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You cannot download interactives. Download and print this coloring page of a famous United States landmark. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. A rainbow is a multicolored arc made by light striking water droplets. The most familiar type rainbow is produced when sunlight strikes raindrop s in front of a viewer at a precise angle 42 degrees.
Rainbows can also be viewed around fog , sea spray , or waterfall s. A rainbow is an optical illusion —it does not actually exist in a specific spot in the sky. The appearance of a rainbow depends on where you're standing and where the sun or other source of light is shining.
The sun or other source of light is usually behind the person seeing the rainbow. In fact, the center of a primary rainbow is the antisolar point , the imaginary point exactly opposite the sun. Rainbows are the result of the refraction and reflection of light.
Both refraction and reflection are phenomena that involve a change in a wave 's direction. A refracted wave may appear "bent", while a reflected wave might seem to "bounce back" from a surface or other wavefront. Light entering a water droplet is refracted. It is then reflected by the back of the droplet.
As this reflected light leaves the droplet, it is refracted again, at multiple angles. The radius of a rainbow is determined by the water droplets' refractive index. A refractive index is the measure of how much a ray of light refracts bends as it passes from one medium to another—from air to water, for example.
A droplet with a high refractive index will help produce a rainbow with a smaller radius. Saltwater has a higher refractive index than freshwater, for instance, so rainbows formed by sea spray will be smaller than rainbows formed by rain.
Rainbows are actually full circles. The antisolar point is the center of the circle. Viewers in aircraft can sometimes see these circular rainbows. Viewers on the ground can only see the light reflected by raindrops above the horizon. Because each person's horizon is a little different, no one actually sees a full rainbow from the ground.
In fact, no one sees the same rainbow—each person has a different antisolar point, each person has a different horizon. Someone who appears below or near the "end" of a rainbow to one viewer will see another rainbow, extending from his or her own horizon. A rainbow shows up as a spectrum of light: a band of familiar colors that include red, orange, yellow, green, blue, and violet.
The name " Roy G. Biv " is an easy way to remember the colors of the rainbow, and the order in which they appear: red, orange, yellow, green, blue, indigo, and violet. Many scientists, however, think " indigo " is too close to blue to be truly distinguishable. White light is how our eyes perceive all the colors of the rainbow mixed together. Sunlight appears white. When sunlight hits a rain droplet, some of the light is reflected. The electromagnetic spectrum is made of light with many different wavelength s, and each is reflected at a different angle.
Thus, spectrum is separated, producing a rainbow. Red has the longest wavelength of visible light, about nanometer s.
It usually appears on the outer part of a rainbow's arch. Violet has the shortest wavelength about nanometers and it usually appears on the inner arch of the rainbow.
At their edges, the colors of a rainbow actually overlap. This produces a sheen of "white" light, making the inside of a rainbow much brighter than the outside.
Visible light is only part of a rainbow. Infrared radiation exists just beyond visible red light, while ultraviolet is just beyond violet. There are also radio wave s beyond infrared , x-ray s beyond ultraviolet , and gamma radiation beyond x-rays. Scientists use an instrument called a spectrometer to study these invisible parts of the rainbow.
The atmosphere opposite a rainbow, facing the sun, is often glowing. This glow appears when rain or drizzle is falling between the viewer and the sun. The sun creates rainbows when white sunlight passes through raindrops.
Here, the raindrops work like tiny prisms that bend the different colors in white light, so the light spreads out into a band of colors that can be reflected back to you as a rainbow. Sunlight is made up of many wavelengths or colors of light.
Every single wave of color has a different length. Usually, some of these wavelengths get bent comparatively more than others the moment the light enters the water droplet.
So when the light exits the water droplet, it is separated into all its wavelengths. We see 7 colors of the rainbow, and they are violet, indigo, blue, green, yellow, orange and red. Red light, for example, has the longest wavelength and only bends at an angle of about 42 degree. Whereas the Violet light has the shortest wavelength and bends at an angle of around 40 degrees before it exits the water droplet. As the wavelength of red light is longer, it mostly appears on the outer edge of the rainbow.
Thus, Red will be on the top and Violet on the bottom. Similarly, the other colors are also ordered as per their wavelength. Likewise, other waves of light are also reflected from the rainbow; however, these light waves are not visible to our naked human eye. Also, these invisible rays are found to be present on both sides of the rainbow. Ultraviolet rays are shorter than violet rays, and x-rays are even shorter than ultraviolet rays.
Gamma radiation normally occurs at the furthest extreme of this side of the rainbow. At the other end of the spectrum is the infrared radiation and radio waves. A professional writer, editor, blogger, copywriter, and a member of the International Association of Professional Writers and Editors, New York.
He has been part of many reputed domestic and global online magazines and publications. An avid reader and a nature lover by heart, when he is not working, he is probably exploring the secrets of life. How do Rainbows Form? Step by Step Process of Formation of a Rainbow The formation of a rainbow is described step by step below: 1. Rainbows are formed when light from the sun is scattered by water droplets e. Refraction occurs when the light from the sun changes direction when passing through a medium denser than air, such as a raindrop.
Once the refracted light enters the raindrop, it is reflected off the back and then refracted again as it exits and travels to our eyes. Sunlight is made of many different wavelengths, or colours, that travel at different speeds when passing through a medium. This causes the white light to split into different colours. Longer wavelengths appear as red and shorter wavelengths appear as blue or violet.
We see the colour spectrum of the rainbow as the light passes through the raindrop at different angles of approximately two degrees, from red to violet.
This is not a true spectrum as the colours mix and blur throughout the spectacle. The angle of scatter from raindrops is different for everyone which means that every rainbow is unique to the observer. However, for the observer to see a rainbow, they must be in a specific position relative to the sun and water droplets -.
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