Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
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
Nearly 50% of the world's scientists are assigned to military projects.
71
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
There are more atoms in one teaspoon of water than there are teaspoons of water in the Atlantic Ocean.
13
The average home creates more pollution than does the average car.
33