Why is visible light arranged into colors in order: red, orange, yellow, gree, blue, indigo, and violet?
Because that part of the electromagnetic spectrum moves from the longest wavelengths (red) to the shortest wavelengths (violet). As the wavelength changes our eyes perceive different wavelengths as different colors. Actually, our eyes see the light, a chemical change takes place, and energy is sent by the optic nerve to the brain which perceives the signal as objects and colors. If you are interested in that aspect of light, look up cis/trans isomerism and how that affects the rhodopsin in the eye.
Ah, the colorful world of visible light! Well, rumor has it that back in the day, when the universe was still in its artsy phase, it decided to organize light into a fashionable rainbow spectrum. Its best friend, the optical prism, was the ultimate stylist who lined up colors in a ROYGBIV order: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. You know, just to keep things visually stunning and, of course, to give Roy and his friends Roy, Gbi, and Vivian a chance to show off their individual flair. It's basically nature's way of giving us a fabulous light palette to admire and appreciate! 😄
Visible light is arranged into colors in the order of red, orange, yellow, green, blue, indigo, and violet because of the phenomenon known as dispersion. Dispersion occurs when light passes through a medium, such as a prism or water droplets, and is separated into its constituent colors based on their different wavelengths.
The light that we see is made up of a range of wavelengths, with each wavelength corresponding to a different color. When white light enters a prism, it is refracted or bent as it passes through the prism. However, different colors of light are refracted at slightly different angles due to their different wavelengths.
The longer wavelengths, such as red, have a lower frequency and are less bent as they pass through the prism, while the shorter wavelengths, such as violet, have a higher frequency and are more bent. As a result, the red light appears to be on one side of the spectrum and the violet light on the other side, with all the other colors in between.
The order of the colors, from red to violet, is often remembered using the acronym ROYGBIV. Although indigo is sometimes included in the spectrum, it is essentially a sub-category of blue and was added by Sir Isaac Newton to match the number of musical notes in an octave.
The visible light spectrum consists of light waves that vary in wavelengths. When light passes through a prism, it refracts or bends, causing the different wavelengths to separate. This separation results in the colors of the rainbow, commonly known by the mnemonic device "Roy G. Biv" (Red, Orange, Yellow, Green, Blue, Indigo, Violet).
To understand why visible light is arranged in this specific order, it's helpful to examine the principles of color perception and light wavelengths.
Light waves with longer wavelengths, such as red, tend to bend less when passing through a prism, while light waves with shorter wavelengths, such as violet, tend to bend more. Thus, when white light passes through a prism, the longer red waves are bent the least, followed by orange and yellow, while the shorter violet waves bend the most.
It is important to note that the concept of indigo being a separate color is somewhat debated. Sir Isaac Newton, who first described the visible light spectrum, included indigo as a distinct color to fit within the framework of seven colors. However, the distinction between indigo and blue can be somewhat arbitrary and subjective.
In summary, the arrangement of colors in the visible light spectrum is based on the varying wavelengths of light and the way they refract when passing through a prism, creating the familiar sequence of colors from red to violet.