enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Black-body radiation - Wikipedia

    en.wikipedia.org/wiki/Black-body_radiation

    For a black body (a perfect absorber) there is no reflected radiation, and so the spectral radiance is entirely due to emission. In addition, a black body is a diffuse emitter (its emission is independent of direction). Blackbody radiation becomes a visible glow of light if the temperature of the object is high enough. [19]

  3. Black body - Wikipedia

    en.wikipedia.org/wiki/Black_body

    A black body or blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The radiation emitted by a black body in thermal equilibrium with its environment is called black-body radiation. The name "black body" is given because it absorbs all colors of light.

  4. Cosmic microwave background - Wikipedia

    en.wikipedia.org/wiki/Cosmic_microwave_background

    The intensity of the radiation corresponds to black-body radiation at 2.726 K because red-shifted black-body radiation is just like black-body radiation at a lower temperature. According to the Big Bang model, the radiation from the sky we measure today comes from a spherical surface called the surface of last scattering.

  5. Planck's law - Wikipedia

    en.wikipedia.org/wiki/Planck's_law

    The importance of the Lummer and Kurlbaum cavity radiation source was that it was an experimentally accessible source of black-body radiation, as distinct from radiation from a simply exposed incandescent solid body, which had been the nearest available experimental approximation to black-body radiation over a suitable range of temperatures.

  6. Emissivity - Wikipedia

    en.wikipedia.org/wiki/Emissivity

    The surface of a perfect black body (with an emissivity of 1) emits thermal radiation at the rate of approximately 448 watts per square metre (W/m 2) at a room temperature of 25 °C (298 K; 77 °F). Objects have emissivities less than 1.0, and emit radiation at correspondingly lower rates.

  7. Cosmic Background Explorer - Wikipedia

    en.wikipedia.org/wiki/Cosmic_Background_Explorer

    The Cosmic Background Explorer (COBE / ˈ k oʊ b i / KOH-bee), also referred to as Explorer 66, was a NASA satellite dedicated to cosmology, which operated from 1989 to 1993.Its goals were to investigate the cosmic microwave background radiation (CMB or CMBR) of the universe and provide measurements that would help shape our understanding of the cosmos.

  8. Limb darkening - Wikipedia

    en.wikipedia.org/wiki/Limb_darkening

    The radiation emitted from a gas is approximately black-body radiation, the intensity of which is proportional to the fourth power of the temperature. Therefore, even in line of sight directions where the optical depth is effectively infinite, the emitted energy comes from cooler parts of the photosphere, resulting in less total energy reaching ...

  9. Rayleigh–Jeans law - Wikipedia

    en.wikipedia.org/wiki/Rayleigh–Jeans_law

    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.