What is light?
Electromagnetic radiation is a form of energy. Radio waves, microwaves, X-rays and gamma rays are some of the forms of electromagnetic radiation. Sunlight is also a form of electromagnetic energy, but visible light is only a small portion of the spectrum, which contains a broad range of electromagnetic wavelengths.
Who discovered light?
Aristotle was responsible for one of the first theories of light. He stated that, “The essence of light is white light. Colors are made up of a mixture of lightness and darkness.” However, It was Sir Isaac Newton who conducted several experiments to understand light. And how light is composed of several wavelengths. In his book, Optiks, Newton describes how he used prisms to disassemble and reassemble light.
Wavelength of visible light
Visible light falls in the spectrum between infra red and ultra violet, the wavelengths easily visible to the human eye. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers.
How do we perceive color?
Cone-shaped cells in our eyes act as receivers tuned to the wavelengths in this narrow band of the spectrum. Other portions of the spectrum have wavelengths too large or too small and energetic for the biological limitations of our perception.