Rainbow – miracle in the sky
Colorful rainbow in the sky has been astonishing and frightening people since ancient times. The ancient Greeks thought these arcs of color were signs from the gods to warn people that terrible wars or storms were going to happen. The Norse people believed a rainbow was a bridge the gods used to walk down from the sky to the Earth. Irish legends said there was a pot of gold at the end of a rainbow.
But rainbows aren’t magic. It is just colored light. The seven colors are always the same and appear in the same order: red, orange, yellow, green, blue, indigo, and violet.
Rainbows often appear after or at the end of a rain. When a beam of sunlight passes through raindrops, it’s broken into the seven different colors. Because only water and light are required for rainbows, one will see them in rain, spray, or even fog.
Sunlight travels through space in the form of waves. Scientists use an idea called wavelength to describe these waves. Some light waves have long wavelengths, while others have short wavelengths. Light waves with different wavelengths appear as different colors.
In 1637 Rene Descartes first discussed the formation of the arc. 30 years after Descartes Isaac Newton discovered that white light was made up of different wavelengths.
No two people will see the same rainbow.
A rainbow lasts only about a half-hour.
The brightness of the colors of the rainbow depends on the size of the raindrops. Large drops create bright rainbows with well-defined colors.
A full 360° rainbow can only be viewed from an airplane.
In many cultures there are legends and myths about the power of the rainbow, people devote it works of art, music and poetry.
Psychologists say that people admire this natural phenomenon, because the rainbow is a promise of a bright, “rainbow” future.
Rainbow can be seen even at night. This phenomenon is called a lunar rainbow. In this case, the rays of light are refracted by reflection from the Moon.