Sunday, May 5, 2013

Shadows on the Trail - Spear Throwing and Baseball Pitching


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        The historical novel Shadows on the Trail takes place in northern Texas and southern Colorado right around 10,700 years ago. Many of the animals the Paleoindians used for food were fast, large, and/or dangerous, so the weapon system used by these Paleoindians meant a great deal towards their surviving or not surviving. Since bow and arrow technology would not show up in North America until sometime around A.D. 500 and domesticated horses did not land with the Spaniards until the late 1500s, the weapon technology used by North American Paleoindians was fairly limited. I sure would not want to hunt some of these big predator and prey animals with the weapons they had.

       North American Paleoindians brought with them from the Old World a technology called the spearthrower or atlatl. An atlatl consisted of a two foot long or so wooden shaft with a handle or finger grips on one end and an attached hook made from antler or bone on the opposite end. Near the center of the atlatl's wooden shaft was often times a rock weight used for balance or whipping action. Figure One demonstrates the use of an atlatl to launch a spear while extending the length of the hunter's throwing arm (Photo courtesy of University of New Mexico).



Figure One
       The basic physics of how an atlatl worked for Paleoindians can be explained using a comparison with a major league baseball pitcher (Figure Two). For baseball pitchers, the force used to throw a baseball X (times) the distance the ball is released from the point of rotation is what matters the most for speed. In baseball pitching and atlatl throwing, the point of rotation is the shoulder. If a longer arm is moving at the same rate of speed as a shorter arm, the ball (or spear) at the point of release is moving faster with the longer arm. An atlatl creates a longer arm for the Paleoindian, therefore, creating more speed from the airborne spear. This was truly an innovative idea.


Figure Two


 
       Another modern-day example that uses the same physics as an atlatl is the tennis ball thrower used in dog parks around the world for throwing tennis balls further and faster for our furry friends to fetch. Figure Three shows a tennis ball thrower used by a dog owner with his attentive pooch sitting beside him, waiting for the chance to retrieve that fuzzy yellow ball.  Replace the tennis ball with a spear and this dog owner resembles a Paleoindian hunter using an atlatl.
            
Figure Three. 

       Now, let's return to 10,700 years ago in our time machine. When a Paleoindian hunter was confronting a large and dangerous prey animal, such as the one and a half ton Bison bison antiquus, he had a choice. The hunter could get close enough to thrust his spear into the vital organs of the dangerous beast or he could throw the spear with his bare arm, at speeds approaching 90 kilometers per hour. An even better approach for the Paleoindian hunter was to use the  trusty spearthrower or atlatl. According to David Meltzer (2009), A spear thrown with an atlatl averages 135 kilometers per hour with speeds exceeding 200 kilometers per hour during certain portions of the flight. Additionally, the world record for distance with an atlatl-assisted spear throw approaches 300 meters. Try that with an unaided hand-thrown spear!

       Below is an excerpt from Shadows on the Trail where our hero Chayton was hunting elk with his atlatl or spearthrower.

Chayton was ready to doze off again when he heard the sound of animal hooves running across the rocks. He focused his eyes on where he had heard the sound. Finally, directly in front of him, he saw two reddish brown patches darting in between the cedar trees. He reached down and carefully picked up a spear. He watched the trees while nervously running his thumb across the stone spear tip. He felt a stab of pain in his thumb and looked down. He had sliced open his thumb with the sharp spear tip.
          Chayton’s weary head pounded as he impatiently waited for the animals’ next move. Then, he realized he was breathing too fast and too loud; they may hear him. He slowed his breathing down and grasped the spear shaft in his hand. He placed the butt end of the spear into the notch of his spear thrower. Then, breathing very slowly, he waited. 
          Two majestic elk, a young bull and a cow, walked out from behind the trees, heading straight at Chayton. The bull led the way while the cow followed behind. The elk held their heads high and sniffed at the air, smelling for any danger that would set them off running. The elk, upwind from Chayton, did not pick up his scent and kept walking towards him.
          Chayton’s left throwing arm was cocked and ready to throw the first spear, but the bull was still walking straight at him. Chayton did not like his chances for a kill with this throw. The bull had no vital organs exposed to Chayton’s line of fire and unless Chayton threw perfectly and severed an artery, the elk would not go down. The last thing Chayton wanted to do was track a wounded elk in this rugged country.

Meltzer, D.J. (2009)  First People in the New World. University Of California Press. Berkeley.  
                              
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