what is the actual reason for formation of rainbow?

Answer 1

First to understand why rainbow have colors or how they get their colors, you will need to know that white light is made up of a spectrum of colors that exhibit the characteristics of a wave. To be more specific, white light ( e.g. the Sun’s light) is made up of wavelengths of different colors of light.This phenomenon can be explained and was demonstrated by mathematician and scientist Sir Isaac Newton 1642-1727 by letting a beam of sunlight (white light ) passing through a prism. He showed that the sunlight is composed of several different colors, (Red, Orange, Yellow, Green, Blue, Indigo and Violet in that order respectively) that human eye doesn’t see separately.
The colors are produced by a phenomenon called dispersion. When white light passes through a prism, it scatters (disperse) the different colors of light according to their wavelength or frequencies, showing a continuous band of colors (called a spectrum) as it travels from one medium (e.g. prism) to another (e.g. air). These different colors of light have all slightly different directions and so display each color components of white light. Thus, the angle of bending is different for different wavelengths of light. This band of colors appears in the same pattern as the colors of a rainbow. This means, all the different colors of light (red, orange, yellow, green, blue, indigo and violet) combine to give you what is called white light. These colors, based on their wavelength, are arranged in the order shown above when they are being scattered. The longest wavelengths of light are on the red end of the spectrum and the shortest wavelengths are on the violet end of the spectrum.

How Rainbows Are Formed/What Causes a Rainbow?

The principle explained above can be applied to how rainbow is formed in the sky. When there are water droplets in the atmosphere for instance, during or immediately following a shower of rain, there will be thousands of these tiny droplets (raindrops) floating around in the air. When light from the Sun encounters a water droplet (spherical in shape), it penetrates the outer boundary of the droplet. As it enters, the light is bent (refracted) and scattered (disperse) into a continuous band of colors (a rainbow of colors). These colors are then reflected from off the back of the drop again as they pass through the front of the drop once more, thus being bent (refracted) still some more. These continuous band of colors as explained above, is due to the fact that the angle of bending is different for different wavelengths of light. This explains the reason for the appearance of the band of colors which is due to their wavelength. There you will always see the colors of a rainbow in the following order of colors; Red, Orange, Yellow, Green, Blue, Indigo and Violet. Red is refracted the least, and violet the most. The other colors are found between these two. Blue light has a shorter wavelength than that of red light because it as a longer wavelength and thus, is refracted more. Therefore resulting a blue light to be located in the inner section of the rainbow and red light to be located in the outer section of the rainbow. This same principle explains the reasons for the order in which the different colors of light appears in a rainbow.
A rainbow is always directly opposite the sun from the observer. That is, the rainbow appears in front of the observer, whose back is to the sun. Therefore the rainbow that the observer will see in the sky will caused by thousands of water droplets acting like thousands of tiny prisms resulting the different component colors of white light (sunlight) to be displayed. Each falling water droplet (raindrops) flashing its colors to the observer for just an instant, before another drop takes its place letting the rainbow appearance remain constant to the observer. The rainbow's location will appear different for observers at different locations, but it is always directly opposite the sun. This means another observer will not see the rainbow if the sun is not behind that person. So, it will all depend on the angle of the Sun in the sky in relation to where you are, providing that enough water droplets are in the atmosphere for you to see this effect. This will not work if the sun is directly over head. Looking on the diagrams you will see why rainbows are only seen when the sun is low in the sky, usually in the late afternoon. It is also important to note that the rainbow is light reflected to the eye at an angle of 42 degrees to the original ray of sunlight. This implies that when we see a rainbow at the 42 degree angle, it is measured from each observers eye thus therefore, no two persons will see exactly the same rainbow.

Answer 2

Sandevyl’s answer is inaccurate in many ways. Most of the inaccuracies are caused by trying to compare rainbows to the spectrum produced by prisms. While related, the two processes are quite different.

The word “dispersion” is a bit of a misnomer. It doesn’t only mean that the colors separate, it means that the angles depend on the color. And while the colors striking a raindrop do separate, they separate differently from different parts of the raindrop and, for the most part, end up re-combining into white light.

