Sep 23 2014
Visible spectrum, radio waves, ultraviolet rays, x-rays, gamma-rays, microwaves and infrared light are various electromagnetic radiations which belong to the electromagnetic spectrum.
The visible spectrum is a small portion in the electromagnetic spectrum that is visible to human eyes. The visible spectrum range is from 780 to 390 nm. Color evolves from light that is made up of different wavelengths or frequencies. The differences in frequencies provide the different colors.
| Visible Light Spectrum |
| Color |
Wavelength (nm) |
| Red |
625 – 740 |
| Orange |
590 – 625 |
| Yellow |
565 – 590 |
| Green |
520 – 565 |
| Cyan |
500 – 520 |
| Blue |
435 – 500 |
| Violet |
380 – 435 |
The connection between the visible spectrum and color vision was analyzed in depth by Thomas Young and Hermann von Helmholtz in the early 19th century. They presented the theory of color vision in which they proposed that the human eye uses three distinct receptors to perceive color.
The visible spectrum is subdivided according to color, with red at the long wavelength end and violet at the short wavelength end. This can be clearly seen in a rainbow, which displays the visible part of the electromagnetic spectrum. Similarly, it can also be seen when white light is passed via a prism and the prism splits it up into the several colors of light.
Visible light is a type of non-ionizing radiation that is not harmful to humans unlike ultraviolet rays and X-rays. Due to visible light, reflection and refraction, and interference and diffraction can be easily observed.
Visible light has been studied in detail using mirrors, lenses, prisms, diffraction gratings, and spectrometers.
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