# translation of kstars_blackbody.po to 
# translation of kstars_blackbody.po to
# translation of kstars_blackbody.po to
# Copyright (C) 2002 Free Software Foundation, Inc.
# Lwandle Mgidlana <lwandle@translate.org.za>, 2002
#
msgid ""
msgstr ""
"Project-Id-Version: kstars_blackbody\n"
"POT-Creation-Date: 2001-02-09 01:25+0100\n"
"PO-Revision-Date: 2002-09-26 12:32+0200\n"
"Last-Translator: Lwandle Mgidlana <lwandle@translate.org.za>\n"
"Language-Team:  <xh@li.org>\n"
"MIME-Version: 1.0\n"
"Content-Type: application/x-xml2pot; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Generator: KBabel 1.0beta2\n"

#: index.docbook:4
#, no-c-format
msgid ""
"<firstname>Jasem</firstname> <surname>Mutlaq</surname> "
"<affiliation><address> <email>mutlaqja@ku.edu</email> "
"</address></affiliation>"
msgstr ""

#: index.docbook:13
#, no-c-format
msgid "Blackbody Radiation"
msgstr ""

#: index.docbook:15
#, no-c-format
msgid ""
"A <firstterm>blackbody</firstterm> refers to an idealized concept of an "
"object that emits <firstterm>thermal radiation</firstterm> perfectly. Since "
"emission of light and absorption of light are inverse processes, a perfect "
"emitter of light would also need to be a perfect absorber of light. "
"Therefore, at room temperature, such an object would appear to be perfectly "
"black. Hence the term <emphasis>blackbody</emphasis>."
msgstr ""

#: index.docbook:25
#, no-c-format
msgid ""
"All objects emit thermal radiation (as long as their temperature is above "
"Absolute Zero, or -273.15 degrees Celsius), but no object is really a "
"perfect emitter; rather, they are better at emitting/absorbing some "
"wavelengths of light than others. These uneven efficiencies make it "
"difficult to study the interaction of light, heat and matter using normal "
"objects."
msgstr ""

#: index.docbook:34
#, no-c-format
msgid ""
"Fortunately, it is possible to construct a nearly-perfect blackbody. "
"Construct a box made of a thermally conductive material, such as metal. The "
"box should be completely closed on all sides, so that the inside forms a "
"cavity that does not receive light from the surroundings. Then, make a very "
"small hole somewhere on the box. The light coming out of this hole will "
"almost perfectly resemble the light from an ideal blackbody, for the "
"temperature of the air inside the box."
msgstr ""

#: index.docbook:45
#, no-c-format
msgid ""
"At the beginning of the 20th century, scientists Lord Rayleigh, Wilhelm "
"Wein, and Max Planck (among others) studied the blackbody radiation using "
"such a device. After much work, Planck was able to perfectly describe the "
"intenisty of light emitted by a blackbody as a function of wavelength. "
"Furthermore, he was able to describe how this spectrum would change as the "
"temperature changed. Planck's work on blackbody radiation is one of the "
"areas of physics that led to the foundation of the wonderful science of "
"Quantum Mechanics, but that is unfortunately beyond the scope of this "
"article."
msgstr ""

#: index.docbook:57
#, no-c-format
msgid ""
"What Planck and the others found was that as the temperature of a blackbody "
"increases, the total amount of light emitted per second increases, and the "
"wavelength of the spectrum's peak shifts to bluer colors (see Figure 1)."
msgstr ""

#: index.docbook:64
#, no-c-format
msgid "Figure 1"
msgstr ""

#: index.docbook:64
#, no-c-format
msgid "The spectrum of three blackbodies at different temperatures."
msgstr ""

#: index.docbook:72
#, no-c-format
msgid ""
"Wilhelm Wein quantified the relationship between blackbody temperature and "
"the wavelength of the spectral peak with the following equation:"
msgstr ""

#: index.docbook:78
#, no-c-format
msgid "lamdba(max} * T = 0.29 cm K"
msgstr ""

#: index.docbook:82
#, no-c-format
msgid ""
"where T is the temperature in Kelvin. Wein's law (also known as Wein's "
"displacement law) can be stated in words as \"the wavelength of maximum "
"emission from a blackbody is inversely proportional to its temperature\". "
"This makes sense; shorter-wavelength (higher-frequency) light corresponds to "
"higher-energy photons, which you would expect from a higher-temperature "
"object."
msgstr ""

#: index.docbook:92
#, no-c-format
msgid ""
"For example, the sun has an average temperature of 5800 K with a wavelength "
"of maximum emission equal to lambda(max) = 0.29 cm / 5800 = 500 nm. This "
"wavelengths falls in the green region of the visible light spectrum, but the "
"sun's continuum radiates photons both longer and shorter than lambda(max) "
"and the human eyes perceives the sun's color as white."
msgstr ""

#: index.docbook:101
#, no-c-format
msgid ""
"In 1879, Austrian physicist Stephan Josef Stefan showed that the "
"<firstterm>luminosity</firstterm>"
", L, of a black body is proportional to the 4th power of its temperature T."
msgstr ""

#: index.docbook:107
#, no-c-format
msgid "L = A * alpha * T^4"
msgstr ""

#: index.docbook:111
#, no-c-format
msgid ""
"where A is the surface area, alpha is a constant of proportionality, and T "
"is the temperature in Kelvin. That is, if we double the temperature (e.g. "
"1000 K to 2000 K) then the total energy radiated from a blackbody increase "
"by a factor of 2^4 or 16."
msgstr ""

#: index.docbook:119
#, no-c-format
msgid ""
"Five years later, Austrian physicist Ludwig Boltzman derived the same "
"equation and is now known as he Stephan-Boltzman law. If we assume a "
"spherical star with radius R, then the luminosity of such a star is"
msgstr ""

#: index.docbook:125
#, no-c-format
msgid "L = 4*PI*R^2 * Alpha * T^4"
msgstr ""

#: index.docbook:129
#, no-c-format
msgid ""
"where R is the star radius in cm, and the alpha is the Stephan-Boltzman "
"constant, which has the value: Alpha = 5.670 * 10^-5 erg/s/cm^2/K^-4."
msgstr ""
