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To: LoneClone who wrote (21203)	9/16/2006 4:06:56 PM
From: E. Charters	Respond to of 78421

It is interesting that some pundita wax supra mathemtically about what gives the atlatl its devastating power, that exceeds that of conventional bows by many times. They have speculated about stored energy etc.. efficient transfer with respect to the obvious lateral flexing of the dart shaft when hurled, and the slight flexing of some atlatl's themselves. The flexing is undeniable, but it is not the cause of the "stored energy" of the shaft. You cannot get more energy out of the dart than you put into it. The secret of the atlatl is its leverage caused by the rotation kinesiology of the human body, something that is impossible to impart to a bow launched dart. The motion is also seen in the primitive sling, the bullwhip, the sword and the boxer's punch. The first rotation given the launcher dart combo is by the spine with horizontal plane rotation, then the lats and traps induce rotation with the large circle of the spine in a vertical plane, then the lat and trap further induce a shoulder roll which has a dual circle radius with the large circle of the humerus, then the lower arm rotates around the elbow inducing ulna-radius relative shortening and rotation of the wrist. Finally when the arm is extended the third class lever effect is induced with the rapidly slowing-in-forward motion-fulcrum being the hand, and the pressure being the stone weight on the atlal, now with all rotations and forward translation turning to rotation on the radius of the atlatl itself. The forward speed of the arm can be up to 60 feet per second (photos of boxer's punches indicate 25 to 40 mph (36-60 fps) hand speeds) normally at this point and the end of the atlatl is a multiple of that, with its own rotation now overtaking that. The end of the atlatl now cracking the whip of a forward moving arm, extending 2-3 feet in the time the arm extends perhaps 12 inches. Using a speed multiple of 2-3 the launch speed of 120 to 180 feet per second is easy to calculate. (reported are 50 -100 MPH atlatl launch speeds = 70-140 fps). It follows that a technique of progressive radius shortening movements using whole body rotation for maximum leverage would cause the greatest launch speed. The function of the stone weight is obviously to reduce load on the ulna-radius by replacing the force required to rotate the shaft with kinetically developed inertia. The lateral flexing of the atl-atl dart shaft has a function in the shafts of arrows which has only recently been seen and properly analysed by using high speed photography. The lateral flexing serves to stabilize flight and break up drag eddy currents, allowing faster flight and more accurate delivery. A similar drag reducing effect is seen in the vibrating spikes on the inlets of supersonic jets. Solid shafts have short range as they quickly overbalance and tend to end-over-end. A shaft that is flexing in the air has its center of mass vibrating laterally to flight direction and the forces that would tip the ends around that vibrating center cannot be developed as the radial forces alternate rapidly. The secret of the massive power of deliver of the dart of the atl-atl is that it has a high sectional density or mass per unit of frontal area, allowing it to go far into an animal and penetrate the skull and bone, even better than a bullet. A tribe of early cro-magnons could easily despatch a charging Mammoth at distances of perhaps 200-300 feet sinking fatal shafts far into the body of the animal and perhaps right through its skull. An atl-atl dart could develop perhaps 94 ft lbs of energy arriving at the target, but its momentum of 1.6 slug-feet per second is double that of a 0.357 Magnum pistol bullet, and its sectional density would be 6.86 times greater than the bullet, giving it 11 times the penetrating power. Given six cavemen with atlatl's versus one cowboy with a Walker Colt, the bet is on the cavemen for bringing down the charging Woolly Mammoth and getting to sing campfire songs about it later. The Walker The Winner

To: LoneClone who wrote (21203)	9/16/2006 7:24:14 PM
From: koan	Read Replies (1) \| Respond to of 78421

Hi LC, I saw both of those. My home page is BBC (24K). One has to figure their brains also operated differently. Maybe they provided hybrid vigor-lol. Their brians were larger than ours and scientists believe they were as smart as we. There brains were 1500 to 1800 CC's ours 1300 to 1500. They call extra brain capacity "residue brain matter"-lol. Neanderthal were about 5'4 but built like weight lifters. They may have been smarter than us-lol. We see dramatic morphological differences in people why not in the brains. Not better or worse, just different. For instance, maybe the Neanderthal could smell better than we could, so a few neanderthall genes would really help wine tasters-lol. Such a facinating universe and people prefer to fight-lol. Any sentient beings which may be aware of our existance probably feel it would be futile trying to explain anything to us. I can't explain bush to any conservatives I know-lol. Hell, 1/2 the country is still buying into our going into Iraq because of 9/11. Maybe the neanderthal were peaceful by nature and we can backbreed hybrid homo sapiens to get more neanderthal genes-lol.