n. (context physics English) The portion of the electromagnetic spectrum which is visible to the human eye.
n. the distribution of colors produced when light is dispersed by a prism [syn: color spectrum]
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 700 nm. In terms of frequency, this corresponds to a band in the vicinity of 430–770 THz.
The spectrum does not, however, contain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink, or purple variations such as magenta, are absent, for example, because they can be made only by a mix of multiple wavelengths. Colors containing only one wavelength are also called pure colors or spectral colors.
Visible wavelengths pass through the " optical window", the region of the electromagnetic spectrum that allows wavelengths to pass largely unattenuated through the Earth's atmosphere. An example of this phenomenon is that clean air scatters blue light more than red wavelengths, and so the midday sky appears blue. The optical window is also referred to as the "visible window" because it overlaps the human visible response spectrum. The near infrared (NIR) window lies just out of the human vision, as well as the Medium Wavelength IR (MWIR) window, and the Long Wavelength or Far Infrared (LWIR or FIR) window, although other animals may experience them.
Usage examples of "visible spectrum".
She was strangely and wonderfully blind, for she could see in the infrared only, from 7,500 angstroms to one millimeter wave lengths, far below the normal visible spectrum.
The five megajoules of energy involved in the test, however, meant that even the least amount of reflection raised an unacceptable risk of blindness and worse if the operation were in the visible spectrum or shorter.
These final torchships came ripping out of the K-star at high boost, their fields venting heat on the visible spectrum, two blazing, white-hot proto-stars spit out from their massive parent, both ships trying to close on the task force that even now was ripping through the system at three-quarters light-speed.
And the viewscreen came alive, filled for those first moments only with a swirling rainbow that occupied the entire human visible spectrum and a few extra angstroms on either side.
To the unaided eye, stars ahead tended to vanish off the upper end of the visible spectrum, while those astern red-shifted off its bottom.
There was one trouble here for Lord Schleim: each time that devil moved it made lights flash off his buttons, and Tolneps had to wear filters to convert to ordinary visible spectrum, so every flash of a button overwhelmed the power of the filter and he was getting a headache.
But because long wavelength light is scattered less than blue, at the extreme red end of the visible spectrum –.
Objective flashes are masses of energy moving through the visible spectrum.
Again, color changing might be far more complex than it appears to be in just the visible spectrum, but the Talin haven’.
By expanding his visible spectrum into the infrared and ultraviolet he could see new, bright stars whose names he did not know.