Is incandescence a purely quantum phenomenon?

  • Context: Graduate 
  • Thread starter Thread starter bakshi
  • Start date Start date
  • Tags Tags
    Phenomenon Quantum
Click For Summary

Discussion Overview

The discussion revolves around the nature of incandescence, specifically whether it is a purely quantum phenomenon or if it can be explained through classical electrical principles and thermal effects. Participants explore the mechanisms behind light emission in incandescent materials, including the role of atomic transitions and vibrational spectra.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant cites Wikipedia, suggesting that incandescence involves electron transitions in atomic orbitals, leading to photon emission based on energy differences in tungsten.
  • Another participant argues that incandescence is primarily a result of resistive heating, asserting that it is not a quantum phenomenon but rather an electrical one, as evidenced by the high temperatures of incandescent bulbs.
  • A different participant supports the view that the emitted light is related to the vibrational spectrum of the material, emphasizing that heating by any method can produce similar effects.
  • Some participants express skepticism about the reliability of Wikipedia as a source for scientific information, while others defend its utility for quick references.

Areas of Agreement / Disagreement

Participants express disagreement regarding the mechanisms of incandescence, with some asserting it is a quantum phenomenon related to atomic transitions, while others maintain it is primarily a thermal effect related to resistive heating and vibrational spectra. No consensus is reached on the nature of incandescence.

Contextual Notes

Participants highlight the complexity of the topic, noting that definitions and assumptions about incandescence may vary. The discussion reflects differing interpretations of the relationship between temperature, electron behavior, and light emission.

bakshi
Messages
10
Reaction score
0
I just read this from Wikipedia:

Incandescence occurs in light bulbs, because the filament resists electron flow. This excites electrons in the filament material to jump to a higher atomic orbital and thus subsequently release a photon when they fall back to their original orbits. Depending on the energy difference between the two orbits, the emitted photon is of a different wavelength.

Which means that if the filament is made of tungsten, then only photons having an energy (wavelength) corresponding to the energy levels of the atoms of tungsten can be emitted. Then how can the observed continuous spectrum be explained?
 
Physics news on Phys.org
I'd be a bit leery of taking Wiki's word on this one. 'Incandescent' simply means that it's hot enough to radiate EM in the visible part of the spectrum. This is caused by the resistance of the filament, not orbital shifts of the electrons. It's not a quantum phenomenon so much as a straight electrical one. A typical household bulb runs at somewhere around 2,500° C., so it covers pretty much the whole visible section plus a lot of infrared.
Electricity isn't even required for incandescence. If you've ever seen a farrier (blacksmith) at work, or a steel plant in operation, then you'll recognize the glow from material heated in another manner.
Better double-check me on this, but I'm pretty sure you don't need to bring stimulated emission into it.
 
Last edited:
Danger is correct. The light being emitted is not due to atomic transition, but rather due to the vibrational spectrum. That, by definition, is related to heat. So you can get the same effect by heating it any way you like. Resistive heating is just one such way.

Just another example why I never use Wikipedia to look up anything.

Zz.
 
ZapperZ said:
Danger is correct. The light being emitted is not due to atomic transition, but rather due to the vibrational spectrum. That, by definition, is related to heat. So you can get the same effect by heating it any way you like. Resistive heating is just one such way.

Just another example why I never use Wikipedia to look up anything.

Zz.

I wouldn't discount it that much. It's a pretty good resource for most things when you need a quick answer.
 
KingNothing said:
I wouldn't discount it that much. It's a pretty good resource for most things when you need a quick answer.

Caveat Emptor..

Zz.
 

Similar threads

High School Frequency of an EM wave in Classical and Quantum Physics
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Do atoms recoil when emitting a photon?
  • · Replies 38 ·
2
Replies
38
Views
7K
Undergrad Frequency of EM waves in classical and quantum physics
  • · Replies 26 ·
Replies
26
Views
3K
High School What happens to excess energy when an electron gets excited by light?
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Electromagnetic radiation, photons, quantized energy levels
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Emission Spectrum & Energy: Exciting Hydrogen Vapor
  • · Replies 3 ·
Replies
3
Views
1K
High School A question of timing in a light bulb
  • · Replies 15 ·
Replies
15
Views
2K
Undergrad Blackbody Radiation: Questions Answered on Causes & Oscillators
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Cause of spontaneous emission?
  • · Replies 15 ·
Replies
15
Views
4K
Graduate Avalanche photon detectors
  • · Replies 0 ·
Replies
0
Views
873