Pneumatised!

MM,

Okay, this has been on my mind so I thought I’d do a little research.

Since I started taking gumdo classes, I pretty much assumed that if a sword generated enough wind, it would snuff out a lit candle. This assumption was based on the fact that a person can blow out a candle if they exhaled enough air at a lit candle. Going further with my assumption, I assumed that a bigger candle flame or more lit candles would need more wind than a small flame or just one candle. Therefore, in trying to snuff out a lit candle with a sword, a significant amount of speed in the sword cut (force) is needed to generate enough wind for the task of snuffing a candle (or two or three or more). Of course, an equivalent amount of control is required to stop the sword from hitting the candle. Now, for some reason, no one seems to believe that a certain amount of force is needed to put out a candle flame with a sword. (Some people may think that since even kids can snuff a candle, it doesn’t require force. Well, I really don’t think people are giving some of these kids enough credit, they may look small but they could actually be generating more force than what is observed – and trust me on this since I know lots of little tykes in martial arts.) Below is a little explanation on blowing out a candle (from Principles of Alchemy).

Well then, how come I can blow out a candle?
Because the candle flame is small and you can blow a lot of air!
The three methods we discussed for extinguishing a flame (Water, Earth and “bad” Air) all smother the fuel, and thus keep the oxygen out. But blowing out a flame doesn’t smother it. Instead you are stripping the fire away from its fuel.
What?! What are you talking about?
Fire makes more fire by continuing to the burn the fuel. Fire needs fire to continue burning.
Nope, I still don’t get it.
OK. As a fire burns in a particular spot, it runs out of fuel. But the heat it gives off is enough to cause the fuel nearby to ignite.
When you say “ignite”, you mean to start burning. Right?
Right. So a fire must constantly search out more fuel to burn if it is to be kept alive.
Yeah. So?
So, when you blow hard on a candle flame you are using your breath to push the hot flame away from the fuel. Remove the heat from the fuel and you’ve stopped the reaction.
Oh, I see. So when I try to blow out a small candle I’m trying to push the flame away from new fuel.
That’s right. A bigger flame requires a bigger push of air from you to push it away from the fuel.
But at some point the fire is too big to blow out. Right?
Right! The bigger the flame the more air you need to push quickly at it in order to push the fire away from the fuel. In the 20th century they have some fire accidents involving very good fuels that produce very big fires. To put out these “super-fires”, they must use explosives to blow the flame away from the fuel.
Wow. Sounds exciting.
But I’ve noticed that I can make a flame grow brighter if I blow it just a little. Gently.
Yes. When you blow gently on a small flame you push a fresh supply of oxygen to it. And you might even help the flame reach new fuel that would normally be out of reach.
So, you can make a fire better or worse by blowing on it!
Yes. It depends on the size of the fire and how hard you blow. I’ve seen people try to swat down a fire with a coat or apron. If the fire is small enough and they swat it correctly, they put out the fire. But sometimes they make it worse! They fan the flames, adding more oxygen and making the fire grow.

Now, let’s extrapolate this to blowing out a candle with a sword. Here’s what happens when a sword is swung down on a candle flame. First, the sword cut generates a certain amount of wind (air). This wind pushes the hot flame away from the wick (the fuel). If there is enough wind to completely push the flame away from the wick, it doesn’t ignite and keep burning. The candle flame will then be snuffed out. The passage above also explains why a candle flame may almost go out but seemingly comes back to life again. If not enough wind is used to push the flame away, the flame just gathers the oxygen and keeps burning the wick. The candle stays lit. It also explains why with more than one candle, one candle may be snuffed out with the sword but then be re-lit by the other candle. The wind can just push the hot flame onto the unlit wick (the fuel) and it will burn again.

Now, I’m not sure about anyone else, but if I swing my sword faster, more wind is generated. Therefore, if I swing my sword at the necessary speed towards the candle flame without hitting it (that is, abruptly stopping the strike thereby exhibiting good control and technique), the candle should snuff out. Yes, candle snuffing with a sword is done with good technique, but with a little help from alchemy.

MM,
Cassandrah
Your local webmistress and swordsperson
Brigid’s Flame