What actually happens is that each raindrop reflects the sunlight back towards the sun, like the beam of a wide flashlight. The width of this beam varies with color – 40 degrees for violet light, and 42 degrees for red. What’s more, each beam is significantly brighter at the very edge. When you look away from the sun under rainbow conditions, if you look 42 degrees away from your shadow, you see only raindrops that reflect very bright red light to you. At 41 degrees, you see very bright green, bright yellow, moderate orange, and faint red. What you perceive is green because the green is so bright, but it is a paler green than you would see from a prism. The violet is paler still. And while you can find the outer (red) edge of the rainbow quite easily, the inner (violet) band does not seem to have an edge at all – it fades to gray.

In a double rainbow, the same thing happens, but the reflected beam is pointed away from you. And it is between 127 and 130 degrees wide. Since this is more than 90 degrees, the beam “wraps around” the top of the sky so that you can see the bright edge of each color’s beam while looking away from the sun. Alexander’s Band is the area that is not in either the primary, or secondary, beam.

Answer 3

First you must know that the light from the sun is asctually made up of 7 visible wavelengths(colours) and also uv and infraredred rays. For a rainbow to form it must be near the horizon and the sun's light must fall either directly on the raindrops or on the treetops/ rooftops and this reflects/refracts light in such a way that a rainbow is usually seen. Most of the time when it rains, rainbows don't form. The reason for this is that rain may have occured only in a small area and/or the rainbow formed is so weak that it is not properly visible.

Answer 4

Rainbows are a striking and beautiful meteorological phenomenon caused by the refraction of light. In order for rainbows to form, the sun must be near the horizon, and there must be a heavy fog, mist, or rain opposite the sun. An observer standing between the sun and the rainbow would see a 180 degree arc of colors which run through the visible spectrum from red to violet. In some cases, if conditions are right, double rainbows will form, with a pale rainbow in reversed colors above the primary rainbow, and in other instances, a fully circular rainbow has been observed, usually from inside an aircraft flying over the Earth.

Although rainbows have been observed, written about, and depicted in art for centuries, their cause was not understood until physics began to explore the properties of light. Essentially, the cause of a rainbow is the reflection of sunlight through individual drops of water. Light enters the water and reflects from the opposite side of the water drop, bouncing back through the point of entry. Because the angle or refraction of the light changes as it bounces back, it filters the light into different colors, which arrange themselves with red at the top and violet at the bottom because red is the longest wave length, and violet is the shortest.

When double rainbows form, the light refracts twice, causing a fainter rainbow to mirror above the primary one. Potentially, a triple rainbow could form as well, although it is extraordinarily rare. As soon as the water dissipates enough or the sun moves, the rainbow will disappear, because conditions are no longer optimal for the refraction of the light through the drops. It is also possible for a moonbow to form, although because humans have difficulty distinguishing color in the dark, it usually appears in shades of white and gray.

Answer 5

What Causes A Rainbow

Answer 6

White light passing through a water droplet is separated into various visible wave lengths .You can make a rainbow with a water hose. Spray water upward and a person on the opposite from the sun can see a small rainbow.

Answer 7

The Higgs Boson particle (an excitation of the Higgs field, like light from an electromagnetic field) has nothing to do with the beginning of the universe. The Higgs field is assumed to be the cause of Mass. According to the standard model, the Higgs field exists and Mass is not an intrinsic property of matter. The Higgs field has never been proven experimentally, only theoretically (until July 2012, they weren't making much progress). String theory has to do with the multiverse idea, but it can coincide with the big bang. To answer your question: The Big Bang theory is the most widely accepted theory for the "beginning" of the universe. It hasn't been proven, though, nor do I think it ever will be.

Answer 8

Light from the sun gets defracted by the tiny water molecules present in cloud. This defracted light at different wavelength (VIBGYOR) are what we perceive as rainbow. This is a simple answer to a relatively complex process of the rainbow creation.

Answer 9

well i agree with some of the ppl
who have written above me

but i just passed high school and want to give that level of answer

when it has rained recently the humidity in the air is present so that means water is present in the air

and when the sun comes up the light RAYS hit the water droplets and get REFRACTED

which means they get bent due to the dense water or humidity on the rare or lighter air

since light has seven colours and the medium is wide and spread apart

the light gets converted to seven rays not only one colour

Answer 10

According to the bible, the first rainbow was made after the great flood (you know, Noah). It was a sign from God that s/he would never destroy life on earth again, a covenant to humans.