1.
In physics, a black body is an idealized object that absorbs all
electromagnetic radiation that falls on it. No electromagnetic
radiation passes through it and none is reflected. Because no
light (visible electromagnetic radiation) is reflected or transmitted,
the object appears black when it is cold. However, a black body
emits a temperature-dependent spectrum of light. This
thermal radiation from a black body is termed black-body radiation.
#
Studying the laws of the black body historically led to quantum mechanics
#
Blackbody radiation is light in thermal equilibrium, light radiation with
a given temperature. It is the basic thermodynamic state of light. Because
light is the oscillation of a continuous electromagnetic field, the study
of blackbody radiation reveals how continuous fields can have a
temperature, something which contradicts classical physics. Because
the thermal state of light was so confusing before the advent of
quantum mechanics, the 19th century arguments that light has a
thermal equilibrium state were made very carefully.
#
Today the black-body cavity may be thought of as containing a gas of photons
#
An almost perfect black-body spectrum is exhibited by the
cosmic microwave background radiation., Hawking radiation is the
hypothetical black-body radiation emitted by black holes.
!!!
#
Super black is an example of such a material, made from a
nickel-phosphorus alloy. More recently, a team of Japanese scientists
discovered a material even closer to a black body, based on
single-walled carbon nanotubes (SWNTs), which absorbs between
97% and 99% of the wavelengths of the light that hits it.
http://en.wikipedia.org/wiki/Black_body2.
Max Laue (who won the Nobel Prize in Physics in 1914 )
called the model of a black body as the ‘ Kirchhoff's vacuum.’
3.
And I have naive question:
Can a ideal black body be model of real Vacuum T= 0K ?
========== .
