Lost knowledge department…
When I was a young boy I found boomerangs fascinating. Living mostly in fairly tight suburbs and not being able to transport myself far it wasn’t something I had any real first-hand experience with, and as such I didn’t really understand the limitations of the returning boomerang, a problem that made a great deal worse by (as I later found) ridiculous exaggerations of what returning boomerangs can do in popular media, which, for me in that time, was mostly comic books and TV.
Even at that age, though, I had some rudimentary research ability, and I remember looking up “boomerang” in different references and finding out to my surprise that returning boomerangs were only one category of a larger type, and that larger type was in itself a part of the still larger category of throwing sticks as weapons, all of which seem to have been crooked. This puzzled me greatly, I understood that a fairly specific shape would be required of a throwing stick that would return to its owner (at least if it didn’t hit anything), but why would it be that throwing-sticks in general, that did not return to the thrower, should be crooked?
It took me a very long time to assemble what seemed to me a fairly complete mental picture of the answer to that question.
Some advantages come to mind. If one throws, say, a dowel or broomstick so that it spins on the way to the target, it’s very likely to rotate around its longitudinal axis in mid-air as well as spinning end-for-end. As it spins end-for-end, then, as each end comes to the top of its rotation it will be spinning in the opposite direction as the previous one. Since the end at the top of the rotation (spinning forward relative to the direction of travel) is traveling through the air faster than the end at the bottom of it’s rotation (spinning backward relative to the direction of travel) and has more friction, the entire object will tend to wobble, oscillate during travel. The energy to make it do that has to come from somewhere, so that wobble is going to reduce its range and impact, not to mention accuracy. Since a stick with a crook in it (in one direction) tends to stabilize in the plane of rotation because of centrifugal force (yes, I know it’s an illusion, but it’s also convenient shorthand) it will avoid this problem, fly straighter and hit harder.
But I don’t think that’s the main reason for using crooked sticks for hunting.
These were used to hunt small game, but mostly birds. If you’re going to throw a stick to get food, and there are places around, fields or bodies of water where birds in great numbers gather, the obvious strategy is to startle them into the air and then throw your stick into a mass of hundreds or thousands at once, greatly increasing your chances of hitting one. This fits with what we know of Aboriginal hunting in Australia and hunting with returning boomerangs as depicted on the murals inside King Tut’s tomb. Done this way there need not be the very difficult kind of accuracy that would be required to hit a single bird in flight, the sticks would merely be thrown into a dense mass of birds hoping to connect with one or more.
We have to assume, though, that with millions of years of evolution behind them, birds are pretty good at avoiding mid-air collisions, and indeed flying predators. I have no doubt that they do so at a reflex level, reacting very quickly when they see something approaching them in the air at speed.
And this, I think, is where another property of a thrown crooked stick comes into play.
If you look at a spinning propeller or fan, you can see the hub of the fan or propeller clearly at the center of rotation but the blades are a blur. You can vaguely see something there, but without having seen it still there is no way to tell, for example, what shape the blades are. The faster the propeller or fan spins, the harder it is to see the blades at all. If you look at a spinning spoked wheel the spokes are nothing more than a blur or almost invisible, but the hub and rim are clearly visible.
Obviously it has no rim, but more importantly a thrown crooked stick of the type we are discussing spins rapidly around a center of rotation that is outside of the object itself. There is no “hub”, there is no matter, no substance at the center of rotation. Thus the entire thing when spinning in the air is just a blur.
I think what’s going on here is simply that the birds don’t see it coming, or at least don’t see it distinctly enough to trigger their avoidance reflexes. Yes, of course the thrown crooked stick will be more visible edge-on if it’s coming right at you, but that’s not the case with a bird in flight, in order for the stick to hit the target they both must converge at a point ahead of, in front of the bird.
I think it was simply a matter of discovering, probably from trial-and-error, that crooked sticks were far more effective in hitting birds in flight, even if it was not understood why.
This might, possible, also finally explain the mysterious question-mark forms of Native American ball-headed war clubs as well, if they were, or originally were hunting weapons more than combat weapons. For a weapon used like an axe or hatchet having the center of inertia far ahead of the handle makes no sense, it will tend to rotate in the hand and considerable extra force must be applied to keep it from doing that. If it was primarily a thrown weapon, a reason for the design finally becomes clear. This also would seem to explain the “gunstock” form of Native American club. If it was thrown such that the center of inertia was behind the grip instead of in front that also explains why, when they were fitted with trade blades, the blade was on the outside of the crook, since that would then be the forward edge in flight.
In understanding these things, we not only can understand a bit more about our stone-age ancestors and how they lived, but we understand the principles that we ourselves would need to apply to such seemingly simple devices as a thrown stick if we ever found ourselves in similar circumstances.
– Robert the Wombat