Showing posts with label science and technology. Show all posts
Showing posts with label science and technology. Show all posts

Friday, 22 May 2020

Let us Know the World

Levallois Technique


Neanderthal craftsmen develop a technique for making better flint tools

             Dating back around 250,000 years, the Levallois technique is the name given to a method of knapping flint that was developed by Neanderthals and other proto-humans. The name derives from the Levallois-Perret suburb of Paris, France, where tools forged by this technique were discovered during archaeological the digs in the nineteenth century.

            The Levallois technique is a more refined version of earlier forms of stone knapping, which involved chipping pieces away from a prepared stone core. It enabled the tool's creator to have much greater Control over the shape and size of the final flake. The technique begins with selecting a pebble about the size of a hand. A striking platform is then formed at one end of the stone, and the edges are trimmed by chipping off pieces around the outline of the intended flake. The base of the stone is then struck in order to produce its distinctive dorsal ridge. When the striking platform is struck, the flake releases from the stone with a characteristic plano-convex configuration and all of its edges sharpened by the earlier chipping. The flake is then ready to use as a knife or as the point of an edged projectile weapon.

 

              Populations distributed over a vast geographical region, from Africa to Northern Europe, employed the Levallois technique. It allowed the Neanderthals to perfect their spear-making industry, which in turn aided in the hunting of large animals. Being able to kill larger animals, and therefore feed more individuals while spending less time hunting, aided in the while formation of stable people groups, enabling greater sedentism. It also allowed for the production of projectile points for early bow and arrow technology. The fact that the Levallois technique was refined and perfected by the Neanderthals gives the lie to the popular conception of them as crude and apelike brutes.


Thursday, 21 May 2020

Let us Know the World

Origin of Science and technology  

Sharp projectiles


Creating tools and weapons with sharpened points or tips

              Humanity’s first use of sharp projectiles predates history, as three wooden spears found in schoningen. Germany, show that Homo heidelbergensis had used projectile weapons by at least 400,000 BCE, and the longest of the three spears measured 7 feet 7inches (2.3m) long and all of them had a thicker section toward the front in the style of the modern javelin, which suggest that they were specifically used for throwing rather than thrusting. By 300,00BCE, Homo heidelbergensis had begun using shaped stone spere point, and by 64,000 BCE stone tipped arrow heads first appeared in south Africa.

                  Until the development of sharp projectiles, humans had to rely on blunt weapons, such as rocks, throwing sticks, and their hands and teeth. Sharp projectiles were far superior to blunt weapons as they were not only deadlier, but also could be used from greater distance. This allowed people to hunt larger, more dangerous game while retaining some measure of security. Sharp projectiles spurred technological development, leading inventors to develop new methods of shaping stones, developing wood working techniques, and eventually, mining and casting metals. 

            As further evidence of their importance, groups of wild chimpanzees in Senegal have recently been observed to fashion their own sharpened projectiles from tree branches for use in hunting. The frequency of projectile use was found to be higher among female chimpanzees, leading researchers to speculate that females may have played a key role in the evolution of tool technology among early humans.

           Ever since the appearance of sharpened projectiles, human cultures have refined, perfected, and revered them for their simplicity and deadly efficiency. As the primary tools of warfare and survival, they were not replaced until relatively recently in human history when firearms became effective and widely available.   

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"சிறிய நம்பிக்கை"

    ஒரு சிறிய கிராமத்தில் மீரா என்ற சிறுமி இருந்தாள். அவளது தந்தை ஒரு விவசாயி. அவர்கள் குடும்பம் மிகவும் எளிமையாக வாழ்ந்தது. மீரா புத்திசால...