Uses of metals and metallic minerals / Использование металлов и рудных минералов

Автор(ы):Chatterjee K.K.
Издание:New age international, 2007 г., 332 стр., ISBN: 978-81-224-2511-6
Uses of metals and metallic minerals / Использование металлов и рудных минералов

On an auspicious day, sometime around a million years ago, a member of the Homo habilis species stood erect and walked steadily on his two feet and his two hands became totally free. A new species – Homo erectus—began its journey on a new evolutionary track. This great change took around four million years after his ancestors – the hominids — broke free from the lineage of apes and chimpanzees. But , perhaps for the next seven to eight hundred thousand years, the descendants of that first Homo erectus kept wondering about what to do with the two free hands apart from holding bones and logs of wood.

That was till someone picked up a stone and threw it to some animal – probably because he was scared and was trying to defend himself, or because he was hungry and wanted to get some flesh to eat. But unconsciously, he began the gainful use of a mineral, and unconsciously again, began the evolution of a new species – Homo sapiens, the modern man. That first success with the stone thrown with the help of his hand triggered an altogether new evolution i.e., technological evolution. And a new age i.e., the Stone Age. Evolving down the generations, man learnt to be choosy in picking up the stones; he realized that all stones are not good for his needs; he tried and erred, and through innumerable trials and errors spanning over tens and hundreds of thousands of years, finally he zeroed in on a sharp-edged hard mineral that we have named flint. With the sharp edges of flint, he could tear animals for hide and flesh; and much later, he could make knives and axes and spear heads. Flint became the backbone of economy. Sometime along the evolutionary journey, on another auspicious day, he accidentally rubbed two pieces of flint and produced a spark of fire. That spark sparked off a revolution, a revolution within his head – a technological revolution. He has invented fire. <...>

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