Throwing Good Knives After Bad

Why?  What do you carry?

Knives are fun.  They’re a great utility for around the house, and a requirement when venturing into the back forty.  A good knife can cut twine and rope, trim a branch, even save a sprinkler connection from being completely dug up and replaced.

Oh, sprinklers.  You will rue the day!

A knife on a camping/hiking trip can be even more handy.  It stands to reason that in fantasy novels and movies, just about every warrior would (and did) carry a knife.  It was the iPhone of its day, allowing a user to leave messages in tree trunks or blood, and helping communicate with others before emoticons. 

A knife pressed against a friend’s throat shares exactly how serious your thoughts are on Scotland’s bid for freedom.

But, and here’s the thing, a serious warrior would never throw his/her knife unless:

A - It was absolutely the last line of defense

B – There was seriously no escape whatsoever

C – He/she hated the knife

D – And wanted to die unarmed and horribly mangled

You got a little something . . . right there.

I know, I know.  Jack Burton throws his knife, with style, in Big Trouble in Little China.  It’s easily one of the most iconic knife throwing scenes ever.  But let’s also recall that Wang Chi and Rain have a sword duel while flying dozens of feet up, and through, the air.  It’s clearly a fantasy-action film, and it has no basis in reality whatsoever.

Which includes Jack Its-all-in-the-reflexes Burton’s knife throwing abilities.

Now don’t get me wrong.  A knife is still a piece of metal, and it’s got an edge on it.  It is made to cut.  It can potentially pass through a couple layers of cloth and stick into someone.  A thrown knife may do some decent damage to the poor human on the receiving end.  It can even prove to be deadly if it hits the right spot at the wrong time.

But sinking through a bad guys rib cage, into an evil vixen’s throat, or even through a minotaur’s eye is tricky under the best of circumstances and borders on the impossible enough that the Mythbusters even did a show on it.  You can see that the speed and the depth of sinking a thrown knife into a block of wood isn’t very accurate or very much.  It's also at a fairly close range lacking all kinds of Hollywood dramatics.

So wait, what’s going on here?  Arrows and spears and axes and bolts and bullets are all thrown.  So

Bigger, stronger, and more hurty.

why wouldn’t a knife be among that group of lauded and much used projectile weaponry?

It’s simply a matter of weight and velocity.  A throwing spear or a throwing axe has a much greater mass behind it, such that its own weight is used to push through the skin and muscle and do such wonderful fantasy damage.  An arrow or a bullet, on the other hand, is using outside energy to launch the projectile at a greater velocity.  The arrow uses the stored mechanical energy from the bow and bowstring.  The bullet uses the chemical energy from the gunpowder.  A knife, which is comparatively smaller, has to rely on the throwing capacity of a mere human arm to carry it across the distance and into (if we’re lucky) the bad guy.

For more on the physics of knife throwing, check out this lovely site here.

And so, on a dark and stormy night when the lightning's crashin' and the thunder's rollin' and the rain's coming down in sheets thick as lead. Just remember what old Jack Burton does when the earth quakes, and the poison arrows fall from the sky, and the pillars of Heaven shake. Yeah, Jack Burton just looks that big old storm right square in the eye and he says, 'Give me your best shot, pal. I can take it.'

But don’t throw your knife away.  Ever.