Rainbows, appearing during rainfall or right after the rain stops, are a beautiful though fairly rare optical and meteorological phenomena. The multicolored arc is caused by reflection of light in water droplets in the Earth’s atmosphere, resulting in a spectrum of light appearing in the sky. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
I captured this rainbow in the Eastern sky looking toward the Short Hill Mountains just as the rain was ending and the sun broke through the clouds.
A rainbow does not exist in a particular location in the sky or at a specific distance, but comes from any water droplets viewed from a certain angle relative to the sun’s rays. The rainbow’s apparent position depends on the observer’s location and the position of the sun. All raindrops refract and reflect the sunlight in the same way, but only the light from some raindrops reaches the observer’s eye. This light is what constitutes the rainbow for that observer.
A rainbow spans a continuous spectrum of colors. Any distinct bands perceived are an artifact of human color vision, and no banding of any type is seen in a black-and-white photo of a rainbow, only a smooth gradation of intensity to a maximum, then fading towards the other side. For colors seen by the human eye, the most commonly cited and remembered sequence is Newton’s seven-fold red, orange, yellow, green, blue, indigo and violet. (source: Wikipedia)
Rainbows form a complete circle, but we only see the top part of the rainbow because the Earth’s horizon blocks our view of the lower arc. To see a full circle rainbow, one would have to be able to look down on it with the sun behind you, which is only possible from an aircraft (or skydiving as in the photo below).
A circular rainbow observed by a skydiver over Rochelle, Illinois (Wikipedia)
Amazing things happen in Nature, but all too often we take them for granted. If we take the time to look just a little deeper, we will discover fascinating things and events unfolding around us every day.
Wood and Field 