The bark of an older redwood tree is fireproof.
65
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
For every gallon of sea water, you get more than a quarter pound of salt.
45
There are more atoms in one teaspoon of water than there are teaspoons of water in the Atlantic Ocean.
13
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
The only letter not appearing on the Periodic Table is the letter "J".
180