic clock beats over nine billion times a second.
43
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17