In the trick where I easily pass my finger through the middle of a candle flame, why does the tip of the flame hurt more than the middle (which is closer to the blue part of the flame, that is supposedly the hottest)?

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In the trick where I easily pass my finger through the middle of a candle flame, why does the tip of the flame hurt and not the middle?

The middle of the flame is closer to the blue part of the flame, supposedly the hottest?

In: Physics

Blue part isn’t the hottest, it’s actually the coldest. [See this image about the distribution of heat within a flame] (https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Anatomy_of_a_candle_flame.svg/220px-Anatomy_of_a_candle_flame.svg.png). The colors don’t only depend on heat, they’re largely caused by a chemical reaction and the amount of oxygen fueling the fire isn’t equal at the bottom and the top. In fact, if you look at that image the hottest part isn’t actually visible.

Candle flames are a mix of burning wax and oxygen. The flame burns the hottest in the part of the flame where there is more oxygen than wax, because then all the wax burns up. But it burns brightest in the part of the flame where there is more wax than oxygen, because the leftover wax heats up and glows. (Oxygen doesn’t glow very well when hot.) When you pass your finger through the tip, you’re passing it through the hot-but-less-bright part instead of the less-hot-more-bright part.