Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Each day, up to 150 species of life become extinct.
-23
One barrel of petroleum holds 42 gallons.
20
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
The only letter not appearing on the Periodic Table is the letter "J".
180
A cubic yard of air weighs about 2 pounds at sea level.
31
In zero gravity, a candle's flame is round and blue.
16