Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Most liquid laundry detergents are alive with living organisms that help to break down stains!
88
One barrel of petroleum holds 42 gallons.
20
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
A cubic yard of air weighs about 2 pounds at sea level.
31
Iron weighs more after it rusts.
68
