Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
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
Sound at the right vibration can bore holes through a solid object.
134
The most expensive material on the planet is antimatter - worth $62.5 trillion per gram.
18
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
In zero gravity, a candle's flame is round and blue.
16
4.5 pounds of sunlight strike the Earth each day.
27