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

  1. Aug 21, 2011 #1
    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?
     
  2. jcsd
  3. Aug 21, 2011 #2

    rcgldr

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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.
     
  4. Aug 21, 2011 #3
    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!
     
  5. Aug 21, 2011 #4
    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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