One barrel of petroleum holds 42 gallons.
20
For every gallon of sea water, you get more than a quarter pound of salt.
45
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Pure water (H2O) does not conduct electricity on its own.
46
Most dust particles in your house come from dead skin.
48
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
One 75-watt bulb gives more light than three 25-watt bulbs.
57