Ibn Sina and uniformitarianism

Although the American Geomorphologists insist that geomorphology is started by William Morris Davis (1850-1934), but it has a much longer history. The philosophers of ancient Greece and Rome pay attention to the formation of mountain ranges and landscapes of the Earth's surface in their writings and presented ideas in this field. In the centuries BC Herodotus, Aristotle, Thales, Xenophanes and so many other had given theories about the origins of valleys, folding and erosion and after years, Avicenna's the eminent Iranian scientist (A.D. 980-1037) given valuable theory in the subject of earth science and geomorphology, that many of those has been confirmed at during the revolution of modern science in 18 century. 2-

In this paper, we first introduce the writings of Avicenna's in landform concepts, and then we emphasized on the most important his writings that have accordance with the uniformitarianism theory and describe the history of this theory in the modern science and pay attention to its roots in the writings of Avicenna. The methodology of this paper is Descriptive – analytical and moreover the use of various books and articles, Tabieyat alshfa book of Ibn Sina translated from the Arabic to the Persian. Then extract the Earth Sciences and Geomorphology theories of this great scientist Iranian and then analyzed with the scientific theories of the new century. 3–

This study investigates the role of Avicenna in Landform knowledge and tries to explain uniformitarianism roots in his publications. Uniormitarianism, the simple notion that: "the present is the key to the past ", is commonly linked to the writings of James Hutton but we found out a clear similarity between Hutton ideas with Avicenna notions. However Hutton's writings were cumbrous same as earlier scientists, Mikhail Lomonosov (1711-1765), Jean-Etienne Guttard(1715-1786), and Nicholas Desmarest (1725-1815), but the essence of his message, notably his theory of Earth history that find " no vestige of a begging-no prospect of an end" (Hutton, 1788), was rescued and clarified by john Playfair(1748-1819). This message has been described with Avicenna that "some mountains are disintegrated and falling and some others are eroded by flowing waters, then all mountains are rejuvenated………finally the form of mountains is changed but we can’t record an exact time for these evolutions"(Avecina,1404, 210). "Exact time..." is referred to "no vestige of ……" which has been recognized by Hutton. Avicenna has described the rock cycle, differential erosion, form and processes based on contemporary sediments and materials, the aim that historical geomorphologists are followed in their investigations. He also believed the evolution of landforms developing gradually, the concept has been presented by john playfair as a gradualism evolution. 

The results indicate that Ibn Sina has theories in the geomorphological issues. He believed that most of the lands have been under the water layer in the past and the sediment in this water is layered and gradually deposits beneath the waters, during a long time. Then, due to tectonic movements the sea had regressed and the remaining sediments turned to stone during the rock formation process and he suggest that the lands of ancient Egypt and Najaf are the example of this case and tell that those lands were under the sea in the past. Ibn Sina attributed the get height of mountains to the internal and external factors. He believe that the get height of mountains is affected by tectonic process and earthquake and also product the carvings due to winds and flooding in the remnant sediments from the sea. Also Ibn Sina with likens the mountains to the loss of people and communities refers to the Palimpsest theory. Moreover, Ibn Sina believes that any object is or in a state of vibration and movement or in a state of quiet and equilibrium and the movement of the all object is for achieve the equilibrium. He named the time to reach this equilibrium as relaxation time. According to the Avicenna's writings and thoughts, can understand that he did not believe in absolute to the uniformitarianism and he has been the uniformity and catastrophe viewpoints together and his writings about the natural factors refer to both sudden and gradual changes that attributed these changes to different environmental conditions. Hi believe that Different forms in the surface of land affected by the changes that occur in the earth system, do not act the same and may its practice be different from the method their forming.