The Munsell color system, showing: a circle of hues at value 5 chroma 6; the neutral values from 0 to 10; and the chromas of purple-blue (5PB) at value 5. Several earlier color order systems had placed colors into a three-dimensional color solid of one form or another, but Munsell was the first to separate hue, value, and chroma into perceptually uniform and independent dimensions, and was the first to systematically illustrate the colors in three-dimensional space. Munsell’s system, particularly the later renotations, is based on rigorous measurements of human subjects’ visual responses to color, putting it on a firm experimental scientific basis. Because of this basis in human visual perception, Munsell’s system has outlasted its contemporary color models, and though it has been superseded for some uses by models such as CIELAB (L*a*b*) and CIECAM02, it is still in wide use today. Munsell color system
Microwave The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph correspond to frequencies at which microwaves are absorbed more strongly. The right half of this graph includes the lower ranges of infrared by some standards Microwaves are a form of electromagnetic radiation with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz. This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm). The prefix "micro-" in "microwave" is not meant to suggest a wavelength in the micrometer range.
Radio waves Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
Wavelength Wavelength of a sine wave, λ, can be measured between any two points with the same phase, such as between crests, or troughs, or corresponding zero crossings as shown. In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. Wavelength is commonly designated by the Greek letter lambda (λ). The concept can also be applied to periodic waves of non-sinusoidal shape. The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. The SI unit of wavelength is the meter.
The electromagnetic waves that compose electromagnetic radiation can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. This diagram shows a plane linearly polarized EMR wave propagating from left to right. The electric field is in a vertical plane and the magnetic field in a horizontal plane. The two types of fields in EMR waves are always in phase with each other with a fixed ratio of electric to magnetic field intensity. Electromagnetic radiation (EM radiation or EMR) is one of the fundamental phenomena of electromagnetism, propagating and traveling through space via photon wave particles, carrying radiant energy. In a vacuum, it propagates at a characteristic speed, the speed of light, normally in straight lines.
Terahertz waves lie at the far end of the infrared band, just before the start of the microwave band. In physics, terahertz radiation, also called submillimeter radiation, terahertz waves, terahertz light, T-rays, T-waves, T-light, T-lux, or THz, consists of electromagnetic waves at frequencies from 0.3 to 3 terahertz (THz). The term applies to electromagnetic radiation with frequencies between the high-frequency edge of the millimeter wave band, 300 gigahertz (3×1011 Hz), and the low frequency edge of the far-infrared light band, 3000 GHz (3×1012 Hz). Corresponding wavelengths of radiation in this band range from 1 mm to 0.1 mm (or 100 μm) Because terahertz radiation begins at a wavelength of one millimeter and proceeds into shorter wavelengths, it is sometimes known as the submillimeter band, and its radiation as submillimeter waves, especially in astronomy. Terahertz radiation
Colour Music Do you like music? And colour? Most of us respond to the simple pleasures to be had from light and sound, whether naturally occurring - the sight of a sunset and the song of a bird - or man-made - a familiar painting or a favourite song.
Visible spectrum The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) 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 430–790 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.
Roy G. Biv The conventional seven colors of the rainbow symbol Natural rainbows show a continuum of colors. A rainbow spans a continuous spectrum of colors; the distinct bands are an artifact of human color vision. In Roy G. Biv, the colors are arranged in the order of decreasing wavelengths, with red being 650 nm and violet being about 400 nm. The Roy G.