How Does A Rainbow Form? Cool Color Facts Explained For Curious Kids

Red, orange, yellow, green, blue, indigo, and violet - learn about the phenomenon that brings these different colors together in a rainbow.

Rainbows have been visible on earth ever since the beginning of time. But how exactly does this arc full of light waves appear in the sky?

A rainbow appears in the sky just after rainfall. Most rainbows have seven colors in them. Those are red, orange, yellow, green, blue, indigo, and violet.

These colors of the rainbow vary in shade and intensity depending on the surrounding conditions. It is said that rainbows are an optical illusion. It is true to some extent.

Optical illusion or not, they look extremely beautiful. There are a total of twelve types of rainbows.

They are called RAB 1, RAB 2, RAB 3, RAB 4, RAB 5, RAB 6, RAB 7, RAB 8, RAB 9, RAB 10, RAB 11, and RAB 12. Rainbows are formed only during the daytime as light is the major component in the formation of rainbows.

Let’s find out what exactly happens that leads to the formation of a rainbow in the sky.

After understanding the role which water droplets perform for different rainbow colors, do check how does rain form, and how do trees grow. 

How does a rainbow form?

The formation of the rainbow is an astonishing phenomenon. We observe a bent, colorful arc high up in the sky and we feel fascinated. This magical visual is a result of a combination of a few scientific phenomena.

Thus, rainbows formed have nothing to do with magic but everything to do with science. It's beautiful how the white light is split into a spectrum of seven colors.

We see that the rainbow is always bent and never straight. This is because rainbows are only formed at an angle of 42° from the sun. The white light undergoes a series of processes to show the beautiful arc.

Rainbows are always formed away from the sun. To observe a rainbow you will have to stand with your back facing the sun. Rainbows are visible just after rainfall in the sky. Raindrops are suspended in the atmospheric air which acts as glass prisms. Sunlight passes through these water droplets at an angle and forms the rainbow.

Sunlight enters the water droplets at a specific angle. On entering, the light gets refracted. Refraction is the phenomenon in which light changes its course on entering another medium. Because of refraction, the white light gets split into seven components.

These rays then get reflected on the opposite wall of water droplets. Reflection is the process when the light gets reflected from a surface. After reflection, the rays again undergo refraction.

Amongst all this, lights get dispersed according to their wavelengths into seven different colors. As a result, you see a rainbow suspended mid-air.

For every person the position of the rainbow is different. If person A is seeing the rainbow exactly near the tower then person B will not see it there. For them, the rainbow might be towards the left of the tower.

How rainbows are formed is an example of what?

Now that we have discovered the answer to the question 'how are rainbows formed?' Let's see what a visible rainbow is an example of. Rainbows are the best example of optical illusion.

The way a rainbow appears through the raindrops by light rays casting a spectrum is a perfect optical illusion. There are several physical phenomena involved in the formation of rainbows. Thus, rainbows prove to be the perfect examples of all these scientific phenomena.

Sunlight as a whole is white light. It enters the water droplets and gets refracted. Thus, rainbows are an example of the refraction of light.

The refracted light gets scattered according to different wavelengths, with shorter wavelengths at the top and longer wavelengths at the bottom. That is why the red light is at the top of the rainbow. Thus, rainbows are examples of the scattering of light.

The light which has entered a water droplet also undergoes reflection. Thus, rainbows are examples of reflections of light.

The atmospheric water droplets act as glass prisms. Glass prisms give similar effects when white light enters the prism at a specific angle. To summarize, how rainbows are formed is an example of optical illusion, refraction of light, scattering of light, and reflection of light.

How does a double rainbow form?

The rarest rainbow on Earth is the double rainbow. Double rainbows have two rainbows lined one above the other. They are called primary rainbows and secondary rainbows respectively. The colors of primary rainbows are brighter as compared to the secondary rainbows. The colors of secondary rainbows look more pastel.

This unique display of spectrum is observed because sunlight bends at two different angles within a single water droplet. The most amazing fact about double rainbows is that the colors of the second rainbow are in reverse order, violet, indigo, blue, green, yellow, orange, and red.

Right after rainfall, when raindrops are suspended in the air, sunlight gets refracted and reflected through them and produces a beautiful atmospheric rainbow that bends just like an arc. A double rainbow is observed when the sunlight that has been refracted undergoes reflection twice inside the water droplet before undergoing refraction as the light rays exit the water droplet.

Due to this double reflection at two different angles, two rainbows are formed in the sky with one of them being in the reverse order.

The reflected light rays undergo reflection once again at another angle when the size of the water droplet is large. It gives more room for the movement of light waves.

During the visual effect of double rainbows, the spectators see the violet light from the water droplets positioned higher in the air and the red light from water droplets positioned lower in the air.

Has anybody ever found the end of a rainbow?

The end of a rainbow is a mythical concept adapted in several fairy tales. No one, to date, has been able to find the end of the rainbow. Now, just because no one has found it does not mean that it doesn't exist.

You are absolutely right. But the thing with rainbows is there have to be specific formations for the rainbow to be visible to the human eye. Without proper orientation, it is impossible to see a rainbow, let alone find its endpoint. You will move towards the surface of the rainbow's end but you will never reach that surface.

The formation of a spectrum of seven colors in the air is termed a rainbow. Several people have searched grounds with the aim of finding the rainbow's end. But all in vain. Because finding the endpoint of a rainbow from the ground is scientifically impossible.

To observe a rainbow you have to be standing with your back to the sun. The rainbow is visible around the anti-solar point. This is the point where sunlight is minimal.

Light waves enter the water droplets suspended in the air and the sunlight bends to form an arc. All this creates an optical illusion. To effectively observe this optical illusion all the criteria should be met.

So when you start walking towards a rainbow you will find that the rainbow actually seems to be walking away from you. How can you find the end of something which you can't even get close to? The answer is simple: you cannot.

From the ground, the rainbow looks like a semicircle. But if you observe it from an airplane you will find that rainbows are actually a complete circle and a circle has no end.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how does a rainbow form, then why not take a look at bird respiratory systems, or honey bees nests.