What Makes Candle Flame Light Thermal Instead of Atomic?

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Discussion Overview

The discussion revolves around the nature of light emitted by a candle flame, specifically exploring whether it is thermal or atomic in origin. Participants examine the characteristics of thermal light compared to atomic light, referencing concepts such as blackbody radiation and atomic emission spectra.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that the yellow light from a candle is likely thermal due to the high temperature of the flame, questioning the nature of thermal light.
  • Another participant confirms the initial claim, explaining that atomic light is emitted during electron transitions in atoms, while thermal light arises from blackbody radiation.
  • A different participant provides examples of thermal emission, such as the glow of heated steel or incandescent light bulbs, to illustrate the concept of thermal light.
  • One participant expresses uncertainty about the accuracy of the previous claims regarding atomic light and thermal light.
  • Another participant asserts that the majority of light from a candle is blackbody radiation, drawing parallels between the light emitted by candles and flashlights that use heated elements.

Areas of Agreement / Disagreement

Participants generally agree on the definitions of atomic and thermal light, but there is disagreement regarding the extent to which candle light can be classified as thermal versus atomic. The discussion remains unresolved with competing views on the nature of the light emitted by candles.

Contextual Notes

Some participants reference specific examples and definitions, but there are unresolved assumptions about the classification of light and the conditions under which different types of light are emitted.

Jules18
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Imagine you're lighting a candle, and it emits yellow light. Because the candle flame is hot, the light is probably thermal (not atomic) in origin. Right?
If you made a spectrum of the candle light, it would appear to be continuous, and that would confirm experimentally that the light was thermal in origin, or so my teacher tells me. But I have no idea why.

I think I get the gist of atomic light. The way I understand, electrons in a certain type of atom absorb light of certain frequencies and then rerelease light of the same frequencies. (eg: neon burns red)
But what's thermal light??
This whole concept drives me crazy.
 
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Everything your teacher has told you is correct. "Atomic" light is the name for photons that are released when an electron undergoes a quantum leap between orbitals which are quantized and thus you only see specific discrete wavelengths emitted. "Thermal" light is photons that come from the blackbody radiation of an object (http://en.wikipedia.org/wiki/Blackbody_radiation)
 
Thank you, that link was helpful.
 
Yellow candle light, red neon light, and yellow sodium light (actually a doublet) are characteristic atomic emission lines of the specific atoms in question. For real thermal emission spectrum, heat a piece of steel with a torch to a red glow, or look at the filament of an incadescent light bulb as a function of input current.
 
OK I'm not sure that's true, but thanks for the input.
 
I'm pretty sure most of the light from a candle is going to be entirely blackbody. Evidenced by the fact that flashlights (which use a heated metal element) and candles give off the same kind of light and furthermore that candles can be made of a number of differnet substances
 

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