Why Do We See Rainbows After Rain?


29 Answers

Anonymous Profile
Anonymous answered
As many of you will probably have seen, a rainbow generally appears when it has been raining and the sun comes out. The reason we see a multitude of beautiful colours in the sky is the result of the sun rays shining through the raindrops at different angles and splits into different colours.
A rainbow is actually an optical illusion. When the sun shines onto the droplets of water, it acts like a prism and takes on the form of a multi-coloured arc with red on the outside and violet on the inside. A double rainbow is when a second, fainter arc with the colours in the opposite order.

Even though a rainbow goes over a spectrum of colours, traditionally the full sequence of colours is most commonly cited as red, orange, yellow, green, blue, indigo and violet. Many people believe that because rainbows are magical and have some special reward at the end, such as a croc of gold. However, although they might appear magical to us, as far as I am aware, they don't have a special surprise at the end of them – although I can't say I've ever reached the end of a rainbow.
Grant Kensington Profile
Light is made up of many different colors, all of which have a different wavelength. Normally when we see light from the sun it appears colorless. So how is it that colorless light gives us colors? What makes a rainbow?
The Spectrum of Colors Sunlight is made up of the whole range of colors that the eye can detect. The range of sunlight colors when combined looks white to the eye. Light of different colors is refracted, or bent, by different amounts when it passes from one transferring medium, like air, into another medium, like water or glass. If you take a prism, you see a spectrum of colors. The band of colors that appears is red, orange, yellow, green, blue, indigo, and violet. The Location of the Sun
When you see a rainbow you first have to keep in mind the position of the sun relative to you, the observer of the rainbow. This physical process is what gives rise to a rainbow. When you see a rainbow the sun is always behind you; when you face a rainbow, the center of the circular arc of the rainbow is in the direction opposite to that of the sun. The Location of the Rain
If the sun is behind you, the rain is in the direction of the rainbow in front of you. To create the rainbow, you need raindrops.
Raindrops Because a typical raindrop is spherical, its effect on sunlight along the axis is symmetrical along the center of the drop. This symmetry creates a focusing effect for each drop such that whenever we view a raindrop along the line of sight defined by the rainbow ray, we will see a bright spot of reflected, refracted, sunlight
E Jacobson Profile
E Jacobson answered
Rainbows occur after rainfall or near a huge waterfall or fountain) because what we are seeing is sunlight which is being refracted by raindrops or drops of water.

Refraction is when light is bent, as is is passing from one medium to another.  So with a rainbow we have light from the sun which is basically being seen through water, millions of tiny droplets usually.  The arch of the rainbow is because it is bening bent over a series of angles.

The reason that we see red, orange, yellow, blue, indigo and violet is because it is a near continuous spectrum of light in the sky.

Frequently rainbows are actually double rainbows, although the second rainbow may not always be ver visible.  The second is always much fainter than the first and the colours bend round in the opposite direction, namely violet to red.

Various cultures have beliefs or myths about rainbows, from the 'pot of gold' at the end of the rainbow, to more ancient beliefs.  For example in Norse Mythology a rainbow connects the homes of the Gods to the land of the humans !
Anonymous Profile
Anonymous answered
What is a rainbow?

A rainbow is merely a large band of parallel stripes, blended at the rims, which displays the full spectrum of colors that make up the sun's white light. This brilliant display appears to the naked eye when the sun's light breaks up as it passes through, the prism-like raindrops during a rain-shower.

This immense, curved spectrum of light appears only when both the elements of sunshine and rainfall present. As the sunlight enters the falling raindrops, it breaks up into its true colors of red, orange, yellow, blue, and violet. These colors are always arranged according to their wavelengths, with red being at one end of the spectrum, and violet at the other. Once inside the droplet, the particles of colored light bounce from side to side, reflect off of the far side of the droplet, exit the droplet, and reassemble, according to their wavelengths, to form a rainbow.

Simply because you happen to be in the right place at the right time, when both elements necessary to form a rainbow are present, does not mean that you will actually see one. For the human eye to see these multi-colored bands, ranging from red to violet, his body must be strategically positioned between the sun and the rain, with his back to the sun.

