The center of the Earth is located approximately 6.440 kilometers from the surface.
Leonardo da Vinci made the first draft for the contact lenses. They should have been made of thin glass filled with water...
Right-handed people on average live nine years longer than left-handed people.
Playing chess without looking at the board, was known in Persia and India back in VIII century.
Contrary to popular belief, donkeys belong to one of the smartest ungulates. They, for example, use their chin hair to test whether there is current going through a wire fence and if they have to walk thru dangerous grounds, they will only start if their master walks through first.
Oysters can change their sex from male to female. They can do this countless times.
