Double Rainbow

Picture courtesy of a DC viewer!!

Some powerful storms rocked the area last night with heavy rain and lots of lightning! But before they made it to the Eastern Shore, they slammed into DC. The above picture was taken from around DC after the storms passed. It's a great shot of a double rainbow. Double rainbows aren't nearly as common as a single rainbow.

Rainbows are caused by the bending of sunlight as it goes through raindrops. The light is first refracted as it enters the surface of the raindrop, then reflected off the back of the drop, and again refracted as it leaves the drop.

Rainbows appear with red on the outer part of the arch and violet on the inner section. Unfortunately, there is no pot of gold at the end of a rainbow. That's because rainbows do not actually exist at a particular location. It is an optical illusion whose position depends on the location of the sun and person viewing it. 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 creates the rainbow for the person. The position of a rainbow is always in the opposite direction of the Sun with respect to the observer, and the interior is always slightly brighter than the exterior.

Occasionally, a second rainbow is found. Usually these are dimmer and thicker than the primary bow. Secondary rainbows are caused by a double reflection of sunlight inside the raindrops. As a result of the second reflection, the colors of a secondary rainbow are in reverse order compared to the primary bow. Violet appears on the outside and red is visible on the inside.


Information courtesy wikipedia.com