Lightning-rods were not first used by Benjamin Franklin, as many people think. A Hebrew book written in the 8th century, a thousand years before Franklin, already tells about the lightning conductor: “Those who put iron posts in their gardens and place rods there have protection against lightning.”
Mountain guides ask people to be quiet when passing under overhanging snow because the vibrations of sound can make the snow fall.
Astronomy is thought to be the oldest science.
The colors of the rainbow are red, orange, yellow, green, blue and violet.
The speed of light was first measured in 1676 by Romer.
