Isaac Newton is mostly known for his discoveries related to gravity, yet he also identified the seven colors of a rainbow. A rainbow is a multicolored circle forming in the sky when the light from the Sun and rain combine in a special way, and is seen as an arc because it is viewed from ground level. They are created by reflection and refraction, which is the bending of light through clear surfaces. The beam of the white light separates into the seven colors as they enter the millions and millions of raindrops in the sky.
The light from the Sun is made up of colors normally that cannot be seen by the naked eye, and when it comes down to Earth it is white. However, when it hits the raindrops at a certain angle, the white light is split, and the colors making up the beam of sunlight separate into the form of a rainbow and its seven colors. The colors in all rainbows are present in the same order: red, orange, yellow, green, blue, indigo, and violet. One of the best ways to remember the different colors in the correct order is by using the name ROY G BIV, which includes the first letter of each color.
Light travels at a certain speed, but the colors of light slow down at different speeds as they enter the raindrop. Light from the Sun then exits each raindrop, and depending on the angle it entered, only a single color exits the raindrop. This is taking place with many raindrops simultaneously and the resulting effect are the different stripes and colors of the rainbow.
Of course, when it is raining and the Sun is shining at the same time, the chances are much better that a rainbow will appear in the sky. In addition, a rainbow can only be seen if the Sun is behind the person looking at the sky and the rain is in the front of the person. A rainbow will only become visible at an angle of about 40° from the horizon.
Occasionally, a second rainbow may be seen above the first rainbow, but the colors are in reverse order. The sky within the main rainbow is brighter than the sky outside of the arc as well. There have also been rare occasions when a third or fourth rainbow appears in the sky.
As well as during periods of rain, rainbows can also be seen when mist, spray, fog, or dew is in the air. In fact, rainbows can be made using a garden hose or a water sprinkler on a sunny day. The sunlight will hit the water droplets in the same way it hits the raindrops and the arc of a rainbow can be seen. Rainbows are not physical objects and cannot be touched.
If two people view a rainbow, they will see different versions of it because they are viewing it from different angles or distances. It may be brighter or seem to fading depending on their location relative to the rainbow.
Finally, there are two other kinds of rainbows: moon bows and fogbows. A moon bow is a rare nighttime rainbow produced by the light from the moon. The fogbow is produced by a cloud and fog droplets. They are very faint and the colors are barely visible, but they are much larger and wider than a regular rainbow.
In summary, rainbows are caused by the light from the Sun reflecting and refracting raindrops in the atmosphere. Rainbows cannot be touched and include seven colors, which can be recalled by using the letters ROY G BIV, red, orange, yellow, green, blue, indigo, and violet.