trick or treat?

Ok, my friends, we've all been there. It's your birthday, you're sitting at the kitchen counter (we always had to eat in the kitchen) and people are singing a dirge-like tune as your mom/dad/aunt sally is slowly bringing in the cake, her hand covering the candle flames so they won't go out before you blow them out and spit all over your cake. They place the cake in front of you, and as the song ends, you screw up your eyes, think hard, and then give a blow (minds out of the gutter, now), extinguishing those small candles with one mighty gust of breath.

But wait? What is this? The stupid candles just re-lit themselves. Is this magic? Horrible crazy voo-doo? Karma? You put them out again, but they keep re-lighting. These. Stupid. Candles. Won't. Go. Out. Finally, you give in to the tears while your mom/dad/aunt sally quickly pluck the candles from your cake and throws them into a sink full of water.

As you sadly eat your cake (yellow cake with chocolate frosting, to be exact), you begin to wonder. What was up with those candles?

Well, my friends, I have a bit of truth for you. You have just been hoodwinked by one of the cruelest birthday tools known to man: trick candles, candles that manage to re-light themselves over and over and cause you to question your sanity.

How do these awful things work, you might wonder. Well, I did a little googling, and I got the chemistry low-down (a science that I passed with flying colors, thank you very much, but I am still going to let someone else explain it to you).

from howstuffworks.com:

The key thing about a normal candle that is important to a trick candle is the moment after you blow out the candle. Normally there is a burning ember in the wick that causes a ribbon of paraffin smoke to rise from the wick. That ember is hot enough to vaporize paraffin but it is not hot enough to ignite the paraffin vapor.

The key to a re-lighting candle, therefore, is to add something to the wick that the ember is hot enough to ignite. That way the ember can ignite this substance and the substance can then ignite the paraffin vapor. In the links below, the most common substance mentioned is magnesium. Magnesium is a metal, but it happens to burn (combine with oxygen to produce light and heat) rapidly at an ignition temperature as low as 800 degrees F (430 degrees C) (aluminum and iron both burn as well, but magnesium lights at a lower temperature).

Inside the burning wick, the magnesium is shielded from oxygen and cooled by liquid paraffin, but once the flame goes out magnesium dust is ignited by the ember. If you watch the ember you will see tiny flecks of magnesium going off. One of them produces the heat necessary to re-light the paraffin vapor, and the candle flame comes back to life!

There you have it, my friends. And a word of advice. Next time someone puts trick candles on your cake, kick them in the shins. No one deserves that on their birthday.