All Questions
Tagged with wavelength thermal-radiation
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Wavelength and frequency of the peak of the black body radiation [duplicate]
Why does the product of the peak wavelength and the peak frequency of Planck's black body radiation not equal to the speed of light?
$$λ_{\mathrm{max}}=\frac{hc}{4.97\mathrm{kT}},$$ while $$ν_{\mathrm{...
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How did Kurlbaum and others measure the intensity of each wavelength to get blackbody radiation curve?
In 1900 Plank was faced with data that didn't agree with the Plank-Wien law. This data that plots different temperature curves - wavelength on the horizontal and intensity on the vertical (or rather ...
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Can something become hot enough that it stops glowing?
So I understand that matter emits EM waves when hot. And that the higher the temperature, the shorter the wavelength, so cooler flames start off orange and the hotter flames reach light blue and white....
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What are the hex color code equivalents for the different classifications of stars?
Stars appear to be of various colors based on the visible light they emit. I am wondering if there is a hex color code that can be considered to be typified or average for the various classifications ...
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A question about colour temperature
This picture from Wikipedia is a table of temperatures vs colour for incandescence, however the problem is that I’ve been told that for a black body, even something with a temperature of say 2000C (E....
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Why does Rayleigh-Jeans law agree with Planck's at long wavelengths?
Why does Rayleigh-Jeans law agree with the Plancks distribution at high wavelengths? I know mathematically, that at higher wavelengths, we can approximate the exponential in the denominator by $1+ \...
user285848
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Max Planck - what does 'per wavelength' mean?
Planck says
$$B_\nu(T)=\frac{2hc^2}{λ^5}\,\frac{1}{\mathrm{e}^{hc/λk_BT}-1}.$$
It's defined as energy emitted per unit volume per wavelength. I'm not sure if this includes per solid angle, but I ...
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Max Planck - what's the $B$?
Planck says
$$B_\nu(T)=\frac{2\nu^2}{c^2}\,\frac{h\nu}{\mathrm{e}^{h\nu/k_BT}-1}.$$
It is power emitted per unit area per unit angle per unit frequency. This is what I'm curious now.
Let's say we ...
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Why the blackbody's spectral emittance isn't a growing exponential in the wavelength?
I have read multiple paragraphs about why we do get the bell shaped curve and the tale goes like this, oscillators with high frequency aren't paying the bell getting excited as they would require ...
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Converting between $F_{\nu}$ and $F_{\lambda}$ spectral density
In papers, spectral energy distributions are given either in $F_\nu$, $\nu F_\nu$, $F_\lambda$ or $\lambda F_\lambda$.
$F_\nu$ has units of Janskys, for example.
Is there a clear explanation online I ...
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Deriving Wien's approximation
Without Planck's law from where and how could one empirically get this.
Could it be got from power is proportional to fourth power of temperature.
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How does thermal wavelength work exactly?
In many sources it is stated that the thermal wavelenth indicates the rough size of the atom. It is then stated that this wavelenght is the de-Broglie wavelength of a particle with a momentum with the ...
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Absorption spectra Oxygen vs temperature
Whilst recently commissioning a spectroscopic Tunable diode laser "Oxygen Analyser" on a waste-to-energy plant, I wondered how the Analyser (which fires a narrow wavelength laser across the ...
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Is energy rule violated here? [closed]
We know that for an EM radiation , energy is given by :
$$E = \frac{hc}{\lambda}$$
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Where $h$ is Planck's constant , $c = 300000000$m/s and $\lambda$ is wavelength of the radiation.
Clearly, energy ...
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What would Planck's law become if derived from Doppler shifted wavelengths?
Derivation of Plancks law does not involve Doppler effects on wavelength. What would Planck's law become if derived from Doppler shifted wavelengths?
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