A Funny Critique of Movie Achery

Loyd, possibly better known as Lindybeige, put a video (several years ago) in which he very humorously critiques the archery in the movie Helen of Troy:

There’s actually a rather important historical / technical point which he left out, however.

One of the recurring jokes he makes is that the arrows limp out of the frame but then, “every one a coconut when it hits”, i.e. they often knock men back, off their feet. Now, you might suspect that I would point out that the same problem applies to bows and arrows as does to guns: recoil. That is, if the projectile was capable of knocking the man back when it hit, it would have enough recoil to knock the archer/rifleman back when it fired. But while that’s true, that’s not the interesting thing Loyd didn’t remark upon.

What was left out is that arrows kill in an entirely different way than guns do. There’s a hint in this difference when you look at the shape: bullets are round and arrows are sharp. So sharp, in fact, that you could shave with them. Bullets kill (mostly) by the simple transfer of kinetic energy damaging internal organs. The more kinetic energy, the more deadly. This is also why you want a bullet to mushroom and become as flat as possible when it hits—if it leaves the body all of the kinetic energy it still has is wasted.

(Incidentally, this is why (Geneva Convention) militaries use full metal jacket bullets. The full metal jacket keeps the bullet from deforming which makes it far more likely to leave the body and only wound the target. A wounded man is still out of combat and it’s better for both sides if fewer people die. There’s also the theory that a dead man will be left where he falls but a wounded man will cause some of his comrades to stop fighting and help him, thus taking even more people away from shooting at your side.)

Arrows, by contrast, kill by slicing arteries and veins which causes the target to rapidly bleed to death. Since the further an arrow goes into a body the more blood vessels it can sever, the goal with an arrow is complete penetration. Once there is enough kinetic energy in the arrow for it to penetrate all the way to the other side of the body and out again additional kinetic energy serves no great purpose. In fact, it can actually cause problems if it results in the arrow bending too much when it hits. (The head slows down faster than the tail, which causes bending. This is why hunters do better with their arrows having the weight disproportionately front-of-center. In tests, an FOC of 30% significantly improves penetration.)

So, back to the movie, the arrows have enough kinetic energy to knock a man off his feet but then only penetrate an inch or two. Which means that the Trojans must have been shooting the dullest arrows ever made by man or beast.

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