Ballistics

Ballistics describes the trajectory of an object when thrown or shot. Upward angle and acceleration are known, then the trajectory can be calculated, means, one knows where it comes down.

Trajectory of a bullet

The first scientist, who mused about the trajectory of thrown objects was, as most in physics, Aristoteles (384 - 322 bc). But this was a speculative task. Nor any precise clocks to measure short times, nor any visual means, to observe fast ongoings.

In the ninteenth century research continued. New measuring and observation methods enabled new insights in shooting. This was interesting as military key knowhow. Ballistics was a main motive to develop calculating machines. Caluculating the trajectories of cannon-bullets was the original task for computers.

Interestingly, ballistic know how is still today a key know how of warship. Intercontinental rockets are sophisticated with maps of the undulations of the earth's gravity field or laser gyrometer which use the cosmic electromagnetic field as the spacial coordinates. And with video, short befor the impact, last curse correctures are done.

Back from space to earth. Quantitative calculations about throwing we found nowhere. But about shooting, quite much is available, even huge table compilations. So let us start at this point, much of it will be transferable to throwing. Three states of a trajectory are to discern, what results in three different ballistics:

(1) Inside Ballistics This describes the ongoings in the muzzle. For throwing this is the time while the device is in hand. This is a extremely short moment with extreme powers and accellerations. It is not observable by the pure eye.

(2) The Outside Ballistics describes the ongoings during the flight, in the air, when no extern powers work on the device. This phase can be watched with the naked eye for throwing. But for shooting not.

(3) The End Ballistics describes the ongoings during the impact. The ongoing itself cannot be watched with the naked eye, only the result can be seen. And of course the sound contains information.

To watch the flight of an axt, is more puzzling than that of a stone or knife. The axe turns seemingly unforseeable.

This center of gravity is it, which performs exactly the above described smooth ballistics. When seeing a tumbling axe, think about it's center of gravity, this point performs the smooth trajectory.