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In particular, there are some extra assumptions that seem essential and must be added to the mathematical model to correctly predict that very small and peculiarly shaped cavities will still ultimately produce the usual BB spectrum.
I smell a philosopher! Indeed, only God can answer the question "why", and as there is no God, the question is meaningless. But if you want to know "how", I refer to the three hon gents I mentioned earlier.
Quote from: Bored chemist on 13/06/2023 13:24:04Incidentally, hot hydrogen atoms do have a strong absorption for red light.It's the hydrogen alpha line looked at from the other point of view.How hot or cold does it take to produce absorption spectrum?
Incidentally, hot hydrogen atoms do have a strong absorption for red light.It's the hydrogen alpha line looked at from the other point of view.
How strongly do you want it to absorb?Hot enough to significantly populate the first excited state.How come you don't know that?
Quote from: Bored chemist on 13/06/2023 13:24:04Incidentally, hot hydrogen atoms do have a strong absorption for red light.It's the hydrogen alpha line looked at from the other point of view.How hot or cold does it take to produce absorption spectrum? http://www.4college.co.uk/as/el/how.gifhttps://www.daviddarling.info/images/types_of_spectra.jpghttps://sites.ualberta.ca/~pogosyan/teaching/ASTRO_122/lect6/figure05-14.jpg
Quote from: Bored chemist on 14/06/2023 08:32:28How strongly do you want it to absorb?Hot enough to significantly populate the first excited state.How come you don't know that?Strong enough to be detected by common phone camera unambiguously. Can it be done under room temperature? Your statement suggests that there's a minimum temperature limit to show the absorption spectrum, contrary to the pictures which suggest that there's a maximum temperature limit instead. What's your reference?
Your statement suggests that there's a minimum temperature limit to show the absorption spectrum
How strongly do you want it to absorb?
You could make it out of small cube shaped BB (for which the maths is known)
And you can then rescale the problem - effectively using a different unit of length-
Can you specify what they are? (extra assumptions for small cavities etc.)
And you failed to answer it. Why is that?
Strong enough to be detected by common phone camera unambiguously.
This tells you about flame absorption spectra.https://www.agilent.com/en/support/atomic-spectroscopy/atomic-absorption/flame-atomic-absorption-instruments/how-does-aas-work-aas-faqs
Specifically, it seems that Nature does NOT see the wall of a cavity as a sharply defined hard wall. For example, not all of the radiation is stopped or bounced back at the inner edge of the wall, radiation of some frequencies may penetrate the wall slightly before being absorbed or bounced back etc. Indeed that does happen and is verifiable in other experiments - e.g. X rays can penetrate most materials to some depth.
Quote from: Bored chemist on 14/06/2023 14:59:11And you failed to answer it. Why is that?It looks like you fail to find my answer. Quote from: hamdani yusuf on 14/06/2023 12:55:49Strong enough to be detected by common phone camera unambiguously.
Quote from: Bored chemist on 14/06/2023 14:59:11This tells you about flame absorption spectra.https://www.agilent.com/en/support/atomic-spectroscopy/atomic-absorption/flame-atomic-absorption-instruments/how-does-aas-work-aas-faqsThe sample shown in the article is Pb. Turning it into gas requires high temperature. If the element is already gaseous in room temperature, like hydrogen, the flame doesn't seem to be necessary.The flame is not shown in the pictures I posted either.
Instead of absorption, the pictures look more like scattering effect.
Quote from: hamdani yusuf on 12/06/2023 10:01:46Something like this.I see no photons.
Something like this.
Quote from: hamdani yusuf on 14/06/2023 13:25:06Instead of absorption, the pictures look more like scattering effect.It's unfortunate that the diagram doesn't mention temperature requirements for the depicted phenomena to be observed. Although the spectrum looks like Balmer series, which implies that the gas is hydrogen.
Before I saw this diagram, I wondered where does the absorbed energy go. I guessed that some are transformed into heat, which is then dissipated to the environment.
The second one is quantization of atomic radiation frequency, which is observed in spectral line emission. Balmer discovered empirical formula to describe the spectral line emissions of the hydrogen atom. Bohr interpreted it as the evidence for the existence of atomic orbitals.
In atomic physics, the Bohr model or Rutherford?Bohr model of the atom, presented by Niels Bohr and Ernest Rutherford in 1913, consists of a small, dense nucleus surrounded by orbiting electrons. It is analogous to the structure of the Solar System, but with attraction provided by electrostatic force rather than gravity. In the history of atomic physics, it followed, and ultimately replaced, several earlier models, including Joseph Larmor's solar system model (1897), Jean Perrin's model (1901),[2] the cubical model (1902), Hantaro Nagaoka's Saturnian model (1904), the plum pudding model (1904), Arthur Haas's quantum model (1910), the Rutherford model (1911), and John William Nicholson's nuclear quantum model (1912). The improvement over the 1911 Rutherford model mainly concerned the new quantum mechanical interpretation introduced by Haas and Nicholson, but forsaking any attempt to explain radiation according to classical physics.https://en.m.wikipedia.org/wiki/Bohr_model
Bohr's model was proposed because then classical physicists thought that accelerating electrons must radiate em wave.
But experiments with superconductor shows that electric current can flow in circular motion without radiating away its energy.