It’s rare to find anyone who does not marvel at the sight of rainbows.The beautiful phenomena with different colors mixed together are a sight to see. Sometimes the inner edge has a blue light, sometimes it’s red.The earth’s surface is made more beautiful by a rainbow. Sometimes, you would find rainbows in places other than the sky also. For instance, you might find rainbow patches in the road, which raises the question, how are rainbows formed? Are the rainbow formations that happen in the sky and the ground the same? We can only answer this if we are aware of rainbows and their formation. So, let us find out how the rainbow formation happens, both in the sky and the road. Afterwards, also check facts about are rainbows real and full rainbow.Why rainbows are curved?Have you ever looked at the rainbow and wondered why it is curved and not straight? If you take a full circle rainbow and cut it in half, that is exactly how the rainbow looks. What gives it a half-circle shape?As you all know, light and water drops cause a rainbow. For the observer’s eye, the rainbow is half of a circular arc. But in reality, the rainbow is not exactly curved. It is in fact a full circle. The full circle rainbow is not visible to the human eye due to the horizon blocking our view. When you look at it from a different angle, that is to say, from an airplane or something the full rainbow will be visible in its full circle glory.The completed circle of rainbows happens because of the refraction of water droplets and the reflection of light. That is, when the sunlight hits each water droplet, it breaks down into its component colors. The light is reflected and the various colors bounce back. The water droplets make the dispersed light concentrate at an angle of deviation at 400-450 from the original position of the light path from the sun.Some of the light rays that enter into the water droplet get refracted, which causes the rainbow to have a curved appearance. The circular arc that these rainbows form as water droplets that disperse light and reflect it back to the observer’s eye. Due to the existence of the horizon, the only part of the full circle rainbow is the circular arc that is visible to you. which is why the rainbow appears to be curved for the human eye.The Formation Of The RainbowNow that we know why the rainbow appears curved for us, the next question would be how these curved rainbows are formed? What are the steps of rainbow formation?The formation of the rainbow includes various phenomena working together. It is a collective result of the interaction between sunlight, water, and air. Primarily, the white light from the sun would hit the water droplets. The light rays hit the water droplets at a certain angle. This angle determines whether or not there will be a visible spectrum of the rainbow. Sometimes, the light hits the water droplet at an angle that does not form a visible rainbow. That is why you won’t see a rainbow every day.When the light ray hits the water droplet, it is reflected. The reflection happens to some light rays only, the other light gets refracted. The reduction of speed of the light when it moves from the air to the denser water is what causes this refraction. Since it is the white light of the sun hitting the water droplets, the light can split into different colors. White light is made up of various colors.The change in medium and speed causes the colors of the light waves to split forming the rainbow colors. The color splitting is known as dispersion. Thus, due to the combined work of reflection, refraction, and dispersion, one can see the beautiful rainbow.The Path Of Light Through A DropletSo, the sunlight hits the water vapor, and the rainbow forms. But as we know by now, the process is not that simple. When the light from the sun hits the water droplet, what is happening inside? How does the light travel through the water surface?The path of light through the water droplet can cause primary and secondary rainbows. In both these rainbows, the path of light is a bit different. In the primary rainbow, the light goes through refraction when it hits the water surface of the droplet and then goes into the water droplet. When the light ray hits the back of the water droplet, it undergoes another refraction.When the light comes out of the droplet, the violet light is more bent than other colors of the visible light. The red light, which is least bent, appears at the top of the primary arc of the primary rainbow. There is an angle of 400-420 of the visible light from the antisolar point. In the case of a primary rainbow, it is two refractions and one reflection. But for a secondary rainbow, it is two refractions and two reflections.The light refracts when entering the droplet and this light undergoes two reflections inside the water droplet before coming out. Also, the angle is 10 degrees more for a secondary rainbow. That is, the visible light forms an angle of 520 from the antisolar point. Another main difference in a secondary rainbow is that the color order is reversed in these rainbows. The red light appears at the bottom and violet light is seen at the top.The secondary rainbow appears lighter in the sky also. The secondary rainbow appears dull than a primary rainbow due to the two reflections that it goes through. The light source intensity is reduced by the second reflection. The secondary rainbow is also called double rainbows. Sometimes both primary and secondary rainbows take place together to form a twinned rainbow.Rainbow On The RoadAfter a rainy day, you might have come across a rainbow on the ground. Since it is rare to see rainbows at ground level, let us understand why such a thing happens. Heads up, it is just liquid water, some oil and light working its magic.On the road, there will always be some quantities of oil coming out from vehicles. On a rainy day, water gets mixed with the oil in the road. Since oil and water do not mix together, a thicker layer of oil is seen above the water surface. The light comes in contact with air, oil, and water in this case. Some of the light that hits the oil gets reflected immediately while the others get refracted and later get reflected back.Since the difference traveled by the light varies for some, all this light gets mixed together to form after reflection. The light with different distances gets mixed together to form various colors in the road. That is how a reflected rainbow is formed in the road. The rainbow formed in the road is a result of the phenomena of constructive and destructive interference, which we have described in simple words.Higher-Order RainbowsThe two types of common and familiar rainbows are primary and secondary rainbows. But, these aren’t the only rainbows that are seen in the atmosphere. There are tertiary and quaternary rainbows. In other words, higher-order rainbows. These are rare yet rainbows that exist. How are these rainbows formed?We have discussed how there are two reflections inside the water droplet for a secondary rainbow. In the same way, a higher-order rainbow will have more than two reflections inside the water droplet. Depending on the number of reflections, the order of the rainbow changes. The scattered light will get dimmer with each reflection so in these higher-order rainbows the red light or blue light may not be so visible like the primary bows and secondary rainbows. The higher-order rainbows are also often confused with reflection rainbows. The reflection rainbow is not a higher-order rainbow, it is merely the primary rainbow that has been reflected by the water. Higher-order rainbows, on the other hand, are formed when light reflects more inside a water droplet. Till this day, up to five orders of the rainbows have been visible but it is possible for more to happen.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for rainbow on the ground then why not take a look at types of rainbows, or rainbow symbolism.
It’s rare to find anyone who does not marvel at the sight of rainbows.
