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
The average temperature at 40,000 feet above sea level is -60 F.
56
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
One barrel of petroleum holds 42 gallons.
20
In zero gravity, a candle's flame is round and blue.
16
Each day, up to 150 species of life become extinct.
-23