Ad
related to: radiance of a body summary by chapter 1 sparknotes
Search results
Results From The WOW.Com Content Network
Brightness temperature or radiance temperature is a measure of the intensity of electromagnetic energy coming from a source. [1] In particular, it is the temperature at which a black body would have to be in order to duplicate the observed intensity of a grey body object at a frequency ν {\displaystyle \nu } . [ 2 ]
Because SparkNotes provides study guides for literature that include chapter summaries, many teachers see the website as a cheating tool. [7] These teachers argue that students can use SparkNotes as a replacement for actually completing reading assignments with the original material, [8] [9] [10] or to cheat during tests using cell phones with Internet access.
Comparison of Rayleigh–Jeans law with Wien approximation and Planck's law, for a body of 5800 K temperature.. In physics, the Rayleigh–Jeans law is an approximation to the spectral radiance of electromagnetic radiation as a function of wavelength from a black body at a given temperature through classical arguments.
A so-called grey body is a body for which the spectral emissivity is independent of wavelength, so that the total emissivity, , is a constant. [3]: 71 In the more general (and realistic) case, the spectral emissivity depends on wavelength.
From Planck's law of black-body radiation at temperature T we have for the spectral radiance (radiance is energy per unit time per unit solid angle per unit projected area, when integrated over an appropriate spectral interval) [26] at frequency ν (,) = /, where [27] =, where is the speed of light and is the Planck constant.
When the body is black, the absorption is obvious: the amount of light absorbed is all the light that hits the surface. For a black body much bigger than the wavelength, the light energy absorbed at any wavelength λ per unit time is strictly proportional to the blackbody curve. This means that the blackbody curve is the amount of light energy ...
Every such black body emits from its surface with a spectral radiance that Kirchhoff labeled I (for specific intensity, the traditional name for spectral radiance). Kirchhoff's postulated spectral radiance I was a universal function, one and the same for all black bodies, only depending on wavelength and temperature.
L is used here instead of B because it is the SI symbol for spectral radiance. The L in c 1L refers to that. This reference is necessary because Planck's law can be reformulated to give spectral radiant exitance M(λ, T) rather than spectral radiance L(λ, T), in which case c 1 replaces c 1L, with