A cesium atom in an atomic clock beats over nine billion times a second.
43
Iron weighs more after it rusts.
68
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Nylon is made from coal and petroleum.
42
One third of the electricity produced on earth is used to power electric light bulbs!
75
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79