Incandescent objects

CCT refers to the appearance of the light generated by a very hot (i.e., incandescent) object, the temperature of which is measured in kelvins (K). As a body is heated, it begins to produce a reddish-yellow, and then a yellow-white light. As temperature increases, the apparent color of the light changes to blue-white. In astronomy, for example, older, cooler... 

Black bodies are ideal incandescent objects they are perfect emitters (and absorbers) of light. The behavior of pyrotechnic spark particles approximates that of black bodies. 

The most important incandescent object for us is the Sun, which is the ultimate source of energy on Earth. The solar spectmm has a maximum near 560 nm. Light is perceived as white if it has a make-up like that of the solar spectrum. The human eye is most sensitive to the maximum in the solar spectrum, which corresponds to yellow-green, and is noticeably less sensitive to violet and red light. 

Color from Incandescence. Any object emits light when heated, with the sequence of blackbody colors, black, red, orange, yellow, white, and bluish-white as the temperature increases. The locus of this sequence is shown on a chromaticity diagram in Eigure 14. 

The CIELAB system (1976) strictly standardizes the light source and the observer. CIE recommends three standard sources, A is an incandescent lamp, and B and C are lamps provided with different two-cell Davis-Gibson liquid hlters that simulate noon daylight and average daylight, respectively. Since the main object of the system is to obtain colorimetric results for normal tri-chromats (people with normal color vision), the standard observer must represent the human population with normal... 

In the conventional bright field microscopy, light from an incandescent source is sequentially transmitted through the condenser, the specimen, an objective lens, and a second magnifying lens, the ocular or eyepiece, prior to reaching the eye. Some microscopes have an internal illuminator, while... 

From the beginning of his studies Langmuir was especially interested in the structure of the atom. The nature of the atom s structure was still very much in doubt. Many had crossed swords with nature to wrest this secret from her. Kelvin had pictured the atom as consisting of mobile electrons embedded in a sphere of positive electrification. J. J. Thomson had developed this same idea but his model, too, had failed because it could not account for many contradictory phenomena. Rutherford s nuclear theory of the atom as a solar system was also objected to as incomplete. The greatest difficulty to the acceptance of these models was that they all lacked a consistent explanation of the peculiar spectra of gaseous elements when heated to incandescence. 

Incandescence is light emission from a heated object, such as the filament in a lamp or the... 

TL uses this same principle to date the object. A small powdered sample of the object is heated and by measuring the emission of light in excess of the incandescent glow that is produced the date of the firing can be calculated. The technique requires calibration of each particular sample, since every clay particle will accumulate defects at a different rate. Although the operational principle of the method appears simple, it requires experience to interpret the data correctly. 

---