Visible light, electromagnetic

In the electromagnetic spectrum, the ultra violet region is between that of X-rays and visible light. This corresponds to the energies hv ot one hundred to a few tens of electron-volts (wavelengths from 180 to 400 nm). 

Electromagnetic radiation of which visible light is but one example has the properties of both particles and waves The particles are called photons, and each possesses an amount of energy referred to as a quantum In 1900 the German physicist Max Planck proposed that the energy of a photon (E) is directly proportional to its frequency (v)... 

Electromagnetic radiation (Section 13 1) Vanous forms of ra diation propagated at the speed of light Electromagnetic radiation includes (among others) visible light infrared ul traviolet and microwave radiation and radio waves cos mic rays and X rays... 

Colorimetry, in which a sample absorbs visible light, is one example of a spectroscopic method of analysis. At the end of the nineteenth century, spectroscopy was limited to the absorption, emission, and scattering of visible, ultraviolet, and infrared electromagnetic radiation. During the twentieth century, spectroscopy has been extended to include other forms of electromagnetic radiation (photon spectroscopy), such as X-rays, microwaves, and radio waves, as well as energetic particles (particle spectroscopy), such as electrons and ions. ... 

The so-called peak power delivered by a pulsed laser is often far greater than that for a continuous one. Whereas many substances absorb radiation in the ultraviolet and infrared regions of the electromagnetic spectrum, relatively few substances are colored. Therefore, a laser that emits only visible light will not be as generally useful as one that emits in the ultraviolet or infrared ends of the spectrum. Further, witli a visible-band laser, colored substances absorb more or less energy depending on the color. Thus two identical polymer samples, one dyed red and one blue, would desorb and ionize with very different efficiencies. 

The scattering of visible light by polymer solutions is our primary interest in this chapter. However, since is a function of the ratio R/X, as we saw in the last section, the phenomena we discuss are applicable to the entire range of the electromagnetic spectrum. Accordingly, a general review of the properties of this radiation and its interactions with matter is worthwhile before a specific consideration of scattering. 

A modem use of uranine is in the manufacture of fluorescent laminates, eg, sheets, glass, and plastic films, that are transparent to electromagnetic waves and visible light rays (45). Such material might be used in windows, viewing partitions, and optical lenses. 

UV Radiation Electromagnetic radiation in the wavelength range of approximately 4 X 10 to 5 X 10 m, i.e., between visible light waves and X-rays. 

In 1957, this team of brothers-in-law started working together on Townes s idea for an optical maser. They found atoms that they felt had the most potential, based on transitional probabilities and lifetimes. However, there was still one major problem In the visible light portion of the electromagnetic spectrum, atoms don t remain in an excited state as long as... 

Visible light, X rays, microwaves, radio waves, and so forth, are all different kinds of electromagnetic radiation. Collective )-, they make up the electromagnetic... 

Electromagnetic radiation of frequency 1 Hz pushes a charge in one direction, then the opposite direction, and returns to the original direction once per second. The frequency of electromagnetic radiation that we see as visible light is close to 1015 Hz, and so its electric field changes direction at about a thousand trillion (1015) times a second as it travels past a given point. 

Arrange the following types of photons of electromagnetic radiation in order of increasing energy -y-rays, visible light, ultraviolet radiation, microwaves, x-rays. 

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