Jean-André de Luc (or Deluc) (1727–1817), who first proposed the term ‘geology’ almost in its modern sense, was one of the most prominent geologists of his time. His ‘theory of the Earth’, published in several versions between 1778 and 1809, divided geohistory in binary manner into two distinct phases. The fossiliferous strata had been formed during a prehuman ‘ancient history’ of immense but unquantifiable duration. Then the present continents had emerged above sea-level in a sudden physical ‘revolution’, at the start of the Earth’s ‘modern history’ of human occupation. De Luc argued that the rates of ‘actual causes’ or observable processes (erosion, deposition, volcanic activity, etc.) provided ‘natural chronometers’ that proved that the ‘modern’ world was only a few millennia in age; and he identified the natural revolution at its start as none other than the Flood recorded in Genesis. So ‘nature’s chronology’ could be constructed from natural evidence, to match the well-established historical science of chronology based on textual evidence from ancient cultures. De Luc’s natural chronology was restricted to the recent past, but it provided a template for later geologists to develop a geochronology extending into the depths of geohistory. The historical importance of de Luc’s work has only been obscured by the myth of intrinsic conflict between science and religion.
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The Age of the Earth: From 4004 BC to AD 2002
The age of the Earth has long been a subject of great interest to scientists from many disciplines, particularly geologists, biologists, physicists and astronomers. This volume, The Age of the Earth: from 4004 BC to AD 2002, brings together contributors from these different subjects, along with historians, to produce a comprehensive review of how the Earth’s age has been perceived since ancient times. Touching on the works of eminent scholars from the seventeenth to nineteenth centuries, it describes how concepts of the Earth’s history changed as geology slowly separated itself from religious orthodoxy to emerge as a rigorous and self-contained science. Fossils soon became established as useful markers of relative age, while deductions made from geomorphological processes enabled the discussion of time in terms of years. By the end of the nineteenth century biologists and geologists were fiercely debating the issue with physicists who were unwilling to give them the time needed for evolution or uniformitarianism.
With the discovery of radioactivity, attempts to calculate the Earth’s age entered a new era, although these early pioneers in radiometric dating encountered many difficulties, both technical and intellectual, before the enormity of geological time was fully recognized. This effort affected both the theory and practice of geology. Geochronology was largely responsible for it maturing into a professional scientific discipline, as increasingly refined techniques measured not only the age of the rocks, but the rate of processes which now elucidate many aspects of the Earth’s evolution.
Even today the Earth’s chronology remains a contentious topic — particularly for those dating the oldest rocks — and it is implicated in debates surrounding our hominid ancestors, the origins and development of life, and the age of the universe.
The Age of the Earth: from 4004 bc to AD 2002 will be of particular interest to geologists, geochemists, and historians of science, as well as astronomers, archaeologists, biologists and the general reader with an interest in science.