I have a lighter at home which everytime I use it, generates little spikes (see picture below) which eventually disappear.
The Spikes are not an effect generated by the camera. I can confirm that since I made the picture.
Essentially this means the flame does not have a nice uniform flame shape, but is interrupted by the spikes.

The Spike in the flame is real and not an error of the camera

Does someone know where this is comming from?

@JamesGaidis suggested to try holding the lighter sideways. It can be observed that the spot of the spike has roughly the same position when holding it sideways (left picture)
enter image description here enter image description here

A different lighter with the same effect, but with the additional feature of beeing able to reduce the gas flow shows, that the spike is independent of the quantity of the gas (right picture).

The height of the spike (distance from the tip of the flame to the tip of the spike) is always the same, thus independent from the quantity of the gas. (In other words: the height from hole that emits the gas to the top the spike is only dependent on the size of the flame)

James did also suggest to light the lighter from an external source, and in this case, no spikes show up.
This implies that its not the gas alone generating this effect, but has rather something to do with the stone.

I don't really know if this is has to do with chemistry at all, or if it has more to do with physics. If thats the case, feel free to redirect me towards the correct SE site.

  • $\begingroup$ I bet it has something to do with speed profile of LPG gas injection stream. The center of ii has the highest speed and it's flame is longest. $\endgroup$
    – Poutnik
    Jan 1 at 11:22
  • $\begingroup$ Perhaps the flame follows or is carried by some particles which are scraped off the flint and carried by the rising gas, but are not sustained by the gas flow. It would be interesting to light the flame by holding the lighter sideways, or swing the lighter while lighting the flame or reduce the gas flow to minimum. Or light the gas flow without the flint - from another source, like a candle flame. $\endgroup$ Jan 1 at 14:36
  • $\begingroup$ @JamesGaidis those are good ideas, I have updated the question to include your suggested experiements $\endgroup$
    – J.Doe
    Jan 1 at 17:18
  • $\begingroup$ How long does this jet/spike last? If it vanishes rapidly, it indicates a solid particle which came out during friction. $\endgroup$
    – M. Farooq
    Jan 1 at 17:57
  • 1
    $\begingroup$ @user79161 I'm not quite sure if get you point correctly. This effect does not come from the camera. I can see the spike with my own eyes. $\endgroup$
    – J.Doe
    Jan 2 at 11:27