Lighting a candle, blowing it out and relighting it by lighting the smoke?

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Discussion Overview

The discussion revolves around the phenomenon of relighting a candle by igniting the smoke produced after blowing it out. Participants explore the underlying mechanisms of this process, including the role of ignitable fumes and the behavior of wax and vapor in the wick.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant shares a link to a visual demonstration and expresses curiosity about the underlying reasons for the phenomenon.
  • Another participant clarifies that the ignitable substances released after blowing out the candle are fumes rather than smoke, suggesting that these fumes can burn in both upward and downward directions.
  • A different participant explains the mechanics of how a candle wick functions, noting that the wick does not burn but instead absorbs melted wax, which then vaporizes and burns. This process is essential for the candle to ignite.
  • Further elaboration is provided on the behavior of vapor and smoke after the candle is extinguished, with a participant hypothesizing that the vapor continues to rise and can be reignited if a visible string of smoke is present, particularly when close to the wick.

Areas of Agreement / Disagreement

Participants present various interpretations and explanations of the phenomenon, with no clear consensus reached. Multiple competing views on the mechanics of the process remain evident.

Contextual Notes

Some assumptions about the behavior of vapor and smoke, as well as the conditions necessary for relighting, are not fully explored or defined, leaving certain aspects of the discussion unresolved.

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http://imgur.com/gallery/VtWhm - I've been trying this ever since I saw this .gif and it works. No idea why. Can anyone help?
 
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After blowing out the candle, ignitable fumes are rising from the wick, not smoke. Since the fumes can be ignited, they will burn both upwards and downwards, with the downward path reaching the wick again.
 
The wick in a candle doesn't actually burn. What happens is the wax melts into a liquid, and travels up the wick. The wick essentially soaks it up. When the liquid gets even hotter, it turns into a vapor - this vapor is what burns. That's why when lighting a candle, you have to hold the match there for a second - to give the wax time to heat into a vapor.

It's a fun trick!
 
So the heat pulls up the wax through the wick as it changes it into a liquid, and then rises as it becomes warmer and less dense up to the point of being an ignitable gas... then when you blow it out the same behavior still remains (the vapor rising due to the heat along with the smoke) for a short while, causing the ability to reignite the fluid in the wick?

I also noticed the relighting of the smoke only occurs when you have a good string like shape of visible smoke leading back to the wick when at a longer distance. Which I'm guessing 'holds' the flammable vapor for a few moments after the flame itself is out, and would explain how it's easier to light the smoke the closer you are to the wick.

Let me know if I'm a bit off in my interpretation, please. And thanks for the responses (they were immediately helpful).
 

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