Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
One third of the electricity produced on earth is used to power electric light bulbs!
75
The average temperature at 40,000 feet above sea level is -60 F.
56
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
If you are locked in a completely sealed room, you will die of carbon dioxide poisoning first before you will die of oxygen deprivation.
117