Beginnings: Prehistory or history?

Historians used to draw a clear line between history and prehistory. The existence of written records was a touchstone if one was dealing with "history". As writing was invented in around 3300 BC in Mesopotamia, all earlier developments were regarded as prehistory. This differentiation has lost much of its significance in recent times. Archaeology and its auxiliary sciences and techniques have progressed to the point where much can be discovered about an ancient civilisation even without written records. Radiocarbon dating, for instance, is based on the decay of the isotope Carbon 14, at the rate of halving every 5730 years. When burned charcoal or the bones of dead animals are found in an excavation, the age of that level can be ascertained.

At first there was much uncertainty about this method, as some of the results were unreliable. Further investigation showed that the reason for this was the past fluctuation in cosmic ray activity. This can now be overcome with the aid of dendrotechnology (a.k.a tree-ring dating) by a special calibration process. Further, objects made of fired clay, such as pottery, can no be dated using thermoluminescence. This is done by reheating the artifact in order to measure the light emitted by electrons which were freed by radioactivity, but remained trapped in the clay. By these and other methods, incredible results have been obtained in the dating of ancient remains.

As a result, events which took place thousands or even millions of years ago can be dated now. Questions such, "As when did man first appear, and where?" can be answered too. When did people emigrate to Europe, America, Australia. When did they first turn to hunting and to agriculture? can be answered with confidence, just as if we had written evidence of these events. Not only can archaeology give the date of a site or an event in the development of man, bit it can also supply details of the culture, customs, and religion of ancient cities and civilizations. the technology of excavation has been refined very much, both by exact stratigraphy (the relation of objects to the layers of deposits in which they are found) and by typology (the classification of objects according to types and their comparison with one another in order to determine chronological, geographical, and technical relationships).

Such related sciences as underwater archaeology, the analysis of food remains and textiles, the diagnosis of disease, o the interpretation of burial customs, have opened up new avenues for research. Our knowledge of what used to be termed as prehistoric cultures and events has advanced in recent years by leaps and bounds, and it is now possible to give a much fuller account of the development of early man than would have been possible even a few years ago.