Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
In the 1950s, the US government placed beer next to an atomic bomb blast to determine if it was still drinkable. The result: in the event of a nuclear war, beer is safe to drink!
16
In zero gravity, a candle's flame is round and blue.
16
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
Every day, plants convert sunlight into energy equivalent to six times the entire power consumption of human civilization.
9