Raise your hand if you remember from grade school how to make rainbows. If that was too long ago, read this to find out how rainbows come to be and learn to make your own rainbows. In order to make rainbows you will first need to understand what they are and how they are formed. So, here's an elementary school rainbow lesson for young and old.
Rainbows are simply the visible spectrum of the colors of light.
When white light passes through a prism, or other glass object, all the colors make an appearance, scattered by their different frequencies. The prism disperses all the colors. Each color travels in a different direction and angle so each is displayed differently. This creates the familiar arc.
Rainbows are actually circular, their visibility is hindered by the horizon line.
Therefore Rainbows make the appearance of an arc, when we are on the ground. A different point of view, such as from the air will sometimes show rainbows in a full circle.
So now you are saying, "There are no prisms or glass jars suspended magically in the sky, so you still haven't told us where rainbows come from." OK, you're right smartypants, do I have to make you go to the principal's office?
There are no prisms or glass jars in the sky, but sometimes there are raindrops.
During and after a heavy rain, small water droplets in the sky act as prisms to refract the light. This causes rainbows to make an appearance. Even though the raindrops are falling, each time one falls, another appears to take it's place. This will make rainbows seem continuous.
I'm guessing that now you may want to know about double rainbows.
Double rainbows make an interesting display. They're caused when light is refracted twice inside the raindrop. With double rainbows, the second rainbow is inverted and therefore not as bright as the first.
One more thing, before we learn to make rainbows.
Rainbows can only be seen directly opposite the sun. That means that in order to see rainbows, a person must face away from the sun. This is why the sun does not make rainbows when directly overhead. To see a real rainbow in the best light, keep your back to the sun when it's low in the sky.
The easiest way to make rainbows is, of course, to use a prism.
Hold it up to the sun and let it do it's thing. There are however, a few ways to make rainbows without the use of a prism. They all require an object that bends the light and separates it into a visible color spectrum.
I'm sure you've seen rainbows formed when using a sprinkler.
Of course they don't always form, because the sun has to be in the right position. So do you and the sprinkler. It also works best when using a fine mist. Make sure to keep your back to the sun and experiment with sprinkler position. Remember the sun must be low in the sky as well.
Another fun way to make rainbows is by lining glasses of water up on a table.
Do this near a window facing the sun. The sunlight will use the water glasses to make rainbows form on the other side of the glasses. They will appear either on the wall or floors, depending on your position and the direction of the sun.
You can also make rainbows without the sun.
Shine a flashlight through a small hole in a piece of cardboard at a glass of water. The flashlight acts as the sun. The cardboard concentrates it's beam. This should make rainbows appear on the other side of the glass on walls or floors as in the sun experiment.
OK, now we all know how to make rainbows and how they are formed.
So, if you're having a bad day, don't whine, pout, cry, or get depressed. Just remember, you make your own rainbows!
Portions of this article were previously published by this author on a now closed Yahoo property.