Editing Electromagnetic spectrum (section)

=== Visible light ===
{{Spectral colors simple table|colour=y}}
{{Main|Visible spectrum}}

Above infrared in frequency comes [[visible light]]. The [[Sun]] emits its peak power in the visible region, although integrating the entire emission power spectrum through all wavelengths shows that the Sun emits slightly more infrared than visible light.<ref>{{cite web|url=http://rredc.nrel.gov/solar/spectra/am1.5/|title=Reference Solar Spectral Irradiance: Air Mass 1.5|access-date=2009-11-12|archive-date=2019-05-12|archive-url=https://web.archive.org/web/20190512190812/https://rredc.nrel.gov/solar//spectra/am1.5/|url-status=live}}</ref> By definition, visible light is the part of the EM spectrum the [[luminosity function|human eye]] is the most sensitive to. Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another. This action allows the chemical mechanisms that underlie human vision and plant photosynthesis. The light that excites the human [[visual system]] is a very small portion of the electromagnetic spectrum. A [[rainbow]] shows the optical (visible) part of the electromagnetic spectrum; infrared (if it could be seen) would be located just beyond the red side of the rainbow whilst [[ultraviolet]] would appear just beyond the opposite violet end.

Electromagnetic radiation with a [[wavelength]] between 380 [[nanometre|nm]] and 760&nbsp;nm (400–790 terahertz) is detected by the human eye and perceived as visible light. Other wavelengths, especially near infrared (longer than 760&nbsp;nm) and ultraviolet (shorter than 380&nbsp;nm) are also sometimes referred to as light, especially when the visibility to humans is not relevant. White light is a combination of lights of different wavelengths in the visible spectrum. Passing white light through a prism splits it up into the several colours of light observed in the visible spectrum between 400&nbsp;nm and 780&nbsp;nm.

If radiation having a frequency in the visible region of the EM spectrum reflects off an object, say, a bowl of fruit, and then strikes the eyes, this results in [[visual perception]] of the scene. The brain's visual system processes the multitude of reflected frequencies into different shades and hues, and through this insufficiently understood psychophysical phenomenon, most people perceive a bowl of fruit.

At most wavelengths, however, the information carried by electromagnetic radiation is not directly detected by human senses. Natural sources produce EM radiation across the spectrum, and technology can also manipulate a broad range of wavelengths. [[Optical fiber]] transmits light that, although not necessarily in the visible part of the spectrum (it is usually infrared), can carry information. The modulation is similar to that used with radio waves.