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  2. Planck units - Wikipedia

    en.wikipedia.org/wiki/Planck_units

    The Planck temperature T P is 1.416 784 (16) ... Normalizes the characteristic impedance Z g of gravitational radiation in free space to 1 (normally expressed as ...

  3. Brightness temperature - Wikipedia

    en.wikipedia.org/wiki/Brightness_temperature

    For a black body, Planck's law gives: [8] [11] = where (the Intensity or Brightness) is the amount of energy emitted per unit surface area per unit time per unit solid angle and in the frequency range between and +; is the temperature of the black body; is the Planck constant; is frequency; is the speed of light; and is the Boltzmann constant.

  4. Black-body radiation - Wikipedia

    en.wikipedia.org/wiki/Black-body_radiation

    Black-body radiation has a characteristic, continuous frequency spectrum that depends only on the body's temperature, [8] called the Planck spectrum or Planck's law. The spectrum is peaked at a characteristic frequency that shifts to higher frequencies with increasing temperature, and at room temperature most of the emission is in the infrared ...

  5. Planck constant - Wikipedia

    en.wikipedia.org/wiki/Planck_constant

    The Planck constant, or Planck's constant, denoted by , [1] is a fundamental physical constant [1] of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and the wavelength of a matter wave equals the Planck constant divided by the associated particle momentum.

  6. Planck's law - Wikipedia

    en.wikipedia.org/wiki/Planck's_law

    According to Planck's distribution law, the spectral energy density (energy per unit volume per unit frequency) at given temperature is given by: [4] [5] (,) = ⁡ alternatively, the law can be expressed for the spectral radiance of a body for frequency ν at absolute temperature T given as: [6] [7] [8] (,) = ⁡ where k B is the Boltzmann ...

  7. Wien's displacement law - Wikipedia

    en.wikipedia.org/wiki/Wien's_displacement_law

    Blacksmiths work iron when it is hot enough to emit plainly visible thermal radiation. The color of a star is determined by its temperature, according to Wien's law. In the constellation of Orion, one can compare Betelgeuse (T ≈ 3800 K, upper left), Rigel (T = 12100 K, bottom right), Bellatrix (T = 22000 K, upper right), and Mintaka (T = 31800 K, rightmost of the 3 "belt stars" in the middle).

  8. Stefan–Boltzmann law - Wikipedia

    en.wikipedia.org/wiki/Stefan–Boltzmann_law

    The temperature Stefan obtained was a median value of previous ones, 1950 °C and the absolute thermodynamic one 2200 K. As 2.57 4 = 43.5, it follows from the law that the temperature of the Sun is 2.57 times greater than the temperature of the lamella, so Stefan got a value of 5430 °C or 5700 K. This was the first sensible value for the ...

  9. Planckian locus - Wikipedia

    en.wikipedia.org/wiki/Planckian_locus

    T is the temperature of the black body h is the Planck constant c is the speed of light k is the Boltzmann constant. This will give the Planckian locus in CIE XYZ color space. If these coordinates are X T, Y T, Z T where T is the temperature, then the CIE chromaticity coordinates will be = + +