Stone Age, the

People have long defined civilizations in terms of the materials societies have used to build and make objects. Historians often divide human history into periods such as the Old, Middle, and New Stones Ages the Bronze Age the Iron Age and, much later on in history, the Age of Plastics. 

Since ancient times, the development and use of materials has been one of the basic objectives of mankind. Eras, that is, the Stone Age, the Bronze Age, and the Iron Age, have been named after the fundamental material used by mankind to construct their tools. Materials science is the modern activity that provides the raw material for this endless need, demanded by the progress in all fields of industry and technology, of new materials for the development of society. 

The recovery of metals from their sources in the earth is the science of extractive metallurgy, a discipline that draws on chemistry, physics, and engineering for its methods. As a science it is a comparatively recent subject, but its beginnings, which were evidently in the Near East about 6000 years ago, marked the emergence of humanity from the Stone Age. The earliest known metals were undoubtedly gold, silver, and copper because they could be found in their native (elemental) states (Fig. 17.15). Gold and silver were valued for their ornamental uses, but they are too soft to have been made into tools. Iron was also found in elemental form— although rarely—in meteorites. 

Much of human history has been influenced by the availability of materials. In fact, history is divided into eras named after the primary materials used the Stone Age, the Bronze Age, and the Iron Age. Similarly, we can assert that in the twentieth century we entered the Polymer Age. 

Material possessions have traditionally represented hnman wealth and defined social relationships. The eras of early human civilization (the Stone Age, the Bronze Age, and the Iron Age) have been named in terms of the materials from which tools and weapons were made. The Bronze Age (approximately 2000 B.C.E. to 1000 B.C.E.), in fact, represents the foundation of metallurgy. Although we do not use the term pottery age, domestic vessels made from baked clay have been valuable in providing clues to daily life in ancient ctiltures, and glass articles from ancient Mesopotamia have been traced back to 4000 B.C.E. 

The history of ceramics is intertwined with human history. From the first use of flint and obsidian during the Stone Age, the formation of vessels from clay, the use of refractories in the iron and steel industry, to the fabrication of optical fibers for high-speed coimnunication ceramics have impacted society and technology in many ways. We mentioned many of the more recent developments in the field of ceramics. The science behind these materials will be described in many of the later chapters. 

During the Stone Age, the material research was limited to the mechanical treatment of natural products. When Dalton discovered atomicity and Mendeleev revealed the periodic table, the research trends drastically changed in the intervening period and research was focussed on fundamental principles of basic molecular structure and simple chemical reactions. During the late twentieth century and the early twenty-first century, an exciting revolution in chemistry has taken place, with multidisciplinary approaches in nanoscience and nanotechnology to the creation of molecules with pre-specified complex structures to perform novel functions, hi the present century, research is focussed on control of crystal structures, nanostractures and microstructures with distinct mechanical, electrical, optical and magnetic properties [1-5]. 

Pre-historic art n. Painting and sculpture produced by artists of the old, nuddle, and new stone ages. The earhest known piece of pre-historic sculpture is the famous Venus of Willendorf (Natural History Museum, Vienna), a small fertihty... 

IN CHAPTER 22 we examined the chemistry of non-metallic elements. In this chapter we turn our attention to metals. Metals have played a major role in the development of civilization. Early history is often divided into the Stone Age, the Bronze Age, and the... 

Man has marked the epochs of his history by the materials that he has used to progress— the Stone Age, the Bronze Age, the Iron Age. If we were to name our own time, it could truly be called the Polymer Age. Each passing year sees unbelievable surges in the production and use of plastics, fibers, films, adhesives, elastomers, and other polymer products. The plastic industry itself continues to grow at a rapid pace not only in the United States but also worldwide (see Fig. 1-1). What has brought this about What is the basis for the importance of polymers in our lives ... 

Throughout history, we have witnessed trends where one material has evolved to replace another for efficiency, performance or economic reasons. Consider the fact that the ages of man to date have been broadly defined In terms of their key materials — the Stone Age, the Bronze Age, the Iron Age and the Age of Steel. 

HISTORY. Copper was discovered and first used by neolithic man during the late Stone Age. The exact date of this discovery will probably never be known, but it is believed to... 

HISTORY OF FISHING. Fishing is one of the oldest and most important activities of man. Ancient remains of spears, hooks, and fishnets have been found in ruins of the Stone Age. The people of early civilizations drew pictures of nets and fishermen lines in their art. Through the ages, men wrote about fishing, used fish in exchange for services, and even learned to fish farm. 

Figure 12.1 shows a prediction made in 1972 of the rate of plastics production in the US, based on an annual increase of 6% [1]. The experimental points added later show that in spite of three oil crises and several recessions, production is still on target. At some point within the range of the actual data, the total volume of plastics exceeded the total volume of steel. It has been traditional to name the ages of human society on the basis of the materials which are used in making tools and in construction. The Stone age, the Bronze age, the Iron age and the Steel age have passed and it is now clearly the Plastics age. 

Materials have played such a critical role in the evolution of technology throughout the history of man that historical epochs, such as the Stone Age, the Bronze Age, the Iron Age, and the Silicon Age have been named for the materials available to mankind at the time. 

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