If the sun, the eye, and the center of the rainbow's arc are not in a straight line, the show is over, before it began. This explains why we only see rainbows in the early morning or late afternoon…it is physically impossible for us to align our eyes with the sun at other times of day, as it is high above our heads! Logically, a morning rainbow appears when the sun shines in the east, and the rain falls in the west, and an afternoon rainbow appears when the sun shines in the west, and the rain falls in the east. If lucky, and a bit superstitious, and you do find a pot of gold somewhere over the rainbow, please let us know. After all, we gave you the directions!
Zeke Zepplin Profile
Zeke Zepplin answered
Ordinary white light, like that from the sun, is made up of many different colors all of which have a different wavelength.  Normally, when we see light from the sun, it appears colorless.  However, Isaac Newton discovered in 1666 that when he passed regular sunlight through a prism (basically, a triangular piece of glass), the prism would split the light up into a band of colors.The band of colors is called the spectrum which appears in the order of red, orange, yellow, green, blue, indigo, and violet.When it rains, the air is filled with raindrops.  These raindrops act like a prism.  If sunlight passes through the raindrops at the proper angle it is split into its spectrum, which is made up of the colors of the rainbow.You can make your own rainbow at home by filling a plastic box with water and placing it near a sunny window.  If the wall next to the window isn’t white, place a piece of white paper next to the window.  Next, place a mirror inside the box of water facing the window.  The mirror needs to be tilted towards the sunlight.  The wedge of water in the front of the mirror acts as the prism and the mirror reflects and image of a rainbow on your wall.
sadman hoque Profile
sadman hoque answered
That is because the rain drops act like a prism and break the white light coming from the sun into the seven colors of the rainbow.
Anonymous Profile
Anonymous answered
A rainbow is the refraction of light.  Refraction is the bending of light ever so slightly which results in the colors of the rainbow.
Anonymous Profile
Anonymous answered
Rainbows appear after rain because the rain acts like a type of mirror and reflects the sun which makes rainbows. Even strangers are smart!!:)
Muddassar Memon Profile
Muddassar Memon answered
A rainbow is a visual and Metrological occurrence that causes a constant occurrence of light in the sky when the sun shines on droplets of moisture on the earth's surface.

Though a rainbow has a spectrum of colors the most common ones seen are red, yellow, green, orange, blue, indigo and violet.

A rainbow effect can be seen whenever there are water drops in the air and there is sunlight shining from behind the observer at a low height and angle. The effect is also commonly seen near waterfalls or fountain. It can also be created in an artificial manner by dispersing water droplets in the air during a sunny day. The best rainbow can be seen when the sky is partially dark. The rainbow is a multi colored arc with the color red on the outside and is violet from inside.
Joe Joe Profile
Joe Joe answered
I don't mean to be bias but I believe that rainbows appear because in the beginning, after there was a huge flood in the world, God promised that there would never be a flood to destroy all life on the planet. And to seal the deal, he created rainbows. He did that so that everytime we would look upon rainbows, we would remember the promise.

Scientifically, (and I just looked this up on the interent), it happens when the rays of the sun hits the droplets of water in the atmosphere of the Earth.
Mateen Raja Profile
Mateen Raja answered
We see rainbows after rain because after rain some drops stays still in the air due to their very small weight and due to these drops , when light passes through them it bends the path of itself.The process of bending of path of light is called Refraction and it occurs when light or another type of ray enters from rarer (whose density is less) medium to the denser (whose density is greater than the earlier) medium.We are able to see seven colours in the rainbow because when rays of light passes through the drops of water , the drops of water acts like a prism (which splits up the light) and they splits the white light coming from sun into seven different colours.So they collectively make a beautifull Rainbow.
tamee kaper Profile
tamee kaper answered
We only usually see them during rain and sun- however there are rainbows in the skies at all times... I learned this due to my obsession with Charmed.
Anonymous Profile
Anonymous answered
Because rain and sun come before the rainbow.The sun and rain mix together to make a bunch of colors and we named it a rainbow.
Adella Svit-Kona Profile
A rainbow is light broken up, so much that it divides and you can see all of the colours that make up light. Diamonds break up light, and so does rain. That's why you see a rainbow after a rain storm.
Fauluz Genjen Macabasco Profile
@ Ceri_o:
I just loved what you've said...
"We each see our very own rainbows. Any other person seeing it at the same time is seeing it from a slightly different position, so is actually seeing a different rainbow. No two people can see exactly the same one, as no two sets of eyes can be in exactly the same place at the same time, so, when you see a rainbow, it is your very own rainbow."
Anonymous Profile
Anonymous answered
Adding to the previous answer: The light is refracted by some form of water in the air (such as a raindrop after it rains)
Anonymous Profile
Anonymous answered
It is due to the dispersion of the light from the sun, as it passes through all the raindrops from the clouds.
Anonymous Profile
Anonymous answered
I think that a rainbow occurs because light gets broken up into piece and forms different colors
Mohith H Profile
Mohith H answered
Because what we are seeing is sunlight which is being refracted by raindrops or drops of water.
Anonymous Profile
Anonymous answered
Pretty good question actually, in my pre ap english class we are talking about this.
I was trying to find out myself and now I have a pretty good idea..
Thanks. :)
Anonymous Profile
Anonymous answered
Because is a biology environment that we see after it basically something weird that people don't know how to define them.

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