Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
The force of a suction cup is calculated using F=AP.
15
The bark of an older redwood tree is fireproof.
65
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
A coal power station puts 100 times more radiation into the air than a nuclear power plant producing the same amount of energy.
7
Nylon is made from coal and petroleum.
42
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6